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054003741	claims	1. A cover for a hook box which encloses a hook and hook block, comprising: a rigid tubular member which is fixedly connected to said hook box in a manner which establishes a water-tight seal therebetween; an expandable bellows member having a lower end and an upper end, the lower end being connected to said rigid tubular member in a manner which defines a water-tight seal, said bellows member and said rigid tubular member defining an air space which extends upwardly from said hook box in a manner which encloses cables which interconnect said hook block with an overhead crane; and a buoyant member which is disposed about the upper end of said bellows member and which is effective to expand said bellows in response to said hook box being lowered into water by a predetermined amount. a reactor pressure vessel disposed in a reactor cavity, said reactor cavity including a separator pool which is separated from said reactor pressure vessel by a separator pool threshold; an overhead crane disposed above said reactor cavity and arranged to lift and transport a device which is normally disposed in said reactor pressure vessel, from said reactor pressure vessel to said separator pool while said reactor cavity is filled to a predetermined depth with water, said overhead crane including: a hook block which is suspended from said crane by cables; a hook operatively connected with said hook block and engageable with said device; a hook box which encloses said hook; a tubular extension which extends upwardly from said hook bock and which encloses said hook block and a portion of said cables; and a bellows arrangement provided at the upper end of said tubular extension, said bellows arrangement including: a flexible corrugated tube section, said flexible corrugated tube section having a lower end which is connected to said tubular extension in a manner which provides a watertight connection; and a buoyant member which is connected to an upper end of said corrugated tube section and effective to float on the surface of the water and cause said flexible corrugated tube to extend when said hook box is lowered to a predetermined depth below a surface of the water. enclosing the hook and hook block in a hook box on which a tubular extension has been provided; providing a bellows arrangement at the top of the tubular extension; and using a buoyant member which forms part of the bellows arrangement and which floats on the surface of water used to suppress radioactive emissions, to elongate a flexible tubular portion which forms part of the bellows arrangement when the hook box submerges by a predetermined amount below the surface of the water. enclosure means which encloses the hook and hook block, said enclosure means including a hook box and a tubular extension which is provided on the hook box and which extends up and around the hook block and cables which support the hook block; and bellows means at the top of the tubular extension, said bellows means including a buoyant member which is effective to float on water and provide lift to elongate a flexible corrugated tubular portion of the bellows arrangement when the hook box submerges by a predetermined amount below a surface of the water and thus prevent the hook, hook block and cables from coming into contact with the water. a container-like structure which encloses said device; a flexible corrugated tube member which is sealingly connected to said container-like structure; and floatation means for causing said flexible corrugated tube member to extend upwardly when said container-like structure is immersed in water and prevent water from entering said container-like structure and coming into contact with said device. 2. A cover as set forth in claim 1, further comprising reinforcement means for reinforcing said extendible bellows member against the pressure applied by water against an external surface thereof. 3. A nuclear reactor system comprising: 4. A method of preventing radioactive contamination of a hook, a hook block and associated cables, by: 5. Apparatus for preventing contamination of a hook, a hook block and associated cables, comprising: 6. An enclosure for a device comprising:
050376063	summary	The invention relates to nuclear fuel particles less than a few millimeters in size and to methods of making nuclear fuel compacts from such particles for use in nuclear reactors. More particularly, the invention relates to improved nuclear fuel particles having fission-product-retentive coatings which are able to withstand high pressures to which they may be subjected during the formation of dense, nuclear fuel compacts and to methods for producing compacts having few fractured particle coatings therein. BACKGROUND OF THE INVENTION Pyrolytic carbon coatings have been used to protect particles of nuclear reactor fuel, i.e., fissile and/or fertile materials, such as uranium, plutonium and thorium in the form of suitable compounds thereof. Coatings of aluminum oxide and other ceramic oxides have also been proposed. Examples of nuclear fuel particles employing pyrolytic carbon coatings include U.S. Pat. No. 3,325,363, issued June 13, 1967; U.S. Pat. No. 3,298,921, issued Jan. 17, 1968, and U.S. Pat. No. 3,361,638, issued Jan. 2, 1968. It is also known to incorporate one or more layers of refractory carbide materials, such as silicon carbide or zirconium carbide, to produce nuclear fuel particles having still better fission product retention characteristics, as disclosed in U.S. Pat. No. 3,649,472, issued Mar. 14, 1972. So long as these fission product retentive coatings remain intact, contamination exterior of the particles by the heavy metal fuel material and/or substantial spread of fission products exterior of the coatings is prevented. Such nuclear fuel particles are usually bonded together in some fashion to create what is termed in the art as a nuclear fuel compact, which is produced using a suitable binder and appropriate pressures. It has been found that fracture and/or cracking of the fission product retentive coatings often occurs during the formation of nuclear fuel compacts wherein these nuclear fuel particles are combined under high pressure with a binder material to produce a relatively dense "green" compact that is later subjected to high temperatures to produce the final nuclear fuel compact suitable for use in a nuclear reactor. It is also known to produce nuclear fuel compacts or nuclear fuel elements for a Pebble-Bed reactor or the like by blending such coated nuclear fuel particles with a carbonaceous thermosetting resin in a powder form and compressing the coated particle-resin mixture under pressures in excess of 20,000 psig to form "green" compacts, and sometimes these particles have been pre-treated with the resin. Nuclear fuel particles which can better tolerate such manufacturing processes are constantly being sought after. BRIEF SUMMARY OF THE INVENTION The invention minimizes the occurrence of fracture and/or cracking in the fission-product-retentive coatings by protecting coated particles by the use of appropriate overcoatings to allow them to achieve high loadings to meet overall nuclear fuel compact specifications. The employment of overcoating material having a density not greater than about 60% of its theoretical maximum density has been found to provide adequate protection for the more fragile fission-product-retentive layers during the green compacting steps when such coated particles are subjected to relatively high pressures. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Very generally, nuclear fuel particles are provided which have central cores of fissile or fertile material surrounded by multiple layers of materials designed to retain within the confines thereof substantially all of the fission products created during burnup of the fissile atoms to a reasonable level. Various layers of materials, such as pyrolytic carbon and silicon carbide, as are known in the art, or other comparable fission-product-retentive materials, can be employed which provide good structural and dimensional stability and fission-product retention even when exposed to high temperatures in high level irradiation for long periods such as will be encountered in the core of a nuclear power reactor. Other suitable fission-product-retentive materials can also be used as a part of the overall fission-product-retentive coating arrangement that surrounds the fissile or fertile cores while still obtaining the benefit the overcoating provides to avoid fracture and/or cracking. Although the central cores of nuclear fuel material may have different shapes, they are normally spheroidal in shape, and generally the diameter of the spheroid will be not greater than about 1 millimeter (1,000 microns). Usually, nuclear fuel will be in the form of spheroids between about 100 microns and about 500 microns in diameter. Preferably, fissile fuel cores have a diameter not greater than about 550 microns, and preferably fertile fuel cores are not greater than about 650 microns in diameter. Such so-called fertile fuel cores may contain mixtures of both fissile and fertile materials, for example, mixtures of uranium and thorium compounds. Core materials in the form of oxides or carbides or mixtures thereof are generally used, although other suitable forms, such as the nitride or the silicide, which are stable at relatively high temperatures, could alternatively be employed. Preferably, the fissile fuel cores are formed of mixtures of uranium oxide and uranium carbide; however, uranium oxide could be employed. On the other hand, fertile fuel cores should contain a suitable, high-temperature, stable thorium material, such as thorium oxide or thorium carbide; and a mixture of thorium carbide and thorium oxide or a mixture of thorium oxide and uranium oxide might be employed. Because nuclear fuel materials generally expand during high-temperature operation and create gaseous and metallic fission products during fissioning, it is well known to make provision to accommodate these effects in order to facilitate prolonged operation under exposure to nuclear flux. Because the density of the core material is usually dictated by other manufacturing process considerations and/or design criteria, cores are normally of relatively dense material and thus unable to accommodate the accumulation of such gaseous fission products within the core region itself. As a result, an initial layer of relatively low density material is provided near the surface of the core to accommodate expansion at a location interior of the outer coatings which constitute the pressure-tight shell and to also accommodate gaseous fission products. The layer which surrounds the core should also be chemically compatible with the core material, both in the environment in which it is deposited and within the nuclear reactor where levels of high neutron flux will be accommodated. Spongy, pyrolytic carbon, which is a soot-like amorphous carbon having a diffuse X-ray diffraction pattern, is well known in the art and commonly employed for this purpose. Such spongy pyrocarbon also attenuates fission recoils and prevents structural damage to the outer layers, and as such it is generally employed somewhere between 20 microns and about 130 microns in thickness, with a thickness of about 50 to 60 microns often being used. The exterior layers which create the pressure-tight shell often combine layers of relatively dense isotropic pyrolytic carbon and one or more layers of silicon carbide or zirconium carbide of sufficient thickness to provide good retention of metallic fission products. In general, dense, isotropic, pyrolytic carbon has good dimensional stability and, as such, is often provided both immediately interior of and exterior of the silicon carbide layer. The interior layer may be about 40-50 microns thick. Generally, a continuous layer of silicon or zirconium carbide between about 20 microns to 45 microns in thickness is employed to assure adequate containment of metallic fission products is achieved. Such silicon or zirconium carbide layers can be applied in any suitable manner to achieve satisfactory densities which are usually at least about 90% of the theoretical maximum density of the carbide material. Such layers can be advantageously deposited from a vaporous atmosphere in a fluidized bed coating apparatus or the like as, for example, that described in detail in U.S. Pat. No. 3,298,921. For example, silicon carbide can be directly deposited from a mixture of hydrogen and methyltrichlorosilane, which easily produces densities of about 99% of maximum theoretical density. Dense isotropic carbon has both good impermeability to gas and good dimensional stability during neutron irradiation, and generally its isotrophy should measure not more than about 1.2 on the Bacon scale. Such dense isotropic pyrolytic carbon can be deposited at relatively low temperatures, e.g., 1250.degree. to 1400.degree. C. or at temperatures at between about 1800.degree. to 2200.degree. C. At higher temperatures, a gas mixture containing about 10% by volume methane can be used, whereas at lower temperatures mixtures of about 20-40% propane or butane can be used. In general, about 25-50 microns of dense isotropic pyrolytic carbon is employed exterior of the metal carbide layer, and it should have a density of at least about 80% of the theoretical maximum density, e.g., about 1.85 to 1.95 g/cm.sup.3. The foregoing describes various of the multiple layer fission-product-retentive coating arrangements that can be used to provide a pressure-tight shell about a nuclear fuel material core, although, as indicated hereinbefore, other suitable fission-product-retentive arrangements can be employed. It is contemplated that these fission-product-retentive nuclear fuel particles should retain substantially all of the fission products generated therewithin throughout a burnup of up to about 30% of the fissile and/or fertile atoms present in the core. Very generally, the exterior dimension of the coated nuclear fuel particle will usually not exceed the range of about 3 to 5 millimeters, even if a nuclear fuel core as large as about 1 millimeter were employed. The protective overcoating is disposed exterior of the outermost layer of the fission-product-retentive shell and has a density of about 60% of its theoretical maximum density or less. As indicated above, normally the exterior surface of the fission-product-retentive arrangement, or a layer very close thereto, will have a density equal to at least about 80% of its theoretical maximum density, and it is this relatively brittle or fragile material to which the overcoating material affords mechanical protection during the ensuing fabrication process. The preferred overcoating material is pyrocarbon having a density not greater than about 1.4 grams per cm.sup.3, and preferably the pyrocarbon is isotropic pyrocarbon having a density between about 0.8 and about 1.4 grams per cm.sup.3. To afford adequate protection, it is believed that the thickness of the protective pyrocarbon should measure at least about 20 microns. Although there is no reasonable upper limit to the thickness of such a layer from the standpoint of affording protection, the necessity to provide adequate nuclear fuel loading within certain spatial parameters places constraints upon the maximum thickness of the overcoating as it does on the maximum thickness of the pressure-tight shell. For this reason, it is felt that a protective overcoating between about 20 and about 70 microns in thickness will be used, and preferably between about 30 and 60 microns of pyrocarbon is employed. More preferably, a pyrocarbon overcoating is used having a thickness of at least about 30 microns and a density between about 1.0 and about 1.3 grams per cm.sup.3. Although pyrocarbon is the preferred protective overcoating material, other chemically compatible substances having suitable nuclear properties might alternatively be employed. For example, aluminum oxide might be employed as a protective overcoating and when used as such might have a density between about 1.5 and about 2.0 grams per cubic centimeter. Of course, the exterior diameter of the coated nuclear fuel particle which includes the protective overcoating will vary depending upon the size of the core and the size of the pressure-tight shell surrounding the core. Preferably, however, the outer diameter of fertile nuclear fuel particles does not exceed about 1300 microns, and the outer diameter of particles having fissile fuel cores does not exceed about 1200 microns. To form the fuel compacts usable in a nuclear reactor, the coated fuel particles having these protective overcoatings are combined in precise amount with a flowable hardenable binder under pressure in a mold of the desired size and shape. Following the hardening of the binder, a nuclear fuel compact of the desired fuel loading is achieved. To achieve the desired fuel density within this compact, the particles and binder are subjected to relatively high pressure, and pressures of at least about 600 psig are commonly employed. Moreover, after the coated particles have been supplied to the mold and before the binder is supplied, the overcoated nuclear fuel particles are often subjected to pre-compacting pressures. For example, pressures between about 100 psig and about 600 psig may be employed. Suitable methods for forming nuclear fuel compacts from coated particles are disclosed in U.S. Pat. No. 4,024,209, the disclosure of which is incorporated herein by reference. Various binders can be used, including binders that are flowable as a result of being in a molten condition and which are hardened by cooling. More commonly, binders of pitch, such as petroleum pitch or coal tar pitch, particularly in mixture with a graphite powder or flour, are used. Suitable compositions of this type, including pitch and certain alcohol and fatty acid additives, are disclosed in U.S. Pat. No. 4,217,174, issued Aug. 12, 1980, the disclosure of which is incorporated herein by reference. Alternatively, other types of resins, such as phenolic resins or furfural resins, which can be carbonized may also be used. The preferred mixtures of petroleum pitch and graphite flour, which is relatively fine particle size graphite of less than about 40 microns, are hardened by heating to a temperature of at least about 1000.degree. C. Generally, so as not to unduly delay fabrication time and so as to assure that complete carbonization is achieved, temperatures of as high as about 2100.degree. C. may be employed. Following cooling to room temperature, the compacts are examined using tests to determine the extent of heavy metal (fissile or fertile) material which is leached from the compacts and to determine which particles suffered fracture damage such as to indicate a substantial loss of the fission-product-retention capability. The amount of contamination detectable from compacts made using features of the invention is a small fraction of that detected following the formation of comparable nuclear fuel compacts from coated nuclear fuel particles which are the same in all respects except for the absence of the protective overcoatings. Such tests show the effectiveness of the overcoatings in protecting the integrity of the pressure-tight shells during the compacting of the green material. Moreover, testing of these compacts following substantial neutron irradiation to a significant burnup of the nuclear fuel also shows equally significant improvement in fission-product retention over compacts made from particles without such protective overcoatings and confirms the test results are obtained by burning one of the compacts in order to ascertain the continued integrity of SiC layers.
	abstract	The present invention provides a high gain collimator producing generally uniform intensity profiles for use in lithography and other applications. A focusing optic is also provided. The collimator includes a reflector and guide channel. The guide channel preferably includes polycapillary tubes and/or microchannel plates. The polycapillary tubes are used to collimate or focus the central portion of the x-ray beam in a circular, elliptic, square, or rectangular shape. A conical, parabolic resonance reflector or grazing incidence reflector with a shape similar to the polycapillary collimator is used to increase the solid angle collected and produce a circular, square, etc. annular x-ray beam whose inside dimensions are approximately equal to the exit dimensions of the polycapillary collimator. The annular beam shape, intensity profile and collimation angle is adjusted, if necessary, by an absorber, or polycapillary tubes to provide the desired intensity profile at the exit aperture of the hybrid x-ray collimator optic. A focusing optic is obtained by placing two collimating optics end to end.
	description	The invention relates to a method for generating electrical energy, which is based on the fusion of protons with the boron isotope 11 using laser radiation and magnetic fields and converting the energy that is released during the fusion into electrical energy. The invention also relates to a laser fusion reactor, which is configured for generating electrical energy by means of the laser-based fusion of protons with the boron isotope 11. Uses for the invention are provided in the field of electric power generation. In the e description of the prior art, reference is made to the following publications: [1] J. Nuckolls and L. Wood, Citation 25 on p. 13 of H. Hora and G. H. Miley Edward Teller Lectures Laser and Inertial Fusion Energy. Imperial College Press, London 2005; [2] H. Hora, Physics of Laser Driven Plasma Wiley, N.Y. 1981, FIGS. 10.18 a & b; [3] R. Sauerbrey, Physics of Plasmas 3, 4712 (1996); [4] H. Hora, J. Badziak et al. Physics of Plasmas 14, 072701 (2007); [5] H. Hora, Laser and Particle Beams 27, 207 (2009); [6] H. Hora et al. Laser and Particle Beams 32, 63 (2014); [7] M. Hohenberger, P. Z. Chang et al. Physics of Plasmas 19, 056306 (2012); [8] S. Fujioka et al. Scientif. Reports 3, 1170 (2013), published 30 Jan. 2013; [9] K. W. Kanngiesser, D. H. Huang and H. Lips, Hochspannungsgleichstromübertragung—Systeme and ihre Planung. EV HA 7, Siemens Monographien, Munich (1994). The most frequently used method of producing energy involves the burning of fossil fuels that contain carbon. For more than 200 years, the burning of fossil fuels has formed the basis for technological progress and economic prosperity. As a disadvantage, however,this process releases the combustion product carbon dioxide into the atmosphere, which can lead to undesirable changes in global climate. Another method for producing energy is based on nuclear fission, in which the nuclear energy that is released is converted first into heat and then into electrical energy. Although the operation of nuclear power plants is economical, it has the disadvantage that the disposal of radioactive waste is costly and risky. Furthermore, it involves the operational risk that a power plant accident can result in extreme, catastrophic damage. Nuclear energy can also be released by nuclear fusion, in which lighter atomic nuclei are fused to form heavier atomic nuclei, releasing the energy E=mc2 (m: nuclear mass defect m, c: speed of light) in the extremely high range of approximately 10 MeV per fusion reaction. However, with the exception of natural processes occurring in stars, nuclear fusion has heretofore been realized only in an uncontrolled manner in the form of exploding a fusion bomb. Controllable fusion power plants have been in development for decades, however despite major research efforts, they have not yet been successfully implemented in practice. A fusion reaction which has been comprehensively studied is based on the fusion of the heavy hydrogen deuterium (D) with the super heavy hydrogen tritium (T) (D-T fusion). However, this fusion reaction is characterized by the undesirable production of radioactive radiation which results from the conversion, with neutrons, of initially non-radiative nuclei of harmless, non-radioactive materials into radioactive isotopes, e.g. within a reactor vessel. All known methods for the controlled generation of nuclear fusion energy have a yield of less than 500 (energy produced per laser energy expended) with one exception. Nuckolls and Wood proposed in 2002 [1] that, as with the “fast ignition” scheme, a nanosecond-long laser pulse will produce approximately 1000 times solid state density deuterium-tritium (DT) plasma, on which a picosecond (ps)-long laser pulse acts, producing a highly intense relativistic electron beam of 5 MeV electron energy. When this electron beam acts on a volume of solid DT of at least 12 times solid state density, a fusion detonation wave is generated in this volume, in which ten thousand times more energy is produced than laser energy is consumed, according to theoretical estimates without further numerical data or implementation known from experimentation. The need for very high energy yields consists in the fact that with pulsed operation in a fusion power plant that operates using lasers, fusion energy up to the gigajoule range (GJ=278 kWh) or higher per reaction per second is generated if at all possible, for reasons of cost. It should be noted that the shock effect caused by the pulse of the nuclear reaction is about 3000 times lower than that of a chemical explosion. In this connection, fusion yields obtained with laser pulses of up to 100 kJ of energy and ps duration as in the system of Nuckolls and Wood [1] are of interest. This is different from all other laser-fusion arrangements with yields below 500. Also of particular interest is the fusion reaction of the hydrogen nuclei (H, protons p) with the boron isotope 11, which is referred to as the HB11 reaction. Each HB11 reaction produces three helium nuclei (alpha particles) with an energy gain of 8.9 MeV. This energy can be converted into heat or electrical energy. The HB11 reaction offers particular advantages in terms of high energy yield, avoiding the radiation problems of D-T fusion and a virtually inexhaustible availability of raw materials. And the HB11 reaction generates less radioactivity per unit of energy produced than the burning of coal, so radioactivity is no problem and can be disregarded. The combination of laser nuclear fusion with magnetic fields is well known, although with the existing magnetic fields below 100 tesla, yields of less than 100 must be expected. The laser effect on solid state density fusion fuel using laser pulses of around ps duration or less is used for generating a cylindrical reaction zone, for which fusion is obtained only with said low yields. The use of magnetic fields was originally introduced in order to curb cylindrical radial losses, after the ps laser pulses for initiating a fusion flame by igniting an ultrahigh accelerated plasma by the nonlinear force of an extended plane geometry had to be restricted to a limited range of interaction—in contrast to the Nuckolls-Wood process—and the geometry was to extend in a cylindrical area under the interaction cross section, avoiding radial losses. These lateral losses could alternatively be eliminated by using a spherical geometry, as was published. In that case, for the reaction of boron isotope 11 with light hydrogen (HB11) in solid state density, only a maximum of all the fuel in the sphere could supply energy, wherein, as in other cases, the yield was limited and exawatt (EW) laser pulses were necessary. It is known, in particular, to initiate the HB11 reaction by laser irradiation of a fusion fuel. With laser-based nuclear fusion, originally thermal processes involving an extremely rapid heating of targets at very high thermal pressures for the thermal ignition of fusion reactions were proposed. Using the most powerful lasers in the world, such as those at Livermore (Calif., USA), laser pulses with a duration of nanoseconds (ns) achieve yields close to breakthrough for a fusion reactor with DT. Furthermore, departing from thermal methods, it has been found that laser energy can be converted directly into mechanical plasma motion, thereby avoiding complicated heating processes, radiation. instabilities and delayed thermal transitions of electrons to the pressure-generating plasma ions (block ignition). This concept is derived from the ponderomotive force, discovered by Kelvin, by which electrically uncharged bodies can be moved by means of electric fields, and the qualification thereof as a non-linear force which is based on the generation of high-frequency electric fields, wherein the optical properties of plasmas had to be generalized by means of Maxwell's stress tensor [2] [4] [5]. Based on measurements of the laser-plasma interaction, non-linear force was introduced on the basis of the optical properties of the high temperature plasmas generated by lasers in the irradiation of materials, with application to ordinary and relativistic self-focusing and plasma motion. However, it was determined [5] (see FIG. 1 of [4]) that in order to ignite a fusion reaction of deuterium and tritium, an energy flux density of 100 million joules per square centimeter would be required within a time of one picosecond (ps), which could not be achieved using the laser sources available for practical use during the 1970's. In 1978, plasma hydrodynamic simulations demonstrated how laser pulses of 1.5 ps duration and a realistic intensity at that time of 1018 W/cm2 could accelerate a 20 wavelength thick layer of deuterium plasma to velocities of 109 cm/s [9]. These were ultrahigh accelerations of more than 1020 cm/s2. Confirmation of these ultrahigh accelerations through experimentation was possible only after the introduction of the CPA method (chirped pulse amplification) for generating ultrashort laser pulses. Since that time, laser intensity (without self-focusing) has increased by ten million times. In ps laser pulses or even shorter laser pulses, the measured power reaches 10 PW (petawatt). With ultrashort laser pulses, the acceleration of plasma blocks in the range of 2×1020 cm/s2 was directly visibly measured with a Doppler shift of spectral lines [3], which corresponded to theoretical simulations [4], [4]. In a summary of these results [5], it was found that when hydrogen-boron (HB11) is used as a fusion fuel instead of D-T, the thresholds for laser ignition were about the same. That came as a big surprise and was possible only because the ps laser pulses provided the non-thermal direct conversion of laser energy to fusion, as opposed to the thermally compressive ignition achieved with ns laser pulses. These computations for HB11 took into account only the binary reactions as in the computations for the D-T reaction. The HB11 reaction, however, produces a secondary reaction following the primary reaction, by elastic collisions of the resulting alpha particles with boron nuclei, causing an avalanche process with much higher reaction yields than with D-T. Furthermore, reactions in plane geometry were expected. For a fusion reactor, however the lateral losses must be considered. The simplest solution is to use spherical geometry. If solid state density fusion fuel is used, however, it is found for both DT and HB11 that for energy yields of up to 100, the necessary power of the radiated laser pulses lies not in the range of petawatts but in the thousands of times higher exawatt range, which can be achieved using current high performance laser sources. For example, a nuclear fusion reactor is proposed, which has negligible radioactivity by laser-driven plasma block ignition of solid state density or moderately compressed fuel, in which the lateral limitation of the reaction is achieved by using magnetic fields and/or a cladding that has a high atomic weight. For the block ignition of nuclear fusion with ps-PW laser pulses, it is known that the ultrahigh plasma acceleration by non-force [2] calculated in 1978 was measured by Sauerbrey [3] in precise conformity [4], and those for initiation of a fusion flame were reproduced with the same threshold values for energy flux density for D-'I′ fusion. The same high energy flux densities were obtained for HB11 fusion [5], solely for binary reactions as for DT. The use of classic magnetic fields with cylindrical geometry up to nearly 100 tesla was found to be insufficient for reducing the lateral losses from he reaction. For spherical geometry it was found that yields of only about 100 were achieved for HB11 reactions using at least exawatt pulses, even when in addition to the binary reactions the avalanche multiplication was included [6]. In [7], a laser-based nuclear fusion reaction is known, in which fusion fuel in the form of capsules is held with a magnetic field strength of 350 tesla. The nuclear fusion reaction is thermal, with laser pulses with a duration in the ns range being used. An object of the invention is to provide an improved method for generating electrical energy by nuclear fusion which avoids the drawbacks and limitations of conventional methods and which is characterized in particular by an increased energy yield and simplified implementation in practice. Another object of the invention is to provide an improved nuclear fusion reactor, with which the drawbacks and limitations of conventional techniques can be avoided, and which is characterized in particular by a simplified, practically implementable structure. These objects are achieved by a method for generating electrical energy and a nuclear fusion reactor having the features of the independent claims. Advantageous embodiments and uses of the invention result from the dependent claims. According to a first broad aspect of the invention, the above object is achieved by a method for generating electrical energy by means of inertial nuclear fusion (inertial confinement fusion) in which a fusion fuel, preferably comprising hydrogen and boron 11, is held within a magnetic field in a cylindrical reaction chamber, and a nuclear fusion reaction is initiated in the fusion fuel by using fusion laser pulses (also referred to as block fusion laser pulses), the pulse duration of which is less than 10 ps and the power of which is more than 1 petawatt. The energy released during nuclear fusion from the nuclei that are produced is converted into electrical energy. According to the invention, the magnetic field has a field strength which is greater than or equal to 1 kilotesla. The nuclear fusion preferably produces an energy yield of more than 500, in particular tore than 1000 per laser energy of the fusion laser pulses used to initiate the fusion flame. The tern fusion flame refers to the fusion reaction by picosecond initiation with block ignition (as distinguished from thermal fusion detonation). According to a second general aspect of the invention, the above object is achieved by a nuclear fusion reactor, which is configured for generating electrical energy, and a magnetic field device which is configured for holding fusion fuel and for generating a magnetic field in a cylindrical reaction chamber, a fusion laser pulse source, configured for emitting fusion laser pulses having a pulse duration of less than 10 ps and a power of more than 1 petawatt and for initiating nuclear fusion in the fusion fuel, and an energy conversion device, which is provided for converting the energy released in the nuclear fusion reaction from the nuclei that are produced into power plant power. The magnetic field device is preferably configured to hold the fusion fuel by means of electrically insulating fibers, e.g. made of quartz. According to the invention, the magnetic field device is configured for generating the magnetic field with a field strength that is greater than or equal to 1 kT. According to the invention, magnetic fields having a field strength of equal to or greater than kilotesia are preferably used, with the fields more preferably being controlled by a laser-controlled discharge. Advantageously, with the magnetic fields used according to the invention, for the first time he radial losses from a magnetic cylindrical reaction chamber of HB11 with consecutive reactions are prevented such that high yields particularly of greater than 1000 and much more are achieved, with the ps laser pulses having a particularly preferred power of a least 10 PW. The inventors have found tha the magnetic fields are suitable for reliably containing the expansion of the reaction volume during ignition of the nuclear fusion. The invention offers the advantage of providing, for the first time, a realistic and economically feasible realization of a fusion-based, practically inexhaustible and inexpensive energy source. The nuclear fusion reactor according to the invention is a fusion power plant for practical use. The invention provides highly efficient laser nuclear fusion with magnetic channeling, in which laser-powered nuclear fusion is achieved with yields greater than 500 by applying extremely high magnetic fields. Advantageously, the ultrahigh magnetic fields [8] of greater than one kilotesla, previously known in only one case, are used, as compared with conventional methods for generating a more than thirty times higher magnetic field, however instead of fusion which is thermally driven in nanoseconds, a non-thermal block ignition achieved with picosecond pulses is used. In dramatic contrast to all previous methods and configurations, this method enables energy yields to be achieved which lead to the realization of economically operated power plants with overall negligible nuclear radiation. According to preferred embodiments of the invention, the fusion fuel has at least one of the following features. According to a first variant, the fusion fuel preferably has a solid state density of up to 20 times the compression as compared with uncompressed fuel, similar to the case of “fast ignition” according to Nuckolls et al. [1]. According to a further variant, the fusion fuel preferably consists of 11B isotopes with up to a 15% deviation of light hydrogen in terms of stoichiometry. According to a further variant, the fusion fuel preferably consists of a mixture of light hydrogen and boron, each in at least a 20% atomic concentration. If, accord g to a further advantageous embodiment of the invention, the energy of the nuclei generated is captured by electrostatic fields, further advantages in terms of energy yield are achieved. The fusion energy can be converted directly into electrical energy. Preferably, the kinetic energy of the alpha particles produced is converted directly into electrical energy. To generate the electrostatic fields, the reaction chamber, more particularly the magnetic field device for forming the reaction chamber, is preferably surrounded by the energy conversion device, the reaction chamber having a negative high voltage relative to the energy conversion device. For this purpose, the reaction chamber, in particular the magnetic field device, is preferably connected to a high voltage source for generating a negative high voltage relative to the energy conversion device. Particularly preferably, the negative high voltage is at least 1 MV. If, according to a further variant of the invention, the energy conversion device is at ground potential, advantages with respect to the configuration of the nuclear fusion reactor and the feeding thereof with fusion fuel are achieved. The energy conversion device is preferably in the form of a spherical, electrically conductive enclosure (housing) around the reaction chamber, in particular the magnetic field. Advantageously, the energy conversion device is thereby optimally adapted to the fusion geometry. Particularly preferably, between the energy conversion device and the reaction chamber a Faraday cage is provided for shielding the static high voltage field from the reaction processes, preventing any penetration of the high-voltage field into the fusion reaction volume. The magnetic field having a field strength of greater than or equal to 1 kilotesla can be realized by any available method for generating strong magnetic fields. According to a particularly preferred embodiment of the invention, the magnetic field is generated by means of an interaction with discharge laser radiation by a discharge current in electrodes which are coupled via at least one coil, in particular a single coil winding. The magnetic field device of the nuclear fusion reactor preferably has a pair of electrodes, two coils and a magnetic field pulsed laser source, which is provided for irradiating the electrodes with discharge laser radiation. Preferably, the magnetic field device is configured to hold the fusion fuel by means of electrically insulating fibers, z. B. made of quartz, on the coils or other support elements of the magnetic field device. Particularly preferably, the magnetic field device is implemented with the configuration described in [8] by S. Fujioka, et al. The discharge laser radiation preferably comprises laser pulses (hereinafter: magnetic field generating laser pulses or magnetic field laser pulses) having a pulse duration of less than 20 ns and energy of more than 100 J. Advantageously, according to a further embodiment of the invention, the magnetic field can be intensified by designing the electrodes for generating the magnetic field to comprise two plates spaced from one another, between which a magnetic field laser pulse absorbing material is arranged, the form of which is adapted to a Rayleigh profile of generated plasma. The material particularly preferably comprises a foam material, such as polyethylene, and the bi-Rayleigh profile of electron density according to FIG. 10.17 of [2] (see FIG. 1 of [4]) is selected. According to a further, particularly advantageous embodiment of the invention, block ignition is initiated by the fusion laser pulses. For this purpose, the fusion laser pulses preferably have a duration of less than 5 ps and/or a power of at least 1 petawatt. The fusion pulsed laser source for generating the fusion laser pulses having a duration of less than 5 ps preferably comprises the same type of source as the 10 PW-ps laser assembly known from the Institute of Laser Engineering at Osaka University. The fusion laser pulses preferably have a contrast ratio of at least 106. To achieve this, advance pulses are particularly preferably suppressed up to a time of less than 5 picoseconds before the arrival of a (main) fusion laser pulse at the fusion fuel. Furthermore, benefits in terms of triggering the fusion reaction result when the fusion laser pulses have an intensity of at least 1017 watts per square centimeter upon arrival at the fusion fuel. According to a further advantageous embodiment of the invention, the fusion fuel is partially or fully encapsulated by a cover layer, particularly on the side of laser-plasma interaction, the cover layer being made of a material which has an atomic weight of greater than 100. The pulse transmission for generating the fusion flame in the reaction fuel is advantageously increased as a result. The cover layer preferably has a thickness equal to or less than 5 microns, and/or it may be formed by vapor deposition. Features of preferred embodiments of the invention are described below primarily with reference to the generation of the magnetic field for holding the fusion fuel and the design of the energy conversion device. Details the invention,such as the details of laser pulse sources, the physical principles of the HB11 reaction, the connection of the fusion reactor to other components of a power plant, in particular for preparing and delivering the fusion fuel, for controlling the fusion reactor, for protecting; the environment against thermal effects and/or electric fields, are not described, as these can be realized by a person skilled in the art based on his/her knowledge of known fusion and plasma physics and conventional power plant engineering, depending on the specific conditions of use of the invention. Reference is made by way of example to a fusion reactor having a single reaction chamber. However, the invention is not limited to this design. Rather, a fusion reactor be equipped with a plurality of reaction chambers, each having a magnetic field device for holding fusion fuel. The reaction chambers may be operated alternatingly in sequence so as to enable a continuous or quasi-continuous generation of electrical energy. FIG. 1 shows a schematic illustration of one embodiment of the nuclear fusion reactor 100 of the invention, which comprises a magnetic field device 10 for holding a fusion fuel 1 with a magnetic field in a cylindrical reaction chamber 2, a magnetic field pulsed laser source 20 for emitting magnetic field laser pulses 3 (or: magnetic field generating laser pulses), a fusion pulsed laser source 30 for emitting fusion laser pulses 4 (or: block fusion laser pulses) and an energy conversion device 40 for converting the energy that is released from the nuclei that are produced during nuclear fusion. The magnetic field device 10 for generating a magnetic field having a strength of e.g. 4.5 kT in reaction chamber 2 comprises two parallel metal plates 11, 12 made of nickel, for example, and having a thickness of e.g. 2 mm and a characteristic expansion of e.g. 3 cm. The metal plates 11, 12 are connected to one another via electrical conductors, which form two windings 13 of a coil. One of the metal plates 11 has an opening 14 through which the magnetic field laser pulse 3 is beamed with a duration of, for example, 1 ns to 2 ns, and e.g. 10 kJ of energy. The plasma produced by each magnetic field laser pulse 3 generates a current surge in the windings 13 with a magnetic field having a volume of a few cubic millimeters and several ns duration. Opening 14 is a circular opening in the upper metal plate 11 in FIG. 1. The diameter and optionally also the geometric shape of opening 14 are selected based on the properties, in particular the intensity, the diameter and the profile, of the magnetic field laser pulses 3. The diameter of opening 14 is 5 mm, for example. Rather than the circular shape, an elliptical shape may also be provided. Opening 14 may be optimized with a view to maximizing the magnetic field for a maximum fusion yield. The second metal plate 12, which faces opening 14, can be provided with an absorption layer which serves to reduce the optical reflection of the magnetic field laser pulses 3 and to increase the dielectric properties of the capacitor formed by the metal plates 11. The absorption layer (not shown) is preferably disposed over the entire surface of the metal plate 12, and is more preferably made of a foam material, for example polyethylene. The foam material is selected such that after laser irradiation, an electron density distribution is formed as a bi-Rayleigh profile. The magnetic field laser pulses 3 are generated by the schematically illustrated magnetic field pulsed laser source 20, which contains, for example, a Nd-YAG laser and other optical components (not shown) for directing the magnetic field laser pulses 3 toward the magnetic field device 10. The duration of the magnetic field laser pulses 3 may optionally be shortened by a time in the nanosecond range by using an iodine laser having a pulse length of 100 ps, and/or with shorter laser pulses following a CPA power increase. The: magnetic field generated by the magnetic field device 10 can thereby be advantageously intensified. The fusion pulsed laser source 30 is configured rate the fusion laser pulses 4 with a duration of less than 5 ps and an intensity in excess of 1019 W/cm2. The fusion laser pulses 4 preferably have a contrast ratio of at least 106 for the duration of less than 5 ps prior to the arrival of the fusion laser pulses 4 at fusion fuel 1. In addition, the fusion laser pulses 4 preferably have an intensity distribution with less than 5% fluctuation over the beam cross section, except in an outer 5% border region of the beam cross section. The block ignition of the fusion reaction in fusion fuel 1 is thereby advantageously optimized. This intensity distribution is achieved, for example, by a fusion pulsed laser source 30 which has a bundle of fiber amplifiers, each individual fiber having a single mode emission. The fusion pulsed laser source 30 further contains a pulsed laser, such as a solid state pulsed laser, for generating ps laser pulses. The magnetic field pulsed laser source 20 and the fusion pulsed laser source 30 are coupled to a control unit 50. Control unit 50 is configured such that the magnetic field laser pulses 3 and the fusion laser pulses 4 are synchronized with one another. In reaction chamber 2, the maximum magnetic field is generated immediately before each fusion laser pulse 4 arrives at fusion fuel 1. Fusion fuel 1 is a solid state, cylindrical body, based on HB11, for example, and having a length of 1 cm and a diameter of 0.2 mm. The surface of fusion fuel 1 has a cover layer over the laser interaction surface which has a thickness of three laser vacuum wavelengths. The top cover layer consists of elements having an atomic weight greater than 100, for example, silver. The cover layer improves pulse transmission for generating the fusion flame in fusion fuel 1. Fusion fuel 1 is held in the magnetic field device by means of quartz fibers. Energy conversion device 40 generally comprises an electrically conductive component (indicated schematically by dashed lines in FIG. 1; see also FIG. 3), which surrounds magnetic field device 10 on all sides. Magnetic field device 10 is supported inside energy conversion device 40 (support not shown in FIG. 1; see, for example, support bar 44 in FIG. 3). Energy conversion device 40 is preferably connected to ground potential, while a negative high voltage, for example −1.4 MV, is applied to magnetic field device 10 by means of a voltage source 15. Energy conversion device 40 is configured to capture high-energy He nuclei (alpha particles) released during the fusion reaction of fusion fuel 1, and convert them by means of high voltage direct current transmission (HVDC) [9] into a discharge current. The discharge current supplies the electrical energy into which the energy released in the fusion reaction is converted. The arrival of the magnetic field laser pulses 3 and fusion laser pulses 4 at the reaction unit formed by magnetic field device 10, is also illustrated in FIG. 2. Magnetic field device 10 is configured as described above in reference to FIG. 1. The magnetic field generating laser pulses 3 generate a magnetic field having a field strength of 10 kT, for example. Fusion fuel 1 is placed (and held in place by the quartz fibers) within axis 1 of reaction chamber 2, which is the same as the axis of the magnetic field, and is acted on by a magnetic field within a time range of nanoseconds. During the period in which the magnetic field is generated, a block ignition is generated in fusion fuel 1 by means of fusion laser pulse 4. Fusion laser pulse 4 has an energy of 30 kJ, for example (equivalent to 30 PW power), so that the products of the nuclear fusion (helium nuclei) have an energy output of about 1 GJ. This energy is converted electrostatically by energy conversion device 40, with low heat loss, into electric power (1 GJ is equivalent to around 280 kWh). This advantageously enables fusion reactor 100 to economically supply a high electric current, even at a low reaction rate of one reaction per second. The fusion reaction destroys magnetic field device 10 by the action of the fusion products, so that for the subsequent fusion reaction, another magnetic field device 10 loaded with fusion fuel must be supplied. In contrast to the diagrams in FIGS. 1 and 2, the direction of incidence of the magnetic field generating laser pulses 3 can be rotated by an angle of up to 80° between the vertical incidence in the plane spanned by the vertical direction of incidence and the normal plane of the magnetic field, with rotation occurring in the plane which is oriented parallel to the coils 13. Further details of an embodiment of the nuclear fusion reactor 100 according to the invention are shown in FIG. 3. In this embodiment of the invention, energy conversion device 40 comprises an electrically conductive sphere, at the center of which magnetic field device 10 of FIGS. 1 and 2 is arranged. Energy conversion device 40 is made, for example, of stainless steel having a thickness of 10 mm and a diameter of at least 1 m. The spherical outer vessel of the reactor must be large enough and its walls must be thick enough to withstand the mechanical shock of the fusion reaction. This results in the advantage that the mechanical pressure amounts to the root of the energy of the nuclear reaction divided by the energy produced in chemical reactions, which is a factor of approximately 3000. The shock on the wall of the sphere transferred by the pulse of the total of generated alpha particles is then equivalent to the explosion of approximately 5 grams of TNT. In a practical embodiment of the invention, all components of fusion reactor 100 are formed with rounded surfaces, which are free of corners and edges. A field emission of electrons and the formation of dark discharges is thereby advantageously avoided. The entire assembly is located under a high vacuum generated by vacuum pumps (not shown). The spherical surface of energy conversion device 40 has a plurality of windows, which comprise a first window 41 for beaming in the magnetic field laser pulses 3, a second window 42 for beaming in the fusion laser pulses 4 and a third window 43 for loading he energy conversion device 40 with the magnetic fi Id device 10 and the fusion fuel 1. Since the interior of energy conversion device 40 is evacuated, the first windows 41 and second windows 42 are formed by pressure-tight, transparent panes, for example, of glass. The third window 43 is open and coupled in a pressure tight connection to an adjacent container, and is used for supplying and supporting he central magnetic field device 10 (reaction unit). This is provided on a rod-shaped fuel carrier 44, which is loaded outside of the energy conversion device 40 with fusion fuel 1, and is inserted and positioned at the center of the sphere, particularly freely floating. Fuel carrier 44 and magnetic field device 10 are located, at a potential of −1.4 MV relative to energy conversion device 40, at ground potential. Fuel carrier 44 is in the form, for example, of a rod with a length of at least one-half the diameter of energy conversion device 40. Inside energy conversion device 40, a spherical or otherwise shaped, e.g. irregularly shaped, Faraday cage 45, is provided, which encloses magnetic field device 10. The Faraday cage 45, e.g. in the form of a mesh or grid, is designed to prevent the static high-current field from influencing the processes involved in generating the magnetic field of the magnetic field device. The energy conversion device 40 is shielded on all sides by the Faraday cage 45. Fuel carrier 44 with magnetic field device 10 and fusion fuel 1 at the electrical potential of 1.4 MV comes from the adjoining container, which is located electrically insulated in the same vacuum as the interior of the spherical energy conversion device 40, so that after each reaction, additional reactor units are brought into the center of the energy conversion device 40 at the same potential. Access to the interior for the loading units of the reaction is provided through air locks. During continuous operation, magnetic field devices 10, loaded with fusion fuel 1, are introduced repeatedly in succession into energy conversion device 40, exposed to the magnetic field generating laser pulses for generating the magnetic field, and during generation of the magnetic field are exposed to the block fusion laser pulses for block fusion, and are then replaced by a new magnetic field device 10 loaded with fusion fuel 1. The double charged alpha particles of the same energy (helium nuclei) generated with each fusion reaction reach the spherical energy conversion device 40 through the mesh of the Faraday cage 45 and release their kinetic energy to the energy conversion device 40. At the potential of −1.4 MV the energy of the alpha particles is available, and at a charge −1.4 MV the energy is supplied as a seconds long discharge current of 714 Amperes by means of the high voltage direct current transmission technique known from [9]. The high voltage direct current is converted into conventional three-phase alternating current in a known manner, as in HVDC technology [9]. The same energy of all alpha particles of 2.9 MeV generated in the fusion process is widened by a secondary avalanche reaction to a spectrum of both higher and lower energies, thereby advantageously improving the energy yield of energy conversion by a few percent more. Refilling for a subsequent reaction at the potential of −1.4 million volts can then be accomplished within only seconds with the prepared fixation of the adjustment of the laser pulses toward the central reaction unit of FIG. 2. Before it is introduced into the reactor sphere (energy conversion device 40), the remains from the preceding reaction can be removed. The cost of each new unit including the HB11 fusion fuel can be held to a fraction of the overhead costs of the generated electrical energy. The features of the invention disclosed in the foregoing description, the drawings and the claims, taken alone, in combination or in sub-combinations, are considered essential to implementing the various embodiments of the invention.
	summary
	description	In order to establish material specifications for zirconium alloys excellent in both corrosion resistance and hydrogen absorption characteristics, we separately reviewed the data on corrosion resistance and those on hydrogen absorption characteristics. With respect to corrosion resistance, it has already been known from Y. Etoh et al. ASTM STP 1354, p. 661 (2000) that if the mean precipitate size is made smaller, the maximum oxide film thickness decreases to improve corrosion resistance. The reason why the oxide film thickness increases with mean precipitate size is that nodular corrosion occurs. On the other hand, the reason why the oxide film thickness decreases with mean precipitate size is that the occurrence of nodular corrosion is prevented. Next, we studied means for lowering hydrogen absorption and reached the conclusion that when the mean size of precipitates in a zirconium-base alloy is made greater, the hydrogen absorption of the alloy becomes lower. The relationship between the hydrogen absorption determined by corrosion tests carried out in water vapor at 400xc2x0 C. and 10.3 MPa for 480 hours and mean precipitate size is shown in the graph in FIG. 3. This graph clearly shows that the greater is the mean precipitate size, the lower is the hydrogen absorption. The graph also shows that this tendency can be observed even when the Fe content is made higher. From the outcome of the studies on the hydrogen absorption characteristics of zircaloys, it can be concluded that it is possible to lower the hydrogen absorption of zircaloys by increasing the mean sizes of precipitates in the alloys or the Fe contents of the alloys. However, with respect to corrosion resistance, if the mean precipitate size is made greater, nodular corrosion occurs to give an oxide film having a greater thickness. It was thus realized that improvement in corrosion resistance and lowering of hydrogen absorption conflicted with each other when viewed from mean precipitate size. As will be described hereinafter in detail, we tried to establish material specifications for zirconium alloys that are excellent in both corrosion resistance and hydrogen absorption characteristics. Firstly, as for corrosion resistance, an oxide film, corrosion layer, formed under such conditions that nodular condition does not occur is extremely thin and uniform and has high corrosion resistance, as long as the mean precipitate size is small. We, therefore, considered that it was important to determine the threshold of occurrence of nodular corrosion, that is, the minimum precipitate size that would be the cause of nodular corrosion. With respect to precipitates in a zircaloy (mainly, two types of precipitates, Zr(Cr, Fe)2 and Zr2(Ni, Fe) are present), it is known that so-called irradiation-induced dissolution occurs, where such atoms as Fe, Cr and Ni are sputtered from the precipitates by irradiation and are dissolved in a metal. From our studies, it was found that this irradiation-induced dissolution phenomenon was closely relates to the occurrence of nodular corrosion. Namely, it was found that nodular corrosion did not occur as long as the rate of dissolution, in a matrix, of Fe and Ni sputtered from precipitates was above a certain value. This correlation is shown in FIG. 4. The graph in FIG. 4 shows the relationship, at three different Fe contents, between mean precipitate size and the rate of dissolution of Fe and Ni, that is, Fe+Ni (at %/s). In FIG. 4, the region under each curve, below the threshold of occurrence of nodular corrosion is a nodular-corrosion-occurring region. These curves show that the threshold precipitate size of occurrence of nodular corrosion increases with Fe content. The threshold of occurrence of nodular corrosion determined as described above is shown on the diagram in FIG. 1. FIG. 1 is a diagram using rectangular coordinates, plotting Fe content (wt. %) as the X-axis and mean precipitate diameter (nm) as the Y-axis. In FIG. 1, the region on the upper left side of the line of the threshold of nodular corrosion is a nodular-corrosion-occurring region. It can be known that the threshold precipitate size of occurrence of nodular corrosion gradually increases with Fe content. Next, the relationship between hydrogen absorption property and mean precipitate size is reviewed. As shown in FIG. 3, although it is clear that the hydrogen absorption lowers as the mean precipitate size increases, it can also be known that the hydrogen absorption depends also on Fe content. Accordingly, the relationship between hydrogen absorption and Fe content and the relationship between hydrogen absorption and means precipitate size were reviewed by referring to the graphed data in FIG. 3. With respect to hydrogen absorption, the hydrogen absorption of Zircaloy-2 having an Fe content of 0.16-0.18 wt. % and a mean precipitate size of 50-90 nm was normalized to be 1. The relative amounts of hydrogen absorption thus normalized are shown in FIG. 1. FIG. 1 shows the lines at relative amounts of hydrogen absorption of 0.5, 0.6, 0.8 and 1.0. It is understood from FIG. 1 that it is possible to lower the hydrogen absorption by increasing the Fe content or mean precipitate size. However, when the mean precipitate size is made greater than the threshold precipitate size of occurrence of nodular corrosion, nodular corrosion occurs to drastically lower the resistance to corrosion. Therefore, for optimum specifications, it is necessary to specify the mean precipitate size smaller than the threshold precipitate size of occurrence of nodular corrosion. On the basis of the above-described outcome of our studies, specifications for zirconium-base alloys that are excellent in both corrosion resistance and hydrogen absorption characteristics are established. Herein obtained are specifications for zirconium-base alloys for nuclear reactors, comprising Sn, Fe, Ni, Cr, Zr and unavoidable impurities, which are the same constituent elements as those of Zircaloy-2. The relative hydrogen absorption rapidly lowers to approximately 0.6, but tends not to become below 0.6 any more because saturation occurs. Therefore, specifications are established so that the relative hydrogen absorption can be 0.6 or less of that of the conventional materials. The Fe content is set at not more than 0.6 wt. % because a zirconium-base alloy having an Fe content of more than 0.6 wt. % has worsened processing characteristics and ductility. Namely, defined herein is a zirconium-base alloy having a composition and mean precipitate size that are included in a region on the x (Fe content wt. %) and y (mean precipitate size (nm)) rectangular coordinates, surrounded by the following five lines: i) Y=xe2x88x92989xc3x97X+362, ii) Y=910xc3x97Xxe2x88x9246, iii) Y =0, iv) Y=300 and v) X=0.6. In the case where specifications that make the hydrogen absorption equal to or less than the current one, that is, specifications that make the relative hydrogen absorption equal to or less than 1, are established by taking the hydrogen absorption range wider as shown in FIG. 2, there is defined a zirconium-base alloy having a composition and mean precipitate size that are included in a region on the x (Fe content wt. %) and y (mean precipitate size (nm)) rectangular coordinates, surrounded by the following five lines: i) Y =xe2x88x92444xc3x97X+154, ii) Y=910xc3x97Xxe2x88x9246, iii) Y=0, iv) Y=300 and v) X=0.6. Further, the mean precipitate size depends on heat treatment conducted in the production process. Annealing parameter (xcexa3Ai) is known as a quantified index of this heat treatment. It is to quantify, by using the following equation, the amount of heat a zirconium-base alloy gains after the xcex1+xcex2 or xcex2-quenching: xcexa3Ai=xcexa3tixc3x97exp (xe2x88x9240,000/Ti) wherein ti is a retention time (h) at a heat treatment temperature Ti, and Ti is a heat treatment temperature (K). Existing between this annealing parameter (xcexa3Ai) and mean precipitate size (nm) is a relationship represented by the following equation: mean precipitate size (nm)=30+1.6xc3x97107xc3x97exp (0.7xc3x97log (xcexa3Ai )). Therefore, the above-established material specifications for two zirconium alloys can be expressed in the below-described way by replacing the mean precipitate size by xcexa3Ai. In FIGS. 1 and 2, the values of xcexa3Ai are plotted as the Y-2 axis, and the upper and lower limits of xcexa3Ai are 1Exe2x88x9215 (i.e., 1xc3x9710xe2x88x9215) and 1Exe2x88x9221 (i.e., 1xc3x9710xe2x88x9221), respectively. If the above-described annealing parameter is used, the aforementioned zirconium-base alloy according to the present invention can be defined as a zirconium-base alloy for nuclear reactors, comprising Sn, Fe, Ni, Cr, Zr and unavoidable impurities, wherein the Fe content (X wt. %) and the annealing parameter (xcexa3Ai) of the zirconium-base alloy are present in a region on the x (Fe content X) and y (annealing parameter) rectangular coordinates, surrounded by the following five lines: i) 30+1.6xc3x97107xc3x97exp (0.7xc3x97log (Y))=xe2x88x92444xc3x97X+154, ii) 30+1.6xc3x97107xc3x97exp (0.7xc3x97log (Y))=910xc3x97Xxe2x88x9246, iii) Y=1xc3x9710xe2x88x9221, iv) Y=1xc3x9710xe2x88x9215, and v) X=0.6. A particularly preferable zirconium-base alloy according to the present invention is one whose Fe content (X wt. %) and annealing parameter (xcexa3Ai) are present in a region on the x (Fe content X) and y (annealing parameter) rectangular coordinates, surrounded by the following five lines: i) 30+1.6xc3x97107xc3x97exp (0.7xc3x97log (Y))=xe2x88x92989xc3x97X+362, ii) 30+1.6xc3x97107xc3x97exp (0.7xc3x97log (Y))=910xc3x97Xxe2x88x9246, iii), Y=1xc3x9710xe2x88x9221, iv) Y=1xc3x9710xe2x88x9215, and v) X=0.6. The zirconium-base alloys according to the present invention comprise Sn, Fe, Ni, Cr, Zr and unavoidable impurities. The Fe content is specified in consideration of correlation with mean precipitate size or annealing parameter (xcexa3Ai), as described above. The contents of the essential components other than Fe are as follows: the Sn content is from 0.5 to 2 wt. %, the Ni content is from 0.03 to 0.2 wt. %, the Cr content is from 0.05 to 0.2 wt. %, and the balance comprises Zr and unavoidable impurities. Sn is a constituent particularly useful for imparting improved strength and corrosion resistance to zirconium-base alloys. A zirconium-base alloy containing less than 0.5 wt. % of Sn cannot show sufficiently high strength, while a zirconium-base alloy containing more than 2 wt. % of Sn has worsened corrosion resistance. Therefore, from 0.5 to 2 wt. % is the Sn content specified in the present invention. A preferable Sn content range in the present invention is from 0.8 to 1.5 wt. %. Ni is a constituent particularly useful for imparting improved corrosion resistance to zirconium-base alloys. When Ni is incorporated into a zirconium-base alloy in an amount of less than 0.03 wt. %, the effect of improving corrosion resistance cannot fully be obtained. On the other hand, a zirconium-base alloy containing more than 0.2 wt. % of Ni has remarkably worsened hydrogen absorption property. The Ni content specified in the present invention is, therefore, from 0.03 to 0.2 wt. %. A preferable Ni content range in the present invention is from 0.05 to 0.10 wt. %. Cr is a constituent particularly useful for imparting improved corrosion resistance to zirconium-base alloys. This element governs the proportions of two types (Zr2(Fe, Ni) type and Zr(Fe, Cr)2 type) of precipitates, mainly present in a zirconium-base alloy containing Fe, Ni and Cr, and indirectly affects the corrosion resistance and hydrogen absorption property of the zirconium-base alloy. When Cr is incorporated into a zirconium-base alloy in an amount of less than 0.05 wt. %, the effect of improving corrosion resistance cannot fully be obtained, while when the Cr content is made more than 0.2 wt. %, the distribution of precipitates is adversely affected. The Cr content specified in the present invention is, therefore, from 0.05 to 0.2 wt. %. A preferable Cr content range in the present invention is from 0.07 to 0.15 wt. %. A zirconium-base alloy according to the present invention can be produced in the following manner, for example. An ingot melt is subjected to hot forging (e.g., at 700 to 750xc2x0 C.) and solution treatment (e.g., at approximately 1000xc2x0 C. for several hours), and is then made into a billet for extrusion by conducting cutting, surface grinding and drilling. A double billet may also be made by the combination use of two alloys having different chemical compositions. The billet for extrusion is then subjected, for example, to hot extrusion at 600 to 700xc2x0 C. to obtain a tubeshell. In general, this tubeshell is alternately subjected to cold rolling and annealing three times to obtain a fuel cladding tube. Alternatively, in order to obtain a fuel cladding tube with improved corrosion resistance, the following method may be adopted: xcex1+xcex2 or xcex2-quenching is conducted before the first, second or third cold rolling step, and, after the xcex1+xcex2 or xcex2-quenching is completed, cold rolling and annealing are alternately conducted. The xcex1+xcex2 or xcex2-quenching, may be conducted in any of the following manners: the outer surface of the tubeshell is heated to a temperature (e.g., approximately 930xc2x0 C.) in the temperature range in which the alloy exists in xcex1+xcex2 phase (a so-called tubeshell heat treatment); the xcex1+xcex2 or xcex2-quenching is conducted in a series of the steps of cold rolling and annealing, usually repeated approximately three times, for making the tubeshell into a fuel cladding tube; or the xcex1+xcex2 or xcex2-quenching is conducted in the course of the production of the tubeshell. The zirconium alloys according to the present invention are applicable to any of the above manners. The quantification of heat treatment by using annealing parameter (xcexa3Ai) can also be applied to any of the above manners. In this case, the amount of heat a zirconium alloy gains after the lastly conducted xcex1+xcex2 or xcex2-quenching is quantified by the annealing parameter. The above-described zirconium-base alloys according to the present invention are excellent in both corrosion resistance and hydrogen absorption property and are useful, for example, for a variety of nuclear reactor components, in particular, for fuel cladding tubes in fuel assemblies, pacer bands, spacer cells and water rods. An example of the practical use of analloy of the present invention as a nuclear reactor material will be given hereinafter. FIG. 5 is a perspective view of a fuel assembly to be placed in a boiling-water reactor, and FIG. 6 is a diagrammatical view of a boiling-water reactor. In the reactor, water 18 is changed to steam 17 by the thermal energy generated by a fuel element 16 in a core 15, and a turbine 19 is rotated by the steam to produce electric power. The steam once used is returned to water by a condenser 20; the water is re-circulated and is changed to steam again. The fuel element 16 shown in FIG. 6 is composed of a plurality of fuel assemblies, one fuel assembly being shown in FIG. 5. The fuel assembly 1 is composed of rod-shaped elements such as a predetermined number of fuel rods 6 and a water rod 7, which are arranged in a grid pattern in a channel box 2. The upper and lower ends of the rod-shaped elements are connected to an upper tie plate 3 and a lower tie plate 4 through an upper end plug and a lower end plug, respectively, and spacers 5 are arranged at predetermined intervals at a plurality of points between upper and lower end plugs. In FIG. 5, the channel box, water rod, fuel rods and spacers are in direct contact with water. These components are currently made from Zircaloy-2 or Zircaloy-4, and are required to show higher corrosion resistance and lower hydrogen absorption. FIG. 7 shows the results (after approximately 1100 hours) of corrosion tests carried out in water vapor at 400xc2x0 C. and 10.3 MPa, using an experimental alloy having a composition within the specifications established in the present invention, and a comparative zirconium-base alloy. Subjected to the corrosion tests were specifically a zirconium-base alloy containing 0.18 wt. % of Fe (Comparative Example 1) and a zirconium-base alloy of the present invention, containing 0.26 wt. % of Fe (Example 1). The mean size of precipitates in each alloy is approximately 80 nm, which is nearly equal to the mean size of precipitates in the conventional Zircaloy-2. Specifically, the alloy of Example 1 and that of Comparative Example 1 are as follows: Comparative Example 1: a zirconium-base alloy containing 1.35 wt. % Sn, 0.18 wt. % Fe, 0.07 wt. % Ni, 0.11 wt. % Cr, and the balance being Zr, and Example 1: a zirconium-base alloy containing 1.35 wt. % Sn, 0.26 wt. %. Fe, 0.07 wt. % Ni, 0.11 wt. % Cr, and the balance being Zr. These two alloys were made in the following manner. A ingot melt was subjected to hot forging (at 700 to 750xc2x0 C.) and solution treatment (at approximately 1000xc2x0 C. for several hours), and was then made into a billet for extrusion by conducting cutting, surface grinding and drilling. This billet for extrusion was subjected to hot extrusion at 600 to 700xc2x0 C. to obtain a tubeshell. The outer surface of this tubeshell was treated by the previously mentioned tubeshell heat treatment, that is, the outer surface of the tubeshell was heated to a temperature (e.g., approximately 930xc2x0 C.) at which the alloy exists in xcex1+xcex2 phase, and was then alternately subjected to cold rolling and annealing three times to obtain a fuel cladding tube. The graph in FIG. 7 shows that the hydrogen absorption of the zirconium-base alloy of Example 1 is 0.8 when the Fe content increases, compared with the zirconium-base alloy of Comparative Example 1. On the other hand, it can be predicted from FIG. 1 that the relative hydrogen absorption will decrease from 1.1 to 0.8 when the Fe content increases from 0.18 wt. % to 0.26 wt. %. This prediction well agrees with the test results shown in FIG. 7. It can thus be known that the improved zirconium-base alloy of the present invention is superior to the conventional alloy in hydrogen absorption property. Thus, by using, instead of Zircaloy-2 or -4, the improved zirconium-base alloy of the present invention for the above-described components, it becomes possible to provide a fuel assembly that is superior to the conventional one particularly in hydrogen absorption property. FIG. 8 is a view showing the spacer shown in FIG. 5. A spacer has the function of bundling fuel rods individually placed in spacer cells to arrange them properly. To achieve higher fuel performance by increasing uranium inventory and by decreasing pressure loss, it is presently required to decrease the wall thickness of spacer cells or spacer bands. However, the concentration of hydrogen in a material increases almost inversely proportional to the thickness of the material, and the ductility and strength properties of the material are greatly governed by the concentration of hydrogen in the material. It is, therefore, difficult to further decrease wall thickness with the conventional hydrogen absorption property left as they are. Decrease in hydrogen absorption is particularly required for spacers. For example, if it is possible to obtain a spacer whose hydrogen absorption is only 50% of that of the conventional spacer, this spacer can have a decreased wall thickness while retaining ductility and strength equal to those of the conventional spacer. If the alloy of the present invention is used for a spacer as shown in FIG. 8, the hydrogen absorption of the spacer becomes 50% of that of the conventional spacer, so that it becomes possible to make the spacer wall thin to an extent unattainable by the use of the conventional materials. FIG. 9 is a view showing the fuel rod 6 shown in FIG. 5. The fuel rod is composed of a nuclear fuel material 9 that causes fissile reaction to generate heat, a fuel cladding tube 8, a plenum 12, an upper end plug 13 and a lower end plug 14. FIG. 9A is a perspective view of the fuel rod, FIG. 9B is a cross-sectional view of the fuel rod, and FIG. 9C is a longitudinal sectional view of the fuel rod. In FIG. 9, reference numeral 8 designates a fuel cladding tube, in which a nuclear fuel material 9 is stacked. A conventional fuel cladding tube 8 is composed of a tube 10 made of zircaloy-2 and a liner layer 11 made of pure zirconium, laid on the inner surface of the tube 10. By producing the tube 10, which is required to have high corrosion resistance and low hydrogen absorption, using the improved zirconium alloy of the present invention in place of Zircaloy-2, it becomes possible to obtain a fuel rod having more excellent corrosion resistance.
	description	1 . . . decontaminated part, 2 . . . circulation line, 3 . . . circulation pump, 4 . . . heater, 5 . . . cooler, 6 . . . catalyst decomposition column, 7 . . . cation resin column, 8 . . . agent tank, 9 . . . agent injection pump, 10 . . . pH adjusting agent tank, 11 . . . pH adjusting agent injection pump, 13 . . . hydrogen peroxide injection pump, 14 . . . mixed-bed resin column, 15 . . . gas-liquid separating tank, 16 . . . UV column, 31 to 45 . . . valve (a solid valve indicates closed, and a hollow valve indicates opened). The present invention will be described below in detail, referring to embodiments. [Embodiment 1] FIG. 1 is a diagram showing the basic system configuration of a chemical decontamination system to which an embodiment of a chemical decontamination method in accordance with the present invention is applied. Components used for performing decontamination are a circulation line 2 connected to a portion 1 to be decontaminated (pipes of a nuclear power plant and so on), a circulation pump 3, a heater 4, a cooler 5, a catalyst decomposition column 6, a cation resin column 7, an agent tank 8, an agent injection pump 9, a pH adjusting agent tank 10, a pH adjusting agent injection pump 11, a hydrogen peroxide tank 12, a hydrogen peroxide injection pump 13 and a mixed-bed resin column 14. Each of the above-described components and each valve to be described later are connected with a piping path. FIG. 7 (A) shows a main process of the present embodiment of a chemical decontamination method. The reducing treatment shown in FIG. 7 indicates decontamination using a reductive agent, and oxidative treatment indicates decontamination using an oxidizing agent. Initially, heat-up mode in the first cycle of FIG. 7 (A) is performed. In the heat-up mode, valves 31, 32, and 34 to 43 are closed and a valve 33 is opened. A circulation operation is performed by driving the circulation pump 3 to allow water to flow in a direction shown by an arrow of the circulation line 2 through the portion 1 to be decontaminated, and liquid temperature of a decontaminating solution is heated up to 90xc2x15xc2x0 C. using the heater 4. The temperture is controlled using a thermometer in an outlet side of the portion to be decontaminated. After completion of heating-up, reducing agent decontamination mode of the first cycle of FIG. 7 (A) is performed. Initially, reducing agent injection mode shown in FIG. 2 is performed. In this mode, the valves 38, 40, 41 are closed and the other valves are opened. The solid valve in FIG. 2 to FIG. 6 indicates that the valve is closed, and the hollow valve indicates that the valve is opened. Predetermined quantities of oxalic acid from the agent tank 8 and hydrazine from the pH adjusting tank 10 are injected into the portion 1 to be decontaminated using pumps 9 and 11, respectively. After starting the injection, water is allowed to flow through the cation resin column 7 in order to collect metallic ions mainly composed of radioactive nuclides and iron dissolved out of the portion 1 to be decontaminated. Since hydrazine of the pH adjusting agent is trapped to the cation resin column 7, hydrazine is decomposed in the catalyst decomposition column 6 while hydrogen peroxide is being injected before water is allowed to flow through the cation resin column 7. The injecting amount of hydrogen peroxide is controlled so as to become a molar number twice as large as a molar concentration of the hydrazine. By doing so, decomposition of the oxalic acid component can be suppressed and only the hydrazine can be selectively decomposed. After adjusting the oxalic acid concentration in the system to 2000 ppm and an indication value of the pH meter in the outlet side of the portion 1 to be decontaminated to 2.5, the reducing agent decontamination mode (the first cycle of FIG. 7(A)) shown in FIG. 3 is performed. In this mode, by closing the valve 31 to stop injecting oxalic acid, decontamination is performed while only hydrazine is being continuously injected by an amount decomposed in the catalyst decomposition column 6 to maintain the pH to 2.5. After a predetermined time period or at the time when dissolution of radioactivity becomes small, the reducing agent decontamination is completed and the processing proceeds to reductive decontaminating agent decomposition mode. FIG. 4 shows detailed contents of the reductive decontaminating agent decomposition mode of FIG. 7(A). The valve 32 is also closed to stop injecting hydrazine, and oxalic acid as well as hydrazine is decomposed at a time by adding an injecting amount of hydrogen peroxide by a mole equal to the molar concentration of oxalic acid. Since the concentration of oxalic acid in the system is decreased every moment, the injecting amount of hydrogen peroxide is decreased by controlling an opening degree of the valve 39 based on an indication of a conductometor in an outlet side of the portion 1 to be decontaminated utilizing that the concentration of oxalic acid is nearly in a proportional relationship to the conductivity. It is confirmed by analyzing the sampling water sampled through a sampling line in an outlet side of the heater 4 that the concentration of oxalic acid in the system becomes below 10 ppm and the concentration of hydrazine becomes below 5 ppm, and then the reductive decontaminating agent decomposing process (the first cycle of FIG. 7(A)) is completed. After that, cleaning mode shown in FIG. 5 (the first cycle of FIG. 7(A)) is performed because the cation resin column 7 can not remove chromic acid ions of anion component. The valves 37, 39, 4243 are closed and the valves 38, 40, 41 are opened. By doing so, water is allowed to flow through the mixed-bed resin column 14 in the system to perform cleaning of the system water for a predetermined time period. Next, the process is entered to the second cycle of FIG. 7(A) to perform oxidizing agent decontamination mode and oxidizing agent decomposition mode shown in FIG. 6. All valves except for the valve 33 are closed. In the oxidizing agent decontamination mode, potassium permanganate of the oxidizing agent is injected from an agent tank (not shown in the figure) and the concentration of potassium permanganate in the system is adjusted to 300 ppm. After the predetermined concentration of the oxidizing agent is obtained, injection of potassium permanganate is stopped and the oxidizing decontamination to the portion 1 to be decontaminated using the potassium permanganate solution is performed for a predetermined time period. After completion of the oxidizing agent decontamination, the oxidizing agent decomposing mode of FIG. 7(A) is performed. In this mode, an amount of oxalic acid of a molar concentration 7 times as much as the molar concentration of the potassium permanganate is injected from the agent tank 8 to decompose permanganate ions to bivalent manganese ions so as to be cleansed by the cation column 7. Carbon dioxide gas generated at the decomposition is exhausted using a vent system provided in the system. After the decomposition is completed and the system water becomes transparent, the second reducing agent decontamination mode, the second reducing agent decomposition mode and the final cleaning mode showing the second cycle of FIG. 7(A) are performed. In the second reducing agent decontamination mode, reducing agent decontamination is performed by adjusting the decontaminating solution to the oxalic acid concentration of 2000 ppm and the pH of 2.5 while oxalic acid and hydrazine are being injected to compensate insufficient amounts of them. The processing after that is the same as that in the first reducing agent decontamination process, that is, decontamination is performed by repeating the oxidizing and the reducing agent decontamination processes necessary times, the final cleaning is performed after decomposing the reducing agent following to sufficient removing of radioactivity of the portion to be decontaminated, cleaning is performed using the mixed-bed resin column 14 until the conductivity of the system water becomes below 1 xcexcs/cm, and thus the decontamination is completed. In order to obtain information on the removed radioactivity and the removed amount of metals, sample water is sampled from sampling lines arranged in the inlet and the outlet of the resin columns 7 and 14 to analyze radioactive nuclides and metallic concentrations in the sample water, and load to the cation resin column 7 (or the mixed-bed resin column 14) can be calculated using a water flow rate and a water flowing time to the resin column 7 (or the resin column 14). The above will be described below in more detail, assuming that a reductive decontaminating agent adjusted to pH 2.5 by adding hydrazine to oxalic acid of 0.2% and an oxidative decontaminating agent of potassium permanganate of 0.03% are used as the decontaminating agents. In the reducing agent decontamination process, the water is heated up using the circulation pump 4 and the heater 4 as shown in FIG. 2, and oxalic acid of the main component of the reductive decontaminating agent is injected into the system from the agent tank 8 using the agent injection pump 9. At the same time, hydrazine of the pH adjusting agent is injected into the system from the pH adjusting agent tank 10 using the pH adjusting agent injection pump 11. At the same time when the decontaminating agent is injected, hydrogen peroxide is injected in the upstream side of the catalyst decomposition column 6 from the hydrogen peroxide tank 12 using the hydrogen peroxide injection pump 13. The injection amount of hydrogen peroxide is an amount necessary for decomposing hydrazine depending on the concentration of hydrazine in the decontaminating solution. In more detail, the upper limit is twice as much as the molar concentration of hydrazine. By doing so, the hydrazine is preferentially decomposed in the catalyst decomposition column 6, and load to the cation resin filled in the cation resin column 7 is suppressed. At the time when the concentration of oxalic acid reaches a predetermined concentration (0.2%), operation of the agent injection pump 9 is stopped to end injection of oxalic acid and to switch to injection of only hydrazine in order to supply hydrazine decomposed and removed by the catalyst decomposition column 6. In the step of decomposing the reductive decontaminating agent after completion of the reducing agent decontamination process (4 hours to 15 hours), operation of the pH adjusting agent injection pump is stopped to increase an adding amount of hydrogen peroxide supplied to the catalyst decomposition column and to change the operating mode so that decomposition of oxalic acid as well as hydrazine is progressed. The concentration of hydrogen peroxide at that time is within the range between a molar concentration equal to a value of the sum of twice of a molar concentration of hydrazine and a molar concentration of oxalic acid as the lower limit and three times of the value as the upper limit, but operation near the lower limit is preferable. The reason why the upper limit is set to the hydrogen peroxide concentration is as follows. That is, although hydrogen peroxide not contributing to the reaction in the catalyst decomposition column is decomposed into oxygen and water by the catalyst, a large amount of partially un-decomposed hydrogen peroxide flows out to the downstream of the catalyst decomposition column 6. In such a case, because the ion exchange resin is deteriorated by the hydrogen peroxide, it possibly happens the radioactive nuclides and so on trapped to the ion exchange resin are released. Since the concentration of hydrogen peroxide in the system is decreased as decomposition of the reductive decontaminating agent is progressed, the injecting amount of hydrogen peroxide is gradually decreased by continuously or intermittently measuring the concentration of decontaminating agent. By doing so, almost all the reductive decontaminating agent in the system is decomposed and accordingly load to the ion exchange resin caused by the un-decomposed reductive decontaminating agent can be suppressed. After completion of decomposing the reductive decontaminating agent, water is allowed to flow through the mixed-bed resin column 14 (or the anion resin column) to remove chromic acid ions remaining in the system water, and potassium permanganate of the oxidative decontaminating agent is injected into the system from the agent injection tank 8 using the agent injection pump 9 to adjust the concentration to a predetermined value (0.05%). At that time, the catalyst column 6 and the resin column 7 are isolated by closing valves. This is because the catalyst and the ion exchange resin are prevented from being deteriorated by the oxidizing agent. After completion of the oxidizing agent decontamination process (4 hours to 8 hours), oxalic acid and hydrazine are again injected in order to decompose and reduce permanganate ions into bivalent manganese ions. After completion of the decomposition, water is re-started to flow through the cation resin column 7 to remove radioactivity and manganese ions, potassium ions released from the cation resin column 7 while hydrogen peroxide is added to the catalyst column 6 by an amount necessary for decomposing the hydrazine, as similarly to in the initial reducing agent decontamination process. After completion of the second reducing agent decontamination process, the reducing agent is decomposed in the same procedure as that in the first reducing agent decomposition process, and after completion of the decomposition the final cleaning is performed using the mixed-bed resin. Although the process in FIG. 7 is assumed the 2-cycle process, it is possible to employ a 3-cycle process if a higher decontamination effect is required. In a case of three or more cycles, one cycle is composed of the oxidizing agent decontamination process, the oxidizing agent decomposition process, the reducing agent decontamination process, the reducing agent decontamination process and the cleaning process, and the process may be modified by inserting necessary number of the cycles between the first cycle and the second cycle. Catalysts capable of being used for decomposing the reductive decomposing agent are noble metal catalysts such as platinum, ruthenium, rhodium, iridium, vanadium, palladium catalysts and the like. A measured result of decomposition ratio at a certain time after adding the catalyst into a beaker. It can be understood from the result that ruthenium catalyst is preferable from the viewpoint of decomposition ratio. Further, it is known that ruthenium catalyst is also effective to decomposition of hydrazine. The decomposition efficiency of ruthenium catalyst to hydrazine is, however, extremely decreased when oxalic acid is mixed in the decontaminating solution, but the decomposition can be progressed by adding hydrogen peroxide to the decontaminating solution. A test was conducted to study decomposition ratios for hydrazine and oxalic acid in the catalyst decomposition column 6. The test was conducted by using 0.5% ruthenium-carbon particles made by N. E. Chemcat Co., and a pre-heated decontaminating solution added with hydrogen peroxide was allowed to flow at a speed of SV 30 to the catalyst decomposition column 6 set the outer surface temperature to 95xc2x0 C. of the upper limit temperature of the decontaminating agent. The test result is shown in FIG. 8. In the case where hydrogen peroxide was not added, both of hydrazine and oxalic acid were little decomposed. In a case where hydrogen peroxide was added by a mole equivalent to a mole of hydrazine, the decomposition ratio for hydrazine was approximately 60%, but oxalic acid was little decomposed. In a case where hydrogen peroxide was added by 3 times as much as the mole of hydrazine, the decomposition ratio for hydrazine was above 98% and the decomposition ratio for oxalic acid was approximately 99%. In a case where hydrogen peroxide was added by 10 times as much as the mole of hydrazine, the result was nearly equal to that in the case where hydrogen peroxide was added by 3 times as much as the mole of hydrazine. In any of the cases, the concentration of hydrogen peroxide at the outlet was below the detective limit. That is, in a case where the catalyst decomposition column 6 is designed under the condition of SV 30, the volume of the catalyst filling portion becomes 100 L when the water flow rate to the catalyst decomposition column 6 is 3m3/h. Since nitrogen is produced when hydrazine is decomposed and carbon dioxide gas is produced when oxalic acid is decomposed, these gases need to be exhausted outside the system. Although any apparatus for removing the gases is not shown in FIG. 1, it is possible to cope with this problem by arranging a vent mechanism having a vent cooler 14 for separating and removing the produced gases in the catalyst decomposition column 6. Although trivalent iron complex and bivalent iron ions are produced by the decontamination, the bivalent iron ions can be removed by the cation resin column 7 in the reducing agent decontamination process. Nearly one-half amount of the trivalent iron complex is removed by the cation resin column 7 in the reducing agent decontamination process. The residual amount of the trivalent iron complex becomes iron hydride by hydrogen peroxide injected in the reducing agent decontamination process and removed by the catalyst. According to the present embodiment, the pH is moderated to 2.5 because hydrazine is added, and consequently the base material of the portion 1 to be decontaminated is suppressed to be dissolved. Therefore, the amount of produced radioactive waste products can be reduced and thinning of the base material can be suppressed. Particularly, when the base material of the portion 1 to be decontaminated is low anti-corrosion carbon steel, the effect of reducing corrosion is very large. [Embodiment 2] Although in Embodiment 1 the vent mechanism is arranged in the catalyst decomposition column 6 in order to remove the produced gas, a gas-liquid separating tank having a vent cooler for separating the gas may be arranged downstream of the catalyst decomposition column 6 and upstream of the cation resin column 7. In this case, there is an advantage in that the gas-liquid separating tank 13 can be also used as a buffer for receiving a volume of liquid increased by injection of the agent. [Embodiment 3] FIG. 9 is a diagram showing the basic system configuration of a chemical decontamination system to which a third embodiment of a chemical decontamination method in accordance with the present invention is applied. The main process in the present embodiment of the chemical decontamination method is shown in FIG. 7(B). A different point of Embodiment 3 from Embodiment 1 (system configuration of FIG. 1) is that the position of the catalyst decomposition column 6 and the position of the cation resin column 7, the mixed-bed resin column 14 and the cooler 5 are in inverse order. In Embodiment 3, the cooler 5, the cation resin column 7 and the mixed-bed resin column 14 are arranged in the upstream side of the catalyst decomposition column 6. An advantage of the system configuration shown in Embodiment 3 is that the concentration of radioactivity in the water flowing to the catalyst decomposition column 6 is low because the water flows into the catalyst decomposition column 6 after flowing through the cation resin column 7, and consequently accumulaion of radioactivity in the catalyst decomposition column 6 can be substantially suppressed. Further, it is unnecessary to decompose hydrazine by the catalyst decomposition column 6 until hydrazine breaks through the cation resin column 7. On the other hand, after hydrazine breaks through the cation resin column 7, injection of hydrazine is unnecessary, and an excessive amount of hydrazine flowing out corresponding to an amount of metallic ions trapped to the cation resin column 7 is decomposed in the catalyst decomposition column 6. The water flow rate to the catalyst decomposition column 6 may be controlled so as to maintain the pH of the decontamination solution to 2.5. The procedure of the other processes is basically the same that of Embodiment 1 (FIG. 1 to FIG. 6). That is, in this embodiment, each of the modes of the main process shown in FIG. 7(B) is successively performed, and opening and closing of the valves and the contents of processing in each of these modes are the same as the processing of Embodiment 1 shown in FIG. 7(A) except for the above-mentioned points. [Embodiment 4] FIG. 10 is a diagram showing the basic system configuration of a chemical decontamination system to which a fourth embodiment of a chemical decontamination method in accordance with the present invention is applied. The main process in the present embodiment of the chemical decontamination method is shown in FIG. 7(C). The system of Embodiment 4 is constructed by adding a UV column (ultraviolet ray irradiation apparatus) 16 to the configuration of Embodiment 3 and arranging the UV column in parallel to the catalyst decomposition column 6. The piping route is branched at the exit of the flowmeter F1 into a route from the exit of the flowmeter F1 to the UV column 16 and the gas-liquid separating tank 15 through a valve 45 and a route from the exit of the flowmeter F1 to the catalyst decomposition column 6 and the gas-liquid separating tank 15 through a valve 44. During the reducing agent decontamination in the first and the second cycles under water flow operation to the cation resin column 7 (the valve 44 is closed and the valve 45 is opened), the water is allowed to flow though the UV column 16, and trivalent iron complex is reduced to bivalent iron ions to be removed by the cation resin column 7. Because the trivalent iron complex can not be removed by the cation resin column 7 due to an anion type, the decontaminating solution with an iron concentration keeping high proceeds to the next process of decomposing the reductive decontaminating agent. In such a case, iron deposits on the catalyst to decrease the catalyst power. The system of Embodiment 4 has an effect to suppress decrease of the catalyst power. Life time of the catalyst can be lengthened and an amount of catalyst disposed as radioactive products can be reduced. The processing and opening and closing of the valves in the other processes in the main process shown in FIG. 7(C) are the same as those of Embodiment 3. However, in the reductive decontaminating agent decomposing mode, the valve 44 is opened and the valve 45 is closed. Particularly, in the reductive decontaminating agent decomposing mode, hydrogen peroxide is injected into the decontaminating solution from the hydrogen peroxide tank 12 by an amount necessary for decomposing both of oxalic acid and hydrazine, similarly to in Embodiment 1. According to the present invention, since increase in the amount of waste products caused by adding hydrazine can be suppressed, it is possible to increase the pH of the decontaminating solution a value higher than that of a decontaminating solution using solely oxalic acid and it is possible to perform decontamination of a system including a low corrosion resistant material. Further, since hydrazine can be selectively decomposed by only one catalyst decomposition column and oxalic acid can be decomposed together with hydrazine, cost in regard to the decontaminating agent decomposition apparatus can be reduced.
	summary
050705199	abstract	An equalization radiography system automatically identifies the lung field in a pre-scan and then carries out an imaging scan in which it equalizes the X-ray exposure but only outside the lung field.
046577270	claims	1. The method of classifying emergency levels in operation of nuclear power plants comprising relating offsite radiation dose to the public to functioning of sequential encompassing barriers A, B and C, the relating step comprises relating the offsite does to the public according to the relationship: EQU Dose f(.phi.,t.sub.o, u/p, t.sub.d).times.f(w).times.f(s).times.f(L.sub.F).times.f(L.sub.RCS).times.f (L.sub.C) And where relatively variable functions are: D=Dose at the site boundary, set at 500 millirems per year; f(L.sub.C)=function of the leak rate of the containment; C.sub.RCS =Concentration of radioactive material in reactor coolant system. C=concentration in uCi/gm. E=average energy of photon emission from the radioactive material. calculating f(L.sub.RCS), wherein f(L.sub.RCS) is a function of the leakage rate of the reactor coolant system, calculating f(L.sub.C), wherein f(L.sub.C) is a function of the leakage rate of the containment relating possible offsite does to the public according to the calculated functions f(L.sub.F), f(L.sub.RCS), and f(L.sub.C), and indicating an emergency level based on the relating of the magnitudes of the functions f(L.sub.F), f(L.sub.RCS), and f(L.sub.C), to predetermined acceptable magnitudes of the functions f(L.sub.F), f(L.sub.RCS), and f(L.sub.C), wherein the acceptable magnitudes are based upon possible offsite dose consequences. 2. The method of claim 1 wherein the relating step comprises calculating the function of the fuel barrier f(L.sub.F). 3. The method of claim 1 wherein the relating step comprises calculating the function of the coolant barrier f(L.sub.RCS). 4. The method of claim 1 wherein the relating step comprises calculating the function of the containment barrier f(L.sub.C). 5. The method of calculating concentration of radioactive material within a coolant barrier corresponding to fuel barrier breach for the purpose of initial designation of criterion of fuel breach according to the equation EQU C.sub.RCS .alpha.D/f(L.sub.C) 6. The method of claim 5, wherein the concentration of radioactive material in the reactor coolant system is expressed in the form: EQU C/E 7. The method of classifying emergency levels in operation of nucelar power plants comprising relationg possible offsite radiation dose and hazard to the public to functioning of sequential encompassing barriers, fuel cladding, reactor coolant system, and containment, the method comprising, calculating f(L.sub.F), wherein f(L.sub.F) is a function of the leakage rate of the fuel cladding,
040100707	claims	1. A pebble-bed reactor comprising a reactor container, fuel pebbles having a characteristic cross-sectional size and forming a reactor pebble bed in said container, and at least one absorber element comprising a rod having an outside diameter substantially the same as said characteristic cross-sectional size of said fuel pebbles, said rod having the shape of a hollow helix-like spiral forming a single thread terminating with a leading tip, said element being substantially vertically positioned so that by applying torque to said element said rod is screwed into said pebble bed like being screwed into a thread with the rod's said tip having a direction of penetration into said pebble bed which deviates from a vertical direction. 2. The reactor of claim 1 in which the rod's said shape forms an interior and convolutions forming spaces, said interior and said spaces having cross-sectional sizes larger than said characteristic cross-sectional size of said pebbles and forming passages for the pebbles.
	claims	1. A method for producing a mirror element that has a substrate and a reflective coating for extreme ultraviolet wavelength radiation, comprising:pre-compacting the substrate by hot isostatic pressing,applying the reflective coating to a surface region of the pre-compacted substrate, and further compacting the pre-compacted substrate by irradiating the pre-compacted substrate with at least one of ions and electrons in a surface region of the substrate,wherein the pre-compacted substrate is irradiated until a density in the surface region is at least 0.5% higher than a density of a remainder of the substrate that is not in the irradiated region. 2. The method according to claim 1, wherein the pre-compacted substrate is irradiated homogeneously before the coating is applied in the surface region. 3. The method according to claim 1, wherein the coating is applied before the pre-compacted substrate is irradiated homogeneously. 4. The method according to claim 1, further comprising selecting a doped glass material or a glass ceramic as the material for the substrate. 5. The method according to claim 1, wherein the temperature during the hot isostatic pressing is selected to be between 1100° C. and 1300° C. 6. The method according to claim 5, wherein the temperature during the hot isostatic pressing is selected to be between 1150° C. and 1250° C. 7. The method according to claim 1, wherein the pressure during the hot isostatic pressing is selected to be between 20 MPa and 250 MPa. 8. The method according to claim 7, wherein the pressure during the hot isostatic pressing is selected to be between 50 MPa and 150 MPa. 9. The method according to claim 1, wherein the holding time during the hot isostatic pressing is selected to be between 0.5 hour and 5 hours. 10. The method according to claim 9, wherein the holding time during the hot isostatic pressing is selected to be between 2 hours and 4 hours. 11. The method according to claim 1, wherein the substrate is compacted by the hot isostatic pressing by at least 1%, preferably by at least 1.5%, in particular by at least 3%. 12. The method according to claim 11, wherein the substrate is compacted by the hot isostatic pressing by at least 3%. 13. The method according to claim 1, wherein at least one of:(a) the ions have an energy of between 0.2 MeV and 10 MeV at a total particle density of from 1014 to 1016 ions per cm2, and(b) the electrons have a dose of between 10 J/mm2 and 1000 J/mm2 at energies of between 10 KeV and 20 KeV. 14. The method according to claim 1, further comprising: carrying out the irradiation until there is obtained in the surface region a density that is at least 1% higher than the density of the remainder of the substrate. 15. The method according to claim 14, wherein the irradiation is carried out until there is obtained in the surface region a density that is at least 1.5% higher than the density of the remainder of the substrate. 16. The method according to claim 14, wherein the surface region extends to a depth of 5 μm from the surface of the substrate.
	abstract	The present invention provides a system and method for a system for accommodating a solid target in an accelerator. The system and method includes a target changer having at least one port for accommodating the solid target, an insert for receiving the solid target in the target changer, a piston for providing a vacuum and a cooling system for the solid target, a cylinder for displacing the piston in one of three positions; and a bracket for securing the insert, piston and cylinder to the target changer.
	description	This application is a divisional of U.S. patent application Ser. No. 10/059,044 filed Jan. 30, 2002, now abandoned, which claims priority from prior provisional patent application Ser. No. 60/264,965 filed Jan. 30, 2001, the entire disclosures of which are incorporated herein by reference. 1. Field of the Invention The present invention relates to feedwater spargers in boiling water reactors and, more particularly, to clamps for the end bracket assemblies of feedwater spargers and to methods of preventing separation of feedwater sparger end bracket assemblies. 2. Brief Discussion of the Related Art Conventional boiling water reactors typically include a reactor vessel, a shroud disposed within the reactor vessel and a fuel assembly within the shroud. Feedwater enters the reactor vessel via a feedwater inlet or nozzle and is distributed circumferentially within the reactor vessel by a feedwater sparger disposed in the reactor vessel between the shroud and the reactor vessel wall. The feedwater sparger comprises a ring-shaped pipe or conduit for carrying the feedwater and having an end attached to a sparger end plate via a feedwater sparger end weld, the sparger end plate and conduit end attached thereto defining an end of the feedwater sparger. A feedwater sparger end bracket assembly couples the end of the feedwater sparger to the reactor vessel wall in spaced relation therewith. The feedwater sparger end bracket assembly normally comprises an attachment plate connected to the sparger end plate via a weld, and the structural components of the feedwater sparger end bracket assembly are ordinarily connected to one another via one or more additional welds. The attachment plate and the sparger end plate attached thereto form a sparger/bracket junction by which the conduit of the feedwater sparger is connected to the feedwater sparger end bracket assembly. The feedwater sparger end bracket assembly defines a load path for transferring loads from the feedwater sparger to a reactor vessel attachment fitting attached to the reactor vessel wall and to which the feedwater sparger end bracket assembly is connected. The structural adequacy of feedwater sparger end welds and feedwater sparger end bracket assembly welds has been questioned in light of cracking identified in these welds. In particular, the weld between the attachment plate and the sparger end plate and the weld between the sparger end plate and the conduit end are primarily fillet welds, and reactor coolant can infiltrate or get between the structural components joined by these fillet welds so that the roots of the fillet welds are exposed to reactor coolant. The geometry of the fillet welds presents a crevice where corrosive products can concentrate and accumulate over time, thereby producing stress corrosion cracking. Cracks large enough to allow significant flow of feedwater from the feedwater sparger may result in direct impingement of the relatively colder feedwater on the reactor vessel wall, causing thermal shock and cracking of the cladding on the interior surface of the reactor vessel wall. In addition, the feedwater sparger end bracket assemblies usually carry an installation preload, and this preload is undesirably compromised or lost in the event of cracking of the feedwater sparger end welds and/or the feedwater sparger end bracket assembly welds, especially in the event of cracking which results in complete detachment of the feedwater sparger end bracket assembly from the feedwater sparger. An example of feedwater sparger end bracket assemblies that have an installation preload are those associated with feedwater spargers that are sprung into place during installation, such as to maintain contact between flow baffles of the feedwater spargers and the reactor vessel wall. The flow baffles, which are ordinarily located at the feedwater nozzles in the reactor vessel, must remain essentially in contact with the reactor vessel wall to effectively eliminate thermal shock conditions at the feedwater nozzles. To assure this, the feedwater spargers are sprung into place at installation, resulting in an installation preload on each feedwater sparger end bracket assembly of about eight thousand pounds. In the event of complete weld failure causing the feedwater spargers to become completely detached from the feedwater sparger end bracket assemblies, the installation preload is lost and the feedwater spargers will not perform as designed. Mechanical solutions to the problems of cracked feedwater sparger end welds and feedwater sparger end bracket assembly welds encounter numerous obstacles in that mechanical devices attached to the ends of the feedwater spargers and the feedwater sparger end bracket assemblies must be capable of maintaining the installation preload in the event of weld failure. Mechanical devices must be capable of balancing all loads and moments to which they are subjected, and particularly must react to the loads and moments created when there is a complete through wall crack of the feedwater sparger end welds and/or the welds of the feedwater sparger end bracket assemblies. Another deterrent to the use of mechanical devices to address the problems of weld failure in the ends of feedwater spargers and in feedwater sparger end bracket assemblies is that existing feedwater sparger end bracket assemblies often have different structural dimensions and/or components. The use of mechanical devices with feedwater sparger end bracket assemblies is thusly impeded by the difficulty involved in designing an essentially standard mechanical device for use with different feedwater sparger end bracket assemblies. A further impediment to the use of mechanical devices in response to cracking of feedwater sparger end welds and feedwater sparger end bracket assembly welds is the need for the mechanical devices to be installed using equipment or tooling operated from a location remote from the reactor vessel. Accordingly, it is a primary object of the present invention to overcome the problems associated with cracking of feedwater sparger end welds and feedwater sparger end bracket assembly welds. Another object of the present invention is to utilize a clamp to prevent separation of feedwater sparger end bracket assemblies. A further object of the present invention is to utilize a clamp to prevent separation of a feedwater sparger end from a feedwater sparger end bracket assembly welded to the feedwater sparger end. The present invention has as another object to constrain a feedwater sparger end bracket assembly from separation in horizontal, vertical and radial directions. It is also an object of the present invention to constrain a feedwater sparger end against separation from a feedwater sparger end bracket assembly in horizontal, vertical and radial directions. An additional object of the present invention is to avoid direct impingement of feedwater from a feedwater sparger on the reactor vessel wall in the event of cracking of a feedwater sparger end weld and/or a feedwater sparger end bracket assembly weld. Yet another object of the present invention is to maintain the preload of a feedwater sparger end bracket assembly in the event of failure of a feedwater sparger end weld and/or a feedwater sparger end bracket assembly weld. Still a further object of the present invention is to balance loads and moments on a clamp for a feedwater sparger end bracket assembly in the event of failure of a feedwater sparger end weld and/or a feedwater sparger end bracket assembly weld. The present invention has as an additional object to adapt a clamp for installation on feedwater sparger end bracket assemblies of various structural dimensions and/or components. Moreover, it is an object of the present invention to utilize a clamp to provide an alternate load path for loads from a feedwater sparger to a reactor vessel attachment fitting. Some of the advantages of the present invention are that the clamp can be adjustably tightened on the feedwater sparger end bracket assembly; the clamp encloses the feedwater sparger end bracket assembly; the clamp holds the feedwater sparger and the feedwater sparger end bracket assembly together in the event of weld failure in any of the welds of the feedwater sparger and/or the feedwater sparger end bracket assembly; the clamp incorporates corrosion resistant materials; the clamp does not require welding to the feedwater sparger end, to the feedwater sparger end bracket assembly or to the reactor vessel; thermal shock and cracking of the cladding on the interior surface of the reactor vessel wall are avoided; the moment created on the clamp in the event of through wall cracking of a feedwater sparger end weld and/or a feedwater sparger end bracket assembly weld is balanced; shims and/or spacers can be used to easily adapt the clamp for installation on feedwater sparger end bracket assemblies having different structural dimensions and/or components; clearances between the clamp and the feedwater sparger and/or between the clamp and the feedwater sparger end bracket assembly can be limited or controlled to ensure a tight fit; proper operation of flow baffles of the feedwater spargers is maintained; the clamp may be installed remotely; and the clamp may be used on both originally installed feedwater sparger end bracket assemblies and replacement feedwater sparger end bracket assemblies. These and other objects, advantages and benefits are realized with the present invention as generally characterized in a clamp for installation on a feedwater sparger end bracket assembly connected to a conduit of a feedwater sparger at a sparger/bracket junction in a boiling water reactor vessel. The clamp includes an upper clamp member for being assembled over a top of the feedwater sparger end bracket assembly, a lower clamp member for being assembled over a bottom of the feedwater sparger end bracket assembly and a connector securing the upper and lower clamp members to one another. The upper clamp member includes a compartment receiving an upper portion of the sparger/bracket junction, and the lower clamp member includes a compartment receiving a lower portion of the sparger/bracket junction. Each compartment comprises opposing walls constraining the sparger/bracket junction in a first direction tangential or horizontal to the boiling water reactor vessel. Each clamp member includes an inner shoulder along an inner side of the feedwater sparger end bracket assembly and an outer shoulder along an outer side of the feedwater sparger end bracket assembly for constraining the feedwater sparger end bracket assembly between the inner and outer shoulders in a second direction radial to the boiling water reactor vessel. The upper clamp member includes a lower surface along the top of the feedwater sparger end bracket assembly. The lower clamp member includes an upper surface along the bottom of the feedwater sparger end bracket assembly, and the feedwater sparger end bracket assembly is constrained between the lower surface and the upper surface in a third direction vertical to the boiling water reactor vessel. The upper clamp member further includes a recessed lower surface along the top of the conduit of the feedwater sparger, and the lower clamp member further includes a recessed upper surface along the bottom of the conduit, the conduit being constrained in the third direction between the recessed lower and upper surfaces. Each clamp member includes a shear tab positioned to be disposed between the conduit of the feedwater sparger and a wall of the boiling water reactor vessel with a close fit. The shear tab balances moments and loads to which the clamp is subjected. The upper clamp member comprises an impingement shield extending downwardly therefrom toward the lower clamp member, and the lower clamp member comprises an impingement shield extending upwardly to meet the impingement shield of the upper clamp member. The impingement shields are disposed between the sparger/bracket junction and the wall of the boiling water reactor vessel and serve to isolate the sparger/bracket junction from the wall of the boiling water reactor vessel. A method of preventing separation of a feedwater sparger end bracket assembly connected to a conduit of a feedwater sparger at a sparger/bracket junction in a boiling water reactor vessel is generally characterized in the steps of vertically separating an upper clamp member of a clamp from a lower clamp member of the clamp, locating the upper clamp member over a top of the feedwater sparger end bracket assembly, locating the lower clamp member over a bottom of the feedwater sparger end bracket assembly, moving the upper and lower clamp members toward one another to position an upper portion of the sparger/bracket junction within a compartment of the upper clamp member and to position a lower portion of the sparger/bracket junction within a compartment of the lower clamp member, securing the upper and lower clamp members to one another, and leaving the upper and lower clamp members in place to constrain the sparger/bracket junction in a first direction, to constrain the feedwater sparger end bracket assembly in a second direction, and to constrain the feedwater sparger end bracket assembly in a third direction. Other objects and advantages of the present invention will become apparent from the following description of a preferred embodiment taken in conjunction with the accompanying drawings, wherein like parts in each of the several figures are identified by the same reference characters. A fragmentary portion of a conventional boiling water reactor 10 is illustrated in FIGS. 1-4 depicting a segment of a wall 11 of reactor vessel 12 and a length segment of feedwater sparger 14 disposed within reactor vessel 12. The reactor vessel wall 11 is generally cylindrical, and the complete reactor vessel wall extends upwardly, downwardly and circumferentially beyond the edges or borders of the wall segment shown in the drawings. A shroud (not shown) is disposed in the reactor vessel 12 in spaced relation with wall 11, and the feedwater sparger 14 is disposed in the circumferential gap or space between the shroud and the reactor vessel wall. The feedwater sparger 14 comprises a hollow conduit or pipe 15 that generally follows the circumferential curvature of the reactor vessel wall 11 and has a terminal end connected to a sparger end plate 16. The complete conduit 15 forms an annular or ring-shaped conduit or pipe in the reactor vessel 12 for carrying feedwater which enters the reactor vessel at one or more feedwater inlets or nozzles in communication with the lumen of conduit 15. The feedwater is distributed circumferentially within the reactor vessel 12 via interiorly directed outlet holes 17 in the conduit 15. A representative conduit 15 has concentric circumferential inner and outer side walls connected by planar top and bottom walls, with the holes 17 being formed in the inner side wall. The conduit 15 has a rectangular cross-sectional configuration with the major cross-sectional dimension thereof extending or oriented vertically in the reactor vessel 12 and the minor cross-sectional dimension thereof extending or oriented radially in the reactor vessel 12. A representative sparger end plate 16 is planar and is of generally rectangular peripheral configuration with the major dimension thereof also extending or oriented vertically to close off the open end of conduit 15. The sparger end plate 16 is typically attached to the end of conduit 15 by a feedwater sparger end weld 18, and the conduit end and the sparger end plate attached thereto define an end of feedwater sparger 14. The sparger end plate 16 is connected to a feedwater sparger end bracket assembly 20 which, in turn, is connected to a reactor vessel attachment fitting 21 connected, typically by welding, to reactor vessel wall 11. The feedwater sparger end bracket assembly 20 thusly couples the end of the feedwater sparger 14 to the reactor vessel 12 in spaced relation with reactor vessel wall 11. Accordingly, there is a circumferential gap or space between the feedwater sparger 14 and the reactor vessel wall 11 as best shown in FIG. 4. As used herein, the terms “top”, “bottom”, “upper”, “lower”, “upward” and “downward” are referenced in a vertical direction; the terms “inner” and “interior” refer to a direction toward a central longitudinal axis of the reactor vessel; the terms “outer” and “exterior” refer to a direction away from the central longitudinal axis of the reactor vessel; the terms “front” and “forward” refer to a direction away from the conduit end; the terms “back” and “rearward” refer to a direction toward the conduit end; the term “vertical” refers to the direction of the central longitudinal axis of the reactor vessel; the term “radial” refers to a direction radial to the reactor vessel wall; and the terms “horizontal” and “tangential” refer to a direction transverse or perpendicular to the vertical and radial directions. As shown in FIGS. 1-5, the feedwater sparger end bracket assembly 20 for a conventional boiling water reactor 10 ordinarily comprises an attachment plate 22 connected to sparger end plate 16 by a weld 23, a side plate 24 connected to attachment plate 22 and extending transversely or perpendicularly therefrom in the forward direction, and upper and lower bracket members 25 and 26, respectively, extending from attachment plate 22 in the forward direction. A representative attachment plate 22 is planar and is of generally rectangular peripheral configuration with the major dimension thereof extending vertically within the reactor vessel 12 and the minor dimension thereof extending radially in the reactor vessel 12. The peripheral configuration of the attachment plate 22 is larger than the peripheral configuration of the sparger end plate 16 such that the sparger end plate does not protrude beyond the periphery of the attachment plate. As best shown in FIG. 4, it is typical for an inner side edge of attachment plate 22 to be spaced interiorly beyond an inner side edge of sparger end plate 16. The attachment plate 22 is parallel to the sparger end plate 16 and has a rearward surface in facing abutment with a forward surface of the sparger end plate, the weld 23 being disposed between the abutting surfaces of the attachment plate and the sparger end plate. The attachment plate and sparger end plate may be provided with through holes to facilitate grasping thereof during installation, the attachment plate 22 being shown with upper and lower through holes aligned with upper and lower through holes of sparger end plate 16. A representative side plate 24 has a straight rearward edge in facing abutment with a forward surface of the attachment plate 22. A weld 27 is disposed between the abutting surfaces of the side plate 24 and the attachment plate 22 and thusly connects the side plate to the attachment plate. The side plate 24 is connected to the attachment plate 22 at a location adjacent or close to the inner side edge of attachment plate 22. The side plate 24 is planar and has a generally rectangular peripheral configuration with the major dimension thereof extending vertically in the reactor vessel 12 and the minor dimension thereof extending perpendicular to the attachment plate. Representative upper and lower bracket members 25 and 26 are also planar, and each bracket member has a straight rearward edge, a beveled forward edge, and parallel inner and outer straight side edges connecting the forward and rearward edges. The rearward edges of the upper and lower bracket members 25 and 26 are each in facing abutment with the forward surface of attachment plate 22, with the bracket members 25 and 26 being perpendicular to the side plate 24 and to the attachment plate 22. Welds 28 connect the abutting surfaces of the upper and lower bracket members 25 and 26, respectively, and the attachment plate 22. The straight inner side edge of each bracket member is in abutting relation with an outer surface of the side plate 24, and welds 29 connect the abutting surfaces of the upper and lower bracket members 25 and 26, respectively, and the side plate 24. The upper and lower bracket members 25 and 26 are parallel to and vertically spaced from one another to closely accommodate the reactor vessel attachment fitting 21 between a lower surface of the upper bracket member 25 and an upper surface of the lower bracket member 26. Accordingly, the inner side edge of upper bracket member 25 is connected to the side plate 24 at a location adjacent or close to an upper edge of side plate 24, and the inner side edge of lower bracket member 26 is connected to the side plate 24 at a location adjacent or close to a lower edge of the side plate 24. The representative feedwater sparger end bracket assembly 20 also includes a pin 30, extending through the upper and lower bracket members 25 and 26 and through the reactor vessel attachment fitting 21, by which the feedwater sparger end bracket assembly is secured or pinned to the reactor vessel attachment fitting. The pin 30 extends in the vertical direction transverse or perpendicular to the upper and lower bracket members 25 and 26, and is inserted through aligned passages in the upper and lower bracket members and the reactor vessel attachment fitting 21. An upper end or head of the pin 30 is disposed above the upper bracket member 25 and is sized and/or configured such that the head cannot pass through the passage in the upper bracket member 25. The passages in the upper and lower bracket members 25 and 36 are ordinarily oval or elliptical in cross-section and have centers, respectively, located centrally between the inner and outer side edges of the corresponding bracket member. A pin retainer 32 is engaged with or secured to the upper bracket member 25 and, as best seen in FIGS. 1 and 2, includes a bridge 33 centered over the head of pin 30 and a pair of legs 34 extending downwardly from opposite ends of bridge 33 to feet 35. The bridge 33 bisects the head of pin 30, and the legs 34 are spaced from one another a sufficient distance to accommodate the head of pin 30 therebetween. The representative pin retainer 32 is located so that the bridge 33 is perpendicular to the attachment plate 22 and parallel to the upper bracket member 25, with the legs 34 extending perpendicular to the bridge 33. The feet 35 extend outwardly from the legs 34, respectively, and are secured to or engaged with the upper bracket member 25 to prevent removal of the pin 30 after it has been inserted sequentially through the passage of the upper bracket member 25, the passage of the reactor vessel attachment fitting 21 and the passage of the lower bracket member 26. In a representative pin retainer 32, the feet 35 extend perpendicular to legs 34 such that the feet 35 are also perpendicular to the attachment plate 22. The representative pin retainer 32 is formed from an elongated, planar strip of material of relatively minimal thickness. A pin bail 36 of the feedwater sparger end bracket assembly 20 has a generally inverted U-shape straddling the head of pin 30. As best seen in FIGS. 3 and 5, pin bail 36 includes a cross-piece 37 extending over bridge 33 perpendicular thereto and spaced, parallel arms 38 extending downwardly from opposite ends of cross-piece 37 to tapered or angled lower ends secured to the head of pin 30. The cross-piece 37 bisects the head of pin 30 along an axis 90° to bridge 33, and the lower ends of arms 38 are secured to the head of pin 30 at locations, respectively, along this axis. The representative pin bail 36 is flat or planar with beveled outside corners joining the arms 38 to opposite ends of cross-piece 37, the pin bail 36 being parallel to attachment plate 22 and perpendicular to both the side plate 24 and the upper bracket member 25. The space between arms 38 defines an opening through which the bridge 33 passes. The pin bail 36 may be used for grasping to facilitate raising and lowering of pin 30 for insertion and/or removal through the aligned passages in the upper and lower bracket members 25 and 26 and the reactor vessel attachment fitting 21 when the pin retainer 32 is not secured in place on the upper bracket member. The reactor vessel attachment fitting 21 includes a base attached to the reactor vessel wall 11 and a nose protruding interiorly from the base in the radial direction. The nose is insertable between the upper and lower bracket members 25 and 26 when the pin 30 is removed from between the bracket members, and has a vertical dimension to fit closely between the upper and lower bracket members. A vertical passage through the nose is aligned with the aligned passages through the upper and lower bracket members 25 and 26, respectively. The pin 30 is inserted in the aligned passages, with insertion of the pin being facilitated by the pin bail 36. The pin 30 is secured in place in the aligned passages, thereby securing the feedwater sparger end bracket assembly 20 to the reactor vessel attachment fitting 21. The pin 30 may be secured in place via a threaded engagement or in any other suitable manner. The reactor vessel attachment fitting 21 can be formed integrally, unitarily with the reactor vessel wall 11 or as a separate component secured to the reactor vessel wall in any suitable manner, such as welding. The base of fitting 21 may have a curved outer end surface in abutting relation with the curved surface of the reactor vessel wall 11, and the curvature of the end surface preferably corresponds to the curvature of the reactor vessel wall. The feedwater sparger end bracket assembly 20 defines a load path for transferring loads from the feedwater sparger 14 to the reactor vessel attachment fitting 21 and the vessel wall 11. An alternative representative feedwater sparger end bracket assembly for use with the clamp of the present invention is illustrated in FIG. 6 at 120. The feedwater sparger end bracket assembly 120 is similar to feedwater sparger end bracket assembly 20 except that the feedwater sparger end bracket assembly 120 includes a shim plate 141 between the sparger end plate 116 and the attachment plate 122. Shim plate 141 is interposed between the forward surface of the sparger end plate 116 and the rearward surface of the attachment plate 122. The representative shim plate 141 is planar and has a generally rectangular peripheral configuration with a major dimension oriented vertically within the reactor vessel, which is not shown in FIG. 6. The peripheral configuration of shim plate 141 is typically larger than the peripheral configuration of both the sparger end plate 116 and the attachment plate 122 so that both the sparger end plate and the attachment plate are disposed within the peripheral configuration of the shim plate. The shim plate 141 has a planar rearward surface in abutting relation with the forward surface of the sparger end plate 116, and a weld 142 disposed between the abutting surfaces of the shim plate and the sparger end plate connects the shim plate to the sparger end plate. The shim plate 141 has a planar forward surface in abutting relation with the rearward surface of the attachment plate 122, and a weld 143 disposed between the abutting surfaces of the shim plate and the attachment plate connects the shim plate to the attachment plate. The additional welds 142 and 143 of the feedwater sparger end bracket assembly 120 present additional potential sites for stress corrosion cracking and concomitant weld failure in the feedwater sparger end bracket assembly 120. From the above, it should be appreciated that the feedwater sparger end bracket assemblies with which the clamp of the present invention may be utilized can include one or more shim plates, such as shim plate 141, to achieve proper fit of the feedwater sparger end bracket assembly with the corresponding reactor vessel attachment fitting. It should be further appreciated that proper fit of the feedwater sparger end bracket assembly with the corresponding reactor vessel attachment fitting may be achieved by varying the thickness of the attachment plate and/or the thickness of the sparger end plate, with or without the use of one or more shim plates. Where a stock thickness for the attachment plate is not sufficient to allow proper fit of the feedwater sparger end bracket assembly with the reactor vessel attachment fitting, one or more shim plates will typically be utilized to make the necessary adjustments. The radial and vertical locations of the attachment plate relative to the sparger end plate may also be varied, as needed, to obtain the proper fit. Since the reactor vessel for a typical boiling water reactor has a plurality of feedwater sparger end bracket assemblies, most typically eight feedwater sparger end bracket assemblies, it can be seen that the combined thickness of the sparger end plate and the attachment plate, including any shim plates, may vary. In other words, the thickness of the sparger/bracket junction, which includes the sparger end plate, the attachment plate and any shim plates, may not be the same for each feedwater sparger end bracket assembly of a boiling water reactor. The clamp of the present invention may be adapted for use on sparger/bracket junctions of different thicknesses, and may be used on originally installed feedwater sparger end bracket assemblies as well as replacement feedwater sparger end bracket assemblies. The feedwater spargers of boiling water reactors may be sprung into place during installation such that there is a shear load on the feedwater sparger end welds and the feedwater sparger end bracket assembly welds. One instance in which feedwater spargers are sprung into place involves the installation of replacement feedwater spargers having flow baffles at the feedwater nozzles of the reactor vessel to eliminate thermal shock conditions at the feedwater nozzles. In order for the flow baffles to work effectively, they must remain essentially in contact with the reactor vessel wall. This is assured by the feedwater spargers being sprung into place at installation, resulting in a load on each feedwater sparger end bracket assembly of approximately 8,000 pounds. In the event of a complete through wall crack of the weld between the conduit end and the sparger end plate and/or the weld between the sparger end plate and the attachment plate, causing the feedwater sparger end bracket assembly to become completely detached from the feedwater sparger, the installation preload would be lost and the feedwater sparger would not perform as designed. A clamp 44 for feedwater sparger end bracket assemblies is illustrated alone in FIGS. 7-12 and installed on the feedwater sparger end bracket assembly 20 in FIGS. 13-20. The clamp 44 includes first and second clamp members 45 and 46, respectively, and a connector 47 such as an externally threaded bolt or screw adjustably connecting the first and second clamp members in spaced relation. First clamp member 45 is an upper clamp member, second clamp member 46 is a lower clamp member, and the connector 47 adjustably connects the upper and lower clamp members in vertical spaced relation. The connector 47 extends through vertically aligned bores in the upper and lower clamp members 45 and 46, respectively, and the bores may be threaded to threadably engage a thread on the connector 47. Alternatively or additionally to the bores being threaded, a threaded nut may be provided on an end of the connector 47. Untightening or unthreading connector 47 allows the clamp to be moved from a closed position shown in FIGS. 7 and 8 to an open position in which the vertical spacing between the upper and lower clamp members is increased, thereby allowing installation of the clamp over a feedwater sparger end bracket assembly. If necessary, the connector 47 may be removed entirely from the lower clamp member to facilitate installation of the clamp on the feedwater sparger end bracket assembly as described further below. Tightening or threading connector 47 closes the clamp to decrease or reduce the vertical spacing between the upper and lower clamp members, thereby securing the clamp in the closed position on the feedwater sparger end bracket assembly as described further below. The upper clamp member 45 comprises a housing having a medial portion 48 between a forward extension 49 and a rearward extension 50 as shown in FIG. 7. The medial portion 48 extends interiorly beyond the forward and rearward extensions 49 and 50, and the bore through which the connector 47 passes extends entirely through the medial portion. The bore extends through the medial portion 48 in the vertical direction and has a central longitudinal axis coaxial with the bore of lower clamp member 46. The forward extension 49 has an L-shaped configuration with a radial extension portion and a horizontal extension portion extending forwardly from the radial extension portion at a right angle. As best shown in FIG. 8, an internal compartment 51 is defined in the upper clamp member 45 and is bounded at the top by a planar internal top wall 52, at the front by a planar internal front wall 53, at the rear by a planar internal rear wall 54 opposing internal front wall 53, at an inner side by a planar internal inner side wall 55, and at an outer side by a planar impingement shield 56 opposing internal inner side wall 55. The internal front and rear walls 53 and 54 are parallel and are perpendicular to internal top wall 52, internal inner side wall 55 and impingement shield 56. The internal inner side wall 55 is parallel to impingement shield 56, and both are perpendicular to internal top wall 52. The compartment 51 is open at the bottom of the upper clamp member, and a mouth or opening along the bottom of the upper clamp member provides communication with the compartment. The top of upper clamp member 45 has a stepped configuration with forward extension 49 protruding above the medial portion 48 and the rearward extension 50. Accordingly, the forward extension 49 has an external top wall 60 spaced upwardly from an external top wall 61 of medial portion 48 and rearward extension 50. The bottom of upper clamp member 45 has a stepped configuration so as to define a downwardly protruding inner shoulder or protrusion 62 extending downwardly from lower surface 63 and recessed lower surface 64 of upper clamp member 45, and a downwardly protruding outer shoulder or protrusion 65 extending downwardly from the lower surface 63. The lower surface 63 is at the bottom of the upper clamp member and is a forward lower surface located to the front of the opening into compartment 51. The recessed lower surface 64 is at the bottom of the upper clamp member and is a rearward lower surface located to the rear of the opening into compartment 51. The forward and rearward lower surfaces 63 and 64 are planar and parallel to one another, and are perpendicular to the internal front and rear walls 53 and 54, the internal inner side wall 55 and the impingement shield 56. Also, the forward and rearward lower surfaces 63 and 64 are parallel to internal top wall 52. The inner shoulder 62 extends along an inner side of upper clamp member 45 in the horizontal or tangential direction and extends between the front and rear walls of compartment 51. The inner shoulder 62 has a planar outer surface 67, coextensive with internal inner side wall 55, perpendicularly joined to the forward lower surface 63 to the front of the opening into compartment 51 and perpendicularly joined to the rearward lower surface 64 to the rear of the opening into compartment 51. The outer surface 67 of inner shoulder 62 extends downwardly from the opening of compartment 51 and is perpendicular to the internal front and rear walls 53 and 54. A shim pad 66 is secured on the outer surface 67 of inner shoulder 62 and extends vertically between the rearward lower surface 64 and a bottom surface of inner shoulder 62. The shim pad 66 extends forwardly from an external rear wall of medial portion 48 to terminate at a forward edge and has a depth or thickness in the radial direction. The forward edge of shim pad 66 is spaced rearwardly from the internal front wall 53 a sufficient distance for the thickness of the sparger/bracket junction to be accommodated in the compartment 51 between the internal front and rear wall 53 and 54. As best shown in FIG. 20 for the lower clamp member 46, a spacer 68 extends radially outwardly from the internal inner side wall 55 and may be secured to the shim pad 66 and/or to the internal inner side wall 55. The distance that the spacer 68 extends radially outwardly from the internal inner side wall 55 is selected such that the spacer limits the clearance between the upper clamp member 45 and the inner side wall of the conduit of the feedwater sparger as explained further below. The outer shoulder 65 extends along the horizontal extension portion of forward extension 49 parallel to inner shoulder 62 and has a planar inner surface 70 extending perpendicularly downwardly from the forward lower surface 63, the inner surface 70 being parallel to the outer surface 67 of inner shoulder 62. The outer shoulder 65 extends along the outer side of the upper clamp member opposite the inner side thereof and has a depth in the radial direction between inner surface 70 and a planar external outer surface 71 of forward extension 49. The outer surface 71 extends in a first direction, i.e. forwardly, from the compartment 51 and forms part of the external outer side wall for the upper clamp member 45. The depth of the outer shoulder 65 allows the outer shoulder to be accommodated between the lower bracket member of a feedwater sparger end bracket assembly and the reactor vessel wall as explained further below. The radial extension portion of forward extension 49 includes a planar external forward wall 72 perpendicularly joined to a planar external inner side wall 73 of the horizontal extension portion at an inside corner. The forward wall 72 has a notch 74 therein adjacent the inside corner at which the forward wall 72 is joined to the inner side wall 73. The forward wall 72 is perpendicularly joined to the forward lower surface 63 along a lower edge of the forward extension, and the notch 74 is located along the lower edge of the forward extension. The notch 74 is open at the front and at the bottom of the radial extension portion. The inner side wall 73 of the horizontal extension portion is parallel to the inner surface 70 of outer shoulder 65 and has a cavity 75 therein of generally rectangular cross-section. The inner side wall 73 is joined to the inner surface 70 of outer shoulder 65 by the forward lower surface 63, the inner side wall 73 being joined to forward lower surface 63 along the lower edge of the forward extension. The cavity 75 is open along the inner side and bottom of the horizontal extension portion, the cavity 75 being open along a lower edge of the horizontal extension portion at which the inner side wall 73 is perpendicularly joined to the forward lower surface 63. The rearward lower surface 64 is recessed upwardly relative to the forward lower surface 63 so that the rearward lower surface 64 is recessed upwardly from the bottom surface of inner shoulder 62 a greater distance than the forward lower surface 63 is recessed upwardly from the bottom surface of the inner shoulder. The rearward extension 50 is connected to the medial portion 48 at a curved inside corner and includes a straight horizontal segment extending rearwardly in the horizontal direction in alignment with the horizontal extension portion of forward extension 49. The horizontal segment of rearward extension 50 has an external outer side wall 77 coextensive with a downwardly protruding shear tab or protrusion 79 which protrudes downwardly from the rearward lower surface 64 along the outer side of the upper clamp member. The outer side wall 77 forms part of the external outer side wall for the upper clamp member and includes a rearward outer side wall segment along shear tab 79 and a forward outer side wall segment extending forwardly from shear tab 79 to impingement shield 56. The forward and rearward outer side wall segments are planar, with the forward outer side wall segment recessed inwardly from the rearward outer side wall segment. The shear tab 79, which is parallel to inner shoulder 62, begins at an external rear wall of the rearward extension 50 and extends forwardly therefrom along part of the horizontal or tangential length of the outer side of rearward extension 50. Accordingly, the shear tab 79 is spaced from compartment 51 in a second direction, i.e. rearwardly, opposite the direction of extension for outer shoulder 65 such that the inner shoulder 62 is located between the outer shoulder 65 and the shear tab 79 but is disposed closer to the outer shoulder than to the shear tab. The shear tab 79 has a planar outer side surface 78 formed by the rearward outer side wall segment and an inner side surface 80 parallel to the outer side surface 78. The inner side surface 80 is parallel to the outer surface 67 of inner shoulder 62 and is joined to the outer side surface 78 at a tapered lower end of the shear tab 79. The shear tab 79 has a depth or thickness in the radial direction between the outer side surface 78 and the inner side surface 80 and has a location rearward of the compartment 51 to fit between the outer side wall of the feedwater sparger conduit 15 and the reactor vessel wall 11 with a close fit as explained below. The impingement shield 56 may be formed integrally, unitarily with the housing of the upper clamp member 45 or as a separate compartment attached to the housing in any suitable manner. The impingement shield 56 is illustrated as a separate component bolted or screwed to the housing. The impingement shield 56 extends vertically from the top of the upper clamp member 45 to a straight, horizontal lower end 82 best shown in FIG. 9. The impingement shield 56 is planar and has a depth or thickness between planar and parallel inner and outer shield surfaces, the outer shield surface being flush or substantially flush with the forward outer side wall segment of rearward extension 50. The lower end 82 of the impingement shield is of reduced thickness to overlap an upper end of an impingement shield for the lower clamp member 46 as explained further below. The impingement shield 56 completes the external outer side wall of upper clamp member 45 and extends from the outer side wall 77 of rearward extension 50 to the outer surface 71 of forward extension 49 such that the compartment 51 is closed off along the outer side of the upper clamp member. The impingement shield 56 extends vertically below the bottom surface of inner shoulder 62 a sufficient distance to meet the impingement shield of the lower clamp member in the closed position for clamp 44 as described below. The lower clamp member 46 is essentially a mirror image of upper clamp member 45 and comprises a housing having a medial portion 83 between a forward extension 84 and a rearward extension 85 as shown in FIG. 7. The medial portion 83 extends interiorly beyond the forward and rearward extensions 84 and 85, and has an external inner side wall including a top portion and a bottom portion angled downwardly from the top portion in the outward direction to meet the bottom wall of the lower clamp member. The bore in lower clamp member 46 through which the connector 47 passes extends entirely through medial portion 83 in the vertical direction. The forward extension 84 has an L-shaped configuration with a radial extension portion and a horizontal extension portion perpendicular to the radial extension portion thereof. An internal compartment 86, best shown in FIGS. 7 and 8, is defined in the lower clamp member 46 as a counterpart to compartment 51 of the upper clamp member 45. Internal compartment 86 is similar to compartment 51 and is bounded at the bottom by a planar internal bottom wall 87 which is parallel to internal top wall 52, at the front by a planar internal front wall 88 which is co-planar with internal front wall 53, at the rear by a planar internal rear wall 89 which is co-planar with internal rear wall 54, at the inner side by a planar internal inner side wall 90 which is co-planar with internal inner side wall 55, and at the outer side by a planar impingement shield 91 which is co-planar with impingement shield 56. The compartment 86 is open at the top of the lower clamp member and has a mouth or opening along the top of the lower clamp member providing communication with the compartment 86. The opening of compartment 86 is in facing relation to the opening of compartment 51 and is vertically aligned therewith. The bottom of lower clamp member 46 is defined by a planar external bottom wall. The top of lower clamp member 46 has a stepped configuration defining an upwardly protruding inner shoulder or protrusion 94 extending upwardly from planar upper surface 95 and planar recessed upper surface 96, and an upwardly protruding outer shoulder or protrusion 97 extending upwardly from the upper surface 95. The upper surface 95, which is at the top of the lower clamp member, is located to the front of the opening into compartment 86 and is a forward upper surface. The recessed upper surface 96 is located to the rear of the opening into compartment 86 at the top of the lower clamp member and is a rearward upper surface. The forward upper surface 95 corresponds to the forward lower surface 63 and is parallel to and vertically aligned with the forward lower surface 63. The rearward upper surface 96 corresponds to the rearward lower surface 64 and is parallel to and vertically aligned with the rearward lower surface 64. The inner shoulder 94 is similar to the inner shoulder 62 and is vertically aligned with the inner shoulder 62. The inner shoulder 94 extends along the inner side of lower clamp member 46 in the tangential or horizontal direction between the front and rear walls of compartment 86 and has a planar outer surface 98 coextensive with internal inner side wall 90, the outer surface 98 being perpendicular to the internal front and rear walls 88 and 89. The outer surface 98 of inner shoulder 94 is perpendicularly joined to forward upper surface 95 to the front of the opening of compartment 86 and is perpendicularly joined to rearward upper surface 96 to the rear of the opening into compartment 86. The outer surface 98 extends upwardly from the opening of compartment 86 and is co-planar with the outer surface 67 of the inner shoulder 62. A shim pad 66 is secured on the outer surface 98 as described above for the upper clamp member 45 and is located at a location corresponding to the shim pad 66 of the upper clamp member. The shim pad 66 of the lower clamp member 46 thusly extends vertically between the rearward upper surface 96 and a top surface of inner shoulder 94. A spacer 68, shown in FIG. 20, extends radially outwardly from the internal inner side wall 90 as described above for the spacer 68 of the upper clamp member. The spacer 68 for the lower clamp member is disposed at a location corresponding to the location for the spacer of the upper clamp member. The outer shoulder 97 is similar to the outer shoulder 65 and is vertically aligned with the outer shoulder 65. The outer shoulder 97 extends along the horizontal extension portion of forward extension 84 parallel to the inner shoulder 94 and has a planar inner surface 99 extending perpendicularly upwardly from the forward upper surface 95. The inner surface 99 of outer shoulder 97 is parallel to the outer surface 98 of inner shoulder 94, and is co-planar with the inner surface 70 of the outer shoulder 65 of the upper clamp member 45. The outer shoulder 97 extends along the outer side of the lower clamp member in the forward direction from compartment 86, and has a depth in the radial direction between inner surface 99 and a planar external outer surface 100 of the forward extension 84. The outer surface 100 forms part of the external outer side wall for the lower clamp member. The top of outer shoulder 97 and the bottom of outer shoulder 65 may have beveled or chamfered edges. The radial extension portion of forward extension 84 includes a planar external forward wall 101 joined to a planar external inner side wall 102 of the horizontal extension portion by an angled corner wall. The forward wall 101, the corner wall and the inner side wall 102 are perpendicularly joined to the forward upper surface 95 along an upper edge of the forward extension 84. The rearward upper surface 96 is recessed downwardly relative to the forward upper surface 95 so that the rearward upper surface 96 is recessed downwardly from the top surface of inner shoulder 94 a greater distance than the forward upper surface 95 is recessed downwardly from the top surface of the inner shoulder 94. The rearward extension 85 is similar to rearward extension 50 and is vertically aligned with the rearward extension 50. The rearward extension 85 has a horizontal segment corresponding to the horizontal segment of rearward extension 50 and has an external outer side wall 103 coextensive with an upwardly protruding shear tab or protrusion 105. The outer side wall 103 forms part of the external outer side wall for the lower clamp member and includes a rearward outer side wall segment along shear tab 105 and a forward outer side wall segment extending forwardly from shear tab 105 to impingement shield 91, with the forward outer side wall segment being recessed inwardly from the rearward outer side wall segment. Shear tab 105 is similar to shear tab 79 and protrudes upwardly from the rearward upper surface 96, the shear tab 105 being disposed at a location corresponding to the location of shear tab 79. Accordingly, the shear tab 105 is spaced from compartment 86 in the rearward direction, opposite the direction of extension for outer shoulder 97, such that the inner shoulder 94 is located between the outer shoulder 97 and the shear tab 105 but is disposed closer to the outer shoulder 97 than to the shear tab 105. The shear tab 105 has a planar outer side surface 104 formed by the rearward outer side wall segment of outer side wall 103 and has an inner side surface 106 parallel to the outer side surface 104. The inner side surface 106 is parallel to the outer surface 98 of inner shoulder 94 and is joined to the outer side surface 104 at a tapered upper end for the shear tab 105 as described for the shear tab 79. The outer side surface 104 of shear tab 105 is co-planar with the outer side surface 78 of shear tab 79. The inner side surface 106 of shear tab 105 is co-planar with the inner side surface 80 of shear tab 79. The impingement shield 91 is similar to impingement shield 56 and extends in the vertical direction from the bottom of the lower clamp member 46 to a straight, horizontal upper end 107 best shown in FIG. 9. The upper end 107 is of reduced thickness to overlap the lower end 82 of impingement shield 56 when the clamp 44 is in the closed position as shown in FIG. 9. With the clamp in the closed position, the planar inner surface of shield 56 is flush or substantially flush with a planar inner surface of shield 91, and the planar outer surface of shield 56 is flush or substantially flush with a planar outer surface of shield 91. The impingement shield 91 completes the external outer side wall of lower clamp member 46 and extends from the outer side wall 103 of rearward extension 85 to the outer surface 100 of forward extension 84 such that the compartment 86 is closed off along the outer side of the lower clamp member. The impingement shield 91 extends upwardly above the top surface of inner shoulder 94 such that the upper edge 107 engages the lower edge 82 of impingement shield 56 when the clamp 44 is in the closed position. The clamp 44 is preferably fabricated primarily from Austenitic 300 series stainless steel. If additional material strength is needed for certain components, XM-19 stainless steel may be used. In a preferred embodiment, the upper and lower clamp members each have a maximum horizontal or tangential dimension of about 16.60 inches and a maximum radial dimension of about 7.75 inches. The upper clamp member has a maximum vertical dimension or height of about 8.00 inches, and the lower clamp member has a maximum vertical dimension or height of about 6.5 inches. The connector is about 1.25 inches in diameter with seven threads per inch and is about 15 inches long including the head thereof. A method of preventing separation of feedwater sparger end bracket assemblies involves installing the clamp assembly 44 on a feedwater sparger end bracket assembly, such as feedwater sparger end bracket assembly 20, with the clamp being lowered into the reactor vessel 12 using remote tooling. The upper and lower clamp members are moved away from one another and are separated vertically to the extent required to obtain an open position for the clamp, allowing the clamp members to fit over the feedwater sparger and the feedwater sparger end bracket assembly. The upper clamp member 45 is disposed over the top of the sparger/bracket junction, and the lower clamp member 46 is disposed below the sparger/bracket with the connector 47 located interiorly of the feedwater sparger 14 and the feedwater sparger end bracket assembly 20. Accordingly, the upper and lower clamp members will be disposed in opposition to one another over the feedwater sparger end bracket assembly. An upper portion of the sparger/bracket junction, i.e. upper portions of sparger end plate 16 and attachment plate 22 which protrude upwardly beyond the conduit 15 and the upper bracket member 25, is aligned with the internal compartment 51 of the upper clamp member 45. A lower portion of the sparger/bracket junction, i.e. lower portions of sparger end plate 16 and attachment plate 22 which protrude downwardly beyond the conduit 15 and the lower bracket member 26, is aligned with the internal compartment 86 of lower clamp member 46. Of course, where the sparger/bracket junction includes a shim plate, an upper portion of the shim plate will be aligned with compartment 51 and a lower portion of the shim plate will be aligned with compartment 86. The connector 47 is then threaded into the lower clamp member, and the connector 47 and/or another tool is used to move the upper and lower clamp members 45 and 46 toward one another. The upper and lower clamp members 45 and 46 are drawn together to obtain the closed position in which the clamp members enclose the upper and lower portions of the sparger/bracket junction. The upper and lower clamp members are securely tightened on the feedwater sparger 14 and the feedwater sparger end bracket assembly 20, and are held in place via the connector 47. The clamp 44 will then be in a closed position with the lower end 82 of impingement shield 56 in overlapping engagement with the upper end 107 of impingement shield 91. The clamp is then left in place in the reactor vessel 12. FIGS. 13-20 illustrate the clamp 44 installed on the feedwater sparger end bracket assembly 20 to form a constrained feedwater sparger end bracket assembly, it being noted that the upper clamp member 45 is not shown in FIG. 20. With the clamp 44 installed on the feedwater sparger end bracket assembly 20, the upper portions of sparger end plate 16 and attachment plate 22 are disposed within the compartment 51 of the upper clamp member 45, and the lower portions of sparger end plate 16 and attachment plate 22 are disposed within the compartment 86 of lower clamp member 46. The leg 34 and/or foot 35 of pin retainer 32 disposed closest to the attachment plate 22 is accommodated in the notch 74. An outer side of pin bail 36 is accommodated in the cavity 75. The upper portions of sparger end plate 16 and attachment plate 22, i.e. the upper portion of the sparger/bracket junction, are constrained in a first or horizontal or tangential direction between the internal front wall 53 and the internal rear wall 54 of compartment 51 with a close fit, i.e. with minimal or no clearance therebetween. The lower portions of sparger end plate 16 and attachment plate 22, i.e. the lower portion of the sparger/bracket junction, are constrained in the horizontal or tangential direction with a close fit between the internal front wall 88 and the internal rear wall 89 of compartment 86. Separation of the feedwater sparger end bracket assembly 20 from the end of the feedwater sparger 14 in a horizontal or tangential direction is thusly prevented. The sparger/bracket junction is constrained in a second or vertical direction due to constraint of the sparger end plate 16 and the attachment plate 22 between the internal top wall 52 of the upper clamp member 45 and the internal bottom wall 87 of the lower clamp member 46. The upper and lower bracket members 25 and 26 are constrained in the vertical direction with a close fit between the forward lower surface 63 of the upper clamp member 45 and the forward upper surface 95 of the lower clamp member 46. The feedwater sparger conduit 15 is constrained in the vertical direction with a close fit between the rearward lower surface 64 of upper clamp member 45 and the rearward upper surface 96 of lower clamp member 46. Accordingly, separation of the feedwater sparger end bracket assembly is prevented in the vertical direction. The outer shoulder 65 of upper clamp member 45 is disposed between the upper bracket member 25 and the reactor vessel wall 11, with the inner surface 70 of outer shoulder 65 disposed adjacent the outer side edge of the upper bracket member with little or no clearance. The shear tab 79 of the upper clamp member 45 is disposed between the conduit 15 and the reactor vessel wall 11 with a close fit, the inner side surface 80 of the shear tab 79 being adjacent the outer side wall of the conduit with little or no clearance therebetween. The outer shoulder 97 of the lower clamp member 46 is disposed between the lower bracket member 26 and the reactor vessel wall 11, with the inner surface 99 of the outer shoulder 97 adjacent the outer side edge of the lower bracket member with little or no clearance therebetween. The shear tab 105 of the lower clamp member 46 is disposed between the conduit 15 and the reactor vessel wall 11 with a close fit, with the inner side surface 106 of the shear tab 105 adjacent the outer side wall of the conduit with little or no clearance therebetween. The outer surface 67 of inner shoulder 62 of the upper clamp member 45 is adjacent the inner side edge of attachment plate 22 with minimal or no clearance therebetween to establish a tight fit between the upper clamp member and the feedwater sparger end bracket assembly. The shim pad 66 of the upper clamp member 45 fills the gap or space between the outer surface 67 and the inner side wall of conduit 15 to establish a tight fit between the upper clamp member and the feedwater sparger. The spacer 68 of the upper clamp member 45 occupies the gap or space between the outer surface 67 and the inner side edge of the sparger end plate 16 as shown in FIG. 20 for the lower clamp member, thereby further ensuring a tight fit between the upper clamp member and the feedwater sparger. The lower clamp member 46 is installed on the feedwater sparger and bracket assembly in the same manner as the upper clamp member. The outer surface 98 of inner shoulder 94 of the lower clamp member 46 is adjacent the inner side edge of attachment plate 22, and the shim pad 66 of the lower clamp member fills the gap or space between the outer surface 98 and the inner side wall of conduit 15. The spacer 68 of the lower clamp member 46 occupies the gap or space between the outer surface 98 and the inner side edge of the sparger end plate 16 as shown in FIG. 20. Separation of the feedwater sparger end bracket assembly 20 is prevented in the radial direction due to the feedwater sparger end bracket assembly being constrained with a close fit between the inner shoulders 62, 94 and the outer shoulders 65, 97. Also, the feedwater sparger 14 is constrained in the radial direction due to constraint of conduit 15 between the inner shoulders 62, 94 and the outer shoulder 65, 97 via the shim pads 66 and due to radial constraint of the conduit 15 between the inner shoulders 62, 94 and the shear tabs 79, 105 via the shim pads 66. The impingement shields 56, 91 are disposed between the sparger/bracket junction and the reactor vessel wall 11. The impingement shields 56, 91 isolate the sparger/bracket junction from the vessel wall 11 and prevent direct impingement of feedwater flow on the reactor vessel wall 11 should a through wall crack develop between the conduit 15 and the sparger end plate 16. Accordingly, direct impingement of relatively colder feedwater on the reactor vessel wall 11 with concomitant thermal shock and cracking of the cladding on the interior surface of the reactor vessel wall is avoided. The shear tabs 79, 105 assist in carrying moment on the clamp 44 that occurs in the event of a complete through wall crack of the welds between the conduit 15 and the sparger end plate 16 or between the sparger end plate 16 and the attachment plate 22. In the event that the feedwater spargers are sprung into place such that there is a shear preload on the welds, the preload is maintained by the clamp 44 in the event of weld failure. If either of the welds between the conduit 15 and the sparger end plate 16 or between the sparger end plate 16 and the attachment plate 22 fails, the load from the feedwater sparger is transferred to the clamp 44 at location A shown in FIG. 20. The clamp 44 reacts to this load at location B, and the couple created by the loads at locations A and B creates a moment that must be balanced. The shear tabs 79, 105 react, at location C, to the couple created by the loads at locations A and B such that all loads and moments are balanced. Accordingly, the outer shoulders 65, 97 and the shear tabs 79, 105 cooperate with the inner shoulders 62, 94 to place the clamp and the feedwater sparger in equilibrium. Since the installation preload is transferred to and maintained by the clamp 44, flow baffles of the feedwater sparger will remain essentially in contact with the reactor vessel wall. Various shims and spacers can be incorporated in the clamp 44 to achieve a tight fit between the clamp and the feedwater sparger and/or the feedwater sparger end bracket assembly, as needed. Various shims and spacers can be incorporated in the clamp 44 to adapt the clamp for installation on feedwater sparger end bracket assemblies having various dimensions and components. The clamp can be installed on feedwater sparger end bracket assemblies having one or more shim plates, such as feedwater sparger end bracket assembly 120, by forming the internal compartments 51, 86 with a distance between the internal front walls and the internal rear walls sufficient to accommodate the sparger end plate, the attachment plate, and any shim plate. A clamp designed for installation on feedwater sparger end bracket assembly 120 can also be installed on the feedwater sparger end bracket assembly 20 by using shims and/or spacers to achieve a close fit between the feedwater sparger end bracket assembly 20 and the clamp. It should be appreciated, therefore, that the clamp 44 can be used on sparger/bracket junctions of different thicknesses. The shims and/or spacers can be incorporated in the clamp at any suitable locations. The clamp 44 positively secures to the feedwater sparger end bracket assembly and holds the feedwater sparger and the feedwater sparger end bracket assembly together in the event of through wall cracking of any or all feedwater sparger and/or feedwater sparger end bracket assembly welds. The clamp prevents separation of the feedwater sparger end bracket assembly in first, second and third directions, i.e. horizontal or tangential, vertical and radial directions. The clamp prevents separation of the feedwater sparger end bracket assembly from the feedwater sparger and prevents separation of the structural components of the feedwater sparger end bracket assembly. The clamp provides an alternate load path for loads from the feedwater sparger to the reactor vessel attachment fitting, and the outer shoulders and shear tabs provide an alternate path for transferring loads from the feedwater sparger to the reactor vessel attachment fitting. The clamp can be installed remotely from a refueling bridge using long-handled tooling. The clamp incorporates corrosion resistant materials and does not require welding to the feedwater sparger, the feedwater sparger end bracket assembly or to the reactor vessel. In as much as the present invention is subject to many variations, modifications and changes in detail, it is intended that all subject matter discussed above or shown in the accompanying drawings be interpreted as illustrative only and not be taken in a limiting sense.
	summary
042661390	abstract	A shielding means for an x-ray machine comprised of a base plate which removably receives overlays masking out selective portions of the base plate to control the passage of the x-rays therethrough. The overlays are generally identical and provided with co-operating removable securing means to permit the same to be stacked one on the other to vary the thickness thereof. Removable mounting rails position and maintain the shielding means on the x-ray machine.
	claims	1. A method of forming a corrosion resistant boundary on a substrate of a component for use in a water cooled nuclear reactor, the method comprising:providing a zirconium alloy substrate;forming on the zirconium alloy substrate, an interlayer with particles selected from the group consisting of Mo, Ta, W, and Nb; andforming a corrosion resistant layer on the interlayer with particles selected from the group consisting of Cr, a Cr alloy, and combinations thereof;wherein the interlayer is formed by a physical vapor deposition process and the corrosion resistant layer is formed by a cold spray thermal deposition process. 2. The method recited in claim 1 wherein Cr alloy of the corrosion resistant layer comprises one of FeCrAl or FeCrAlY. 3. The method recited in claim 1 wherein the cold spray process comprises:heating a pressurized carrier gas to a temperature between 100° C. and 1200° C.;adding the particles to the heated carrier gas; andspraying the carrier gas and entrained particles at a velocity of 800 to 4000 ft./sec. (about 243.84 to 1219.20 meters/sec.). 4. The method recited in claim 3 wherein the carrier gas is selected from the group consisting of nitrogen (N2), hydrogen (H2), argon (Ar), carbon dioxide (CO2), and helium (He) and combinations thereof. 5. The method recited in claim 1 wherein the physical vapor deposition process is selected from the group consisting of cathodic arc vapor deposition, magnetron sputtering deposition, and pulsed laser deposition. 6. The method recited in claim 1 further comprising, following the formation of the interlayer, at least one of grinding, buffing, and polishing to increase the smoothness of the coating. 7. The method recited in claim 1 further comprising, following the formation of the corrosion resistant layer, at least one of grinding, buffing, and polishing to increase the smoothness of the coating. 8. The method recited in claim 1 wherein the particles forming the corrosion resistant layer are pure chromium particles. 9. The method recited in claim 1 wherein the particles forming the corrosion resistant layer are Cr alloy particles. 10. The method recited in claim 1 wherein the particles forming the corrosion resistant layer are selected from the group consisting of FeCrAl and FeCrAlY particles. 11. The method recited in claim 1 wherein the particles forming the interlayer are Mo particles. 12. The method of claim 1, wherein the thickness of the interlayer is between 100 and 300 microns and the thickness of the corrosion resistant layer is between 100 and 300 microns. 13. A method of forming a corrosion resistant boundary on a substrate of a component for use in a water cooled nuclear reactor, the method comprising:providing a zirconium alloy substrate;forming on the zirconium alloy substrate, an interlayer with particles selected from the group consisting of Mo, Ta, W, and Nb; andforming a corrosion resistant layer on the interlayer with particles selected from the group consisting of Cr, a Cr alloy, and combinations thereof;wherein the interlayer is formed by a cold spray thermal deposition process and the corrosion resistant layer is formed by physical vapor deposition.
	abstract	A system includes a plurality of sensors configured to measure one or more characteristics of an impeller. The system also includes an impeller condition indicator device, which includes a plurality of sensor interfaces configured to receive input signals associated with at least one stage of the impeller from the sensors. The impeller condition indicator device also includes a processor configured to identify a fault in the impeller using the input signals and an output interface configured to provide an indicator identifying the fault. The processor is configured to identify the fault by determining a family of frequencies related to at least one failure mode of the impeller, decomposing the input signals using the family of frequencies, reconstructing a impeller signal using the decomposed input signals, and comparing the reconstructed impeller signal to a baseline signal. The family of frequencies includes a vane pass frequency and its harmonics.
	claims	1. A radioactive-material container comprising:a container body configured to shield nuclear radiation, the container body including a cavity configured to store a basket containing a recycle fuel assembly;a lid configured to cover the cavity; anda double-ring metal gasket including:a pair of coil springs made of a metal in circular shape, each coil spring having different hoop-diameters which are distances from a center of the container body;a pair of inner covers made of a metal configured to cover the coil springs in circular shape;a pair of outer covers made of a metal, which is softer than a material forming the container body and lid, configured to cover the inner covers in circular shape, the outer covers having areas configured to seal the nuclear radiation, wherein the areas make a physical contact with the container body and the lid, whereinthe areas have a top and a bottom opposing one another, said top and bottom have flat surfaces, wherein said areas have no intentional projecting parts before being sealed and during being sealed between said container body and said lid, said areas are configured to disperse tightening stress acting on the metal gasket when sealed between said container body and said lid, whereina ratio of a wire diameter d of the coil spring to a sectional diameter D of the metal gasket, d/D, is approximately equal to or more than 0.02 and equal to or less than 0.08, whereind is approximately equal to or more than 0.35 millimeter and equal to or less than 0.8 millimeter, andD is approximately equal to or more than 5.0 millimeters and equal to or less than 12.0 millimeters. 2. The radioactive-material container according to claim 1, whereinthe metal forming the outer cover has a higher corrosion potential than a material forming the container body and the lid.
048329037	abstract	A storage arrangement for nuclear fuel has a plurality of storage tubes connected by individual pipes to manifolds which are connected, in turn, to a venting system for maintaining the tubes at supra-atmospheric, atmospheric, or subatmospheric pressure, and means for producing a flow of a cooling fluid, such as air, over the exterior surfaces of the tubes.
	summary
	claims	1. An inspection device evaluation system connected to a plurality of inspection devices via a network for evaluating images obtained by these inspection devices, wherein the inspection device evaluation system evaluates the image resolution of the images obtained by the plurality of inspection devices, wherein, upon failure of an evaluation value meeting a predetermined allowable value or set value, an instruction is issued to adjust the inspection conditions of the inspection devices so as to bring the image resolution into conformity with the predetermined allowable value or set value,wherein the evaluation of the image resolution of the images comprises calculating the resolution of a plurality of partial regions in which a plurality of pixels are arranged in a matrix, and averaging the image resolutions of the plurality of partial regions thus calculated. 2. The inspection device evaluation system according to claim 1, wherein the inspection device evaluation system calculates the resolution of the partial regions based on the density gradient of the partial regions of the image. 3. The inspection device evaluation system according to claim 1, wherein the inspection device evaluation system calculates the resolution evaluation value periodically, and displays or stores the thus calculated resolution evaluation value together with time transition information. 4. The inspection device evaluation system according to claim 1, wherein the inspection device evaluation system calculates, along with the resolution, image noise of the image, an S/N ratio of the image, or at least one of image quality evaluation parameters calculated based on the resolution. 5. The inspection device evaluation system according to claim 1, wherein the inspection device evaluation system comprises the function of setting a threshold value for the resolution evaluation value, image noise, S/N ratio of the image, or an at least one of image quality evaluation parameters, wherein, upon the resolution, image noise, S/N ratio of the image, or the image evaluation parameter exceeding the threshold value, a relevant indication is displayed on a display unit or stored. 6. The inspection device evaluation system according to claim 1, wherein the inspection device evaluation system evaluates the resolution evaluation value, image noise, S/N ratio of the image, or an at least one of the image evaluation parameters periodically to generate an image evaluation value, and displays or stores the image evaluation value together with time transition information. 7. The inspection device evaluation system according to claim 1, wherein the inspection device evaluation system controls a display unit to display magnification accuracy or magnification error. 8. The inspection device evaluation system according to claim 1, wherein the unit of the resolution evaluation value is length. 9. The inspection device evaluation system according to claim 1, wherein the inspection device evaluation system determines a local resolution based on the density gradient in each of the partial regions, and performs weighted averaging over the entire image or a portion of the image. 10. The inspection device evaluation system according to claim 9, wherein the inspection device evaluation system allocates a curved surface or a plane of a multi-order or linear function z=f(x, y) to each of the partial regions, where z is the density of the image and (x, y) is the position of an arbitrary partial region within the image, wherein the control processor determines the density gradient based on a differential value of the function. 11. An inspection device evaluation system connected to a plurality of inspection devices via a network for evaluating images obtained by these inspection devices, wherein the inspection device evaluation system evaluates the image resolution of the images obtained by the plurality of inspection devices, wherein, upon failure of an evaluation value meeting a predetermined allowable value or set value, the system comprising a display unit for displaying a relevant indication,wherein the evaluation of the image resolution of the images comprises calculating the resolution of a plurality of partial regions in which a plurality of pixels are arranged in a matrix, and averaging the image resolutions of the plurality of partial regions thus calculated. 12. The inspection device evaluation system according to claim 11, wherein the inspection device evaluation system calculates the resolution of the partial regions based on the density gradient of the partial regions of the image. 13. The inspection device evaluation system according to claim 11, wherein the inspection device evaluation system calculates the resolution evaluation value periodically, and displays or stores the thus calculated resolution evaluation value together with time transition information. 14. The inspection device evaluation system according to claim 11, wherein the inspection device evaluation system calculates, along with the resolution, image noise of the image, an S/N ratio of the image, or at least one of image quality evaluation parameters calculated based on the resolution. 15. The inspection device evaluation system according to claim 11, wherein the inspection device evaluation system comprises the function of setting a threshold value for the resolution evaluation value, image noise, S/N ratio of the image, or an at least one of image quality evaluation parameters, wherein, upon the resolution, image noise, S/N ratio of the image, or the image evaluation parameter exceeding the threshold value, a relevant indication is displayed on a display unit or stored. 16. The inspection device evaluation system according to claim 11, wherein the inspection device evaluation system evaluates the resolution evaluation value, image noise, S/N ratio of the image, or an at least one of the image evaluation parameters periodically to generate an image evaluation value, and displays or stores the image evaluation value together with time transition information. 17. The inspection device evaluation system according to claim 11, wherein the inspection device evaluation system controls a display unit to display magnification accuracy or magnification error. 18. The inspection device evaluation system according to claim 11, wherein the unit of the resolution evaluation value is length. 19. The inspection device evaluation system according to claim 11, wherein the inspection device evaluation system determines a local resolution based on the density gradient in each of the partial regions, and performs weighted averaging over the entire image or a portion of the image. 20. The inspection device evaluation system according to claim 19, wherein the inspection device evaluation system allocates a curved surface or a plane of a multi-order or linear function z=f(x, y) to each of the partial regions, where z is the density of the image and (x, y) is the position of an arbitrary partial region within the image, wherein the control processor determines the density gradient based on a differential value of the function.
	claims	1. A method of adding a fret resistant layer to a reactor component comprising:entraining fret resistant particles in an applied material;melting a surface layer of the reactor component;forming the fret resistant layer by,applying the applied material and fret resistant particles to the melted surface layer of the reactor component, wherein the applied material includes a chemical element and the reactor component includes the same chemical element, andallowing the fret resistant layer and the reactor component to cool. 2. The method of claim 1, wherein the applied material and the surface layer of the reactor component are chemically compatible, such that the applied material and the surface layer of the reactor component do not cause an adverse chemical reaction with each other, and do not create an adverse material phase within the fret resistant layer, due to an electrochemical potential difference between the applied material and the surface layer of the reactor. 3. The method of claim 1, wherein the chemical element is zirconium. 4. The method of claim 1, wherein the composition of the applied material is at least 90% by weight of the chemical element, the 90% by weight not including the weight of the entrained fret resistant particles. 5. The method of claim 4, wherein the composition of the applied material is at least 95% by weight of the chemical element. 6. The method of claim 1, wherein the fret resistant particles also share the chemical element. 7. The method of claim 6, wherein,the chemical element is zirconium,the reactor component is zirconium cladding, andthe applied material is a zirconium alloy. 8. The method of claim 7, wherein the fret resistant particles are one of zirconium carbide and yttria stabilized zirconia. 9. The method of claim 1, wherein the fret resistant particles exist within the applied material at about 10-20% by volume. 10. The method of claim 1, wherein the fret resistant particles are ceramic particles with a hardness of at least 1300 kg/mm2. 11. The method of claim 1, wherein a thickness of the fret resistant layer is 10 mils or less. 12. The method of claim 1, wherein the applying of the applied material and fret resistant particles to the melted surface layer of the reactor component involves an electro-spark discharge (ESD) process. 13. The method of claim 12, wherein the applied material is an ESD electrode. 14. The method of claim 1, wherein the applying of the applied material and fret resistant particles to the melted surface layer of the reactor component involves a cold spray process. 15. The method of claim 14, wherein the applied material is a cold spray coating powder. 16. A reactor component with a fret resistant layer, comprising:the reactor component of claim 1; andthe fret resistant layer that is applied to the surface layer of the reactor component using the method of claim 1,wherein the fret resistant layer includes,the melted and cooled surface layer of the reactor component,the applied material, andthe fret resistant particles. 17. The reactor component of claim 16, wherein the applied material and the melted and cooled surface layer of the reactor component are chemically compatible, such that the applied material and the melted and cooled surface layer of the reactor component do not cause an adverse chemical reaction with each other and do not create an adverse material phase within the fret resistant layer, due to an electrochemical potential difference between the applied material and the surface layer of the reactor. 18. The reactor component of claim 16, wherein the chemical element is zirconium. 19. The reactor component of claim 16, wherein the fret resistant particles also share the chemical element. 20. The reactor component of claim 16, wherein,the chemical element is zirconium,the reactor component is zirconium cladding, andthe applied material is a zirconium alloy. 21. The reactor component of claim 20, wherein the fret resistant particles are one of zirconium carbide and yttria stabilized zirconia. 22. The reactor component of claim 16, wherein the fret resistant particles are ceramic particles with a hardness of at least 1300 kg/mm2. 23. The reactor component of claim 16, wherein a thickness of the fret resistant layer is 10 mils of less. 24. A system, comprising:a light water reactor;the reactor component of claim 1 in the reactor; andthe fret resistant layer that is applied to the surface layer of the reactor component using the method of claim 1,wherein the fret resistant layer includes,the melted and cooled surface later of the reactor component,the applied material, andthe fret resistant particles.
	description	This application is a National Phase Entry of International Application No. PCT/FR2009/001065, filed on Sep. 4, 2009, which claims priority to French Patent Application Serial No. 08/55987, filed on Sep. 5, 2008, both of which are incorporated by reference herein. The invention relates to an amplifying optical cavity of the FABRY-PEROT type which can be used in combination with a high-rate picoseconds pulsed laser for producing monochromatic X rays. The present invention relates to the technical field of amplifying optical cavities for producing monochromatic X rays through a COMPTON reaction, that is, through the interaction of electron packets propagated in a vacuum tube of an accelerator with a pulsed laser signal feedback-controlled on an ultra-fine optical resonator. The aimed applications are numerous since they require a source of high-flux monochromatic X-rays that is sufficiently compact for use in local study centers rather than in specialized test centers having bulky equipments. For example, such a device may be employed in the medical field, more particularly in resonant radiotherapy, high contrast radiography or angiography. There also exist other application fields in pharmacology in the frame of the analysis of protein and molecule structures, in nuclear industry in the frame of waste retreatment through non-destructive container analysis, in particle physics in the frame of the implementation of polarized positron beam sources, etc. It is known from the prior art various methods for increasing the power of a laser source. The most conventional method among these consists in using a doped-fiber amplification cascade, making it possible to highly increase the peak power Ppeak of the laser signal. Nevertheless, with such a method it is not possible to obtain a sufficient mean power Pmean for the aimed applications since it does not generally exceed a hundred Watts. Another method consists in amplifying the laser signal in an optical resonator, or amplifying cavity, of the FABRY-PEROT type. In fact, in order to increase the number of photons produced through the COMPTON effect when the electron beam and the laser beam cross each other, it is necessary to reduce to the maximum the transverse and longitudinal dimensions of both beams. Nevertheless, in order to reduce the minimal transverse dimension of a laser beam within a FABRY-PEROT cavity composed of spherical mirrors, it is necessary that the distance between these two mirrors be as close as possible to twice the curvature radius of the mirrors. Nevertheless, such a cavity being instable, it cannot be used in the frame of a real application. This is the reason why many devices for producing monochromatic X-rays generated through the COMPTON effect, such as those illustrated in OPTICS LETTER review, vol. 32, No. 19, Oct. 1, 2007, as well as in patent document No US 2008002813, use an amplifying cavity of the FABRY-PEROT type having four coplanar mirrors out of which two are spherical. The minimal transverse dimension may then be reduced of about tens of microns while exhibiting a good mechanical stability. Meanwhile, the eigen states of polarization of a cavity with four coplanar mirrors have been calculated and it has been found that when the fineness of the cavity is high, that is, when the cavity gain is higher than about 1000, these eigen states vary strongly depending on inevitable mirror misalignments and vibrations. The polarization of the laser beam injected in the cavity being fixed, such variations lead not only to a variation of the intra-cavity polarization but also to an intra-cavity power variation. These power variations are detrimental in that the mean intra-cavity power Pmean is reduced. Further, the existing devices also exhibit defects relating to the laser orientation precision that determines in part, the transverse dimensions of the laser beam. More particularly, the combination of mechanical parts used to orient the optical reflectors within the cavity and in vacuum experimental conditions lead to clearances that alter the cavity fineness. Another problem raised by these systems relates to the use of motors in a vacuum medium. In fact, standard motors commercially available as being UHV compatible do not totally satisfy the requirements of ultrahigh vacuum such as required when using an optical resonator, in particular, owing to the high non pollution restrictions associated to the integration on the accelerator. In commercially available products, the hinges of the optical mounts are made with very weak or prestressed clearances, thus, greased to guarantee a precise positioning with no seizing risk. Two reasons exclude this type of hinging in vacuum conditions. On one hand, the use of grease is prohibited, and, on the other hand, between contact surfaces of a same nature, are generated microbonding phenomena which make their relative sliding impossible, particularly under vacuum conditions where the parts are very clean so as to satisfy the UHV conditions. These problems become even more essential as the number of motors required for the settings of the cavity considerably increases the level of pollution. The aim of the present invention is to overcome the drawbacks of the prior art thanks to an amplifying optical cavity of the FABRY-PEROT type making it possible to obtain a highly focused pulsed laser ray and exhibiting a strong mean power Pmean stability. Also, the aim of the invention is to provide an amplifying optical cavity exhibiting a strong setting sensitivity, that is, a laser beam having reduced transverse dimensions, generating no noises within the vacuum enclosure. Moreover, the aim of the invention is to implement a system for producing high-flux monochromatic X-rays through the COMPTON effect, which is both compact and powerful. In order to stabilize the polarization of the eigen mode of the amplifying cavity, and thus, the intra-cavity power, the invention proposes the implementation of a configuration of non planar mirrors, and more particularly of a substantially tetrahedron shape. More specifically, the object of the invention is an amplifying optical cavity of the FABRY-PEROT type for producing monochromatic X-rays through the COMPTON reaction of a high-rate picoseconds pulsed laser beam with a synchronized electron beam, the cavity having a closed enclosure capable of being vacuumed, traversed by an electron beam tube, the enclosure including laser beam input means, maintaining and positioning means for maintaining and positioning two plane optical reflectors, maintaining and positioning means for maintaining and positioning two spherical optical reflectors capable of focusing the laser beam at the point of interaction with the electron beam, wherein the optical reflector maintaining and positioning means are arranged such that said optical reflectors substantially define the vertexes of a tetrahedron. Such a tetrahedron configuration makes it possible to obtain a high-fineness beam while obtaining interesting stability features. The eigen modes of such a cavity are called “generalized astigmatic” modes, that is, the intensity profile is elliptic and the natural axes thereof rotate during the propagation, which slightly affects the luminosity geometric factors of the electron-laser interaction compared to the “standard astigmatic” modes of a four-mirror planar cavity. The astigmatism, that is, the ratio of the beam size along the major and minor axis of the ellipse, also decreases compared to an equivalent planar configuration. According to an embodiment, the means for maintaining and positioning both spherical optical reflectors have two complementary clearances, arranged so as to define a bay for the passage of the electron beam tube. The implementation of two additional complementary clearances in the spherical reflector maintaining and positioning means makes it possible to arrange the spherical mirrors as close as possible to the electron beam and thus to obtain the narrowest angle at the point of collision between the laser and the electron beam. Advantageously, the means for maintaining and positioning at least one optical reflector comprise a member for orienting said reflector made from a single mechanical piece, composed of at least three distinct portions, movable relative to each other by means of a flexible hinge. The use of a mirror orienting member made from a single piece having flexible hinges makes it possible to perform frictionless and clearance-free relative movements. Such a configuration is particularly adapted to ensure a precise positioning in ultrahigh vacuum. Preferably, the three distinct portions of the orienting member are movable around two rotation axes converging at one point and substantially confounded with the center of the optical reflector. The fact that the three distinct portions of the orienting member are movable around two converging rotation axes and substantially confounded with the optical center of the reflector eases the adjustment of the reflector orientation and makes it possible to obtain a precise orientation. Advantageously, the optical reflector maintaining and positioning means are actuated by linear electrical motors encapsulated within a sealed enclosure made of stainless steel extended by a bellows. The encapsulation of the linear motors within a sealed enclosure extended by a bellows makes it possible to clear the non pollution restrictions relating to the accelerator integration. On the other hand, the use of grease between the moving parts becomes again possible and the choice of the motors is no longer determined by the ability to operate under vacuum, but depends essentially on the mechanical and positioning precision characteristics. This also makes it possible to independently adjust the orientations and the position of the mirrors along a z-axis. Preferably, the linear electric motors are maintained in permanent contact with regard to the optical reflector maintaining and positioning means by means of a spring element generating a return force. The use of a spring element makes it possible to counteract the vacuum force and to hold a permanent point contact between the motor shaft and the part to be translated. Advantageously, the means for maintaining and positioning at least one optical reflector have a z-axis translation table, the translation table supporting two linear motors capable of actuating the reflector orienting member. The use of a translation table supporting the linear motors used for moving the orienting member makes it possible to improve the precision of the device. Preferably, the means for maintaining and positioning at least one optical reflector comprise a piezoelectric actuator oriented along the direction of the reflector optical axis and maintained in position via a spring ring. With the piezoelectric actuator mounted on the mirror support element it is possible to adapt the length of the optical path of the laser beam to a few nanometers at frequencies of few hundreds of Hertz. It makes it possible to implement a feedback control between the length of the round trip in the cavity and the distance between two successive electron packets. Moreover, the use of a spring ring to maintain this piezoelectric actuator makes it possible, when the clamping is at its maximum, to apply on the mirror a given holding stress, relating to the geometry of the resilient parts and to the mirror thickness. Advantageously, all the optical reflector maintaining and positioning means are positioned on a main support, said main support being the only piece contacting the closed enclosure. Also, with this construction it is possible to isolate the cavity from external vibrations by restricting the contact points with the enclosure. According to another aspect, the invention also relates to a system for producing monochromatic X-rays through a COMPTON reaction, including an optical cavity such as described above. General Description FIG. 1 represents a functional flow diagram of the system for producing monochromatic X-rays through a COMPTON reaction according to the invention. A pulsed laser cavity 10 produces a pulsed laser beam 12. This laser beam 12 is advantageously controlled by two types of actuators gathered within an actuator and associated driving electronic module 14. The pulsed laser cavity 10 have a wavelength of 800 nm, that is, in the infrared domain, a pulse energy of 10 nJ and a mean power of 1 W. It comprises a laser producing a continuous beam of 6 W used for pumping a Titanium:Sapphire crystal located within an optical resonator whose 2 m length between the mirrors thereof determines the repetition frequency of 76 MHz of the emitted pulses. A first type of actuators makes it possible to feedback-control the length of the pulsed laser cavity 10 to the length of an amplifying optical cavity of the FABRY-PEROT type 40 (described later on). This first type of actuators is composed of a piezoelectric actuator 14a along with a linear translation motor 14b both being physically integrated inside the pulsed laser cavity 10. The piezoelectric actuator 14a, driven by associated electronics, makes it possible to change the relative deviation ΔL between the length of the resonator cavity and that of the FABRY-PEROT cavity 40, in the frequency band 0-40 KHz, with about 100 picometers to 1 micrometer dynamics. The linear translation motor 14b makes it possible to change the relative deviation ΔL between the length of the resonator cavity and that of the FABRY-PEROT cavity 40, in the 0-10 KHz band with about 100 nanometers to a plurality of millimeters dynamics. The driving electronics of this linear translation motor 14b is provided with the motor. A second type of actuators makes it possible to correct phase Δø between the electromagnetic field and its envelope in the FABRY-PEROT cavity 40. They include an optical pumping modulator 14c and a frequency modulator 14d, both of which being located outside the pulsed laser cavity 10. Both of the optical pumping modulator 14c and the frequency modulator 14d are advantageously acoustic-optical modulators which respectively allow the modulation of the optical pumping power and the offsetting the laser optical spectrum so as to change the relative phase Δø between the electromagnetic field and its envelope in the FABRY-PEROT cavity. Once the feedback control performed, the power inside the FABRY-PEROT cavity 40 is amplified by a coefficient which depends on the Fineness of the mirrors contained therein. The feedback control requires a plurality of specific measurements, gathered within a measurement and associated interface electronic module 20 which is composed of: One element 20a, for independent transmission measurement, called Front End Transmission which processes the optical signal transmitted at the output of the FABRY-PEROT cavity 40. One element 20b for a more complex reflection measurement, called Front-End reflection which processes the optical signal reflected at the input of the FABRY-PEROT cavity 40 though the use of a particular so called Pound-Drever-Hall technique. This technique is particularly continuously described in the publication R W. Dreyer et al., laser phase and frequency stabilization using an optical resonator. Appl. Phys. B 31, 97-105 (1983), and in pulsed mode in publication R. J. Jones and J C. Diels, Stabilisation of femtosecond lasers for optical metrology and direct optical to radio frequency synthesis. Phys. Rev. Lett. 86, 3288-3291 (2001). A feedback control electronic system 22 acquires and converts numerically analogical signals from the Front-Ends in transmission and in reception, performs real time feedback-control calculations and outputs the driving instructions transmitted to actuators 14a and 14d so as to maintain the FABRY-PEROT cavity 40 resonating. Description of the Optical Portion FIG. 2 represents a general flow diagram of the optical portion of the system used to accumulate, inside the FABRY-PEROT optical cavity 40, the optical energy of the short laser pulses, until it reaches a level of plural micro-Joules per pulse, with a repetition frequency of about a hundred MHz. To this end, a laser pulse train from the pulsed laser cavity 10 is feedback-controlled on a FABRY-PEROT optical cavity 40 by the so-called Pound-Drever-Hall technique so as to have image electrical amounts of the optical features of the controlled beam. Advantageously, the optical portion of the system is composed of: A picoseconds pulse width laser with a repetition rate of 76 MHz, including actuators. There is no limitation as to the repetition frequency within an interval of a few MHz to some GHz. Likewise, the time period may be selected within a time interval from a few femtoseconds to some tens of picoseconds; An amplifying optical cavity of the FABRY-PEROT type 40 to be described in more detail later; Optical elements 24 allowing the transport of the laser beam from the pulsed laser cavity 10 to FABRY-PEROT cavity 40; and A diffraction array 26 making it possible to separate the parameters to be feedback controlled. A picoseconds pulse train is emitted by the Titanium:Sapphire laser (Ti:Sa) operating in a mode locking operating condition. The energy of a pulse is of about 10 nJ, the pulse repetition frequency of 76 MHz. The pulse train is sent on an electro-optical modulator 24a which generates two lateral bands around each frequency comb line of the laser that are employed by the so-called Pound-Drever-Hall technique to obtain the error signals. There is no restriction as to the choice of the wavelength provided that the oscillator is of the passive mode locked type. A Faraday isolator 24b shields the pulsed laser of the ray reflected by the FABRY-PEROT cavity 40 and the beam separator 24c sends the beam to the array 26. The beam separator 24c in association with a quarter wave plate 24d form an assembly that separates the ray reflected by the FABRY-PEROT cavity 40. A Galilean telescope 24e is used to perform a positional and diametrical tuning of the laser beam parameters with the mode parameters of the cavity. Moreover, two external mirrors 24f align the cavity mode and laser beam axis directions. The laser beam 12 reflected by the cavity is redirected by the beam separator 24c on the diffraction array 26 thus allowing the scattering of the different spectral components in separate spatial directions. The signals of a plurality of photodiodes 28 acquire the different portions of the spectrum and are used for producing error signals transmitted to the electronic feedback control system 22. Description of the Fabry Perot Type Optical Cavity FIG. 3 represents a perspective view of an amplifying optical cavity 40 of the FABRY-PEROT type according to the invention. This cavity is provided with a closed enclosure 42 which is only partially represented as well as an ultrahigh vacuum ionic pump 44. The FABRY-PEROT cavity 40 comprises four independent mirrors, out of which two are plane mirrors M1 and M2, and two are spherical mirrors M3 and M4. It also includes an electron beam vacuum tube 46 traversing it on either side. The pulsed laser beam 12 is injected in the cavity 40 through the first plane mirror M1, then redirected towards plane mirror M2, then towards spherical mirrors M3 and M4 and back to plane mirror M1, to then repeat the same range. The total length travelled is referred to as LCAV. The aim of the ABRY PEROT cavity 40 is to cause laser beam 12 interact with an electron beam propagating within the electron beam tube 46. To this end, an arrangement and an orientation of mirrors M1 to M4 with respect to the electron beam tube 46 is as represented on FIGS. 4a and 4b. The centers of both planar mirrors M1 and M2 and of both spherical mirrors M3 and M4 define the vertexes of a tridimensional geometry shaped as a tetrahedron. With this configuration it is possible to stabilize the polarization of the natural modes of the FABRY PEROT cavity 40, thus, the intra cavity power. The tetrahedron shape is not necessarily smooth, so as to preserve the possibility to have different distances between the two spherical and the two planar mirrors. To note that the precision of the positioning and of the orientation of the mirrors is essential to cause pulsed laser beam 12 interact with the electron packets. Thus, each mirror M1 to M4 is supported by maintaining and positioning means SM1 to SM4 independent from each other, and having various settings. Thus, each mirror M1 to M4 exhibits a degree of freedom in terms of rotation around an axis X and a degree of freedom in terms of rotation around a substantially perpendicular axis Y. The angular settings ⊖x and ⊖y make it possible to align laser beam 12 within cavity 40. Each mirror M1 to M4 further exhibits a translation setting along the translation direction confounded with axis Z perpendicular to axes X and Y. the translation setting ΔZ between the two spherical mirrors M3 and M4 makes it possible to adjust the size of the beam, or waist, at the point of intersection with the electron beam while keeping length LCAV between both plane mirrors M1 and M2 constant. By means of a piezoelectric actuator (described later), plane mirror M2 could be displaced along its optical axis by some hundreds nanometers at frequencies of a few hundreds of Hertz so as to tune the length of the optical cavity 40 with the interval between two packets of the electron beam. According to an embodiment, it is possible to eliminate two translation settings along axis Z on one of the two plane mirrors and on one of the two spherical mirrors. A particularly advantageous solution would be to mount the piezoelectric actuator on one of the plane mirrors and the Z-axis translation means on the other plane mirror so as to avoid mechanical resonance. Description of the Actuators FIGS. 5a and 5b represent a cross-sectional and a perspective view of an actuator for moving mirrors M1 to M4. The maintaining and positioning means for maintaining and positioning mirrors M1 to M4 are actuated by means of twelve linear motors 50, preferably identical, encapsulated within a sealed enclosure 52 within which they operate at atmospheric pressure. Advantageously, this sealed enclosure 52 is made from stainless steel. Thus, the choice of the motor is no longer determined by its ability to operate under vacuum, but depends essentially on its mechanical characteristics and its positioning precision. Moreover, inside this enclosure 52, the use of grease between the moving parts becomes again possible. This system is developed in order to obtain a precise positioning over a stroke of about ±2 mm. According to a preferred embodiment, the motor operates at atmospheric pressure and only the exterior of the sealed enclosure 52 contacts the ultrahigh vacuum. The mechanical pieces involved in the transmission of the movement are isolated from ultrahigh vacuum by means of bellows 54. Thus, motor 50 is fixed on a support and the part to be translated is connected to the end of bellows 54. The part to be translated is not supported by the bellows 54, yet, it is only pushed via a point contact thanks to a ball located at the end of the motor shaft. Moreover, a return spring 56 makes it possible to counteract the force due to the vacuum and to keep a permanent point contact between the motor shaft and the part to be translated. In order to guarantee the contact quality, the ball bears on a hard steel pad. This contact may possibly be greased as it is positioned inside the sealed enclosure 52. The electrical connections of the motor are made through a sealed bushing located at the rear of the enclosure 52, from where originates a bundle 58 of individual wires, advantageously isolated by an ultrahigh vacuum Kapton sheath and provided with crimped connectors, eventually connected to the general enclosure 44 of the cavity by means of another similar sealed bushing. Description of the Mirror Orienting Member FIGS. 6a, 6b and 6c represent a perspective view and two right and left views of an orienting member 60 for orienting mirror M1; M2; M3; M4 which may be used to make an optical cavity according to the invention. For instance, according to an aspect of the invention, the maintaining and positioning means for maintaining and positioning mirrors M1 to M4 comprise an orienting member 60 for orienting mirror M1; M2; M3; M4 adopting the principle of a converging axes and central pivot dial. In this regard, mirror M1; M2; M3; M4 orienting member 60 includes 3 distinct portions, a top portion 60a, an intermediary portion 60b and a fixed portion 60c movable relative to each other through flexible hinges 64 made in a single and same mechanical piece. Flexible hinges 64 use the natural flexibility of the metal, and are obtained by creating a weakness point deformable while remaining in the elastic domain. As mentioned earlier, the rotation axes of the orienting member makes it possible to orient mirror M1; M2; M3; M4 around two directions X and Y perpendicular and converging at a crossing point 62, confounded with the center of the mirror M1; M4. With this principle it is possible to perform frictionless, clearance-free relative movements between two parts. Consequently, it is particularly adapted to guarantee a precise positioning under ultrahigh vacuum. The incidence angles of the laser beam 12 and mirrors M1 to M4 are relatively high as they are between 6 and 8°. The setting amplitudes of the orienting member 60 for orienting mirrors M1; M2; M3; M4 being low (±20 mrad), it is preferably convenient to provide this deviation from 6 to 8° over the mirrors orienting member 60. Thus, the offset is no longer on the means SM1 to SM4 for maintaining and positioning mirrors M1 to M4, but on orienting member 60. FIG. 7a illustrates a carriage 66 supporting mirror M1 to M4 orienting member 60. Mirrors M1 to M4 setting around axes X and Y is made through two connecting arms 68 connected to the upper part of orienting member 60. These mirrors M1 to M4 are actuated by two linear motors 50 positioned in their respective sealed enclosure 52 and supported by carriage 66. The length of connecting arms 68 allows a greater precision. FIG. 7b represents the accelerator tube 46 as seen in end view, two mirrors M3, M4 maintained in position by two carriages 66, as well as two connecting arms 68 each and an orienting member 60 each. As seen, in order to obtain the narrowest angle at the point of collision between laser 12 and the electron beam, it is advantageous that the spherical mirrors M3, M4 be positioned the closest possible to the electron beam tube 46. To this end, the maintaining and positioning means for maintaining and positioning both spherical optical reflectors M3, M4 have two complementary clearances 69, arranged so as to define a bay for the passage of the electron beam tube 46. Thus, both spherical optical reflectors are positioned on either side and in the vicinity of the electron beam tube. Description of the Translation Table The assembly composed of mirror M1 to M4 orienting member 60, both connecting arms 68 and both linear motors 50a, 50b actuating arms 68 is further advantageously positioned over a translation table 70 along the Z axis perpendicular to axes X and Y. Such a translation table 70 is represented by perspective and front views in FIGS. 8a and 8b. It comprises three balls 72, a metal sheet 74, two rails 76 and two supporting elements 78. The three balls 72 define a plane and provide a good prestressing-free stability. Two balls 72 out of the three roll between rails 74 and provide the translation direction, whereas the third ball 72 defines the translation plane. The displacement of supporting elements 78 is integrally made by frictionless rolling. The three balls 72 move at the same speed and a fine metal sheet 74 makes it possible to determine and maintain a spacing therebetween. Rails 76 are made from stainless steel and balls 72 may advantageously be made from the following materials: ceramics, ruby or stainless steel. If made from stainless steel as for the rails 76, then these balls must be processed through molybdenum disulphide scaling so as to avoid microbonding phenomena. The holding together of the two parts and the guiding efficiency is made possible thanks to the weight of the element to be displaced. The center of gravity of the element to be displaced is positioned as low as possible and located the as close as possible to that of the triangle formed by the three balls. FIG. 9 represents a perspective view of a translation table 70 mounted on a main support 80 and on which are disposed upper carriage 60, mirror orienting member 60, both motors 50 encapsulated within a sealed enclosure 52 for positioning around axes X and Y as well as a linear motor 50 also encapsulated within an enclosure 52 so as to allow the translation displacement of carriage 66 along axis Z. The assembly of the construction and the use of motors 50 encapsulated makes it possible to mount the four mirrors, with their independent settings, over main support 80 which becomes the only part contacting enclosure 42. This main support 80 connected to enclosure 42 by three very rigid points makes it possible to guarantee the geometrical stability between the four mirrors M1 to M4 of the cavity. With this construction it is also possible to isolate the cavity from external vibrations by restricting at the most the contact points with the enclosure. Thanks to the motors 50 it is also possible to adjust a distance from the cavity during the accelerator functioning. The Z-axis positioning motors are mounted over an Invar support (a 64% Iron and 36% Nickel alloy) of which thermal expansion coefficient is very low (2.69 μm/° C.) makes it possible to minimize the feedback-controls required to keep this length constant. Advantageously, these parts are made in a single mechanical piece so as to minimize the number of assemblies. Furthermore, the parts are voluntarily bulky so as to increase their inertia and limit the vibration propagation. To note that the length of the cavity, referred to as LCAV, is equal to the distance travelled by the laser between the four mirrors, that is, 1679.5 mm. Description of the Mirror Support Element with PZT In order to obtain a feedback-control between the cavity length and the distance between two electron packets, it is required to displace the lens of at least one of the plane mirrors M1 or M2 on its optical axis. With regard to a mirror M1 or M2 having a diameter of 25.4 mm and a thickness of 6 mm, the displacement to make is of about some hundreds of nanometers at frequencies of some hundreds of Hertz. FIG. 10 illustrates two perspective views, one of which being an exploded view, of an exemplary embodiment of a plane mirror M1; M2 supporting element 82 comprising a piezoelectric actuator 84. Advantageously, this supporting element 82 includes successively, a rear supporting element 86, the piezoelectric actuator 84, a piezoelectric actuator 84 prestressing ring 88, a plane mirror M1; M2 and a spring ring 90. It is advantageous to incorporate the piezoelectric actuator 84 on the means SM1; SM2 for maintaining and positioning this plane mirror M1; M2 so as to manage, with the required precision, the displacement of the plane mirror M1; M2 along the lens optical axis. Moreover, the spring ring 90 has mechanical characteristics affording it to deform when the three fixing screws are clamped. A precise mechanical calculation makes it possible to apply on the mirror, when the clamping is at its maximum (which further avoids loosening), a given holding stress, relating to the geometry of the flexible parts and to the mirror thickness. In order to obtain the prestress over the piezoelectric actuator 84, the same principle is used, involving, in this case, the prestressing ring 88 and the rear support 86. The plane mirror M1; M2 is fixed on the front of the prestressing ring 88 and the rear support 86 also allows the fixing of the supporting element 82 on the mirror M1, M2 orienting member. Such a configuration is advantageous in that the fixing of mirror M1; M2 is rigid such that it perfectly follows the movement, yet without a too great stressing force to avoid birefringence optical phenomena. It also allows the integration of the supporting element 82 on the mirror orienting member 48 while minimizing the weight of the moving parts so as to achieve the desired frequencies and amplitudes. The invention is not limited to the described and represented exemplary embodiments. For instance, the cavity may be used with other time periods, up to the femtosecond.
	claims	1. A diagnostic device for use in a communication network comprising network equipments, said device comprising:diagnostic means that are adapted to determine the cause of problems occurring within said network on the basis of information provided by said network equipments, the diaanostic means comprising;a knowledge base in the form of basic diagnostic units, andprocessing means comprising a rules engine adapted to establish hierarchical associations between basic diagnostic units selected in said knowledge base by means of selected rules to constitute configurable diagnostic models adapted to determine said causes of said problems. 2. The device claimed in claim 1 wherein at least some of said rules are of a statistical or probabilistic type. 3. The device claimed in claim 2 wherein said processing means are adapted to associate selected statistical or probabilistic weights with at least certain of said basic diagnostic units and/or at least certain of said rules and/or at least certain of said models. 4. The device claimed in claim 1 wherein said processing means are adapted to associate at least some of said basic diagnostic units by means of selected models. 5. The device claimed in claim 1 wherein said processing means are adapted to associate certain selected basic diagnostic units in selected trees constituting certain of said diagnostic models. 6. The device claimed in claim 1 wherein said processing means are adapted to associate selected administrative costs with at least certain of said basic diagnostic units and/or at least certain of said rules and/or at least certain of said models. 7. The device claimed in claim 1 wherein at least certain of said diagnostic models take the form of a Bayesian network. 8. The device claimed in claim 1 wherein at least certain of said basic diagnostic units take the form of a Bayesian network. 9. The device claimed in claim 1 wherein at least certain of said basic diagnostic units take the form of sets of hierarchical tests. 10. The device claimed in claim 1 wherein said processing means are adapted to modify at least certain of said basic diagnostic units and/or at least certain of said rules and/or at least certain of said models and/or .at least certain of said statistical or probabilistic weights and/or at least certain of said administrative costs. 11. The device claimed in claim 1 wherein said processing means comprise a man/machine interface adapted to enable a user to effect said associations and/or said modifications.
	abstract	A Hall thruster with a shared magnetic structure including a plurality of plasma accelerators each including an anode and a discharge zone for providing plasma discharge. An electrical circuit having one or more cathodes connected to the plurality of plasma accelerators emits electrons that are attracted to the anode in each of the plasma accelerators. A shared magnetic circuit structure establishes a transverse magnetic field in each of the plurality of plasma accelerators that creates an impedance to the flow of electrons toward the anode in each of the plurality of plasma accelerators and enables ionization of a gas moving through one or more of the plurality of plasma accelerators. The impedance localizes an axial electric field in the plurality of plasma accelerators for accelerating ionized gas through the one or more of the plurality of plasma accelerators to create thrust.
	summary
059149981	abstract	A method of generating an X-ray microbeam of the present invention generates an X-ray microbeam having a restricted divergence angle and desirable planeness in regions other than the focus. With this method, it is possible to compensate for a change in the degree of asymmetry ascriable to a change in the wavelength of X-rays selected, and therefore to maintain the degree of asymmetry constant. In addition, the condensing conditions including the energy of X-rays and beam size each can be set independently of the others. A device for practicing the above method is also disclosed.
	description	1. Field The disclosed and claimed concept relates generally to control circuitry and, more particularly, to an improved apparatus for detecting a position of a rod such as a drive rod that is movable within a passageway such as an interior of a drive rod housing within a nuclear containment. 2. Related Art Nuclear power plants are generally well known and can be said to include nuclear reactors that may typically be a Pressurized Water Reactors (PWRs) or Boiling Water Reactors (BWRs). Nuclear power plants having a PWR can generally be stated as comprising a reactor that includes one or more fuel cells, a primary loop that cools the reactor, and a secondary loop that drives a steam turbine which operates an electrical generator. Such nuclear power plants typically additionally include a heat exchanger between the primary and secondary loops. The heat exchanger typically is in the form of a steam generator which comprises tubes that carry the primary coolant and a plenum that carries the secondary coolant in heat-exchange relationship with the tubes and thus with the primary coolant. Alternatively, a BWR power plant typically operates at relatively lower pressures and temperatures and employs fuel cells that generate steam which is provided directly to a steam turbine. The nuclear reaction that occurs within a fuel cell typically is controlled by a number of control rods that are translatable into and out of the fuel cells in a known fashion. The control rods typically are operated by drive rods that are connected directly with the control rods and that are moveably situated within drive rod housings disposed above the fuel cells. Since the control rods control the reaction of the fuel cell, it is desirable to know the precise position of each control rod at all times. Previous systems for determining the positions of control rods have relied upon a plurality of detectors mounted outside and concentric with a drive rod housing, with the detectors each consisting of a coiled wire slipped over the housing and spaced along its length at regular intervals such as 3.75 inch intervals. As the drive rod moves past the coils, the magnetic flux from the coils changes, and the changing magnetic flux would be processed by signal processing systems. While such systems have been generally effective for their intended purpose, they have not been without limitation. The various coils have required cable assemblies and AC current to generate the needed electromagnetic field. Also, the accuracy of a detector having coils spaced as mentioned above is only within a range of 3.125 inches. It thus would be desirable to provide a simpler system that provides better accuracy. Accordingly, an improved apparatus for determining the position of a rod such as a drive rod within a passageway such as the interior of a drive rod housing includes a transmission antenna at one location on the housing and a receiving antenna at another location on the housing. An electromagnetic excitation signal sent to the transmission antenna is detected, at least in part, by the receiving antenna, and the received signal is processed with a vector network analyzer to model the drive rod housing as a wave guide having a filter response. In particular, a group delay is detected and is compared with a calibration data set which provides a current position of the drive rod that corresponds with the group delay. Accordingly, an aspect of the disclosed and claimed concept is to provide an improved apparatus for determining a current position of a rod that is moveable within at least a portion of a passageway. Another aspect of the disclosed and claimed concept is to provide such an apparatus that can be employed on a drive rod that is moveable within a drive rod housing within a nuclear containment. Another aspect of the disclosed and claimed concept is to provide an improved method for determining a current position of a rod that is moveable within at least a portion of a passageway. Another aspect of the disclosed and claimed concept is to provide an improved method for developing a set of calibration data that can be employed by an improved apparatus for determining a current position of a rod that is moveable within at least a portion of a passageway. These and other aspects of the disclosed and claimed concept are provided by an improved method of determining a current position of a rod that is movable within at least a portion of a passageway. The method can be generally stated as including transmitting an electromagnetic signal at a first location along the passageway, detecting as an input at least a portion of the electromagnetic signal at a second location along the passageway, determining a group delay of at least a portion of the input, and employing the group delay in conjunction with a calibration data set in determining a current position of the rod that corresponds with the group delay. Other aspects of the disclosed and claimed concept are provided by an improved method of generating a calibration data set that can be used for determining a current position of a rod that is movable within at least a portion of a passageway. The method can be generally stated as including transmitting a calibration electromagnetic signal at a first location along the passageway, moving the rod to each of a plurality of positions within the passageway, detecting as a plurality of calibration inputs at least a portion of the electromagnetic signal at a second location along the passageway for each of at least some of the plurality of positions of the rod within the passageway, determining a calibration group delay for each of at least some of the plurality of calibration inputs, and developing a calibration data set based at least in part upon the calibration group delays. The calibration data set is structured to provide a current position of the rod that corresponds with a group delay determined from an input in the form of a detection of at least a portion of an electromagnetic signal at the second location along the passageway when the electromagnetic signal has been transmitted at the first location along the passageway. Other aspects of the disclosed and claimed concept are provided by an improved apparatus for determining a current position of a rod that is movable within at least a portion of a passageway. The apparatus can be generally stated as including a processor apparatus, an input apparatus, and an output apparatus. The processor apparatus can be generally stated as including a processor and a memory. The input apparatus is in communication with the processor apparatus and can be generally stated as including at least a first transmission antenna structured to be situated at a first location along the passageway and at least a first receiving antenna structured to be situated at a second location along the passageway. The output apparatus is in communication with the processor apparatus. The memory has stored therein a number of routines including a signal analysis routine which, when executed on the processor, cause the apparatus to perform certain operations. The operations can be generally stated as including transmitting an electromagnetic signal from the at least first transmission antenna, detecting as an input at least a portion of the electromagnetic signal from the at least first receiving antenna, subjecting at least a portion of the input to the signal analysis routine to determine a group delay of the input, employing the group delay in conjunction with a calibration data set in determining a current position of the rod that corresponds with the group delay, and outputting the current position with the output apparatus. Similar numerals refer to similar parts throughout the specification. An improved apparatus 4 for detecting a position of a rod that is moveable within the interior of a passageway is depicted generally in FIGS. 1 and 2. In the exemplary embodiment depicted herein, the apparatus 4 is employed to detect an instantaneous position of a drive rod 8 that is moveable within the cylindrical interior of a drive rod housing 12 that is situated within a schematically represented nuclear containment 16. As is generally understood in the relevant art, the drive rod 8 is axially connected with the end of a control rod (not expressly depicted herein) that is reciprocated into and out of a fuel cell (not expressly depicted herein) within the nuclear containment 16 in order to control the nuclear reaction within the fuel cell. The drive rod housing 12 is depicted herein as including a connector 20 at its lower end that connects with the top of the Control Rod Drive Mechanism (CRDM). The apparatus 4 is schematically depicted in FIGS. 1 and 2 as comprising a processor apparatus 24, an input apparatus 28, and an output apparatus 32. The input apparatus 28 and the output apparatus 32 are connected with the processor apparatus 24. The processor apparatus 24 includes a processor 36 and a memory 40 that are connected together in a known fashion. The processor 36 can be any of a wide variety of processors such as microprocessors and the like without limitation. The memory 40 can be any of a wide variety of storage devices such as RAM, ROM, EPROM, EEPROM, FLASH, and the like without limitation, and such memory 40 may include an array of removable storage media without departing from the present concept. The memory 40 has stored therein a number of routines that are collectively referred to with the numeral 44 and which include a signal analysis routine 44 that performs functions such as those that are performed by known vector network analyzers. The routines can also include a correction routine 44 that applies a temperature-based correction factor to position results. Other routines 44 that perform other functions are also stored in the memory 44. The memory 40 further has stored therein a calibration set 48 and a correction data set 52 that are employed by the routines 44 to output an instantaneous, i.e., current, position of the drive rod 8 within the drive rod housing 12 in a fashion that will be set forth in greater detail below. Moreover, the calibration set 48 and the correction data set 52 can be obtained in any of a variety of fashions as will likewise be set forth in greater detail below. The input apparatus 28 depicted herein includes both a transmission component and a reception component. More particularly, at a first location along the longitudinal extent of the drive rod housing 12, the input apparatus 28 includes a primary transmission antenna 56 and a secondary transmission antenna 60 that are diametrically opposed to one another and that serve as the transmission component. In the exemplary embodiment depicted here, the first location is generally at the bottom of the drive rod housing 12 adjacent the connector 20. At a second location along the longitudinal extent of the drive rod housing 12, the input apparatus 28 further includes a primary receiving antenna 64 and a secondary receiving antenna 68 that are likewise diametrically opposed to one another that serve as the reception component. As can be understood from FIGS. 1 and 2, the exemplary second location is generally at the top of the drive rod housing 12. It is understood, however, that the first and second locations can be different than those expressly depicted herein without departing from the present concept. While in other embodiments the primary transition and receiving antennas 56 and 64 could be employed without additionally providing the secondary transition and receiving antennas 60 and 68, it is understood that the secondary transmission and receiving antennas 60 and 68 desirably serve as backup antennas in the event that one of the primary antennas may fail. That is, in the environment of a nuclear reactor, the failure of a probe could require a shutdown of a reactor if a backup probe is not also provided. Hence, the secondary transmission and receiving antennas 60 and 68 are provided at the same locations along an interior 70 of the drive rod housing 12 as the corresponding primary antennas, although being situated at positions diametrically opposed from the primary antennas. The input apparatus 28 further includes a temperature sensor 72. The temperature sensor 72 in the exemplary embodiment depicted herein is a resistive thermal device (RTD), but it may be of other configurations without departing from the present concept. In accordance with the disclosed and claimed concept, the signal analysis routine 44 generates and transmits from the primary and secondary transmission antennas 56 and 60 an excitation electromagnetic signal that propagates along the interior 70 of the drive rod housing 12 and is received, at least in part, by the primary and secondary receiving antennas 64 and 68. The excitation signal can be any of a wide variety of electromagnetic signals such as an amplitude modulated signal having a variety of frequency components, or any other type of appropriate signal. The interior 70 of the drive rod housing 12 functions as a wave guide for the excitation signal, and an input that is detected by the primary and secondary receiving antennas 64 and 68 is therefore in the nature of a signal that has been subjected to a high pass filter. That is, the signal analysis routine 44 generates the excitation electromagnetic signal for transmission by the primary and secondary transmission antennas 56 and 60, and when the signal is received by the primary and secondary receiving antennas 64 and 68, the detected signal appears to have been subjected to a high pass filter. This is the typical behavior of a wave guide as is generally known in the relevant art. The drive rod 8 possesses certain dielectric properties, and the coolant water that is disposed within the drive rod housing 12 and which is displaced by the drive rod 8 possesses other dielectric properties. It thus can be understood that the position of the drive rod 8 within the drive rod housing 12 affects the overall dielectric properties that exist between the first location (where the primary and secondary transmission antennas 56 and 60 are disposed) and the second location (where the primary and secondary receiving antennas 64 and 68 are disposed) along the drive rod housing 12. It is known that the dielectric properties of a wave guide can affect a cutoff frequency of the high pass filter behavior of the wave guide, as is indicated in Equation 1: f c = x mn ⁢ c 2 ⁢ π ⁢ ⁢ a ⁢ e r Equation ⁢ ⁢ 1 where fc is the cutoff frequency; where Xmn is the dominant TE11 mode excited in the wave guide; where c refers to the speed of light; where a refers to the radius of the wave guide; and where er refers to the dielectric coefficient. A group delay that is determined to exist in the signal detected by the primary and secondary receiving antennas 64 and 68 can be correlated to the cutoff frequency fc (from Equation 1) of a filter of a wave guide according to Equation 2: groupdelay = length c ⁢ 1 - c 2 2 ⁢ ⁢ a - f c Equation ⁢ ⁢ 2 where groupdelay refers to the group delay of an input signal; where length is a fixed value; where c refers to the speed of light; where a refers to the radius of the wave guide; and where fc is the cutoff frequency. It thus can be seen that an instantaneous, i.e., current, position of the drive rod 8 within the drive rod housing 12, which affects the dielectric coefficient between the first and second locations along the drive rod housing 12, can be correlated to a group delay of a signal that is transmitted from the first location and is received at the second location. As such, the calibration data set 48 provides a correlation between the group delay that is determined to exist in the signal detected at the primary and secondary receiving antennas 64 and 68 and the corresponding current position of the drive rod 8 within the drive rod housing 12. If the relationship between a given position of the drive rod 8 and the corresponding group delay is desired to be developed empirically, it may be desirable to calculate the particular dielectric coefficients er for each of a plurality of positions of the drive rod 8 along the drive rod housing 12 in order to calculate the group delay that corresponds with each such position of the drive rod 8. However, the relationship will likely be more accurately characterized if the calibration data set 48 is derived experimentally, i.e., if the drive rod 8 is disposed in a particular position within the drive rod housing 12, a correlation signal is detected by the primary and secondary receiving antennas 64 and 68, and a corresponding group delay is determined from the signal analysis routine 44. The particular position of the drive rod 8 and the determined corresponding group delay can then be added as a data point to the calibration data set 48 for subsequent retrieval. In this regard, it is noted that the calibration data set 48 can alternatively be in the nature of an algorithm that is developed from such data points and that can calculate rather than retrieve a drive rod position that corresponds with a given detected group delay. Moreover, when the reactor has been shut down and the drive rod housing 12 is partially filled with air instead of water, the air likewise has dielectric properties that are different from those of the drive rod 8 and the coolant water. It thus may be desirable to likewise develop an alternative calibration data set 84 wherein a relationship is established between the position of the drive rod 8 within the drive rod housing 12 and a corresponding group delay when the drive rod housing 12 is filled to a certain extent with air. It is also noted that the temperature of the environment within the drive rod housing 12 can affect the group delay that is determined to exist by the signal analysis routine 44. That is, for a given position of the drive rod 8 within the drive rod housing 12, the corresponding group delay can vary depending upon the temperature of the drive rod 8 and the liquid coolant within the interior 70. As such, additional temperature-directed data is stored in the correction data set 52 in order to generate and provide a correction factor which is applied to the current position of the drive rod 8 that is output by the signal analysis routine 44. That is, the input signal that is detected by the primary and secondary receiving antennas 64 and 68 is input to the signal analysis routine 44 which outputs a corresponding current position of the drive rod 8. Additionally, the temperature sensor 72 provides a temperature input to the correction routine 44, which employs the correction data set 52 to provide a temperature correction factor. The temperature correction factor is applied to the current position of the rod 8 that is output by the signal analysis routine 44 in order to generate a corrected current position of the rod 8. The corrected current position of the rod 8 is then output by the output apparatus 32 on, for instance, an output line 80 that is provided as an input to, for instance, a control system for the nuclear power plant, by way of example. It is understood that the correction data set 52 could also be in the form of a routine that calculates a correction factor based upon a temperature input rather than merely retrieving a corresponding correction factor from a database, for instance. It is also noted that the correction data set 52 may use more inputs than simply a temperature value from within the interior 70 of the drive rod housing 12 or from the vicinity of the drive rod housing 12. That is, other inputs such as pressure, time within the duty cycle of the fuel cell, the current position of the drive rod 8, and other inputs, by way of example, may be employed in establishing the correction factor that is applied to the current position of the drive rod 8 to determine the corrected current position of the drive rod 8. FIG. 3 depicts an exemplary flowchart that demonstrates certain aspects of an improved method of determining the position of the drive rod 8 in relation to the drive rod housing 12. Such position can be used to determine a position of a control rod, by way of example, within the nuclear containment 16. Processing begins, as at 106, where an electromagnetic excitation signal is produced from the primary and secondary transmission antennas 56 and 60 that are situated at first location along the interior 70 of the drive rod housing 12. At least a portion of the electromagnetic signal is detected, as at 110, as an input at the primary and secondary receiving antennas 64 and 68. As set forth above, the primary and secondary receiving antennas 64 and 68 are disposed at a second location along the interior 70 of the drive rod housing 12. A signal analysis routine 44 is then employed, as at 114, to determine a group delay of the input signal that is detected at 110. The group delay is then employed, as at 118, in conjunction with the calibration data set 48 in order to determine a current position of the drive rod 8 within the interior 70 of the drive rod housing 12. In this regard, it is noted that the interior 70 is in the nature of a passageway, and it is reiterated that the passageway functions as a wave guide for the excitation signal that is transmitted, as at 106, from the primary and secondary transmission antennas 56 and 60. The current position of the rod 8 can then be output by the output apparatus 32. As suggested above, a correction factor from the correction data set 52 may be applied to the current position in order to generate and output a corrected current position of the drive rod 8. As further suggested above, either such output can be provided to other control systems within the nuclear power plant and can be used for various purposes. It is reiterated that the position of the drive rod 8 is desirably known not only during operation of the nuclear power plant, but is also desirably known when the nuclear power plant has been shut down. That is, during operation of the nuclear power plant, the drive rod housing 12 typically will be filled with coolant water except as displaced by the drive rod 8 that is movably received within the interior 70 of the drive rod housing 12. However, when the nuclear power plant has been shut down, the interior 70 of the drive rod housing 12 may be partially or completely emptied of coolant water, with the drive rod 8 thus being at least partially surrounded by air or other gases. It thus would be desirable to have an alternative calibration data set 84 stored in the memory 40 that provides a correlation between group delay and position of the drive rod 8 when some or all of the coolant water has been removed from the interior 70 of the drive rod housing 12. In this regard, it likely will be necessary to derive or experimentally develop an entirely new calibration data set or algorithm since the dielectric properties of air are significantly different than those of the coolant water of a nuclear reactor. Regarding the development of the calibration data set 48 and the alternative calibration data set 84, FIG. 4 depicts a flowchart which generally shows certain aspects of improved method of experimentally developing the calibration data set 48. A similar methodology can be employed to develop the alternative calibration data set 84. Processing begins, as at 222, where a calibration electromagnetic excitation signal is transmitted from the primary and secondary transmission antennas 56 and 60. The calibration electromagnetic signal may be (and likely will be) the same as the excitation signal that is generated by the signal analysis routine 44. The drive rod 8 is then moved among each of a plurality of positions within the interior 70 of the drive rod housing 12, as at 226. For each such position of the drive rod 8, a calibration input is detected from the primary and secondary receiving antennas 64 and 68, as at 230. A calibration group delay is then calculated for each such calibration input, as at 234. The various calibration group delays are then employed, as at 238, in conjunction with the various positions of the drive rod 8 to develop the calibration data set 48, which is based upon the calibration group delays. As mentioned above, the calibration data set 48 can be either in the form of a routine 44 or in the form of a table such as a database, by way of example. It is reiterated that the aforementioned procedure may desirably be repeated for an alternative environment in which the reactor has been shut down and the interior 70 of the drive rod housing 12 is at least partially filled with air or other gases to develop the alternative calibration data set 84. FIG. 5 depicts certain aspects of the development of the correction data set 52 that are employed to provide a thermal correction factor that can be applied to the current position of the drive rod 8 that results solely from the calibration data set 48. Processing begins, as at 342, where the group delay is determined for a given position of the drive rod 8 at each of a plurality of temperatures within the interior 70 of the drive rod housing 12. While the temperature sensor 72 is depicted as being in direct communication with the interior 70, it is understood that an alternative embodiments the temperature sensor 72 may be otherwise positioned so that it detects the temperature in the vicinity of the drive rod housing 12. In this regard, any such temperature may be employed in developing the correction factor as long as the temperature can thereafter be detected during operation of the nuclear reactor in order to determine what the proper correction factor should be. In the flowchart of FIG. 5, the variation in temperature indicated at 342 is suggested to occur across a plurality of temperatures for the same position of the drive rod 8. In this regard, it is understood that since that the temperature of the reactor is likely to be more difficult to change than the position of the drive rod 8, the more likely scenario for the actual taking of data would be to cause the temperature in at least the vicinity of the drive rod housing 12 to change to a different temperature and then to move the drive rod 8 to each a plurality of positions and to determine the resultant group delay and record the corresponding temperature. Moreover, it is likely that a group delay need not necessarily be recorded for each incremental position of the drive rod 8 along the drive rod housing 12 at each different temperature. Rather, it may be sufficient to merely perform a limited number of determinations of group delay at a limited number of positions of the drive rod 8 along the drive rod housing 12 for a given temperature in order to gain an understanding of the relationship between temperature and group delay. That is, it is possible that the temperature correction factor may be based upon relatively simple data and/or algorithms that do not require the detailed measurement that is required in developing the calibration data set 48, although the potential for this will be apparent from the results of the experimental process. Processing continues, as at 346, where the various experimental data such as the change in group delay and the corresponding change in temperature are recorded. The data recorded at 346 can then be used to develop and store, as at 350, the correction data set 52 which, as set forth above, can be in the nature of an algorithm or can be in the nature of a data set stored in a table or database. The improved method and apparatus 4 thus advantageously enable the determination of a current position of the drive rod 8 within the drive rod housing 12, which can be used to determine the current position of a control rod within a fuel assembly of a nuclear power plant. The resulting apparatus 4 is less expensive to build and maintain and has greater accuracy than previously known systems. Further advantageously, the greater rod position accuracy that is afforded by the improved apparatus 4 can improve the efficiency of a reactor by reducing safety margins. Other advantages will be apparent to those of ordinary skill in the art. The present disclosure may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
063058421	claims	1. An X-ray examination apparatus comprising: an X-ray source and a diaphragm unit connected to the X-ray source, the diaphragm unit further comprising shutters for limiting a radiation cone beam emanating from a focal spot of the X-ray source, and a light source for generating a light cone beam which traverses the shutters via a reflector device, wherein the shutters include correction shutters which are transparent to X-rays but impervious to light and limit the light cone beam and two preferably adjustable pairs of shutter plates having pair-wise parallel shutter edges for limiting the radiation cone beam in two mutually perpendicular directions, wherein one of the correction shutters is connected to each shutter plate in such a manner that its edge extends parallel to the shutter edge and wherein the correction shutters connected to a pair of shutter plates are situated in mutually offset planes. an X-ray source and a diaphragm unit connected to the X-ray source, the diaphragm unit further comprising shutters for limiting a radiation cone beam emanating from a focal spot of the X-ray source, and a light source for generating a light cone beam which traverses the shutters via a reflector device, wherein the shutters include correction shutters which are transparent to X-rays but impervious to light and limit the light cone beam and two preferably adjustable pairs of shutter plates having pair-wise parallel shutter edges for limiting the radiation cone beam in two mutually perpendicular directions, wherein one of the correction shutters is connected to each shutter plate in such a manner that its edge extends parallel to the shutter edge, wherein the correction shutters connected to a pair of shutter plates are situated in mutually offset planes, wherein the focal spot of the X-ray source is inclined relative to the planes of the correction shutters, and wherein the offset between the planes of the correction shutters is chosen to be such that the asymmetry of the radiation cone beam, imposed by the inclination, is at least partly compensated for by a corresponding asymmetry of the light cone beam. 2. An X-ray examination apparatus comprising:
	summary
	summary
043080995	abstract	A safety system (10) for shutting down a nuclear reactor under overload conditions is provided using a series of parallel-connected computing modules (14a, 14b, 14c, 14d, 14e) each of which receives data on a particular reactor parameter (P, T, .phi..sub.T, .phi..sub.B, W) and each of which produces a function [f(P), f(T), f(.phi..sub.T), f(.phi..sub.B), f(W)] indicating the percentage of maximum reactor load that the parameter (P, T, .phi..sub.T, .phi..sub.B, W) contributes. The various functions [f(P), f(T), f(.phi..sub.T), f(.phi..sub.B), f(W)] are added together to provide a control signal (S) used to shut down the reactor under overload conditions.
	summary
	description	As shown in FIG. 1, a nuclear power station conventionally includes a reactor pressure vessel 10 with various configurations of fuel and reactor internals for producing nuclear power. For example, vessel 10 may include a core shroud 30 surrounding a nuclear fuel core 35 that houses fuel structures, such as fuel assemblies 40. Core 35 may be bounded vertically by top guide 45 and core plate 70. Fuel assemblies 40 may extend between and seat into core plate 70 and top guide 45, which may include several openings shaped to receive ends of assemblies 40. Other core structures, such as control elements and instrumentation tubes, may likewise extend through and/or between core plate 70 and/or top guide 45. One or more control rod drives 1 may be positioned below vessel 10 and connect to control rod blades or other control elements that extend among fuel assemblies 40 within core 35. An annular downcomer region 25 may be formed between core shroud 30 and vessel 10, through which fluid coolant and moderator flows into the core lower plenum 55. For example, in US Light Water Reactor types, the fluid may be purified water, while in natural uranium type reactors, the fluid may be purified heavy water. In gas-cooled reactors, the fluid coolant may be a gas such as helium, with moderation provided by other structures. The fluid may flow upward from core lower plenum 55 through core 35. In a boiling water-based reactor, a mixture of water and steam exits nuclear fuel core 35 and enters core upper plenum 60 under shroud head 65. Nuclear reactors are refueled periodically with new fuel to support power operations throughout an operating cycle. During shutdown for refueling, the vessel 10 is cooled, depressurized, and opened by removing upper head 95 at flange 90. With access to the reactor internals, equipment may be shifted or removed and some or all of fuel bundle assemblies 40 may be replaced and/or moved within core 35. Maintenance on other internal and external structures may be performed during such an outage. As shown in FIGS. 2A and 2B, one or more fuel support castings 48 may sit on and/or extend through core plate 70. Casting 48 may include several orifices 49 to receive fuel assemblies and/or control elements, aligning them with respect to one another and with core plate 70 and directing coolant up through such components. Casting 48 may accommodate several fuel assemblies in various orifices 49 while maintaining other space on core plate 70. For example, an instrumentation tube 50 may penetrate core plate 70 and be positioned next to casting 48, allowing tube 50 to extend vertically adjacent to several fuel assemblies positioned in casting 48. Similarly, one or more source holder penetrations 75 may extend into core plate 70 adjacent to casting 48. Source holder penetration 75 may hold a startup source, such as a sealed Californium or Plutonium-Beryllium isotope that emits substantial and detectable neutron spectra, which reliably begins the nuclear chain reaction in a new core with completely fresh fuel, or after excessively long shut-down periods when spontaneous fission is unreliable in burnt fuel. Co-owned “General Electric Systems Technology Manual,” Dec. 14, 2014, Chapter 5.1, describes helpful technological context and is incorporated by reference herein in its entirety. As seen in the top-down view of FIG. 2B, source holder penetration 75 may position the source in a desired static relation with instrumentation tube 50, permitting detection of neutrons from a source in penetration 75 to compare to neutrons generated through fission during startup, and fuel assemblies in casting 48. In this way, core plate 70 and casting 48 may radially/horizontally align several different core components at a base of a core and ensure they maintain desired positioning throughout an axial/vertical extent of the core. Example embodiments include holders for materials that are to be subject to irradiation in free core positions while sealed in a nuclear reactor core. Example embodiments can include lower and/or upper ends that mate with or otherwise join to reactor components to position holders within the core, in close proximity to neutron-generating fuel and moderator. Holders may robustly seal in irradiation targets and daughter products produced through irradiation with neutron flux, such as in internal cavities of any shape or size that houses desired targets. As an example, a holder may be shaped to minimally join with an existing core plate and/or fuel castings at a bottom of the core and span up to a top guide opening at a top of the core, resulting such an example holder being secured in, but easily removable from, the core at either end, while positioning the holder in an otherwise open space in the core. Such a space may be vacated by an unused startup source holder, for example. Irradiation targets may absorb neutron flux encountered at a position within the holder. Example methods include installing and irradiating target holders in operating nuclear reactors. Holders can be placed directly within a fuel core in example methods, without any structure between the holders and fuel and/or moderator, for higher irradiation by radiation encountered in the core during operation. For example, holders can be placed in positions vacated by conventional core components, and holders may be specifically shaped and dimensioned to be compatible with such positions. During operation, the installed holder may remain stationary within the core and generate larger amounts of desired daughter products through absorption and potentially radioactive decay without significantly contributing to reactivity where installed. Following an operational cycle of several months or other period of operation, the holders can be retrieved from the nuclear core without involvement with fuel or other core structures, yet holders may remain shielded in a moderator during such operations, allowing safer and easier handling and harvesting. Because this is a patent document, general broad rules of construction should be applied when reading and understanding it. Everything described and shown in this document is an example of subject matter falling within the scope of the appended claims. Any specific structural and functional details disclosed herein are merely for purposes of describing how to make and use example embodiments or methods. Several different embodiments not specifically disclosed herein fall within the claim scope; as such, the claims may be embodied in many alternate forms and should not be construed as limited to only example embodiments set forth herein. It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will be understood that when an element is referred to as being “connected,” “coupled,” “mated,” “attached,” or “fixed” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between”, “adjacent” versus “directly adjacent”, etc.). Similarly, a term such as “communicatively connected” includes all variations of information exchange routes between two devices, including intermediary devices, networks, etc., connected wirelessly or not. As used herein, the singular forms “a”, “an” and “the” are intended to include both the singular and plural forms, unless the language explicitly indicates otherwise with words like “only,” “single,” and/or “one.” It will be further understood that the terms “comprises”, “comprising,”, “includes” and/or “including”, when used herein, specify the presence of stated features, steps, operations, elements, ideas, and/or components, but do not themselves preclude the presence or addition of one or more other features, steps, operations, elements, components, ideas, and/or groups thereof. It should also be noted that the structures and operations discussed below may occur out of the order described and/or noted in the figures. For example, two operations and/or figures shown in succession may in fact be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Similarly, individual operations within example methods described below may be executed repetitively, individually or sequentially, so as to provide looping or other series of operations aside from the single operations described below. It should be presumed that any embodiment having features and functionality described below, in any workable combination, falls within the scope of example embodiments. Applicants have recognized that most methods for generating materials through neutron capture in a nuclear reactor insert irradiation targets into fuel or instrumentation tubes, or form irradiation targets as existing core structures like control blades. Applicants have recognized that these methods tend to tie generation to reactor operations, requiring the targets to be moved and harvested with fuel, or require complex configurations to interact with instrumentation tubes or existing core structures. Applicants have further newly identified that startup holder positions in most nuclear reactors have a distinct functionality that is no longer needed following operation of the reactor. To overcome these newly-recognized problems as well as others, the inventors have developed methods and systems that independently place irradiation targets directly into a nuclear fuel core without impacting fuel or other core structures or operation. These methods and systems may provide new functionality to startup holder positions and other core locations available during operation. The present invention is irradiation target holders for use in a nuclear reactor and methods of using the same. In contrast to the present invention, the few example embodiments and example methods discussed below illustrate just a subset of the variety of different configurations that can be used as and/or in connection with the present invention. FIG. 3 is an illustration of an example embodiment incore irradiation target holder 100. As shown in FIG. 3, holder 100 may span core 35 in a vertical or axial dimension between core plate 70 and top guide 45, irrespective of other core internals. For example, holder 100 may be shaped and sized to fit among several fuel assemblies, instrumentation tubes, control elements, etc. typically found in a nuclear core. Although example embodiment holder 100 is shown spanning an entire vertical distance from core plate 75 to top guide 45, it is understood that partial extension is possible with proper connections. As shown in FIG. 3, example embodiment incore irradiation target holder 100 is configured to insert into—to securely mate with—a source holder penetration 75 in core plate 70. For example, source holder penetration 75 may be an existing hole or other aperture in core plate 75 into which a startup source holder is originally placed and later removed by the plant operator or other servicer; or for example, source holder penetration 75 may be a penetration never used for any purpose or made ad hoc during an outage or other period of access to core 35. Source holder penetration 75 may be one or more inches deep with an approximate one-inch diameter and may extend entirely or partially through core plate 70. Source holder penetration 75 may be placed in other structures besides a core plate 70; however, placement of source holder penetration 75 provides vertical clearance above penetration 75 that is not blocked by other core internals such as fuel assemblies, fuel castings, instrumentation, flow devices, etc. common to nuclear cores. Example embodiment holder 100 may seat into penetration 75 through gravity, operator insertion, and/or under the force of a spring or other retention lock or mechanism during both installation and operation. For example, holder 100 may screw into penetration 75, lock into the same through a tang-and-mating, or simply sit through gravity in penetration 75. As such, an axially lower end of example embodiment holder 100 may be specifically shaped, sized, or otherwise configured to match a desired penetration 75 for insertion. As shown in FIG. 3, if example embodiment holder 100 runs a vertical length of core 35 holder 100 may seat into a top hole 145 in top guide 45. For example, in a boiling water reactor, core 35 may be approximately 13 feet or longer, and holder 100 may extend all or any of this distance. Top hole 145 may be similar to source holder penetration 75 in that it may be preexisting or newly formed. Top hole 145 may be aligned and pre-purposed for retaining a startup source holder in conjunction with penetration 75 in core plate 70. Example embodiment holder 100 may seat into top hole 145 through operator insertion. As such, an axially higher end of example embodiment holder 100 may be specifically shaped, sized, or otherwise configured to match a desired top hole 145 for insertion and retention. Holder 100 may be under the force of a spring or bias or other locking mechanism provided during installation and/or operation. For example, holder 100 may seat into top hole 145 due to a spring in penetration 75 biasing example embodiment holder 100 upward vertically into hole 145. A spring in top hole 145 may similarly bias example embodiment holder 100 downward axially into opposite penetration 75, permitting a desired degree of axial securing. Example embodiment incore irradiation target holder 100 may further include one or more casting fins 110 that extend radially—horizontally—or otherwise with respect to core 35 to mate with fuel castings nearby. As shown in FIG. 4, a simplified detail of a base of example embodiment holder 100, fins 110 may be captured by a side of fuel casting 48. For example, fuel casting 48 may include a slot configured to receive a part of a startup source holder or other core component, and fin 110 may be shaped and sized to fit within such a slot. Holder 100 may include, for example, four perpendicular fins 110 that insert into up to four adjacent castings 48. Example embodiment holder 100 may thus seat between and into several adjacent casting 48 that anchors one or more fuel assemblies 40, such that holder 100 is positioned adjacent to assemblies 40 extending upward in a vertical or axial direction. While penetration 75 and hole 145 may provide axial securing to holder 100 shaped to seat therein, fins 110 shaped to seat into an adjacent casting 45 may provide rotational securing and/or prevent radial translation of holder 100. Fins 110 may lock into or removably seat in casting(s) 48 at other angles and positions in order to orient holder 100 at other positions and/or mate with other structures entirely to take advantage of other existing spaces and securing penetrations within a nuclear core. Similarly, example embodiment holder 100 may include any or neither of fins 110 and an end seating into penetration 75 (FIG. 3) to achieve a desired positioning and level of securing within a nuclear core. Through the above-described example features, an example embodiment holder 100 may include any number of retaining features that are very similar to existing structures in startup holders that mate with other core features like a core plate and top guide, in order to replace the same without modification and/or disruption of existing core features. An operator or other servicer may install example embodiment holder 100 during an outage or other access period in combination with such existing core features. For example, a reactor may be operated for a period of months or years to sustain a nuclear chain reaction that generates heat that is in turn converted to electricity. The reactor may then be shut down by terminating the nuclear chain reaction, and operators can access the reactor internals for maintenance and refueling. During such an outage, reactor internals, one or more fuel assemblies 40, and potentially any unnecessary startup source may be removed and/or shuffled within the core, and fresh fuel may be added. In the same timeframe, example embodiment holder 100 may be installed where the startup source was or would have been within the nuclear core. The reactor may then be brought back to operation to sustain the nuclear chain reaction and irradiation inherent therein, and example embodiment holder 100 may remain in the installed position during such operation and irradiation and retrieved at a later time, such as during a subsequent outage. As shown in FIG. 3, example embodiment holder 100 may include an internal cavity 150 that houses one or more irradiation targets 151 that convert to a desired daughter product when exposed to radiation in an operating nuclear reactor. For example, internal cavity 150 may be an integrally-formed housing within holder 100 into which an irradiation target 151 may be inserted at fabrication and removed through destruction of holder 100. Similarly, internal cavity 150 may be selectively opened and/or segmented to allow segregation of multiple desired targets at differing positions and nondestructive removal. Compatible designs of fuel rod bodies and irradiation target holders are shown in co-owned patent publications 2009/0122946 published May 14, 2009 to Fawcett et al.; 2009/0135983 published May 28, 2009 to Russell, II et al.; and 2009/0274260 published Nov. 5, 2009 to Russell, II et al., which are useable as central portions of example embodiment holder 100, these publications being incorporated herein in their entireties. Example embodiment incore irradiation target holder 100 may otherwise be fabricated of materials that substantially maintain their physical properties in an operating nuclear reactor environment so as to preserve positioning and containment of irradiation targets 151 retained in internal cavity 150. For example, holder 100 may be fabricated of stainless steel, a zirconium alloy, and aluminum alloy, etc. If fuel casting 48, core plate 70 and/or tope guide 45 are fabricated of one material, such as stainless steel, example embodiment holder, at least in structures that directly contact these core structures, may be another material, such as zirconium alloys, in order to enhance material compatibility and eliminate voltaic potential and fouling. Such materials may further have minimal impact on radiation, having minimal scattering and absorption cross-sections for neutron flux encountered in a reactor. Example embodiment holder 100 may match geometries of startup source holders at vertical ends, so as to mate with existing core structures that retain such startup holders; however, the remainder of holder 100 may be any shape that maximizes desired daughter material production in core 35. For example, as shown in the cross-section of FIG. 5A, internal cavity 150 may be round, or as shown in FIG. 5B, cruciform. Internal cavity 150 may similarly be helical, square, planar, etc. and extending in any degree in a horizontal position in order to accommodate irradiation targets 151 of a matching shape and/or maximize radiation exposure at desired positions within a nuclear fuel core. Internal cavity 150 may further include a moderator and/or coolant such as a liquid water reservoir 152 shown in FIG. 5A or other structure that enhances geometry, irradiation, and/or cooling of any irradiation targets 151 contained in example embodiment holder 100. Example embodiment holder 100 may be relatively small, such as cylindrical as shown in radial cross-section in FIG. 5A and approximately half to a full inch in diameter. If holder 100 is up to 13 feet in axial length and spans an entire vertical length of core 35, internal cavity 150 may be approximately 8 feet in axial length to match lengths of fueled sections of the core. Even this smaller example sizing may accommodate, for example, 250 cubic centimeters of irradiation targets. Or for example, as shown in radial cross-section in FIG. 5B, with a larger cruciform cavity 150, 1-2 inches in total arm length, 570 cubic centimeters of irradiation targets may be accommodated. Depending on the parent irradiation target, these sizes may enable several thousands of curies of activity for a produced radioisotope or several moles of atoms of a produced isotope from a parent material and sufficient irradiation. As shown in FIG. 3, source holder penetration 75 and/or top hole 145 may be intentionally positioned within core 35 to receive a startup source holder, and thus either or both penetration 75 and top hole 145 may be free post-startup or in the event such startup sources are not used at startup. Penetration 75 and top hole 145 may further provide an open passage between the two for accommodating a startup source holder, providing close proximity to fuel elements or fuel assemblies 40 (FIG. 4) generating large amounts of neutron flux during operation. This open passage may typically be readily accessible with fuel out during refueling outages every 2-3 years, and this passage may typically be underwater or otherwise shielded with fuel. Based on the above characteristics of existing source holder penetrations 75 and/or top holes 145, example embodiment incore irradiation target holder 100 may take advantage of vacated passages between holder penetration 75 and top hole 145 following startup to generate desired daughter products from irradiation targets, including industrially-valuable elements and radioisotopes. Particularly, in the case of parent material Cobalt-59, significant irradiation with thermal neutrons for an operating cycle in holder 100 placed between bundles in a typical startup holder position within a nuclear core will generate large amounts of Cobalt-60, which is medically useful for its high-energy gamma rays. Of course, other irradiation targets, like iridium-193 or any other non-fissionable isotope with an atomic number under 90 and an appreciable thermal neutron absorption cross-section, such as a cross-section exceeding one barn, are useable as irradiation targets in example embodiments. Accessing such a holder 100 may be relatively simple during fuel movements in an operational outage, when source holder locations can be readily exposed through fuel moves. Advantageously, holder 100 may be entirely separate from any fuel in the core and shielded from operators during such accessing by a moderator such as coolant light water or other shield. This permits easy and safe handling of example embodiment holder 100 in a fuel core without involvement with nuclear fuel. FIG. 6 is a graph showing improved yields from use of example embodiment holder 100 at existing source holder penetrations 75 and/or top holes 145 between fuel assemblies compared to an expected best-yield at a corner fuel rod in a fuel assembly. FIG. 6 reports activation levels in Curies per gram of irradiation target versus axial level for two different positions within a same simulated core with all other variables constant. As shown in FIG. 6, over the same amount of time in the same core, the example embodiment holder containing a same mass of Cobalt-59 irradiation targets will achieve higher activation—a higher percentage of nuclides converted to Cobalt-60—when positioned between fuel assemblies at a source holder location as compared to a corner rod position in a fresh fuel bundle. This improvement is seen at every axial position, due to improved moderator and neutron flux access at the source holder positions with which example embodiments are compatible. Example embodiments and methods thus being described, it will be appreciated by one skilled in the art that example embodiments may be varied and substituted through routine experimentation while still falling within the scope of the following claims. For example, a variety of different available source holder locations, in several different types of reactor designs, are compatible with example embodiments and methods simply through proper dimensioning of example embodiments—and fall within the scope of the claims. Such variations are not to be regarded as departure from the scope of these claims.
	abstract	Non-destructive testing method may include providing a source material that emits positrons in response to bombardment of the source material with photons. The source material is exposed to photons. The source material is positioned adjacent the specimen, the specimen being exposed to at least some of the positrons emitted by the source material. Annihilation gamma rays emitted by the specimen are detected.
	description	This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2003-63723 filed on Mar. 10, 2003; the entire contents of which are incorporated herein by reference. The present invention relates to steam turbine plant. More specifically, the invention relates to steam turbine plant for power generation, which is provided with a feedwater heater in a steam condenser. A steam turbine plant includes steam generator, high pressure turbine, a plurality of low pressure turbines. The steam turbine plant further includes a plurality of steam condensers which condense steam from the plurality of low pressure turbines and a plurality of low pressure feedwater heaters which are provided within the steam condensers as the structural elements respectively. A feedwater heater which is provided within a steam condenser is also called as a neck heater, since the feedwater heater is installed at an upper (neck) portion of the steam condenser. The low pressure feedwater heaters constitute a plurality of feedwater heating lines which are arranged and connected in parallel. The steam turbine plant has a plurality of high pressure feedwater heaters which heat a feedwater from the low pressure feedwater heaters by steam bled from the high pressure turbine. Each of the steam condensers are connected to each of adjacent steam condensers by a connection shell. The steam condensers, the feedwater heating lines which are provided with the low pressure feedwater heaters arranged and connected in parallel, the high pressure feedwater heaters and steam generator are connected in series by feedwater line. The low pressure feedwater heaters use bled steam from low pressure turbines as a heating source of the feedwater. Generally, tiers of low pressure feedwater heaters arranged in series in the feedwater heating lines increase, the amount of heat exchanged in the low pressure feedwater heater also increases, which may contribute to high efficiency in view of thermal or plant efficiency. Moreover, when the low pressure feedwater heaters are installed inside of the steam condensers to save space of the steam turbine plant, it is desirable to reduce pressure drop of the steam discharged from the low pressure turbines and flowing around the low pressure feedwater heaters. For this reason, a neck heater type of structure is adopted for the steam condensers of conventional steam turbine plant. The neck heater type of structure is that the low pressure feedwater heaters are installed and arranged inside of the steam condensers at neck portions, which are a space above a portion where the steam discharged from the low pressure turbines condenses in the steam condensers. Therefore, in conventional steam turbine plant, which includes n units of casings, n units of low pressure turbines and n units of steam condensers, constitute n pieces of the feedwater heating lines inserted in series to the feedwater line respectively. Each of the feedwater heating lines has a same number of the low pressure feedwater heaters, which are connected in series, inside of the steam condensers. The same numbers of the low pressure feedwater heaters are arranged in each of the steam condensers. Additionally, since each of the steam condensers are connected to the adjacent steam condenser by connection shell, differences of pressure distribution among the steam condensers are mitigated. Nevertheless, since each of the low pressure feedwater heaters are connected with the bleeding lines, which extend from the casings of the low pressure turbines as a heating source, space of the neck portion of the steam condensers is relatively small. Especially, the bleeding lines have a large diameter for the low pressure feedwater heaters, which are provided at an upstream side of the feedwater heating lines, because the feedwater heaters at an upstream side of the feedwater heating lines employs the steam bled from a downstream side of the low pressure turbines as the heating source. This causes difficulty in planning such a steam turbine plant, especially in designing an arrangement of bleeding lines, feedwater heating lines or supports of these bleeding lines or low pressure feedwater heater at the neck portions. And it may result in necessity of further internal structure inside the steam condensers. This may cause necessity of enlarging space for the plant itself. And it may cause not only increase of costs but also pressure drop of the steam flowing inside of the steam condensers, which may effects reduction of the plant efficiency. From a viewpoint of the feedwater, the feedwater line has feedwater heating lines whose number is the same as the steam condensers and which are arranged in parallel in conventional steam turbine plant. However, in order to avoid unbalance of the feedwater among the feedwater heating lines, it is desirable to provide less numbers of feedwater heating lines, which may contribute to increasing redundancies of controls of the steam turbine plant, especially for nuclear power plant. Accordingly, an advantage of an aspect of the present invention is to provide a steam turbine plant which has less internal structure, e.g. The low pressure feedwater heaters, bleeding lines or so on, inside the steam condensers. To achieve the above advantage, one aspect of the present invention is to provide a steam turbine plant that comprises a steam generator, a plurality of low pressure turbines being driven by steam from the steam generator, a plurality of steam condensers to condense the steam from the low pressure turbines into condensed water, a feedwater line which supplies the condensed water to the steam generator as feedwater, the feedwater line including a plurality of feedwater heating lines connected in parallel, a number of feedwater heating lines being less than a number of steam condensers, and a plurality of low pressure feedwater heaters, wherein each of the feedwater heating lines includes at least one low pressure feedwater heater provided in at least one of the steam condensers to heat the condensed water by steam bled from the low pressure turbines. Another aspect of the present invention is to provide a steam turbine plant that comprises a steam generator, a plurality of low pressure turbines being driven by steam from the steam generator, a plurality of steam condensers to condense the steam from the low pressure turbines into condensed water, a feedwater line which supplies the condensed water to the steam generator as feedwater, the feedwater line including a plurality of first feedwater heating lines connected in parallel and a plurality of second feedwater heating lines connected in parallel and coupled to the downstream side of the first feedwater heating lines, a first number of first feedwater heating lines being different than a second number of second feedwater heating lines, and a plurality of low pressure feedwater heaters, wherein each of the first and second feedwater heating lines includes at least one low pressure feedwater heater provided in at least one of the steam condensers to heat the condensed water by steam bled from the low pressure turbines. Another aspect of the present invention is to provide a steam turbine plant that comprises a steam generator, a plurality of low pressure turbines being driven by steam from the steam generator, a plurality of steam condensers to condense the steam from the low pressure turbines into condensed water, a feedwater line which supplies the condensed water to the steam generator as feedwater, the feedwater line including a plurality of feedwater heating lines connected in parallel and a plurality of low pressure feedwater heaters, wherein each of the feedwater heating lines includes at least one low pressure feedwater heater provided in at least one of the steam condensers to heat the condensed water by steam bled from the low pressure turbines, and wherein a first number of low pressure feedwater heaters provided in a first steam condenser is different than a second number of low pressure feedwater heaters provided in a second steam condenser. In accordance with the aspect of the present invention, feedwater heating lines provided inside of the steam condensers are reduced so that space efficiency inside the steam condensers are improved and that the costs for a construction of the steam turbine plant are also reduced. First embodiment in accordance with the present invention will be explained with reference to FIG. 1 to FIG. 14. FIG. 1 is a schematic diagram of a steam turbine plant in accordance with the present invention, which includes n units of low pressure turbines, n units of casings, and n units of steam condensers. Steam generator 1, which is connected with a heating source (not shown), for example nuclear reactor or boiler, generates steam. The steam passes through high pressure turbine 2 and steam line 9, then lead to a plurality of casings 12a, 12b, 12c, . . . and 12n of low pressure turbines 3a, 3b, 3c, . . . and 3n. Generally, the number of low pressure turbines 3a, 3b, 3c, . . . and 3n are more than or equal to three (3). Each of low pressure turbines 3a, 3b, 3c, . . . and 3n are installed in casings 12a, 12b, 12c, . . . and 12n, whose number is also the same as the number of low pressure turbines 3a, 3b, 3c, . . . and 3n. The steam led to each of the casings 12a, 12b, 12c, . . . and 12n drives each of low pressure turbines 3a, 3b, 3c, . . . and 3n. The steam is then discharged from low pressure turbines 3a, 3b, 3c, . . . and 3n to each of steam condensers 4a, 4b, 4c, . . . and 4n as discharged steam. Each of steam condensers 4a, 4b, 4c, . . . and 4n are placed beneath each of low pressure turbines 3a, 3b, 3c, . . . and 3n and are connected with each of the casings 12a, 12b, 12c, . . . and 12n. Each of the steam condensers 4a, 4b, 4c, . . . and 4n are connected to each of adjacent steam condensers 4a, 4b, 4c, . . . and 4n by a connection shell 11. In steam condensers 4a, 4b, 4c, . . . and 4n, the discharged steam is cooled down and condenses into water as a condensed water (condensate). The condensed water (condensate) is gathered and led to feedwater line 8. In feedwater line 8, condensate pump 5 (pressurizer) give pressure to the condensed water (condensate) as a feedwater. The feedwater is led to low pressure feedwater heaters 6a, 6b, 6c, . . . and 6(n-1) and is heated up. The feedwater, after heated up in low pressure feedwater heaters 6a, 6b, 6c, . . . and 6(n-1), is further pumped up by feedwater pump 20 (pressurizer) as a high pressure feedwater pump. The feedwater pumped up to high pressure by feedwater pump 20 (pressurizer) then led to high pressure feedwater heaters 7a and 7b in feedwater line 8. In high pressure feedwater heaters 7a and 7b, the feedwater is further heated up and then supply to steam generator 1 from feedwater line 8. In this manner, the steam turbine plant constitutes closed-loop as a Rankine Cycle. Bled steam for low pressure feedwater heaters 6a, 6b, 6c, . . . and 6(n-1) is taken out from the middle of low pressure turbines 3a, 3b, 3c, . . . and 3n. The bled steam is led to bleeding lines 10a, 10b, 10c, . . . and 10(n-1) as bleeding steam lines from an opening provided in the casings 12a, 12b, 12c, . . . and 12(n-1) of low pressure turbines 3a, 3b, 3c, . . . and 3(n-1). Each of bleeding lines 10a, 10b, 10c, . . . and 10(n-1) are connected to each of feedwater heaters 6a, 6b, 6c, . . . and 6(n-1) High pressure feedwater heaters 7a and 7b are employ bled steam from high pressure turbine 2 or from steam line 9 as a heating source (not shown). Low pressure feedwater heaters 6a, 6b, 6c, . . . and 6(n-1) are shell and tube type heat exchangers. The shell and tube type heat exchangers are constituted by a shell and a plurality of tubes arranged inside the shell. Feedwater is passed through the tubes and exchanging heat, while the steam for heating is led to a shell side of the shell and tube type heat exchanger. Low pressure feedwater heaters 6a, 6b, 6c, . . . and 6(n-1) are installed inside a neck portion of steam condensers 4a, 4b, 4c, . . . and 4(n-1) to improve a space efficiency. The neck portion is a space above a portion where the steam that passed through low pressure turbines 3a, 3b, 3c, . . . and 3n condenses in each of steam condensers 4a, 4b, 4c, . . . and 4n. Thus, low pressure feedwater heaters 6a, 6b, 6c, . . . and 6(n-1) are arranged inside the space of steam condensers 4a, 4b, 4c, . . . and 4(n-1). Steam condensers 4a, 4b, 4c, and 4n are closely arranged each other. (n-1) units of low pressure feedwater heaters 6a, 6b, 6c, . . . and 6(n-1) are provided inside steam condensers 4a, 4b, 4c, . . . and 4(n-1). Feedwater line 8 includes a plurality of feedwater heating lines 6A, 6B, 6C, . . . and 6(N-1). Each of the feedwater heating lines 6A, 6B, 6C, . . . and 6(N-1) has one of low pressure feedwater heaters 6a, 6b, 6c, . . . 6(n-1) respectively. Low pressure feedwater heaters 6a, 6b, 6c, . . . 6(n-1) are arranged and connected in parallel inside of steam condensers 4a, 4b, 4c, . . . and 4n. Feedwater heating lines 6A, 6B, 6C, . . . and 6(N-1) are provided between condensate pump 5 (pressurizer) and high pressure feedwater pump 20 (pressurizer) in feedwater line 8. Feedwater lines 8 includes feed water heating lines 6A, 6B, 6C, . . . and 6(N-1) as a constituent elements. Feedwater heating lines 6A, 6B, 6C and 6N are seriesly inserted in feedwater line 8 as a whole. Each of feedwater heating lines 6A, 6B, 6C, . . . and 6(N-1) may have a plurality of low pressure feedwater heaters arranged and connected in series. In this case, all of steam condensers 4a, 4b, 4c, . . . and 4n may have at least one of low pressure feedwater heaters, and the number of the low pressure feedwater heaters may be greater than the number of steam condensers 4a, 4b, 4c, . . . and 4n. There is a less number of the feedwater heating lines, which are connected in parallel and inserted in series in feedwater line 8, than the number of steam condensers 4a, 4b, 4c, . . . and 4n. The number of the feedwater heating lines may be one (1) or more, but is less than the number of steam condensers 4a, 4b, 4c, . . . and 4n. Bleeding steam lines 10a, 10b, 10c, and 10(n-1) may be connected to any of casings 12a, 12b, 12c, and 12n of low pressure turbines 3a, 3b, 3c, . . . and 3n. According to this embodiment, the number of the low pressure feedwater heaters disposed inside of steam condenser 4a, 4b, 4c, . . . and 4n are lessened compared with a conventional steam turbine plant. In order to keep the amount of heat exchanged in the low pressure feedwater heaters at a preferable level, each of low pressure feedwater heaters 6a, 6b, 6c, . . . and 6(n-1) may be enlarged in size to increase the amount of heat. However, internal structures, such as bleeding lines, of steam condensers 4a, 4b, 4c, . . . and 4n maybe lessened to improve pressure drop of the steam inside steam condensers 4a, 4b, 4c, . . . and 4n. And the size of steam condensers 4a, 4b, 4c, . . . and 4n may be reduced. Some detailed configurations of the first embodiment having three (3) units of the low pressure turbines, the casings and the steam condensers are explained below with reference of FIGS. 2 to 14. FIGS. 2 to 7 are schematic diagrams of a detailed configuration of the first embodiment of a steam turbine plant in accordance with the present invention, including three (3) units of low pressure turbines, three (3) units of casings, and three (3) units of steam condensers. FIG. 2 especially features an arrangement of feedwater heaters inside steam condensers. The number of the casings 12a, 12b and 12c of steam turbine 3a, 3b and 3c is three (3). Each of the casings 12a, 12b and 12c is connected with each of steam condensers 4a, 4b and 4c respectively. As described in FIG. 2, feedwater line 8 is divided into two (2) parallel feedwater heating lines 6A and 6B at a downstream side of condensate pump 5 (pressurizer) in feedwater line 8. Low pressure feedwater heaters 6a1 to 6a4 are connected in series in feedwater heating line 6A, while low pressure feedwater heaters 6b1 to 6b4 are connected in series in feedwater heating line 6B. Low pressure feedwater heaters 6a1 to 6a4 and 6b1 to 6b4 are neck heaters, which are disposed inside of steam condensers 4a, 4b and 4c. Each four (4) of low pressure feedwater heaters 6a1 to 6a4 and 6b1 to 6b4, which are connected in series in either of feedwater heating lines 6A or 6B, are dispersed in two (2) of steam condensers 4a, 4b and 4c. Steam condenser 4a accommodates low pressure feedwater heaters 6a1, 6a2 and 6a3 as neck heaters. Steam condenser 4b accommodates low pressure feedwater heaters 6a4 and 6b4 as neck heaters. Steam condenser 4c accommodates low pressure feedwater heaters 6b1, 6b2 and 6b3 as neck heaters. Feedwater heating lines 6A and 6b are merged into one at an upstream side of high pressure feedwater pump 20 in feedwater line 8. The feedwater, from steam condensers 4a, 4b and 4c, is divided into two flows and is led to each of feedwater heating lines 6A and 6B. In feedwater heating line 6A, The temperature of the feedwater rises as the feedwater flow through low pressure feedwater heaters 6a1, 6a2, 6a3 and 6a4 in this order. In the same manner, the temperature of the feedwater rises as the feedwater flows through low pressure feedwater heaters 6b1, 6b2, 6b3 and 6b4 in this order in feedwater heating line 6B. As a heating source, steam bled from low pressure steam turbine 3a, 3b and 3c are introduced to low pressure feedwater heater 6a1 to 6a4 and 6b1 to 6b4. Connections of bleeding lines are explained with reference to FIGS. 3 to 7. FIG. 3 is a schematic diagram of a detailed configuration of the first embodiment shown in FIG. 2, especially featuring an arrangement of bleeding lines. Since four (4) low pressure feedwater heaters 6a1 to 6a4 and 6b1 to 6b4 are connected in series respectively in each of feedwater heating lines 6A and 6B, four (4) different conditions of bled steam is used for each of tiers of low pressure feedwater heaters 6a1 and 6b1, 6a2 and 6b2, 6a3 and 6b3, 6a4 and 6b4 as the heating source. As mentioned above, bled steam, as the heating source, is taken out (bled) from low pressure turbines 3a, 3b and 3c. As shown in FIG. 3, each of casings 12a, 12b and 12c are provided with four (4) openings 13a, 13b, 13c and 13d so as to take out steam of four (4) different conditions from low pressure turbines 3a, 3b and 3c as bled steam. Since the temperature and the pressure of steam decreases as the steam flows inside of low pressure turbines 3a, 3b and 3c from an upstream side to a downstream side, the condition of the steam, which is taken out (bled) from low pressure turbines 3a, 3b and 3c, may easily determined by a position of openings 13a, 13b, 13c and 13d in casings 12a, 12b and 12c. In FIG. 3, each of openings 13a, 13b, 13c and 13d exists substantially in a same position for each of casings 12a, 12b and 12c. Bleeding lines 10a1 to 10a4 and 10b1 to 10b4 are connected to low pressure feedwater heater 6a1 to 6a4 and 6b1 to 6b4 respectively. More precisely, openings 13a are connected to low pressure feedwater heaters 6a1 and 6b1 by bleeding lines 10a1, openings 13b are connected to low pressure feedwater heaters 6a2 and 6b2 by bleeding lines 10a2, openings 13c are connected to low pressure feedwater heaters 6a3 and 6b3 by bleeding lines 10a3, and openings 13d are connected to low pressure feedwater heaters 6a4 and 6b4 by bleeding lines 10a4. Bleeding lines 10a1 to 10a4 and 10b1 to 10b4 may pass through connection shells 11. The connections of bleeding lines 10a1 to 10a4 may be determined suitably provided that the conditions, such as the temperature or the pressure, of bled steam supplied to each of low pressure feedwater heater 6a1 to 6a4 and 6b1 to 6b4 are determined appropriately. FIG. 4 shows an arrangement of the bleeding lines, especially featuring bleeding lines which supply bled steam to low pressure feedwater heaters 6a1 and 6b1 shown in FIGS. 2 and 3. In FIG. 4, only a part of openings 13a and bleeding lines 6a1 and 6b1 are shown, however, other bleeding openings are arranged as shown in FIG. 3. As shown in FIG. 4, since each of low pressure turbines 3a, 3b and 3c has symmetrical configuration, two (2) openings 13a are symmetrically disposed in each of casings 12a, 12b and 12c. So, six (6) openings 13a are disposed in casings 12a, 12b and 12c. As described above, two (2) low pressure feedwater heaters 6a1 and 6b1, one of which is disposed inside of steam condenser 4a and the other is disposed inside of steam condenser 4c, use bled steam from openings 13a as the heating source. Therefore, bleeding lines 10a1 and 10b1 are connected so that the bled steam from each three (3) of openings 13a is merged and is led to each of low pressure feedwater heaters 6a1 and 6b1. In FIG. 4, since low pressure feedwater heater 6a1 is disposed inside of steam condenser 4a, the bled steam from two (2) openings 13a inside of steam condenser 4a and from one (1) opening 13a, which is close to steam condenser 4a, inside of steam condenser 4b, is led to low pressure feedwater heater 6a1 by bleeding line 10a1. The bled steam from other three openings 13a, which are relatively close to low pressure feedwater heater 6b1, is led to low pressure feedwater heater 6b1 by bleeding line 10b2. Other bleeding lines are arranged and connected in the same manner, though these are not shown in FIG. 4. FIG. 5 shows another arrangement of the bleeding lines, especially featuring bleeding lines which supply bled steam to low pressure feedwater heaters 6a1 and 6b1 shown in FIGS. 2 and 3. In FIG. 5, though only a part of openings 13a and bleeding lines 6a1 and 6b1 are shown like FIG. 4, Other bleeding openings are arranged as shown in FIG. 3. In FIG. 5, bleeding steam header 22 is disposed inside of steam condensers 4a, 4b and 4c. Bleeding steam header 22 is connected to each of openings 13a by bleeding lines 10-1. Bleeding steam supply lines 14a1 and 14b1 are connected between bleeding steam header 22 and low pressure feedwater heaters 6a1 and 6b1 respectively. Thus, the bled steam, which is taken out from low pressure turbine 3a, 3b and 3c, is gathered inside of bleeding steam header 22, and then is led to each of low pressure feedwater heaters 6a1 and 6b1 as the heating source. In other word, bleeding steam header 22 is used as a buffer of the bled steam taken out from low pressure turbines 3a, 3b and 3c. Bleeding steam header 22 may be disposed outside of steam condensers 4a, 4b and 4c. Though, not shown in FIG. 5, other bleeding steam headers for the bled steam, which is to be led the bled steam to other tiers of the low pressure feedwater heaters, may be disposed. FIG. 6 is a schematic diagram of another detailed configuration of the first embodiment shown in FIG. 2, especially featuring an arrangement of bleeding lines. As shown in FIG. 6, two (2) sets of openings 13a, 13b, 13c or 13d, each of which bleed different conditions of steam from low pressure turbine 3a, 3c and 3c, are symmetrically disposed in casings 12a, 12b and 12c. However, openings 13a, 13b and 13c are disposed in casings 12a and 12c, while openings 13d are disposed in casing 12b. Low pressure feedwater heaters 6a1, 6a2 and 6a3 are installed in steam condenser 4a, which is connected with casing 12a. So, openings 13a, 13b and 13c disposed in casing 12a are connected with low pressure feedwater heaters 6a1, 6a2 and 6a3 by bleeding lines 10a1, 10a2 and 10a3. In the same manner, openings 13d disposed in casing 12b are connected with low pressure feedwater heaters 6a4 and 6b4 by bleeding lines 10a4 and 10b4. Openings 13a, 13b and 13c disposed in casing 12c are connected with low pressure feedwater heater 6b1, 6b2 and 6b3 by bleeding lines 10b1, 10b2 and 10b3. In other words, bleeding lines 10a1, 10a2 and 10a3 are disposed inside of steam condenser 4a. Bleeding lines 10a4 and 10b4 are disposed inside of steam condenser 4b. Bleeding lines 10b1, 10b2 and 10b3 are disposed inside of steam condenser 4c. Thus, each of bleeding lines 10a1 to 10a4 and 10b1 to 10b4 are disposed inside of the steam condenser which is connected with the casings, to which each of respective bleeding lines 10a1 to 10a4 and 10b1 to 10b4 are connected. This configuration enables to avoid leading the bleeding lines around steam condensers 4a, 4b and 4c. FIG. 7 is a schematic diagram of modified configuration of the first embodiment of a steam turbine plant in accordance with the present invention, including three (3) units of low pressure turbines, casings, and steam condensers, which especially shows an arrangement of feedwater heaters inside of steam condensers. The number of the casings of steam turbine 3a, 3b and 3c is also three (3). Each of the casings is connected with each of steam condensers 4a, 4b and 4c respectively. As is the same manner with FIG. 2, feedwater line 8 is divided into two (2) feedwater heating lines 6A and 6B connected in parallel at a downstream side of condensate pump 5 (pressurizer) in feedwater line 8. Low pressure feedwater heaters 6a1 to 6a4 are connected in series in feedwater heating line 6A, while low pressure feedwater heaters 6b1 to 6b4 are connected in series in feedwater heating line 6B. Low pressure feedwater heaters 6a1 to 6a4 and 6b1 to 6b4 are neck heaters, which are disposed inside of steam condensers 4a, 4b and 4c. Each four (4) of low pressure feedwater heaters 6a1 to 6a4 and 6b1 to 6b4, which are connected in series in either of feedwater heating lines 6A or 6B, are dispersed in two (2) of steam condensers 4a, 4b and 4c. Steam condenser 4a accommodates low pressure feedwater heaters 6a2, 6a3 and 6a4 as neck heaters. Steam condenser 4b accommodates low pressure feedwater heaters 6a1 and 6b4 as neck heaters. Steam condenser 4c accommodates low pressure feedwater heaters 6b1, 6b2 and 6b3 as neck heaters. Feedwater heating lines 6A and 6b are merged into one line at an upstream side of high pressure feedwater pump 20 in feedwater line 8. According to this configuration, total amount of the low pressure feedwater heaters may be also lessened compared to the conventional steam turbine plant. It may contribute to improve pressure drop inside the steam condensers 4a, 4b and 4c, to reduce internal constructions or the size of steam condensers 4a, 4b and 4c itself. FIG. 8 is another schematic diagram of modified configuration of the first embodiment of a steam turbine plant in accordance with the present invention, including three (3) units of low pressure turbines, casings, and steam condensers, and which especially shows an arrangement of feedwater heaters inside of steam condensers. The number of the casings of steam turbine 3a, 3b and 3c is also three (3). Each of the casings is connected with each of steam condensers 4a, 4b and 4c respectively. As is the same manner with FIG. 2, feedwater line 8 is divided into two (2) parallel feedwater heating lines 6A and 6B at a downstream side of condensate pump 5 (pressurizer) in feedwater line 8. Low pressure feedwater heaters 6a1 to 6a4 are inserted and connected in series in feedwater heating line 6A, while low pressure feedwater heaters 6b1 to 6b4 are inserted and connected in series in feedwater heating line 6B. Low pressure feedwater heaters 6a1 to 6a4 and 6b1 to 6b4 are neck heaters, which are disposed inside of steam condensers 4a, and 4b. Steam condenser 4a accommodates low pressure feedwater heaters 6a1, 6a2, 6a3 and 6a4 as neck heaters. Steam condenser 4b accommodates low pressure feedwater heaters 6b1, 6b2, 6b3 and 6b4 as neck heaters. Steam condenser 4c is free of any low pressure feedwater heater 6a1 to 6a4 and 6b1 to 6b4. Feedwater heating lines 6A and 6b are merged into one at an upstream side of high pressure feedwater pump 20 in feedwater line 8. According to this configuration, total amount of the low pressure feedwater heaters may be also lessened compared to the conventional steam turbine plant. It may contribute to improve pressure drop inside the steam condensers 4a, 4b and 4c, to reduce internal constructions or the size of steam condensers 4a, 4b and 4c itself. Furthermore, an arrangement of low pressure feedwater heaters 6a1 to 6a4 and 6b1 to 6b4 inside of steam condenser 4a and 4b may be substantially the same. FIG. 9 is another schematic diagram of modified configuration of the first embodiment of a steam turbine plant in accordance with the present invention, including three (3) units of low pressure turbines, casings, and steam condensers, which especially shows an arrangement of feedwater heaters inside of steam condensers. This configuration is a modification of the configuration shown in FIG. 8. As shown in FIG. 8, steam condenser 4a is free of any low pressure feedwater heater 6a1 to 6a4 and 6b1 to 6b4. Steam condenser 4b accommodates low pressure feedwater heater 6a1, 6a2, 6a3 and 6a4 as neck heaters. Low pressure feedwater heaters 6a1 to 6a4 are inserted and connected in series in feedwater heating line 6A. Steam condenser 4c accommodates low pressure feedwater heater 6b1, 6b2, 6b3 and 6b4 as neck heaters. Low pressure feedwater heaters 6b1 to 6b4 are inserted and connected in series in feedwater heating line 6B. Steam condenser 4a accommodates two (2) high pressure feedwater heater 7a and 7b as neck heaters instead of low pressure feedwater heater 6a1 to 6a4 and 6b1 to 6b4. This configuration may reduce a size of the steam turbine plant itself, since it is not usual for conventional steam turbine plant to arrange high pressure feedwater heaters 7a and 7b inside steam condensers 4a, 4b and 4c as neck heaters. Steam condenser 4a, which is provided with the high pressure feedwater heater may be determined in suitable way. In other words, it may be steam condenser 4b or 4c. FIG. 10 is another schematic diagram of modified configuration of first embodiment of a steam turbine plant in accordance with the present invention, including three (3) units of low pressure turbines, casings, and steam condensers, which especially shows an arrangement of feedwater heaters inside of steam condensers. This configuration is a modification of the configuration shown in FIG. 7. As shown in FIG. 7, a dual heater is adopted for low pressure feedwater heaters 6b2 and 6b3, which are connected in series in feedwater heating line 6B. The dual heater, which also has a shell and tube type configuration, is assembled so that two feedwater heaters are combined and form one feedwater heater. The dual heater has a partition inside of the shell. So, the shell of the dual heater is divided in two parts by the partition. Two (2) sets of tubes are installed to each of the parts of the shell. According to this configuration, the dual heater itself may be larger than a single low pressure feedwater heater, such as low pressure feedwater heater 6b1 or 6b4, still the dual heater is smaller size when compared to two (2) of the low pressure feedwater heaters arranged and connected separately. Therefore, it may improve a space efficiency inside steam condensers 4a, 4b and 4c or it may reduce a size or inner structures of steam condensers 4a, 4b and 4c. And it may also improve the pressure drop inside the steam condensers 4a, 4b and 4c. As the dual heater, two of low pressure feedwater heaters 6a1 to 6a4 and 6b1 to 6b4 may be selected in suitable way. The steam condenser which is provided with the dual heater may also be determined suitably. FIG. 11 is another schematic diagram of modified configuration of the first embodiment of a steam turbine plant in accordance with the present invention, including low pressure turbines, casings, and steam condensers of the number of three (3), which especially shows an arrangement of feedwater heaters inside steam condensers. This configuration is a modification of the example shown in FIG. 8. As shown in FIG. 11, a dual heater is adopted for low pressure feedwater heaters 6a3 and 6a4, which are inserted and connected in series in feedwater heating line 6A. Another dual heater is also adopted for low pressure feedwater heaters 6b3 and 6b4, which are inserted and connected in series in feedwater heating line 6A. According to configuration, since arrangements of low pressure feedwater heater 6a1 to 6a4 and 6b1 to 6b4 are the same, pressure drop of inside steam condensers 4a and 4b are almost the same. This may improve simplicity of designing the insides of steam condensers 4a and 4b. FIG. 12 is another schematic diagram of modified configuration of the first embodiment of a steam turbine plant in accordance with the present invention, including low pressure turbines, casings, and steam condensers of the number of three (3), which especially shows an arrangement of feedwater heaters inside steam condensers. This configuration is a modification of the configuration shown in FIG. 2. As shown in FIG. 12, a dual heater is adopted for low pressure feedwater heaters 6a2 and 6a3, which are connected in series in feedwater heating line 6A. Another dual heater is also adopted for low pressure feedwater heaters 6b2 and 6b3, which are connected in series in feedwater heating line 6A. According to configuration, the space efficiency inside of steam condensers 4a, 4b and 4c are improved because of use of the dual heater. Furthermore, since arrangements of low pressure feedwater heater 6a1 to 6a3 and 6b1 to 6b3 may be the same in each of steam condensers 4a and 4c, pressure drop of inside steam condensers 4a and 4c are almost the same. This may improve simplicity of designing inside of steam condensers 4a and 4c. FIG. 13 is another schematic diagram of modified configuration of the first embodiment of a steam turbine plant in accordance with the present invention, including low pressure turbines, casings, and steam condensers of the number of three (3), which especially shows an arrangement of feedwater heaters inside steam condensers. This configuration is a modification of the example shown in FIG. 9. As shown in FIG. 13, Two (2) lines with two (2) tiers of high pressure feedwater heaters 7a1, 7a2 and 7b1, 7b2 are connected in parallel and are adopted for this configuration. Each two series of feedwater heaters 7a1, 7a2 and 7b1, 7b2 is constructed as the dual heater. According to this configuration, one of steam condensers 4a, 4b and 4c has high pressure feedwater heaters 7a1, 7a2 and 7b1, 7b2 instead of the low pressure feedwater heaters 6a1 to 6a4 or 6b1 to 6b4. This configuration may reduce a size of the steam turbine plant itself, since it is not usual for a conventional steam turbine plant to arrange high pressure feedwater heaters 7a and 7b inside steam condensers 4a, 4b and 4c as neck heaters. Steam condenser 4a, which is provided with the high pressure feedwater heater may be determined in suitable way. In other words, it may be steam condenser 4b or 4c. Second embodiment in accordance with the present invention will be explained with reference to FIG. 13 to FIG. 15. FIG. 14 is a schematic diagram of a steam turbine plant in accordance with the present invention, which includes n units of low pressure turbines, n units of casings, and n units of steam condensers. As is the same manner with the first embodiment shown in FIG. 1, steam generator 1 generates steam. The steam passes through high pressure turbine 2 and steam line 9, then lead to a plurality of casings 12a, 12b, 12c, . . . and 12n of low pressure turbines 3a, 3b, 3c, . . . and 3n. Each of low pressure turbines 3a, 3b, 3c, . . . and 3n are installed in casings 12a, 12b, 12c, . . . and 12n, whose number is also the same as the number of low pressure turbines 3a, 3b, 3c, . . . and 3n. The steam led to each of the casings 12a, 12b, 12c, . . . and 12n drives each of low pressure turbines 3a, 3b, 3c, . . . and 3n. The steam is then discharged from low pressure turbines 3a, 3b, 3c, . . . and 3n to each of steam condensers 4a, 4b, 4c, . . . and 4n as discharged steam. Each of steam condensers 4a, 4b, 4c, . . . and 4n are placed beneath each of low pressure turbines 3a, 3b, 3c, . . . and 3n and are connected with each of casings 12a, 12b, 12c, . . . and 12n. In steam condensers 4a, 4b, 4c, . . . and 4n, the discharged steam is cooled down and condenses into water as a condensed water (condensate). The condensed water (condensate) is gathered and led to feedwater line 8. In feedwater line 8, condensate pump 5 (pressurizer) gives pressure to the condensed water (condensate) as a feedwater. The feedwater is led to low pressure feedwater heaters 6a1, 6b1, 6c1, . . . and 6n1 and is heated up. The feedwater, after heated up in low pressure feedwater heaters 6a1, 6b1, 6c1, . . . and 6n1, is merged and is led to low pressure feedwater heater 6a2, 6b2, 6c2, . . . and 6(n-1)2. The feedwater passes through low pressure feedwater heater 6a2, 6b2, 6c2, . . . and 6(n-1)2 and is further pumped up by feedwater pump 20 (pressurizer) as high pressure feedwater pump. The feedwater pumped up to high pressure by feedwater pump 20 (pressurizer), then led to high pressure feedwater heaters 7a and 7b in feedwater line 8. In high pressure feedwater heaters 7a and 7b, the feedwater is further heated up and then supply to steam generator 1 from feedwater line 8. In this manner, the steam turbine plant constitutes closed-loop as a Rankine Cycle. Bled steam for low pressure feedwater heaters 6a1, 6b1, 6c1, . . . 6n1 and 6a2, 6b2, 6c2, . . . 6(n-1)2 is taken out from the middle of low pressure turbines 3a, 3b, 3c, . . . and 3n as the same manner with the first embodiment. The bled steam is led to the bleeding lines (not shown) and is supplied to low pressure feedwater heaters 6a1, 6b1, 6c1, . . . 6n1 and 6a2, 6b2, 6c2, . . . 6(n-1)2. Low pressure feedwater heaters 6a1, 6b1, 6c1, . . . 6n1 and 6a2, 6b2, 6c2, . . . 6(n-1)2 are installed inside of neck portions of steam condensers 4a, 4b, 4c, . . . and 4n to improve a space efficiency. Steam condensers 4a, 4b, 4c, and 4n are closely arranged each other. N units of low pressure feedwater heaters 6a1, 6b1, 6c1, . . . and 6n1 are provided inside steam condensers 4a, 4b, 4c, . . . and 4n. (n-1) units of low pressure feedwater heaters 6a2, 6b2, 6c2, . . . and 6(n-1)2 are provided inside steam condensers 4a, 4b, 4c, . . . and 4(n-1). Feedwater line 8 includes a plurality of first feed water heating lines 61A, 61B, 61C, . . . and 61N. Each of first feed water heating lines 61A, 61B, 61C, . . . and 61N has one of low pressure feedwater heaters 6a1, 6b1, 6c1, . . . 6n1 respectively. Low pressure feedwater heaters 6a1, 6b1, 6c1, . . . 6n1 are arranged and connected in parallel inside of steam condensers 4a, 4b, 4c, . . . and 4n. First feedwater heating lines 61A, 61B, 61C, . . . and 61N are provided between condensate pump 5 (pressurizer) and high pressure feedwater pump 20 (pressurizer) in feedwater line 8. Feedwater line 8 further includes a plurality of second feed water heating lines 62A, 62B, 62C, . . . and 62(N-1) at a downstream side of first feedwater heating lines 61A, 61B, 61C, . . . and 61N. Each of second feed water heating lines 62A, 62B, 62C, . . . and 62(N-1) has one of low pressure feedwater heaters 6a2, 6b2, 6c2, . . . 6(n-1)2 respectively. Low pressure feedwater heaters 6a2, 6b2, 6c2, . . . 6(n-1)2 are arranged and connected in parallel inside of steam condensers 4a, 4b, 4c, and 4(n-1). Second feedwater heating lines 62A, 62B, 62C, . . . and 62(N-1) are connected in parallel and inserted in series at a downstream side of first feedwater heating lines 61A, 61B, 61C, . . . and 61N in feedwater line 8. Thus, feedwater lines 8 includes first feed water heating lines 61A, 61B, 61C, . . . and 61N and second feed water heating lines 62A, 62B, 62C, . . . and 62(N-1) as a constituent elements. First feedwater heating lines 61A, 61B, 61C and 61N as a whole are seriesly inserted in feedwater line 8. Second feedwater heating lines 62A, 62B, 62C, . . . and 62(N-1), whose number is less than the number of first feedwater heating lines 61A, 61B, 61C, . . . and 61N, are coupled to a downstream side of first feedwater heating lines 61A, 61B, 61C, . . . and 61N and are seriesly inserted in feedwater line 8 as a whole. Each of second feedwater heating lines 62A, 62B, 62C, . . . and 62(N-1) may have a plurality of low pressure feedwater heaters arranged and connected in series. In this case, all of steam condensers 4a, 4b, 4c, . . . and 4n may have at least one of low pressure feedwater heaters, and the number of the low pressure feedwater heaters may be greater than the number of steam condensers 4a, 4b, 4c, . . . and 4n. Still there is a less number of the second feedwater heating lines than the number of steam condensers 4a, 4b, 4c, . . . and 4n. The number of the feedwater heating lines may be one (1) or more, but is less than the number of steam condensers 4a, 4b, 4c, . . . and 4n. The bleeding steam lines may be connected to any of casings 12a, 12b, 12c, and 12n of low pressure turbines 3a, 3b, 3c, . . . and 3n as the same manner with the first embodiment. According to this embodiment, the number of the low pressure feedwater heaters disposed inside of steam condenser 4a, 4b, 4c, . . . and 4n are lessened compared with a conventional steam turbine plant. In order to keep the amount of heat exchanged in the low pressure feedwater heaters at a preferable level, each of low pressure feedwater heaters 6a, 6b, 6c, . . . and 6(n-1) may be enlarged in size to increase the amount of heat. However, internal structures, such as the bleeding lines, of steam condensers 4a, 4b, 4c, . . . and 4n may be lessened to improve pressure drop of the steam inside steam condensers 4a, 4b, 4c, . . . and 4n. And the size of steam condensers 4a, 4b, 4c, . . . and 4n may be reduced. Some detailed configurations of the second embodiment having three (3) units of the low pressure turbines, the casings and the steam condensers are explained below with reference of FIGS. 15 and 16. FIGS. 15 and 16 are schematic diagrams of a detailed configuration of the first embodiment of a steam turbine plant in accordance with the present invention, including three (3) units of low pressure turbines, three (3) units of casings, and three (3) units of steam condensers. FIG. 14 especially features an arrangement of feedwater heaters inside steam condensers. The number of the casings 12a, 12b and 12c of steam turbine 3a, 3b and 3c is three (3). Each of the casings 12a, 12b and 12c is connected with each of steam condensers 4a, 4b and 4c respectively. As described in FIG. 15, feedwater line 8 is divided into three (3) of first feedwater heating lines 61A, 61B and 61C at a downstream side of condensate pump 5 (pressurizer). Feedwater line 8 is further divided at a downstream side of first feedwater heating lines 61A, 61B and 61C into two (2) second feedwater heating lines 62A and 62B. Low pressure feedwater heaters 6a1, 6b1 and 6c1 are connected in series in each of first feedwater heating lines 6A, 6B and 6C respectively. Low pressure feedwater heater 6a2 to 6a4 are connected in series in second feedwater heating line 62A, while low pressure feedwater heaters 6b2 to 6b4 are connected in series in second feedwater heating line 62B. Low pressure feedwater heaters 6a1 to 6a4 and 6b1 to 6b4 are neck heaters, which are disposed inside of steam condensers 4a, 4b and 4c. Each three (3) of low pressure feedwater heaters 6a2 to 6a4 and 6b2 to 6b4, which are connected in series in either of second feedwater heating lines 62A or 62B, are dispersed in two (2) of steam condensers 4a, 4b and 4c. Steam condenser 4a accommodates low pressure feedwater heaters 6a1, 6a2 and 6a3 as neck heaters. Steam condenser 4b accommodates low pressure feedwater heaters 6a4, 6b1 and 6b4 as neck heaters. Steam condenser 4c accommodates low pressure feedwater heaters 6c1, 6b2 and 6b3 as neck heaters. Feedwater heating lines 6A and 6b are merged into one at an upstream side of high pressure feedwater pump 20 in feedwater line 8. The feedwater, from first feedwater heating lines 61A, 61B and 61C, is divided into two flows and is led to each of feedwater heating lines 62A and 62B. In feedwater heating line 62A, The temperature of the feedwater rises as the feedwater flow through low pressure feedwater heaters 6a2, 6a3 and 6a4 in this order. In the same manner, the temperature of the feedwater rises as the feedwater flows through low pressure feedwater heaters 6b2, 6b3 and 6b4 in this order in feedwater heating line 62B. As a heating source, steam bled from low pressure steam turbine 3a, 3b and 3c may be introduced to low pressure feedwater heater 6a1 to 6a4 and 6b1 to 6b4 as the same manner shown in FIGS. 3 to 7. FIG. 16 is other schematic diagram of modified configuration of the second embodiment of a steam turbine plant in accordance with the present invention, including low pressure turbines, casings, and steam condensers of the number of three (3), which especially shows an arrangement of feedwater heaters inside steam condensers. This configuration is a modification of the configuration shown in FIG. 15. As shown in FIG. 16, a dual heater is adopted for low pressure feedwater heaters 6a4 and 6b4, which are connected in series in each of second feedwater heating line 62A or 62B respectively. According to this configuration, the space efficiency inside of steam condensers 4a, 4b and 4c are improved because of use of the dual heater. Furthermore, since arrangements of low pressure feedwater heater 6a1 to 6a3 and 6b1 to 6b3 may be the same in each of steam condensers 4a and 4c, pressure drop of inside steam condensers 4a and 4c are almost the same. This may improve simplicity of designing the insides of steam condensers 4a and 4c. Other embodiments of the present invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and example embodiments be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following.
051075296	abstract	A radiographic equalization apparatus comprises a plurality of juxtaposed disks each having a plurality of unique filtration patterns annularly disposed therearound. The disks are rotated relative to one another to obtain a unique attenuation pattern for correcting for overexposures in an x-ray image.
	summary
	claims	1. A method for operating a Raman sensor, comprising:performing a plurality of ancillary data checks that monitor operating conditions of system components of a Raman sensor comprising a laser, a spectrograph and an intensified charge coupled device (ICCD);acquiring Raman spectral data as a result of pulsing the laser and passing returning light from a sample illuminated by the laser through the spectrograph and capturing Raman spectra of the spectrograph by the ICCD;performing a plurality of data quality checks related to the Raman spectral data acquired during said acquiring step;determining, based on results of the data quality checks, whether to further process the Raman spectral data acquired during said acquiring step and, if so, storing the Raman spectral data acquired during said acquiring step for further processing;repeating successively, a predetermined number of times, said step of acquiring Raman spectral data and said step of performing a plurality of data quality checks related to the Raman spectral data, and then again performing said step of performing a plurality of ancillary data checks;storing in a log file a series of acquired Raman spectral data, and closing the log file after said predetermined number of times; andafter said closing step, acquiring a predetermined number of dark spectral data and revising a previously calculated dark spectral data median. 2. The method of claim 1, wherein said step of performing a plurality of ancillary data checks comprises monitoring a state of each of the ICCD and the laser. 3. The method of claim 2, further comprising monitoring a temperature of one or more components of the Raman sensor. 4. The method of 1, wherein said step of performing a plurality of ancillary data checks comprises monitoring a linear focus actuator of an autofocus subsystem to maintain proper focus of the optics which collect the Raman spectrum. 5. The method of claim 1, wherein said step of performing a plurality of data quality checks comprises monitoring laser energy. 6. The method of claim 1, wherein said step of performing a plurality of data quality checks comprises determining whether the Raman spectral data acquired during said acquiring step is saturated or is of insufficient amplitude. 7. The method of claim 1, further comprising halting further Raman spectral data acquisition upon a failure of one of the plurality of ancillary data checks. 8. The method of claim 1, further comprising adjusting a gain for the ICCD in response to one of the plurality of data quality checks. 9. A method of operating a Raman spectroscopy device, the device comprising a laser, a spectrograph, an intensified charge coupled device (ICCD), and an autofocus subsystem, the method comprising:performing a plurality of ancillary data checks that monitor operating conditions of at least the laser, the ICCD, and the autofocus subsystem;acquiring Raman spectral data by pulsing the laser and collecting resulting Raman spectra with the ICCD via the spectrograph;performing a plurality of data quality checks related to the Raman spectral data acquired during said acquiring step;determining, based on results of the data quality checks, whether to further process the Raman spectral data acquired during said acquiring step and, if so, storing the Raman spectral data acquired during said acquiring step for further processing;repeating successively, a predetermined number of times, said step of acquiring Raman spectral data and said step of performing a plurality of data quality checks related to the Raman spectral data;storing in a log file a series of acquired Raman spectral data, and closing the log file after said predetermined number of times; andafter said closing step, acquiring a predetermined number of dark spectral data and revising a previously calculated dark spectral data median. 10. The method of claim 9, further comprising, repeating said step of performing a plurality of ancillary data checks after said repeating successively. 11. The method of claim 9, further comprising halting further Raman spectral data acquisition if one of the plurality of ancillary data checks indicates a failure. 12. The method of claim 9, further comprising storing Raman spectral data that has passed the plurality of data quality checks for agent identification processing. 13. The method of claim 9, further comprising adjusting a gain of the ICCD in response to at least one of the plurality of data quality checks. 14. A Raman spectroscopy system, comprising:a laser that is configured to pulse at a predetermined frequency;an autofocus subsystem that controls focus of a telescope that is directed, optically, at the same spot illuminated by the laser;a spectrograph and an intensified charge coupled device (ICCD) that are configured to receive Raman spectra resulting from the laser pulse via the telescope; anda processor and associated memory, the memory being configured to store the individual Raman spectra as individual records of Raman spectral data as captured by the ICCD, the processor being configured to execute a plurality of ancillary data checks that monitor operating conditions of at least the laser, the ICCD, and the autofocus subsystem, and to execute a plurality of data quality checks related to the usefulness of the Raman spectral data,wherein the processor is further configured to determine, based on results of the data quality checks, whether to store Raman spectral data in a log file for further processing and whether to repeat execution of the plurality of ancillary data checks, andwherein the processor is still further configured to store in the log file a series of acquired Raman spectral data, to close the log file after a predetermined number of series have been stored; and after the log is closed to acquire a predetermined number of dark spectral data and revise a previously calculated dark spectral data median. 15. The system of claim 14, further comprising a rangefinder subsystem that operates in conjunction with the autofocus subsystem. 16. The system of claim 14, wherein the processor is configured to determine whether a given collected Raman spectrum is saturated, corrupted, or is of insufficient amplitude. 17. The system of claim 16, wherein the processor is configured to initiate a routine to adjust a gain of the ICCD when a determination is made that the given collected Raman spectrum is saturated or is of insufficient amplitude.
	description	Embodiments of a method for manufacturing a control rod for boiling water reactor and a control rod for boiling water reactor according to the present invention will hereinafter be described with reference to the accompanying drawings. FIG. 1 is a partly exploded perspective view showing a general structure of a control rod for boiling water reactor according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the section plane indicated by IIxe2x80x94II in FIG. 1, in which fuel assemblies N are also shown. In FIGS. 1 and 2, a control rod 1 for boiling water reactor is provided with a control rod supporting structural body 2 and four blades 3 each of which extends from an axis center 2A of the control rod supporting structural body 2 (or an axis center 4A of a tie rod 4 to be described later in this specification) toward four directions. The control rod 1 as a whole has a cruciform cross section. The control rod supporting structural body 2 is provided with a tie rod 4 having the cruciform cross section, a handle 5 fixed to an upper end of the tie rod 4 and a velocity limiter 6 fixed to a lower end of the tie rod 4. Each of the blades 3 comprises hafnium flat tubes 7 serving as a neutron absorbing member and sheaths 8 covering the hafnium flat tubes 7. Each of the blades 3 is provided with four hafnium flat tubes 7, two of which being provided in a direction of the axis center 2A of the control rod supporting structural body 2, other two of which being provided in a direction extending outward from the axis center 2A of the control rod supporting structural body 2. Here, upper ends of the hafnium flat tubes 7 which are provided at an upper part are fixed to the handle 5 with pins (not shown), lower ends of the hafnium flat tubes 7 which are provided at a lower part are fixed to a base member 6a of the velocity limiter 6 with pins (not shown), and the sheaths 8 press the hafnium flat tubes 7 to fix the hafnium flat tubes 7 to the control rod supporting structural body 2. Each of the sheaths 8 is prepared by bending a stainless steel plate, for example, to form a U-shape, and each of tips of the sheath 8 is provided with projections 8a and recesses 8b. The projections 8a are welded to each of tips 4a of the arms of the tie rod 4, an upper edge 8c of the sheath 8 is welded to a lower end 5a of the handle 5, and a lower edge 8d of the sheath 8 is welded to an upper end 6a1 of the velocity limiter base member 6a, to thereby fix the sheath 8 to the control rod supporting structural body 2. Each of the sheaths 8 is provided with a plurality of cooling holes 9 which serve as paths for a coolant. The method for manufacturing each of main parts of the thus-structured control rod for boiling water reactor according to the first embodiment of the present invention will be described with reference to FIG. 3. A plate 10 is prepared by rolling a material in Step 10 of FIG. 3. Next, in Step 20, the plate 10 is cut in such a manner as to form the projections 8a and the recesses 8b, and then punched to form the cooling holes 9, to thereby obtain a flat sheath 11. In Step 30, the sheath 8 is obtained by bending the flat sheath 11 in such a manner as to form a U-shape using a press machine. A drawn tie rod 12 is formed by drawing a material in Step 40 of FIG. 3, and then the drawn tie rod 12 is cut in Step 50 to give a tie rod 4 (hereinafter, for the distinction from the drawn tie rod 12, the tie rod 4 will be referred to as cut tie rod 4 when so required). Details of shapes of the drawn tie rod 12 and the cut tie rod 4 will be described below with reference to FIGS. 4A and 4B. FIG. 4A is a top view or a bottom view of the drawn tie rod 12, and FIG. 4B is a top view or a bottom view of the cut tie rod 4. In these drawings, the drawn tie rod 12 is the tie rod formed by drawing a material in Step 40, which is provided with steps 12b formed at both sides of a tip 12a of each of arms. A corner 12b1 of each of the steps 12b is slightly R-shaped (curved). In turn, the cut tie rod 4 is provided with steps 4b formed at both sides of a tip 4a of each of arms like the drawn tie rod 12. It is formed by cutting each of the steps 12b of the drawn tie rod 12 in Step 50 to eliminate the R-shape of the corner 12b1. Thus, each of the steps 4b has a precise rectangular shape. The steps 4b are provided for the purpose of fitting the projections 8a of the tips of the sheath 8 thereonto at the time of welding the sheath 8 to the tie rod 4 in Step 110 which will be described later. Referring back to FIG. 3, the handle 5, velocity limiter 6 and other members constituting the control rod 1 for boiling water reactor are manufactured by subjecting materials to machining, assembling, welding and so forth in Step 60. In Step 70 of FIG. 3, the handle 5 manufactured in Step 60 is fixed to an upper end of the cut tie rod 4 by an assembly welding; the velocity limiter 6 manufactured in Step 60 is fixed to a lower end of the cut tie rod 4 in the same manner; and other members are properly assembled and welded, so that the control rod supporting structural body 2 is completed. In FIG. 3, a hafnium plate 13 is formed by rolling a material in Step 80. Both ends of each of two hafnium plates 13 are bent, and then, in Step 90, the hafnium plates are assembled in such a manner as to face each other, followed by welding seams thereof, so that a hafnium flat tube 7 is completed. In FIG. 3, the hafnium flat tube 7, which has been manufactured in Step 90 in the manner described in the item (5), is fixed to the control rod supporting structural body 2 which has been manufactured in Step 70 in the manner described in the item (4). Here, the upper and lower ends of each of the hafnium flat tubes 7 to be provided in the upper and lower parts are fixed to the handle 5 and the base member 6a of the velocity limiter 6 with pins as described above, respectively. The hafnium tubes 7 fixed to the four positions as described above are then covered with the sheaths 8, respectively, in such a manner that the sheaths 8 respectively incorporate the hafnium tubes 7 from a tip of the U-shape, and the projections 8a of each of the sheaths 8 are fitted onto the steps 4b of each of the arms of the tie rod 4. Here, the lower end 5a of the handle 5 and the upper end 6a1 of the base member 6a of the velocity limiter 6 are provided with a step 5b (see FIG. 9) and a step 6ab (see FIG. 11) similar to the steps 4b, and an upper edge 8c and a lower edge 8d of each of the sheaths 8 are fitted onto the steps 5b and 6ab, respectively. In Step 110, fitting portions of the projections 8a in the steps 4b, the upper edges 8c in the step 5b, and the lower edges 8d in the step 6ab are subjected to a laser welding. Thus, the sheaths 8 are fixed to the control rod supporting structural body 2, so that the control rod 1 for boiling water reactor is completed. In the method for manufacturing the control rod 1 for boiling water reactor through the above-described process steps, the greatest characteristic is that, in performing the laser welding with the projections 8a, the upper edge 8c and the lower edge 8d of each of the sheaths 8 being fitted onto the steps 4b, the step 5b and the step 6a1, a beam axial center position of the laser beam is shifted from an end face position of the sheath 8 to a side opposite to the sheath 8 to weld them. Hereinafter, details of the laser welding will be described taking an example when welding the sheath 8 on the tie rod 4. FIG. 5 is a conceptual block diagram showing a general construction of a YAG laser welding machine used in the laser welding. In FIG. 5, a YAG laser welding machine 14 is provided with a machining table 15 on which the tie rod 4 and the sheath 8 are placed, a holding fixture 16 for holding the sheath 8, a laser beam machine 17, a laser oscillator 18 for emitting a YAG laser beam 23 which will be described later and a control device 19. The laser welding machine 17 is provided with rails 17a, a frame 17b capable of moving in directions indicated by the arrow A, a support member 17c having a substantially L shape which is mounted on the frame 17b, a slider 17d capable of moving in directions indicated by the arrow C, a support rod 17e extending downward from the slider 17d and a machining head 17f capable of moving in directions indicated by the arrow B along the support rod 17e. Owing to this structure, the machining head 17f can move in three axial directions of A, B and C with respect to the machining table 15. The control device 19 is connected with the frame 17b of the laser beam machine 17 and with the laser oscillator 18 respectively by a signal line 20 and a signal line 21, while the laser oscillator 18 is connected with the machining head 17f by an optical fiber 22. Further, an operation panel (not shown) is connected with the control device 19, so that an operator uses the operation panel to control a position of the machining head, laser output and so forth. Here, the projections 8a constitute the tips of the U-shape of each of the sheaths which are recited in the appended claims. Next, details of the first embodiment of the method for manufacturing a control rod for boiling water reactor using the cut tie rod 4 of the above-described structure will be described with reference to FIGS. 6 and 7. FIG. 6 is a perspective view showing an enlarged part of welded portion of the sheath 8 and the tie rod 4 which are welded using the YAG laser welding machine 14, and FIG. 7 is a cross-sectional view taken along the section plane indicated by VIIxe2x80x94VII in FIG. 6. In FIGS. 6 and 7, according to the present embodiment, the operator uses the operation panel, while moving the machining head 17f in a longitudinal direction (in a direction of the arrow D) of the tie rod 4, to perform a continuous laser welding of the projection 8a of the sheath 8 on the step 4b of the tie rod 4. In this laser welding, a shield gas 24 is fed from the machining head 17f at the same time with the irradiation of the YAG laser beam 23 to prevent oxidization of the welded portion. Further, since a welding bead (not shown) immediately after the welding is susceptible to the oxidization, a trailer gas 26 is blown to the welding bead from a trailer nozzle 25 to prevent the oxidization. It is the greatest characteristic of the present embodiment that, the axial center position 23A (see FIG. 7) of the YAG laser beam 23 is shifted from an end face 4b1 of the tie rod step 4b toward the tie rod 4 (to the side opposite to the sheath 8) to irradiate a surface of the tie rod 4 directly with the YAG laser beam 23 for laser welding. In the conventional technique, wherein the axial center position of the beam is shifted toward the sheath 8 (in a side opposite to the tie rod 4) from the end face 4b1 of the tie rod step 4b, it is necessary to control an irradiation position of the YAG laser beam 23 to be located in a very narrow overlap L1 (see FIG. 7) as mentioned above. If an error in the axial center position 23A of the YAG laser beam 23 occurs to irradiate a portion which is shifted from the overlap L1 toward the sheath 8 with the YAG laser beam 23, the sheath 8 is heated too much since heat generated by the irradiation of the YAG laser beam 23 is difficult to be transferred to the tie rod 4. Thus, in the conventional technique, the projection 8a of the sheath 8 has been melted down, resulting in a welding failure in some cases. By contrast, according to the present embodiment, the surface of the tie rod 4 is firstly irradiated with the YAG laser beam 23, and then heat generated by the irradiation is transferred from the surface of the tie rod 4 to the sheath 8 via the tie rod step 4b. Accordingly, even if a small error in the axial center position 23A of the YAG laser beam occurs and the YAG laser beam slightly deviates from the target position, the heat is transferred to the sheath 8 after passing the contact portion of the tie rod step 4b with the sheath 8 without fail, to thereby prevent the welding failure which otherwise would be caused by the melt-down of the projection 8a of the sheath 8. Therefore, as compared with the conventional technique, the present embodiment prevents the melt-down of the sheath 8 to secure a good weldability without controlling the axial center position 23A of the YAG laser beam 23 with high precision. Thus, the present embodiment facilitates the laser welding control and the manufacture of the control rod 1 for boiling water reactor, and achieves a reduction in manufacturing cost. Description has been made on an example in the welding of the sheath 8 on the tie rod 4, while the following describes an example in the welding of the sheath 8 on the handle 5. FIG. 8 is a perspective view showing an enlarged part of a welding portion in the welding of the sheath 8 on the handle 5 using the YAG laser welding machine 14. FIG. 9 is a cross-sectional view taken along the section plane indicated by IXxe2x80x94IX in FIG. 8. Among the elements shown in FIGS. 8 and 9, those also shown in FIGS. 6 and 7 are denoted by the same reference numerals, and explanations therefor will be omitted in the following description. In the welding of the sheath 8 to the handle 5, the machining head 17f is moved in a direction along the upper edge 8c of the sheath 8 (in a direction indicated by the arrow E) to perform a continuous laser welding of the upper edge 8c of the sheath 8 on the step 5b (see FIG. 9) of the lower end 5a of the handle 5 as shown in FIGS. 8 and 9. Here, in the same manner as in the welding of the sheath 8 on the tie rod 4 described above, the axial center position 23A of the YAG laser beam 23 is shifted from an end face 5b1 (see FIG. 9) of the handle step 5b toward the handle 5 (to the side opposite to the sheath 8) to directly irradiate a surface of the handle 5 with the YAG laser beam 23 for laser welding. In this case, too, heat generated by the irradiation of the YAG laser beam 23 is transferred from the surface of the handle 5 to the sheath 8 via the handle step 5b. Therefore, similarly to the above described welding of the sheath 8 on the tie rod 4, the present embodiment prevents the melt-down of the sheath 8 to secure the good weldability without controlling the axial center position 23A of the YAG laser beam 23 with high precision. Thus, the present embodiment facilitates the laser welding control and the manufacture of the control rod 1 for boiling water reactor, and achieves the reduction in manufacturing cost. Next, the welding of the sheath 8 on the base member 6a of the velocity limiter 6 will be described. FIG. 10 is a perspective view showing an enlarged part of the welding portion of the sheath 8 on the base member 6a of the velocity limiter 6 which are welded by using the YAG laser welding machine 14. FIG. 11 is a cross-sectional view taken along the section plane indicated by XIxe2x80x94XI in FIG. 10. Among the elements shown in FIGS. 10 and 11, those also shown in FIGS. 6 and 7 are denoted by the same reference numerals, and explanations therefor will be omitted in the following description. In the welding of the sheath 8 on the velocity limiter base member 6a, the machining head 17f is moved in a direction along the lower edge 8d of the sheath 8 (in a direction indicated by the arrow F in FIG. 10) to perform a continuous laser welding of the lower edge 8d of the sheath 8 on the step 6ab (see FIG. 11) of the upper end 6a of the velocity limiter base member 6a as shown in FIGS. 10 and 11. Here, in the same manner as in the welding of the sheath 8 on the tie rod 4 described above, the axial center position 23A of the YAG laser beam 23 is shifted from an end face 6ab1 (see FIG. 11) of the step 6ab of the velocity limiter base member 6a toward the velocity limiter base member 6a (to the side opposite to the sheath 8) to directly irradiate a surface of the velocity limiter base member 6a with the YAG laser beam 23 for laser welding. In this case, too, heat generated by the irradiation of the YAG laser beam 23 is transferred from the surface of the velocity limiter base member 6a to the sheath 8 via the velocity limiter base member step 6ab. Therefore, similarly to the above described welding of the sheath 8 on the tie rod 4, the present embodiment prevents the melt-down of the sheath 8 to secure the good weldability without controlling the axial center position 23A of the YAG laser beam 23 with high precision. Thus, the present embodiment facilitates the laser welding control and the manufacture of the control rod 1 for boiling water reactor, and achieves the reduction in manufacturing cost. In addition, although the tie rod 4, the handle 5 and the velocity limiter base member 6a as members to be welded are directly irradiated with the YAG laser beam 23 in the first embodiment of the present invention, a welding rod may be used for promotion of fusion (see FIG. 23). In this case, since the welding rod is irradiated with the YAG laser beam 23, heat generated by the irradiation is transferred from the welding rod (more precisely, a melted welding rod) to the sheath 8 to prevent the melt-down of the sheath 8, thereby achieving the good weldability. Next, a method for manufacturing a control rod for boiling water reactor and the control rod for boiling water reactor according to a second embodiment of the present invention will be described with reference to FIGS. 12 to 15. In the present embodiment, the control rod for boiling water reactor is manufactured by using the above-described drawn tie rod 12 which is formed only by drawing, or, without the cutting process. FIG. 12 is a partly exploded perspective view showing a general structure of the control rod for boiling water reactor according to the present embodiment. Among the elements shown in FIG. 12, those also shown in FIG. 1 are denoted by the same reference numerals, and explanations therefor will be omitted in the following description. In FIG. 12, a control rod 1xe2x80x2 for boiling water reactor is provided with a control rod supporting structural body 2xe2x80x2 comprising the drawing tie rod 12, a handle 5 which is fitted onto an upper end of the drawing tie rod 12 and a velocity limiter 6 which is fixed to a lower end of the drawn tie rod 12. Process steps for manufacturing the control rod for boiling water reactor according to the second embodiment of the present invention will be described with reference to FIG. 13. Among the elements shown in FIG. 13, those also shown in FIG. 3 are denoted by the same reference numerals, and explanations therefor will be omitted in the following description. Steps 10 to 30 for manufacturing sheaths 8, Step 40 for manufacturing the drawn tie rod 12 and Step 60 for manufacturing the handle 5, velocity limiter 6 and other members are the same as those of the first embodiment. Although the cutting process is performed in Step 50 succeeding to Step 40 in the first embodiment as shown in FIG. 3, the cutting process is not performed in the present embodiment. The handle 5 and the velocity limiter 6 are fixed to the upper end and the lower end of the drawn tie rod 12, respectively by an assembly welding, and the other members are assembled and welded as required in Step 70, so that the control rod supporting structural body 2xe2x80x2 is completed. Steps 80 and 90 for manufacturing hafnium flat tubes 7, Steps 100 and 110 for manufacturing the control rod 1xe2x80x2 for boiling water reactor are the same as those of the first embodiment. Here, the drawn tie rod 12 constitutes the tie rod for fixing the sheaths which is prepared by drawing and provided with steps at each of the tips of the arms of the cruciform as recited in the appended claims. Next, details of the method for manufacturing the control rod for boiling water reactor of the present embodiment will be described. As shown in FIGS. 14 and 15, a machining head 17f is moved in a longitudinal direction of the drawn tie rod 12 (in a direction indicated by the arrow G) to perform a continuous laser welding of the projection 8a of the sheath 8 on the step 12b of the drawn tie rod 12 in the present embodiment. Here, in the same manner as in the first embodiment, an axial center position 23A (see FIG. 15) of a YAG laser beam 23 is shifted toward the drawn tie rod 12 (to the side opposite to the sheath 8) from an end face 12b2 of the drawn tie rod step 12b to directly irradiate a surface of the drawn tie rod 12 with the YAG laser beam 23 for laser welding. Since each of corners 12b1 (see FIG. 15) of the step 12b of the drawn tie rod 12 is in a slightly R-shape due to the omission of the cutting process as described above, the projection 8a of the sheath 8 is not completely fitted onto the end face 12b2 of the step 12b. More specifically, an overlap L2 (see FIG. 15) in the present embodiment is narrower than the overlap L1 of the sheath 8 with the cut tie rod 4 of the first embodiment. In the conventional technique, wherein the laser welding is performed with the axial center position 23A being shifted toward the sheath 8 (in a direction opposite to the drawn tie rod 12) from the end face 12b2 of the step 12b, it is necessary to control the irradiation position of the YAG laser beam 23 to be located inside the very narrow overlap L2 which is yet narrower than the overlap L1 in the first embodiment, to thereby increase the possibility of the melt-down of the sheath 8 due to an error in controlling the laser irradiation position. Also, since a thermal transfer from the sheath 8 to the drawn tie rod 12 is smaller due to the narrowed overlap L2, the possibility of the melt-down of the sheath 8, which results in a welding failure, is further increased in the conventional technique. By contrast, in the present embodiment, since the surface of the drawn tie rod 12 is irradiated with the YAG laser beam 23, heat generated by the irradiation is transferred from the surface of the drawn tie rod 12 to the sheath 8 via the drawn tie rod step 12. Therefore, the present embodiment prevents the melt-down of the projection 8a of the sheath 8 and the welding failure even if a small error in the irradiation position of the YAG laser beam 23 occurs. More specifically, according to the present embodiment, by shifting of the irradiation position of the YAG laser beam 23 toward the drawn tie rod 12 (in a direction opposite to the sheath 8), it is possible to prevent the melt-down of the sheath 8 and to secure the good weldability even if the drawn tie rod 12 is not machined into the precise rectangular shape and remains the R-shape on the corner 12b1. Thus, it is possible to omit the machining step from a typical tie rod manufacturing process consisting of the process steps of formation of the drawn tie rod 12 from a material by drawing and machining of the steps 12b to achieve the rectangular shape, thereby enabling the control rod 1xe2x80x2 for boiling water reactor to be manufactured by using the drawn tie rod 12 prepared only by the drawing process. Therefore, the present embodiment facilitates the manufacture of the control rod by a step corresponding to the omitted machining process, which leads to a reduction in manufacturing cost. In addition, the welding rod described in the first embodiment may be used also in the present embodiment for promotion of fusion (see FIG. 23). In this case, too, it is possible to achieve the above-described effects of the present embodiment. Next, a third embodiment of the method for manufacturing a control rod for boiling water reactor of the present invention will be described with reference to FIGS. 16 to 23. In the present embodiment, weldings of sheath 8 on the tie rod 4, the sheath 8 on the handle 5, the sheath 8 on the velocity limiter base member 6a are automated. For the purpose of automating the laser welding, the inventors of the present invention have conducted welding experiments using the sheath 8 and the tie rod 4 under various welding conditions to find out a welding condition under which a prevention of the melt-down of the sheath 8 as well as a perfect weld penetration are achieved. FIG. 16 shows a range of the welding conditions. As a result of the welding experiments, states after the weldings are broadly classified into three states of a state wherein a penetration bead is not formed and the perfect weld penetration is not achieved, a state wherein the perfect weld penetration is achieved and a state wherein the sheath 8 is melted down. Then, the inventors have converted the three states onto numerical values by using a heat input parameter Po which relates to an amount of heat input. More specifically, the state wherein the perfect weld penetration is not achieved due to an insufficient heat input is represented by Po=xe2x88x921, the state wherein the perfect weld penetration is achieved is represented by Po=0, and the state wherein the sheath 8 is melted down is represented by Po=1. Further, the inventors have conducted multiple regression analyses of welding conditions associated with the above three states to obtain an analysis parameter P represented by the following equation: P=0.184+1.11xc3x97G+0.964xc3x97A+1.07xc3x97Hxe2x88x921.17xc3x97Dxe2x88x920.11xc3x97Wxe2x88x920.807xc3x97L where G represents a gap (mm) between an inner surface 8a5 (see FIG. 21) of a sheath projection 8a and a base 4b3 of a tie rod step 4b in a state where the sheath projection 8a is fitted onto the tie rod step 4b; A represents a distance (mm) (hereinafter referred to as xe2x80x9claser irradiation position Axe2x80x9d when so required) from an axial center position 23A of a YAG laser beam 23 to an edge 8al (see FIG. 20) of the sheath projection 8a on the premise that a direction toward the sheath 8 is a positive direction and a direction toward the tie rod 4 is a negative direction; H represents heat input (kj/cm) by the YAG laser beam 23; D represents a beam converging diameter (mm) of the YAG laser beam 23; W represents a supply (g/m) of a welding rod 30 for one meter of welding length; and L represents an overlap (mm) (see FIG. 20) of the inner surface 8a5 of the sheath projection 8a with the base 4b3 of the tie rod step 4b in the state where the sheath projection 8a is fitted onto the tie rod step 4b. FIG. 17 shows a relationship between the heat input parameter Po and the analysis parameter P. According to FIG. 17, the heat input parameter Po becomes 0 when the analysis parameter P is in the range of xe2x88x920.5 to 0.5 to achieve the perfect welding. More specifically, as can be seen from FIG. 17, if values for the gap G, laser irradiation position A, heat input H, beam converging diameter D, control rod supply W and overlap L are given, it is possible to find out the state after welding by the heat input parameter Po since the heat input parameter Po is dependent on the analysis parameter P. According to the inventors"" research, the most satisfactory conditions of the above values are in the following range: 0 to 0.3 mm of the gap G; 0 to xe2x88x920.5 mm of the laser irradiation position A; 0.89xc2x10.2 kj/cm of the heat input H; 0.57 to 0.6 mm of the beam converging diameter D; 3.16 to 4.06 g/m of the welding rod supply W; and 0.3 to 0.6 of the overlap L. FIG. 18 is a conceptual block diagram showing a general construction of an automatic YAG laser welding machine which performs the automatic welding using the above analysis parameter P. Among the elements shown in FIG. 18, those also shown in FIG. 5 of the first embodiment are denoted by the same reference numerals, and explanations therefor will be omitted in the following description. In FIG. 18, the automatic YAG laser welding machine 27 is provided with a laser scanning two-dimensional displacement sensor (not shown) attached to the machining head 17f, an welding rod supply device (not shown) for performing an automatic supply of a welding rod 30, which is to be described later in this specification, as being attached to the machining head 17f, a processor 29 which is connected with the control device 19 via a signal line 28, and a servo motor (not shown) for moving the machining head 17f to a welding start position and a welding completion position which are instructed by the control device 19. The processor 29 calculates the welding start position, welding completion position, gap G and overlap L from values detected by the laser scanning two dimensional displacement sensor, and further calculates the laser irradiation position A, heat input H, beam converging diameter D and welding rod supply W from the gap G and overlap L using the analysis parameter P. Next, details of the method for manufacturing a control rod for boiling water reactor of the present embodiment using the above-described automatic YAG laser welding machine 27 will be described. FIG. 19 shows a scanning method of the laser scanning two dimensional displacement sensor; FIG. 20 is a cross-sectional view taken along the section plane indicated by XXxe2x80x94XX in FIG. 19; and FIG. 21 is a longitudinal sectional view taken along the section plane indicated by XXIxe2x80x94XXI in FIG. 19. Referring to FIGS. 19 to 21, the automatic YAG laser welding machine 27 detects coordinates of an edge 8b1 (see FIG. 20) of a recess 8b of the sheath 8 and an outer corner 4b2 (see FIG. 20) of the step 4b near a tip of the tie rod 4 by automatically scanning in a direction indicated by the arrow H in FIG. 19. Also, the automatic YAG laser welding machine 27 detects coordinates of both edges 8a2 and 8a3 (see FIG. 21) of the projection 8a of the sheath, a height of the base 4ba (see FIG. 21) of the step 4b of the tie rod 4 and a height of an outer surface 8a4 of the sheath projection 8a by scanning in a direction indicated by the arrow I in FIG. 19. The processor 29 calculates the gap G between the sheath 8 and the tie rod 4 and the overlap L of the sheath 8 with the tie rod 4 from the data which are obtained by the two scannings of the laser scanning two dimensional displacement sensor as well as a length of the sheath projection 8a (a distance between the edge 8a1 of the sheath projection 8a and the edge 8b1 of the sheath recess 8b) and a thickness of the sheath 8 which are inputted by, for example, the operator. The coordinates of the both edges 8a2 and 8a3 of the projection 8a of the sheath 8 which are obtained by the above scanning are used as the welding start position and the welding completion position as they are. Also, the processor 29 calculates the laser irradiation position A, heat input H, beam converging diameter D and welding rod supply W to achieve the analysis parameter P of not less than xe2x88x920.5 to not more than 0.5 by using the thus obtained gap G and overlap L. At this point, a value of the laser irradiation position A is set to a negative value (i.e. to be shifted in a direction toward the tie rod 4) in advance of the calculation by, for example, the operator in view of the prevention of the melt-down of the sheath 8 similarly to the first and the second embodiment. The control device 19, which has obtained from the processor 29 the welding start and completion positions, gap G, laser irradiation position A, heat input H, beam converging diameter D, welding rod supply W and overlap L, controls the laser welding machine 17 and the laser oscillator 18, and performs the automatic laser welding of the sheath 8 on the tie rod 4, so that the welding rod 30 is irradiated with the YAG laser beam 23 as being placed at a position corresponding to the axial center position 23A of the YAG laser beam 23 which is shifted toward the tie rod 4 (in a direction opposite to the sheath 8) from the end surface 4b1 of the tie rod step 4b as shown in FIGS. 22 and 23, thereby automatically achieving the perfect weld penetration. According to the present embodiment described above, since the YAG laser beam 23 irradiates the welding rod 30, heat generated by the irradiation is transferred from the welding rod 30 to the sheath 8. In particular, since the welding rod 30 is irradiated with the YAG laser beam 23 which is shifted toward the tie rod 4 in the same manner as in the first and second embodiments, a surface of the tie rod 4 is irradiated with the YAG laser beam 23 if the irradiation position is erroneously deviated from the welding rod 30. More specifically, heat generated by the irradiation transfers from the surface of the tie rod 4 to the sheath 8 via the tie rod step 4b in the same manner as in the first embodiment. Therefore, according to the present embodiment, the melt-down of the sheath 8 is prevented without fail to achieve the good weldability. Further, according to the present embodiment, since the automatic YAG laser welding machine 27 performs the laser welding to automatically achieve the perfect weld penetration by calculating the laser irradiation position A, heat input H, beam converging diameter D and welding rod supply W, it is possible to prevent the melt-down of the sheath 8 more securely to achieve the good weldability. Moreover, owing to the automatic laser welding, effects such as a reduction in workload of welding operators and improvements in productivity of control rods are achieved. Although the present embodiment is described in connection with the welding of the sheath 8 on the tie rod 4, it is possible to perform the automatic weldings of the sheath 8 on the handle 5, and the sheath 8 on the velocity limiter base member 6a by the same process steps to achieve the same effects.
055219500	abstract	A tool set and a method of using those tools in combination is disclosed that are especially well adapted to the function of rearranging and/or replacing the control rods and fuel supports in a boiling water reactor. The tool set includes a grapple that is capable of simultaneously picking up both a control rod and its associated fuel support. A separate unlatching tool is provided for pulling the control rod's release handle in order to decouple the control rod from a control rod drive. A storage rack that may be mounted in the reactor pressure vessel is provided for storing a fuel support and a pair of control rods when the positions of selected control rods are being shifted about the reactor core area. In the method aspect of the invention, the unlatching tool is used to pull the control rod's release handle. Thereafter, the grapple lifts the control rod and its associated fuel support as a unit. When rearranging the positions of the control rods, a first control rod and its associated fuel support are placed the storage rack. Then a second control rod/fuel support assembly is removed in a similar manner and the second control rod is placed in the storage rack. Thereafter, the first control rod may be removed from the storage rack and placed in the position formally occupied by the second control rod with the same fuel support that was removed from the second location.
	claims	1. A method for removing debris from nuclear power reactor coolant, the method comprising:identifying a flow path from the reactor to a coolant source where coolant will flow when escaping from a reactor system;flooding the coolant source;operating the reactor to produce electricity with the coolant source flooded; andafter the flooding, installing a coolant filter in the flow path and outside the coolant source. 2. The method of claim 1, wherein the installing is performed during an operational outage of the nuclear power reactor. 3. The method of claim 1, wherein the coolant source is a suppression pool holding coolant that is injected into the reactor during a transient. 4. The method of claim 3, wherein the flow path passes through at least one of a floor grating in a containment building of the nuclear power reactor and a downcomer tube connecting a drywell of the nuclear power reactor to the suppression pool. 5. The method of claim 4, wherein the installing includes installing a first coolant filter substantially throughout an intersection of the drywell with the downcomer tube and a second filter under the floor grating. 6. The method of claim 1, wherein the filter includes a plurality of rigid and open channels through which coolant can flow. 7. The method of claim 6, wherein the filter is fabricated of only metal and does not substantially absorb any coolant. 8. The method of claim 1, wherein the installing installs the coolant filter within a containment building of the nuclear power reactor so as to come into contact with the coolant only in the instance of a leak when the coolant flows from the reactor into the source. 9. The method of claim 1, wherein the installing installs the coolant filter entirely vertically above the coolant source, and wherein the coolant source includes no filter. 10. The method of claim 1, wherein the coolant source is a suppression pool including a vent to receive steam to be condensed in the suppression pool, wherein the suppression pool is connected to an injection line connecting coolant from the suppression pool to the reactor, and wherein the installing installs the coolant filter entirely separate from the vent and the injection line. 11. The method of claim 1, wherein the installing is performed with the coolant source in a flooded state throughout the installing. 12. The method of claim 6, wherein the filter includes a plurality of waveform plates, and wherein the channels are created by paired peaks and troughs of directly adjacent plates. 13. The method of claim 6, wherein the channels extend at an angle from a central axis of the filter. 14. The method of claim 6, wherein the flow path is in a containment building and originates at a failure in the reactor system, and wherein the filter is installed in the flow path in an open air position in the containment. 15. The method of claim 1, wherein,the coolant source is a suppression pool including a vent to receive steam that is condensed in the suppression pool,the suppression pool is connected to an injection line connecting coolant from the suppression pool to the reactor,the suppression pool is in a flooded state throughout the installing, andthe coolant filter includes a plurality of angled channels forms between adjacent waveform plates.
046876278	description	DETAILED DESCRIPTION OF THE INVENTION In the following description, like reference characters designate like or corresponding parts throughout the several views of the drawings. Also, in the following description, it is to be understood that such terms as "forward", "rearward", "left", "right", "upwardly", "downwardly", and the like, are words of convenience and are not to be construed as limiting terms. In General Referring now to the drawings, and particularly to FIG. 1, there is shown several fuel assemblies, in which the central one is generally designated by the numeral 10 while the adjacent assemblies are indicated by 10A and 10B, in combination with an upper core support plate 12 and a spider assembly 14. The upper core support plate 12 is disposed above and extends across the tops of the fuel assemblies 10,10A,10B and, in turn, has the spider assembly 14 disposed above it. The fuel assembly 10 (it being understood that assemblies 10A and 10B are identical thereto), being shown in vertically foreshortened form in FIG. 1, basically includes a lower end structure or bottom nozzle 16 for supporting the assembly on a lower core plate (not shown) in the region of a reactor (not shown), and a number of longitudinally extending guide thimbles 18 which project upwardly from the bottom nozzle 16. The assembly 10 further includes a plurality of transverse grids 20 axially spaced along the guide thimbles 18 and an organized array of elongated fuel rods 22 transversely spaced and supported by the grids 20. Also, the assembly 10 has an instrumentation tube 24 located in the center thereof and an upper end structure or top nozzle 26 attached to the upper ends of the guide thimbles 18. With such an arrangement of parts, the fuel assembly 10 forms an integral unit capable of being conveniently handled without damaging the assembly parts. As mentioned above, the fuel rods 22 in the array thereof in the assembly 10 are held in spaced relationship with one another by the grids 20 being spaced along the fuel assembly length. Each fuel rod 22 includes nuclear fuel pellets (not shown) and the opposite ends of the rod are closed by upper and lower end plugs (not shown). The fuel pellets composed of fissible material are responsible for creating the reactive power of the reactor. A liquid moderator/coolant such as water, or water containing boron, is pumped upwardly through the fuel assemblies of the core in order to extract heat generated therein for the production of useful work. The upper core support plate 12, being conventional, extends across the top of the fuel assembly 10 as well as across the top of the other fuel assemblies, such as adjacent fuel assemblies 10A,10B arranged within the core. To control the fission process, the core plate 12 has a number of coolant flow openings 28 defined therethrough (only one being seen in FIG. 1) to allow coolant to pass upwardly through the core. At least some of these openings 28 are aligned over several of the guide thimbles 18 such that the improved water displacer rods 30 of the present invention (one of which is seen in FIG. 1) connected at their upper ends to the spider assembly 14 can be moved by the spider assembly at selected times during operation of the reactor down through the core plate 12 and and be inserted into the respective guide thimbes 18 of fuel assemblies 10,10A,10B so as to displace coolant from the thimbles. Improved Water Displacer Rod Generally speaking, water displacer rods, as their name implies, are inserted into guide thimbes in the fuel assemblies to initially displace moderator-coolant water therein and decrease the reactivity of the reactor core. Thus, the purpose of displacer rods is to displace moderator water and not to absorb neutrons. Then, at some later point during the core cycle as reactivity is consumed, the rods are removed from the core so that the amount of moderation and therewith level of reactivity in the core are increased. In order for the displacer rods to carry out their intended purpose satisfactorily, it would seem that a primary goal might be to design the rods so that they will have a high probability of successfully withstanding the extreme pressures generated within the reactor core, which often reach, for example, 2200 psi, so as to avoid rupture and entry of water therein. However, assuming that failure of a displacer rod specifically designed to withstand high external pressure will inevitably occur, it would seem that a secondary goal might then be to design the rods so that little or none of the displaced water will be able to enter the ruptured rod. The improved water displacer rod 30 of the present invention, as illustrated in greater detail in FIG. 2, satisfies both of these primary and secondary design goals. As seen in FIG. 2, the improved water displacer rod 30 basically includes an elongated hollow hermetically-sealed tubular member 32 and a plurality of pellets 34 disposed in a stacked relationship within the tubular member. The tubular member 32 is formed by an elongated thin-walled, metallic cladding or tube 36 having respective upper and lower end plugs 38,40 for sealing the opposite ends of the tube. The upper end plug 38 has an upwardly extending integrally formed stem section 42 with an externally threaded end 44 for connection to the spider assembly 14. The lower end plug 40 is cone-shaped. The pellets 34, tube 36 and end plugs 38,40 are all preferably composed of Zircaloy material. The hollow tube 36 is thin-walled to minimize its moment of inertia and thereby increase its lateral flexibility which adapts the dispacer rod incorporating the tube for insertion into fuel assemblies being in a variety of structural conditions, such as ones which are warped or bowed do toextended use in the extreme environments found in nuclear reactor cores. The pellets 34 which fill the tube 36 between its end plugs 38,40 bolster its resistance to collapse due to the high pressures imposed upon the exterior of the tube while resident in the reactor core. At least a substantial proportion of the pellets 34 of each dispacer rod 30 have the construction seen in FIGS. 2-5. The pellet 34 has a body 46 which fits concentrically within the interior surface of the tube 36 and has a hollow annular cross-sectional shape defining a central void 48 through the pellet. The use of hollow pellets minimizes the mass added to the weight of the rod 30 by the addition of the pellets. Also, a pair of solid webs 50,52 extend across and close the void 48 at the opposite ends of the pellet body 46 so as to encapsulate or seal the void of each individual pellet. Therefore, although the stack of pellets 34 augments the collapse resistance of the tube 36, should any breach of the tube still occur the central voids 48 of the pellets cannot fill with reactor coolant. Consequently, little or no water will enter the failed tube because the water has no empty space therein which is accessible to it. In effect, the rod 30 contains a double barrier against entry of moderator water into the rod interior. The body 46 and one end web 50 of the Zircaloy pellet 34 can be fabricated by drilling the central bore of void 48 in ground bar stock having the desired outside diameter. Then the other end web 52 in the form of a cap could be stamped from Zircaloy sheet material and coined to form the weld projections 54 shown in FIG. 6. The body 46 and cap 52 can then be resistance welded together using conventional techniques, such as by using welding heads 56 which apply force and electric current to both ends of the pellet 34, as diagrammatically depicted in FIG. 6. Other techniques could also be used to attach the cap 52 to body 46. By using the end webs 50,52, the pellet 34 can be thinner walled but yet more resistant to external pressure than a purely annular pellet without solid ends due to the radial support provided by the webs at each end of the pellet 34. In summary, the annular pellet body 46 within its ends sealed by webs 50,52 encapsulates the central void 48, minimizes the mass of material in the displacer rod 30 and assures that the rod 30 will not be flooded in the event of tube rupture. FIGS. 7-11 illustrate alternative forms of the pellet 34. In FIG. 7, a pellet 58 is composed of a pair of identical halves which each include a short body portion 60 and a solid web 62 integrally formed on one end of the body portion. Then the two body portions 60 are welded together at their respective open ends 63 so as to seal the void 64 defined by the welded pellet halves. FIG. 8 illustrates a pellet 66 substantially identical to the pellet 34 of FIG. 4, but having the added feature of its void 67 being prepressurized with an inert gas through a passage 68 which is then welded shut at 70. This would allow the pellet 66 to have an even thinner wall and still withstand the same leve of external pressure as pellet 34. FIG. 9 shows a pellet 72 in which each of the webs is a cap 74 similar to the cap 52 of the pellet 34. As in the case of cap 52, each cap 74 is attached, such as by electric welding, to an opposite end of the hollow body 76 to form the pellet 72. FIG. 10 illustrates a pellet 78 having the configuration of the pellet 58 of FIG. 7, but being formed of two identical pieces each of which is composed of a hollow annular body 80 with an integrally connected end solid web 82 which are generally similar to the body 46 and integral web 52 of the pellet 34. The two pieces are then welded together at their respective open ends to seal the void 83 formed by the pieces. The pellet 78 is approximately twice the length of the pellet 58 shown in FIG. 7. Finally, FIG. 11 shows a pellet 84 which is substantially identical to pellet 34 absent its end cap 52. The pellet 84 does not encapsulate its central void 86 but its integral web 88 does provide radial support. Also, when the pellets 84 are disposed in a stacked relationship within a displacer rod 80 with each pellet 84 oriented in the same way in the stack with respect to adjacent pellets, the end solid web 88 of each pellet 84 contacts the open end 90 of the next pellet 84 in the stack thereof such that, in effect, the respective voids 86 are individually enclosed, one from the next. It is thought that the improved water displacer rod of the present invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement thereof without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred or examplary embodiment thereof.
	description	The present application is a U.S. national stage application under 35 U.S.C. § 371 of PCT/US2013/056023 filed Aug. 21, 2013, which claims the benefit of U.S. provisional application No. 61/694,058, filed Aug. 28, 2012, the disclosures of which are incorporated herein by reference in their entirety. The field of the present invention relates to systems and methods for storing nuclear fuel. A freestanding fuel rack includes an array of vertical storage cavities used to store nuclear fuel in an upright configuration. Each storage cavity generally provides a square prismatic opening to store one spent nuclear or fresh (unburned) fuel. The cross section of the openings is slightly larger than that of the fuel assembly to facilitate the latter's insertion or withdrawal. From the structural standpoint, the fuel rack is a cellular structure supported on a number of pedestals that transfer the dead load of the rack and its stored fuel to the pool's slab. It is preferable to install the racks in a freestanding configuration to minimize cost and dose (if the pool is populated with irradiated fuel). The rack modules in a fuel pool typically have the appearance of a set of rectangular cavities arranged in a rectilinear array. The racks are typically separated by small gaps. Freestanding racks, however, are liable to slide or rotate during seismic event. If the plant's design basis is moderate then the kinematic movement of the racks may not be enough to cause inter-rack collisions or rack-to-wall impacts. However, if the seismic event is strong then the response of the racks may be too severe (e.g., large displacements, significant rack impact forces, etc.) to be acceptable. Reducing the kinematic response of the racks under strong seismic events (e.g., earthquakes) while preserving their freestanding disposition is therefore desirable. The present invention is directed toward a system and method for minimizing lateral movement of one or more nuclear fuel storage racks in a storage pool during a seismic event. In both the system and the method. Lateral movement of a storage rack may be limited either by limiting lateral movement of the rack toward the side wall of the storage pool, or by limiting lateral movement of a first storage rack with respect to another object. In a first separate aspect of the present invention, a system for storing nuclear fuel includes a nuclear fuel storage rack and a bearing pad. The storage rack includes an array of cells, each cell configured to receive and store nuclear fuel rods, a base plate configured to support the array of cells, and a support structure configured to support the base plate and to allow cooling fluid to circulate under and up through apertures in the base plate. The bearing pad is coupled to the support structure and configured to limit lateral movement of the storage rack independent from lateral movement of the bearing pad. The base plate defines a base plate profile in a horizontal plane of the base plate, and the bearing plate defines a bearing pad profile in the horizontal plane of the base plate, wherein the bearing pad profile extends outside of the base plate profile. In a second separate aspect of the present invention, the system for storing nuclear fuel includes first and second adjacent storage racks and a bearing pad. Each storage rack includes, respectively, an array of cells, each cell configured to receive and store nuclear fuel rods, a base plate configured to support the an of cells, and a support structure configured to support the base plate and to allow cooling fluid to circulate under and up through apertures in the base plate. The bearing pad is coupled to the support structure of each of the storage racks, and it is configured to limit lateral movement of each storage rack independent from lateral movement of the bearing pad. In a third separate aspect of the present invention, a method of placing a nuclear fuel storage rack into a storage pool includes placing a bearing pad on the bottom of the storage pool, then placing a storage rack into the storage pool. The storage rack includes an array of cells, a base plate, configured to support the array of cells, and a support structure configured to support the base plate, wherein each cell of the array of cells being, configured to receive and store nuclear fuel rods. In placing the storage rack, the bearing pad is coupled to the support structure, and the bearing pad is configured to limit lateral movement of the storage rack independent from lateral movement of the bearing pad. The base plate defines a base plate profile in a horizontal plane of the base plate, the bearing pad defines a bearing pad profile in the horizontal plane of the base plate, and the bearing pad profile extends outside of the base plate profile. In a fourth separate aspect of the present invention, a method of placing, a first nuclear fuel storage rack and a second nuclear fuel storage rack into a storage pool includes placing a bearing pad on a bottom of a storage pool, placing the first storage rack into the storage pool, then placing, the second storage rack into the storage pool. Each storage rack includes, respectively, an array of cells, each cell configured to receive and store nuclear fuel rods, a base plate configured to support the array of cells, and a support structure configured to support the base plate and to allow cooling fluid to circulate under and up through apertures in the base plate. The first storage rack is placed into the storage pool so that the hearing pad is coupled to the respective support structure of the first storage rack. The second storage rack is placed into the storage pool so that the bearing pad is coupled to the respective support structure of the second storage rack. The bearing pad is configured to limit lateral movement of each storage rack independent from lateral movement of the bearing pad. In a fifth separate aspect of the present invention, any of the foregoing aspects may be employed in combination. Accordingly, an improved system and method for minimizing lateral movement of one or more nuclear fuel storage racks in a storage pool during a seismic event are disclosed. Advantages of the improvements will be apparent from the drawings and the description of the preferred embodiment. The description of illustrative embodiments according to principles of the present invention is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description of embodiments of the invention disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down.” “lull,” “right,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation unless explicitly indicated as such. Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected” and similar refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Moreover, the features and benefits of the invention are illustrated by reference to the preferred embodiments. Accordingly, the invention expressly should not be limited to such preferred embodiments illustrating some possible non-limiting combinations of features that may exist alone or in other combinations of features; the scope of the invention being defined by the claims appended hereto. Turning in detail to the drawings, an array of fuel storage racks 101 is shown in FIG. 1. Each storage rack 101 is itself an array of fuel cells 103, and each is generally square in cross section, with each fuel cell 103 also being square in cross section. Such storage racks, and their construction, are generally known in the art. For example, U.S. Pat. No. 4,382,060 to Holtz et al. describes a storage rack and details how each fuel cell is configured to receive and store nuclear filet. Typically, the storage racks are used for storing nuclear fuel underwater in storage pools. Each storage rack 101 includes a base plate 105, which may be formed integrally as the bottom of the fuel cells 103, or it may be coupled with an appropriate fastening system. Each base plate 105 is disposed atop a bearing pad 107, with a support structure (not shown in FIG. 1; See, e.g., FIG. 4) providing structural support between, and coupling together, the base plate 10 and the bearing pad 107. The bearing pad 107 may, in certain instances, be considered a coupler pad in that it couples multiple fuel racks together as discussed in greater detail below. The support structure, as is further discussed below, is also constructed to allow cooling fluid (e.g., water, among other liquids) to circulate under the base plate and up through apertures in the base plate. As shown in the embodiment depicted in FIG. 1, the bearing pad 107 may be a single sheet of material that contiguously extends under all the storage racks 101 forming the array. When used in this configuration, the bearing pad acts to couple the various racks of the array to each other, so that each storage rack 101 is limited in the amount of independent lateral movement with respect to both the bearing pad 107 and each of the other storage racks 107. By restricting the lateral movement of the individual storage racks in this manner, the bearing pad causes all the storage racks coupled thereto to move largely in unison in any direction, and significant movement of the entire coupled array occurs only when the bearing pad slides on the bottom surface of the pool. Thus, the bearing pad aids in reducing the kinematic response of individual racks under strong seismic conditions by coupling together the individual racks so that the kinematic responses of all the racks together are effectively coupled together, and the kinematic response of the some racks within the array may serve as at least a partial offset to the kinematic response of other racks within the array. In addition, while the bearing pad serves to could each storage rack in the array of storage racks together, it also enables each storage rack to effectively remain free-standing. Having free-standing storage racks in a pool is important in that each storage rack may be placed and removed individually and separately from each of the other storage racks. A top view of an array of storage racks 111 is shown in FIG. 2. These storage racks 111 are coupled to a bearing pad 113 as discussed above. In this embodiment, the bearing pad 113 extends outward from the periphery of the array of storage racks 111. This outward extension of the bearing pad 113 is configured to maintain a predetermined distance between the storage racks and the side of a storage pool (not shown). By maintaining the predetermined distance between the storage racks and the side of as storage pool, the array of storage racks 111 may be prevented from moving close enough to the side of the storage pool so that an impact between one or more of the storage racks 111 and the side wall of the storage pool is likely during a seismic incident. This predetermined distance, which is the distance the bearing pad 113 extends beyond the outer lateral dimensions of the storage racks, may be as little as about inch. Preferably, the largest outer lateral dimension of each storage rack is defined by the base plate for each storage rack. Those of skill in the art will recognize that the size of this predetermined distance may be influenced by many other factors associated with the configuration of storage racks and the configuration of the storage pool. By coupling multiple storage racks with one or more bearing pads, the movement of the freestanding racks can be significantly reduced, if not minimized, on the pool's surface under a severe earthquake. For purposes of this disclosure, a severe earthquake or seismic event is empirically defined as one in which the seismic accelerations are large enough to move a short square block of steel (i.e., a squat and rigid body) on the pool slab by at least 2 inches. By coupling storage racks together using the bearing pads, the relatively uncoordinated motion of the freestanding storage racks produced by a seismic event is exploited to dissipate dynamic energy of the various individual storage racks. During a seismic event, the fuel modules attempt to move in various different directions and thereby exert the lateral forces on the storage racks, which in turn exert lateral forces on the bearing pad(s). This leads to a reduced net resultant force, when the lateral forces of all coupled storage racks are combined. The bearing pad therefore preferably has a bottom surface which provides sufficient friction, under load, with the bottom of the storage pool. During seismic events that are less than a severe seismic event, the lateral forces generated by coupled storage tanks will generally not exceed the friction force between the loaded bearing pad and the bottom of the storage pool, wherein the load on the bearing pad has contribution from the combined vertical load of all participating pedestals. In such circumstances, the bearing pad should not slide on the bottom of the storage pool, and thus the kinematic movement of the racks will be substantially suppressed. A seismic analysis of the coupled storage rack array shown in FIG. 2 has been performed, and the under three dimensional seismic motion, the sliding response of the coupled storage rack array may be reduced by an order of magnitude as compared to the sliding response of freestanding storage racks that are not coupled by a bearing pad. FIGS. 3 and 4 illustrate an embodiment of the support structure that may be used to couple between the base plates of the storage racks and the bearing pad. For simplicity and purposes of illustration, a smaller version of a storage rack 121 is shown in FIG. 3, having only two fuel cells 123 per side. In addition, as an alternative embodiment, only one storage rack 121 is placed on the bearing pad 125. In this alternative embodiment, the bearing pad 125 helps to maintain spacing between the storage rack 121 and the walls of the storage pool, and between other storage racks placed on their own bearing pads that may be placed within the same storage pool. However, by placing each storage rack within a storage pool on its own individual bearing pad, much of the advantage of coupling the storage racks to help offset the kinematic response of individual storage racks may be lost. The base plate 127 of the storage rack 121 has multiple support pedestals 129 affixed thereto, and these pedestals serve as the support structure between the base plate 127 and the bearing pad 125. The spacing between the support pedestals 129 is provided for liquid to circulate between the base plate 127 and the bearing pad 125. The base plate 127 also includes apertures 131, which allow the cooling liquid to pass through the base plate 127 and rise up into the fuel cells 123. The support pedestals 129 in this embodiment are each disposed within a recess cavity 133 formed in the bearing pad 125. The support pedestals 129 and the respective recess cavities 133 may have any desired shape which enables the support pedestals to couple with the recess cavities. Two design features for a support pedestal and/or a recess cavity are preferably included in the configuration of one or both of the paired support pedestals and the recess cavities. The first feature is the inclusion of a guide surface on one or both of the support pedestal 129 and the recess cavity 133. The guide surface aids in guiding one into the other when the storage rack 121 is lowered onto the bearing pad 125 within the storage pool. As can be seen in FIG. 4A, the support pedestal 129 includes a rounded end 137 to serve as a guide surface, and the recess cavity 133 includes a beveled edge 139 to server as a guide surface. Both the rounded end 137 and the beveled edge 139 aid in guiding the support pedestal 129 into the recess cavity 133 when the storage rack 121 is lowered into position on the bearing pad 125 within a storage pool, especially when every support pedestal 129 and every recess cavity 133 include such guide surfaces. The second feature that is included in the pairs of support pedestals and recess cavities is the lateral tolerance, t, between the maximum effective outer dimension of the support pedestal, OD, and the minimum effective inner dimension of the recess cavity, ID. FIG. 4B shows the profile 141 of the support pedestal 129 and the profile 143 of the recess cavity 133 along the line T. Since each profile 141, 143 is round, the maximum effective outer dimension of the support pedestal, OD, is the diameter of the support pedestal, and the minimum effective inner dimension of the recess cavity, ID, is the diameter of the recess cavity, along the line T. When this lateral tolerance, t, for each support pedestal/recess cavity pair is the same, it defines the maximum lateral distance the storage rack 121 can move laterally independent of the bearing pad 125. Preferably, this lateral tolerance, t, is no more than the predetermined distance that the bearing pad 125 extends beyond the outer lateral dimensions of the storage rack, the latter being discussed above. In the case of two storage racks coupled together by a bearing pad, this lateral tolerance is preferably less than or equal to half the predetermined distance separating the base plates of adjacent storage racks. Those of skill in the art will recognize that either or both of the support pedestals and the recess cavities may have profiles that are of any desired geometrical shape that enables coupling between the base plate and the bearing pad, and allows for limited lateral movement of the storage rack with respect to the bearing pad within an established lateral tolerance. By including the lateral tolerance, t, at the point of coupling between the bearing pad and the storage rack, movement of the storage rack, independent of movement of the bearing pad, is limited by the amount of the lateral tolerance, t. Any lateral movement of the storage rack that is greater than the lateral tolerance, t, will necessarily require either movement of the bearing pad or decoupling of the storage rack from the bearing pad. Due to the weight of a fully loaded storage rack, decoupling is unlikely. A bearing pad 151 having multiple recess cavities 153 is illustrated in FIG. 5. This bearing pad is configured to be placed in the bottom of a storage pool and have a plurality of storage racks lowered into the pool so that each support pedestal of the storage racks couples into one of the recess cavities 153 of the bearing pad 151. The bearing pad 151 may therefore have as many recess cavities as all the storage racks combined have support pedestals. The bearing pad also has a substantially flat bottom, which enables it to slide on the bottom of the pool under the loads that ma be caused by a seismic event. The bottom of the bearing pad may also be coated to help control the amount of sliding that may occur. As an alternative, if the storage racks have support pedestals of different lengths extending from the base plate, then the longer support pedestals may be coupled into recess cavities, and the shorter support pedestals may extend to the top surface of the bearing pad for supporting the storage rack, but such shorter support pedestals would not couple to the hearing pad, in that they would not serve to restrict lateral movement of the storage rack during a seismic event. An alternative embodiment for the support structure between the base plate 161 of a storage rack and a bearing pad 16 is shown in FIG. 6. In this embodiment, the bearing pad 163 includes upward-extending support columns 165, and the base plate 161 includes downward-extending receptacles 167 to couple with each support column. The support columns include top beveled edges 169 to act as a guide surface, and the receptacles include a lower beveled edge 171 to similarly act as a guide surface. As should be evident from the different embodiments described, the support structure and the base plate be couple together by forming the support structure as a first engagement feature affixed to the base plate (e.g. support pedestals, receptacles) and coupling the first engagement feature to a second engagement feature formed as part of or affixed to the bearing pad (e.g., recess cavities, support columns). Thus, it should be apparent that the first and second engagement features may take on any desirable configuration from those described above, to combinations of those described above, and to other structural configurations, with the following concepts generally taken into account: 1) providing appropriate, structural support and lift to the storage rack to thereby allow circulation of cooling liquid under and up through the base plate, and 2) limiting lateral movement of the storage rack independent from the bearing pad. The first aforementioned concept allows appropriate circulation of cooling liquid, while the second concept is used to reduce the likelihood of an impact with the wall of a storage pool when the bearing pad is used with a single storage rack, and also to reduce lateral movement of an array of storage racks during a seismic event when the bearing pad couples two or more storage racks together. An array of two storage racks 181 disposed in a storage pool 191 is shown in FIG. 7. The two storage racks 181 are coupled together by a single bearing pad 183, with the base plates 185 of the storage racks 181 having support pedestals 187 that extend down into recess cavities (not shown in this figure) formed in the bearing pad 183. As an alternative, the bearing pad may be integrally formed in the bottom surface 193 of the storage pool 191. Each storage rack 181 also includes a collar 189 affixed to a top of and extending around each rack 181, each collar 189 forming a spacer at the top of each storage rack 181. Each collar 189 extends outward from the sides of the storage rack 181 to which it is affixed, respectively, toward the collar 189 on the other storage rack 181, so that there is a second predetermined distance between the two collars 189. The base plates 185 of each storage rack 181 extends outward from the respective storage rack 181 further than the collar 189, such that the predetermined distance between the two base plates 185 is greater than the predetermined distance between the two collars 189. Configured in this way, and considering the lateral tolerance of the support pedestals 187 within the recess cavities, during a seismic event, the support pedestals and the recess cavities form a primary impact zone, the base plates 185 of the adjacent storage racks 181 form a secondary impact zone, and the collars 189 of the adjacent storage racks form a tertiary impact zone. The spacer for each storage rack may have other configurations, and need not extend around the entire top of the storage rack. For example, the spacers may be formed as individual outcroppings affixed to the storage racks, and set so that the spacers on one storage rack are opposite the spacers on an adjacent storage rack. The purpose is to set spacers between adjacent racks so that the spacers impact each other during a seismic event instead of the fuel cells of the adjacent racks impacting. FIG. 8 shows profiles of a storage rack and the bearing pad to which it is coupled in the horizontal plane of the base plate of the base plate of the storage rack, to show the difference in sizes, although each profile of each part shown in this figure is not to scale. In the configuration shown, the bearing pad extends entirely under the storage rack. The portion of the storage rack which includes the array of cells is the storage rack profile 201. The collar profile 203 is shown, along with the profile of attachment points 205 to the storage rack profile 201. The collar profile 203 is larger than, and extends outside of, the storage rack profile 201. The base plate profile 207 is shown, and it is larger than, and extends outside of, both the storage rack profile 201 and the collar profile 203. The bearing pad profile 209 is larger than and extends outside at the base plate profile 207. FIG. 9 shows profiles of an array of two storage racks and the associated bearing pad to which both are coupled, with the profiles being shown in the horizontal plane of the base plates of the storage racks. In this configuration, the bearing pad extends entirely under both storage racks. The portion of the storage racks which include the respective arrays of cells are the storage rack profiles 211. The collar profiles 213 for each storage rack are larger than the storage rack profile 211 for each respective storage rack. Similarly, the base plate profiles 215 for each storage rack are larger than the respective collar profiles 213. The bearing pad profile 217 is larger than the combined two base plate profiles 215, extending outside of both. An alternative embodiment of a bearing pad 221 is shown in FIGS. 10A-C. This bearing pad 221 includes four recess cavities 223. This bearing pad 221 may be placed under adjacent sides of two adjacent storage racks, with two support pedestals from each storage rack being placed in the four recess cavities 223. Alternatively, as illustrated in FIG. 10B, it may be placed under the corners of four adjacent storage racks (the outlines of the corners 225 are shown), with one support pedestal from each of the four storage racks being placed in the four recess cavities 223. In either of these embodiments, the support pedestals placed in the recess cavities are adjusted to be shorter than those that extend to the bottom of the storage pool and not placed in recess cavities. FIG. 11 shows profiles of an array of two storage racks and the associated bearing pads, of the type shown in FIGS. 10A-C, to which both the storage racks are coupled, with the profiles being shown in the horizontal plane of the base plates of the storage racks. The portion of the storage racks which include the respective arrays of cells are the storage rack profiles 231. The collar profiles 233 for each storage rack are larger than the storage rack profile 231 for each respective storage rack. Similarly, the base plate profiles 235 for each storage rack are larger than the respective collar profiles 233. In this configuration, each base plate is coupled at the corners to one of four separate bearing pads, and the bearing pad profiles 237 are shown in position with respect to the base plate profile 235. In this configuration, even though the bearing pads are dimensionally smaller than the base plates, the smaller bearing pad profiles 237 still extend outside of the base plate profiles 235, and each bearing pad is also coupled to both storage racks. As should be understood from the various embodiments of the bearing pad disclosed above, the bearing pad may couple to the entire support structure of a storage rack, or it may couple to only a portion of the support structure. For example, a bearing pad may be configured to couple to just the corners of the support structure, or one may be configured to couple along an entire side of the support structure, but not the support structure nearer the middle of the storage rack. While the invention ha been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. Thus, the spirit and scope of the invention should be construed broadly as set forth in the appended claims.
	abstract	Techniques for forming a directional drillhole for hazardous waste storage include identifying a subterranean formation suitable to store hazardous waste; determining one or more faults that extend through the subterranean formation; forming a vertical drillhole from a terranean surface toward the subterranean formation; and forming a directional drillhole from the vertical drillhole that extends in or under the subterranean formation and parallel to at least one of the one or more faults. The directional drillhole includes a hazardous waste repository configured to store the hazardous waste.
	summary
	abstract	A method and apparatus satisfying growing demands for improving the precision of angle of incidence of implanting ions that impact a semiconductor wafer and the precision of ribbon ion beams for uniform doping of wafers as they pass under an ion beam. The method and apparatus are directed to the design and combination together of novel magnetic ion-optical transport elements for implantation purposes. The design of the optical elements makes possible: (1) Broad-range adjustment of the width of a ribbon beam at the work piece; (2) Correction of inaccuracies in the intensity distribution across the width of a ribbon beam; (3) Independent steering about both X and Y axes; (4) Angle of incidence correction at the work piece; and (5) Approximate compensation for the beam expansion effects arising from space charge. In a practical situation, combinations of the elements allow ribbon beam expansion between source and work piece to 350 millimeter, with good uniformity and angular accuracy. Also, the method and apparatus may be used for introducing quadrupole fields along a beam line.
052415694	abstract	Neutron activation analysis method and apparatus are disclosed wherein a sample in a vacuum chamber is irradiated with neutrons, the time when and energy of emitted gamma rays from a sample are detected, and delayed Beta-electrons emitted from the sample are detected and the positions of emission are imaged. Time coincidence between detected gamma rays and delayed Beta-electrons is determined and the location of elements on the sample is established from the detected coincidence and the image of the location on the sample where the delayed Beta-electrons were emitted.
	summary
	claims	1. A method for designing a nuclear fuel assembly which is intended to be positioned in a nuclear reactor, the assembly comprising a plurality of guide tubes and a control cluster which comprises a plurality of control rods and a support for the control rods, the control rods and the guide tubes extending in parallel with a longitudinal direction, each of the control rods being received in a guide tube in order to form pairs comprising guide tubes/control rods, each of the guide tubes comprising a lower damping portion which comprises at least a section of reduced inside diameter, the lower damping portion configured to contain a fluid for damping a fall of the control rod which is received in the guide tube, the section of reduced inside diameter surrounding the control rod with a radial passage gap when the control rod is introduced in the guide tube, the method comprising:calculating an expected falling speed of the control rods upon entry into the lower damping portions when the control cluster falls in an event of a shutdown of the nuclear reactor;calculating, based on the falling speed, a progression of the falling speed of the control rods in the lower damping portions;calculating, based on the progression of the falling speed of the control rods in the lower damping portions, a maximum elevated pressure produced in the fluid contained in the lower damping portions;calculating, based on the maximum elevated pressure, a maximum circumferential stress produced in the lower damping portions; anddesigning the guide tubes as a function of the maximum circumferential stress so that a maximum stress admissible by the guide tube is not exceeded. 2. A method for designing a nuclear fuel assembly which is intended to be positioned in a nuclear reactor, the assembly comprising a plurality of guide tubes and a control cluster which comprises a plurality of control rods and a support for the control rods, the control rods and the guide tubes extending in parallel with a longitudinal direction, each of the control rods being received in a guide tube in order to form pairs comprising guide tubes/control rods, each of the guide tubes comprising a lower damping portion which comprises at least a section of reduced inside diameter, the lower damping portion configured to contain a fluid for damping a fall of the control rod which is received in the guide tube, the section of reduced inside diameter surrounding the control rod with a radial passage gap when the control rod is introduced in the guide tube, the method comprising:calculating an expected falling speed of the control rods upon entry into the lower damping portions when the control cluster falls in an event of a shutdown of the nuclear reactor;calculating, based on the falling speed, a progression of the falling speed of the control rods in the lower damping portions;calculating, based on the progression of the falling speed of the control rods in the lower damping portions, a maximum elevated pressure produced in the fluid contained in the lower damping portions;calculating, based on the maximum elevated pressure, a maximum circumferential stress produced in the lower damping portions; anddesigning the guide tubes as a function of the maximum circumferential stress; andverifying, using the maximum circumferential stress, that a maximum stress admissible by the guide tube has not been exceeded. 3. The method according to claim 1, wherein the calculating, based on the falling speed, of a progression of the falling speed of the control rod in the lower damping portion, is performed using a higher value for the radial passage gap and the step of calculating, based on the progression of the falling speed of the control rod in the lower damping portion, a maximum elevated pressure produced in the fluid contained in the lower damping portion, is performed using a lower value for the radial passage gap. 4. The method according to claim 3, wherein the higher value is the maximum statistical value for the passage gap. 5. The method according to claim 3, wherein the lower value is the minimum statistical value for the passage gap. 6. The method according to claim 2, wherein the calculating, based on the falling speed, of a progression of the falling speed of the control rod in the lower damping portion, is performed using a higher value for the radial passage gap and the step of calculating, based on the progression of the falling speed of the control rod in the lower damping portion, a maximum elevated pressure produced in the fluid contained in the lower damping portion, is performed using a lower value for the radial passage gap. 7. The method according to claim 6, wherein the higher value is the maximum statistical value for the passage gap. 8. The method according to claim 6, wherein the lower value is the minimum statistical value for the passage gap.
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060118261	summary	BACKGROUND OF THE INVENTION Field of the Invention The invention relates to a steam power station, in particular a nuclear power station, including a steam conduit leading through a wall and forming a fixed point with the wall for the introduction of forces and moments, a main valve connected to the steam conduit at the fixed point, without a high-pressure pipe being interposed, and satellite valves having smaller nominal widths than the main valve and being fastened to the housing of the main valve, without a high-pressure pipe being interposed. Such a steam conduit is known from German Patent DE 27 08 642 C3. That steam conduit is fed through the wall of a containment of a nuclear power station. It extends from a steam generator into the containment. The steam conduit forms a fixed point with the wall in a leadthrough through the wall. A conical supporting body is provided, inter alia, for that purpose. The fixed point serves for introducing forces and moments from the steam conduit into the wall, so that damage to the steam conduit is avoided. A German patent corresponding to French Patent FR 2 259 420 is cited in German Patent DE 27 08 642 C3. Three fittings shown therein are disposed in a row one behind the other so that passages form a straight pipe. Such a linear configuration can enter into mechanical vibrations, if no supports are provided. A solution to that problem was already mentioned in German Patent DE 27 08 642 C3. It is known from German Patent DE 27 08 642 C3 for the housing of a main valve to be connected directly to the fixed point outside the wall. The housings of a plurality of other valves are connected directly to that housing. Those other valves may be referred to as satellite valves, since they are disposed on circles around a center point of the main valve. Each satellite valve is connected directly to the main valve, without a pipe piece being interposed. In that case, the nominal width of the satellite valve is smaller than the nominal width of the main valve. The forces and moments which act on the satellite valves are introduced into the wall at the fixed point through the use of the so-called satellite configuration of valves on the steam conduit. No additional supports are needed. It has heretofore been customary for additional valves which are required and for which there is no room on the housing of the main valve, to be mounted separately. Specific supports for those additional valves were necessary for that purpose. Furthermore, precautions had to be taken to ensure that conduits required between valves which are supported at the fixed point on one hand, and additional valves on the other hand, could not be damaged by forces and moments which are introduced. SUMMARY OF THE INVENTION It is accordingly an object of the invention to provide a steam power station, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and in which no special supporting devices are necessary even for such additional valves. With the foregoing and other objects in view there is provided, in accordance with the invention, a steam power station, comprising a wall; a steam conduit leading through the wall and forming a fixed point with the wall for introduction of forces and moments; a main valve having a housing and a given nominal width, the main valve connected to the steam conduit at the fixed point, without a high-pressure pipe interposed; satellite valves having housings and nominal widths smaller than the given nominal width, the satellite valves fastened to the housing of the main valve, without a high-pressure pipe interposed; and at least one additional valve having a housing fastened to the housing of at least one of the satellite valves, without a high-pressure pipe interposed and without any support. It became clear, surprisingly, that even in the case of a valve configuration in which the known satellite configuration is supplemented by additional valves on the satellite valves in the manner described, forces and moments which take effect can be introduced into the wall without difficulty at the existing fixed point. This affords the advantage of permitting a markedly larger number of valves than heretofore to be held at a fixed point. There is no need for complicated additional vibration-proof supports. In accordance with another feature of the invention, the housings of a plurality of additional valves form a row and only the housing of the first additional valve in the row is fastened to the housing of a satellite valve. This affords the advantage of permitting even more additional valves than otherwise to be connected to a satellite valve, without a high-pressure pipe being interposed. In accordance with a further feature of the invention, there is provided at least one supplementary valve which can also be fastened through the use of its housing to the housing of an additional valve, without a high-pressure pipe being interposed and without any support. In accordance with a concomitant feature of the invention, there is provided a row formed of supplementary valves, this row can be fastened to the housing of an additional valve. In this case, the configuration and fastening are provided in a similar way to the row of additional valves. The steam conduit according to the invention affords the advantage of allowing all valves connected to such a steam conduit to be held securely in the wall at only one fixed point. Forces and moments acting on the valve group are advantageously introduced into the wall at only one fixed point. Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in a steam power station, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
	abstract	In a method and a device for testing a weld seam (8), located on the inner surface of a reactor pressure vessel (2), by which the outer circumference of an instrumentation nozzle (4) leading into the interior of this reactor pressure vessel (2) is welded onto the reactor pressure vessel (2), an ultrasound test probe (20) with a linear ultrasound transducer array (30) is inserted into the instrumentation nozzle (4), which ultrasound transducer array (30) is parallel to the central axis (12) of the instrumentation nozzle (4) in terms of its longitudinal direction, and is used to couple a transmitted ultrasound signal (S) into the instrumentation nozzle (4) in the region of the weld seam (8) and to receive a reflected ultrasound signal (R).
	abstract	An ion implanter for creating a ribbon or ribbon-like beam by having a scanning device that produces a side to side scanning of ions emitting by a source to provide a thin beam of ions moving into an implantation chamber. A workpiece support positions a workpiece within the implantation chamber and a drive moves the workpiece support up and down through the thin ribbon beam of ions perpendicular to the plane of the ribbon to achieve controlled beam processing of the workpiece. A control includes a first control output coupled to said scanning device to limit an extent of side to side scanning of the ion beam to less than a maximum amount and thereby limit ion processing of the workpiece to a specified region of the workpiece and a second control output coupled to the drive simultaneously limits an extent of up and down movement of the workpiece to less than a maximum amount and to cause the ion beam to impact a controlled portion of the workpiece.
051480409	description	DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to various figures of the drawing wherein like reference numerals refer to like parts there is shown at 20 in FIGS. 1 and 2 a radiation blocking shield constructed in accordance with this invention and arranged to be used with any type of radiation detecting probe 22. In accordance with a preferred embodiment of this invention the probe 22 is a small, hand-held unit like any of the types disclosed in the aforementioned patent applications of the assignee of this invention, although other probes can also be used. The probe 22, being a small, hand-held unit, is particularly suitable for use in the operating room to assist the surgeon in detecting and localizing the presence of radioactively tagged tissue 24 within the body of the patient. The probe consists of a cylindrical radiation shielding body, radiation detection means (not shown) located within the body, and collimating means (not shown) to establish the conical (solid angle of acceptance) field of view (shown by the broken lines designated by the reference numeral 26 in FIG. 1). The probe's body 22 has a proximal portion 22A of a generally cylindrical shape and size to be readily held in one's hand. The body portion 22A terminates in a distal portion or tip 22B extending at an acute angle, e.g., 60 degrees, to the longitudinal axis of the body portion. The angular orientation of the tip with respect to the hand grip portion 22A of the probe's body facilitates operator comfort and ease of aiming. In use the probe 22 is arranged to detect the presence of radiation within its field of view, and to provide electrical output signals indicative thereof, via a cable or wiring harness (not shown), to a conventional analyzer (not shown) or other conventional monitoring or imaging apparatus (not shown) so that the location of the source of radiation may be determined. Thus, the probe 22 is held adjacent to a portion of the patient's body usually exposed during surgical operations where the cancerous tissue is suspected to be in order to detect if any radiation is emanating from that site, thereby indicating that cancerous tissue is likely to be found there. As will be appreciated by those skilled in the art, radiation from the tagged tissue scatters off of the various surrounding body tissues or organs, thereby rendering the localization of the source of the radiation difficult. More importantly, current radiolabelled monoclonal antibodies also localize non selectively in liver and kidneys, providing intense background activity near tumor sites. The probe 22 provides significant shielding for radiation from all directions other than that within its field of view 26 by virtue of the materials used and the shape and organization of the probe. Thus, the probe 22 can be used with high energy radioisotopes, such as Indium 111, to expedite the localization procedure. As will be appreciated by those skilled in the art Indium 111 has approximately ten times the energy of Iodine 125 (e.g., 247 KEV versus 25-30 kev). Without good shielding and collimation the use of such high energy materials would be precluded for use in some applications, e.g., detecting tagged cancerous tissue located near the liver, kidneys, or blood vessels, any of which locations would include significant accumulations of the isotope on a non-specific basis. The use of shield 20 with the probe 22 provides a significant aid in the localization procedure since it serves to shield the probe from radiation emanating from sources within the probe's field of view 26 but located behind the tissue/organ 24 being examined by the probe. The shield 20 basically comprises a relatively thin sheet or disk formed of any suitable radiation blocking material, e.g., a material selected from the group comprising pure tungsten, tungsten alloys, tungsten powder suspended in gold, pure gold, gold alloys, pure platinum, and platinum-iridium alloys. The shield 20 is arranged to be placed within a space, e.g., an incision, in the body of the patient which is located immediately behind the tissue or organ 24 being investigated by the probe 22 so that the tissue/organ is interposed between the shield and the probe as shown in FIG. 1. The shield 20 is of a sufficient size, e.g., approximately 3 inches (7.62 cm) wide by 3.5 inches (8.89 cm) high, so that it completely covers the probe's field of view 26. By so doing any radiation from a source located behind the shield 20 will be blocked by it and thus prevented from reaching the probe. The shield is configured so that it is of an appropriate thickness to provide good radiation blocking characteristics without taking up substantial space within the patient's body. To that end when the shield is formed of tungsten it is approximately 1/8 inch (0.32 cm) thick. Inasmuch as the shield 20 is arranged to be located within the body of the patient, depending upon the material making up the shield, its entire exposed exterior surface 20A may be plated or coated to ensure that it is non-toxic. For example, when the shield is formed of tungsten, tungsten alloys, or tungsten powder suspended in gold, the shield is preferably chrome plated. Other suitable, non-toxic plating or coating materials may be used. The embodiment of the invention shown in FIG. 1 the shield 20 is arranged to be mounted onto the probe 22, whereas the embodiment of the shield shown in FIG. 2 is arranged to be used without attachment to the probe. The mounting of the shield 20 on the probe 22, as shown in FIG. 1 is effected by use of a mounting assembly 28. The assembly 28 basically comprises a mounting sleeve 30 and associated yoke 32. The sleeve 30 is a hollow tubular member having a central bore 34 configured to receive the distal end or tip 22B of the probe 22. The distal end 22B of the probe includes a window (not shown) through which the radiation within the field of view 26 may pass to the radiation detecting means in the probe's body. Each end of the central bore 34 of the sleeve is open so that radiation may pass through the lower end to the window unobstructed by the sleeve. The yoke 32 basically comprises two leg sections 32A, 32B. Each leg section is an elongated member formed of any material suitable for disposition within the body of a living being. The leg section 32A projects radially outward from the sleeve 30 and is fixedly secured thereto. The outer end of the leg section 32A extends perpendicularly to the remainder of the section 32A and is in the form of an elongated tube 40A. The leg section 32B is constructed similar to leg section 32A, with its perpendicularly extending portion 40B telescopically disposed within the tube 40A. The leg section 32B includes a free end 44 at which the shield 20 is fixedly mounted. Accordingly, the spacing between the sleeve 30 and the shield 20 can be adjusted by sliding the portions 40A and 40B with respect to each other. A thumb screw 46 is provided at their interface to lock the leg sections together at the desired position. As can be seen clearly in FIG. 1 shield 20 is fixedly mounted on the free end of the leg section 32B so that it is located opposite to the distal end of the probe tip and centered within the probe's field of view 26 when the sleeve is in place on the probe tip. It should be pointed out at this juncture that the use of the means for establishing the adjustablity of the legs of the yoke is merely exemplary and thus other means may be employed. In fact, the yoke may be constructed so that it is not adjustable, i.e., the position of the shield with respect to the sleeve is fixed. Moreover other means than a sleeve may be used to mount the shield on the probe tip. An annular recess or groove 36 is provided about the periphery of the distal end of the probe to cooperate with means forming a portion of the sleeve 30 to releasably mount the sleeve 30 thereon at selected longitudinal positions. This feature enables the shield to be quickly and easily located at various distances from the probe as may be required during the radiation localization procedure without requiring the adjustment of the thumbscrew 46 and associated telescoping leg sections 40A and 40B (in the case where the yoke is itself constructed to be adjustable). The means for releasably mounting the sleeve 30 onto the probe tip 22B basically comprises a plurality of annular grooves 30A, 30B, and 30C which extend about the periphery of the bore 34. Each recess has disposed therein a respective resilient material, e.g., rubber, O-ring 38. The sleeve is mounted on the probe's tip 22B by inserting that tip within its bore so that the O-ring 38 in a desired one of the grooves 30A-30C is located opposite to the recess 36 in the probe's tip at the desired longitudinal position for the sleeve. Accordingly, the O-ring will snap-fit into that recess, thereby holding the sleeve 30 in place at that particular longitudinal position along the tip. Without further elaboration the foregoing will so fully illustrate our invention that others may, by applying current or future knowledge, adopt the same for use under various conditions of service.
	description	The present application is continuation of and claims priority of U.S. Ser. No. 10/249,699 filed Apr. 30, 2003, the disclosure of which is incorporated herein by reference. The present invention relates generally to diagnostic imaging and, more particularly, to an integrated scintillator and collimator and method of manufacturing same. Typically, in computed tomography (CT) imaging systems, an x-ray source emits a fan-shaped beam toward a subject or object, such as a patient or a piece of luggage. Hereinafter, the terms “subject” and “object” shall include anything capable of being imaged. The beam, after being attenuated by the subject, impinges upon an array of radiation detectors. The intensity of the attenuated beam radiation received at the detector array is typically dependent upon the attenuation of the x-ray beam by the subject. Each detector element of the detector array produces a separate electrical signal indicative of the attenuated beam received by each detector element. The electrical signals are transmitted to a data processing system for analysis which ultimately produces an image. Generally, the x-ray source and the detector array are rotated about the gantry within an imaging plane and around the subject. X-ray sources typically include x-ray tubes, which emit the x-ray beam at a focal point. X-ray detectors typically include a collimator for collimating x-ray beams received at the detector, a scintillator for converting x-rays to light energy adjacent the collimator, and photodiodes for receiving the light energy from the adjacent scintillator and producing electrical signals therefrom. As stated above, typical x-ray detectors include a collimator for collimating x-ray beams such that collection of scattered x-rays is minimized. As such, the collimators operate to attenuate off-angle scattered x-rays from being detected by a scintillator cell. Reducing this scattering reduces noise in the signal and improves the final reconstructed image. Therefore, it is necessary that the scintillator array and the collimator, typically plates extending along one dimension above the scintillator array, are uniformly aligned. That is, exact mechanical alignment is required between the collimator plates and the cast reflector lines in the array of scintillators. Known manufacturing processes attempt this exact alignment by constructing a continuous collimator that is sized to dimensionally match the width and length of the entire detector array. That is, the collimator plates are arranged or arrayed in a continuous consistent pattern or pitch that spans the entire detector length and is placed and attached to the detector rail structure. As such, individual scintillator arrays or packs are must then be exactly aligned to the continuous collimator to ensure that all scintillator cells and collimator cells are aligned exactly; otherwise the collimator must be discarded or repaired, or the scintillator packs must be discarded. This process requires excessively tight tolerancing and requires great operator skill and patience to assemble. Accordingly, these known processes are susceptible to waste of parts, material, and labor. Additionally, as CT detectors grow in the z-direction, alignment requirements will tighten and the number of cells requiring alignment will increase. Therefore, the low process yields and high-end process scrap and re-work associated with these known manufacturing processes will increase the cost and time associated with CT detector assembly. Notwithstanding the advances made in CT detector manufacturing, these known detector assemblies and assembly processes result in a detector with less than optimal collimation. Referring to FIG. 10, a known CT detector 1 fabricated according to known manufacturing processes is shown. The CT detector 1 includes a series of tungsten collimator plates 2 that collimate x-rays projected toward scintillator cells 3 of a scintillator array 4. As shown, each of the collimator plates 2 is generally aligned with a reflector line 5 disposed between adjacent scintillators 3. The reflector lines 5 prevent light from being emitted between adjacent scintillators. The scintillator array is coupled to a photodiode array 6 that detects light emissions from the scintillator array and transmits corresponding electrical signals to a data acquisition system for signal processing. As readily shown, the collimator plates are not integrated with the individual scintillator elements 3. That is, an air gap 7 exists between the collimator plates and the scintillator cells 3. The air gap 7 typically results in a separation between the collimator plates and the scintillator array of approximately two to four thousands of an inch. This air gap occurs as a result of the manufacturing process whereupon the collimator plates are formed as a single collimator assembly that accepts and aligns an array of scintillators. The air gap, however, makes the CT detector susceptible to x-rays received between two collimator plates impinging upon an adjacent scintillator thereby resulting in undesirable anomalies in the final reconstructed CT image. Therefore, it would be desirable to design an integrated scintillator and collimator absent the aforementioned air gap as well as a method of manufacturing such an integrated scintillator and collimator. The present invention is directed to an integrated scintillator and collimator and method of manufacturing same that overcome the aforementioned drawbacks. The integrated scintillator and collimator reduces x-ray cross-talk between adjacent detector cells and improves dimensional alignment between collimator septum and scintillator reflector walls by integrating collimator plates with a top reflector surface of a scintillator. A pixilated array of scintillators is placed on a tooling base whereupon a mold having a series of parallel aligned air cavities is positioned atop the array of scintillators. The air cavities within the mold are positioned such that each aligns with a reflector line in the scintillator array. Using high precision tooling, the mold and the scintillator array are precisely aligned relative to one another. Upon proper alignment, a vacuum pump is used to remove the air cavities from within the mold. Thereafter, an injector is used to dispose collimator mixture within the mold and which is allowed to cure. Once the collimator mixture has cured, the integrated scintillator/collimator is formed. Therefore, in accordance with one aspect of the present invention, a method of manufacturing a detector having an integrated scintillator and collimator is provided. The method includes the steps of positioning an array of scintillator elements or pack on a tooling base and positioning a collimator mold housing having a collimator mold cavity therein on the block. As a result, the mold cavity will be very accurately aligned to the scintillator array pattern. A collimator mixture is then disposed into the mold cavity and allowed to cure to form an integrated scintillator and collimator. In accordance with another aspect of the present invention, a detector for a CT system includes an array of scintillation elements arranged to convert received x-rays to light. A plurality of collimator elements is integrally formed in a top surface of the array of scintillation elements and operates to attenuate off-angle scattered x-rays from being detected by scintillator elements. The detector further includes an array of photodiode elements arranged to receive light emissions from the array of scintillation elements. According to another aspect of the present invention, an integrated scintillator and collimator array is formed by the steps of placing an array of pixilated scintillators on a tooling base and positioning a collimator mold defining a plurality of cavities that extend to a top surface of the array adjacent the array. A collimator material is then disposed within the plurality of cavities and cured so as to form the integrated scintillator and collimator array. In accordance with yet another aspect of the present invention, an apparatus for manufacturing an integrated scintillator and collimator includes a tooling base designed to support a block of scintillating material and a mold to be positioned on the block of scintillating material. An alignment mechanism is provided to align the block in the mold in an aligned arrangement as well as a mold evacuator designed to remove air cavities within the mold. A collimator mixture supply is also provided to supply collimator material to the mold. According to yet another aspect of the present invention, a system to manufacture an integrated scintillator/collimator includes means for positioning a block of scintillator pack on a tooling base as well as means for positioning a collimator mold over the block. Means for aligning the block and the collimator mold is provided as well as means for removing air cavities from the mold. The system also includes means for disposing collimator material into a volume previously occupied by the removed air cavities and means for curing the collimator material to form an integrated scintillator and collimator. Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings. The operating environment of the present invention is described with respect to a four-slice computed tomography (CT) system. However, it will be appreciated by those skilled in the art that the present invention is equally applicable for use with single-slice or other multi-slice configurations. Moreover, the present invention will be described with respect to the detection and conversion of x-rays. However, one skilled in the art will further appreciate that the present invention is equally applicable for the detection and conversion of other high frequency electromagnetic energy. The present invention will be described with respect to a “third generation” CT scanner, but is equally applicable with other CT systems. Referring to FIGS. 1 and 2, a computed tomography (CT) imaging system 10 is shown as including a gantry 12 representative of a “third generation” CT scanner. Gantry 12 has an x-ray source 14 that projects a beam of x-rays 16 toward a detector array 18 on the opposite side of the gantry 12. Detector array 18 is formed by a plurality of detectors 20 which together sense the projected x-rays that pass through a medical patient 22. Each detector 20 produces an electrical signal that represents the intensity of an impinging x-ray beam and hence the attenuated beam as it passes through the patient 22. During a scan to acquire x-ray projection data, gantry 12 and the components mounted thereon rotate about a center of rotation 24. Rotation of gantry 12 and the operation of x-ray source 14 are governed by a control mechanism 26 of CT system 10. Control mechanism 26 includes an x-ray controller 28 that provides power and timing signals to an x-ray source 14 and a gantry motor controller 30 that controls the rotational speed and position of gantry 12. A data acquisition system (DAS) 32 in control mechanism 26 samples analog data from detectors 20 and converts the data to digital signals for subsequent processing. An image reconstructor 34 receives sampled and digitized x-ray data from DAS 32 and performs high speed reconstruction. The reconstructed image is applied as an input to a computer 36 which stores the image in a mass storage device 38. Computer 36 also receives commands and scanning parameters from an operator via console 40 that has a keyboard. An associated cathode ray tube display 42 allows the operator to observe the reconstructed image and other data from computer 36. The operator supplied commands and parameters are used by computer 36 to provide control signals and information to DAS 32, x-ray controller 28 and gantry motor controller 30. In addition, computer 36 operates a table motor controller 44 which controls a motorized table 46 to position patient 22 and gantry 12. Particularly, table 46 moves portions of patient 22 through a gantry opening 48. As shown in FIGS. 3 and 4, detector array 18 includes a plurality of scintillators 57 forming a scintillator array 56. A collimator (not shown) is positioned above scintillator array 56 to collimate x-ray beams 16 before such beams impinge upon scintillator array 56. In one embodiment, shown in FIG. 3, detector array 18 includes 57 detectors 20, each detector 20 having an array size of 16×16. As a result, array 18 has 16 rows and 912 columns (16×57 detectors) which allows 16 simultaneous slices of data to be collected with each rotation of gantry 12. Switch arrays 80 and 82, FIG. 4, are multi-dimensional semiconductor arrays coupled between scintillator array 56 and DAS 32. Switch arrays 80 and 82 include a plurality of field effect transistors (FET) (not shown) arranged as multi-dimensional array. The FET array includes a number of electrical leads connected to each of the respective photodiodes 60 and a number of output leads electrically connected to DAS 32 via a flexible electrical interface 84. Particularly, about one-half of photodiode outputs are electrically connected to switch 80 with the other one-half of photodiode outputs electrically connected to switch 82. Additionally, a reflector layer (not shown) may be interposed between each scintillator 57 to reduce light scattering from adjacent scintillators. Each detector 20 is secured to a detector frame 77, FIG. 3, by mounting brackets 79. Switch arrays 80 and 82 further include a decoder (not shown) that enables, disables, or combines photodiode outputs in accordance with a desired number of slices and slice resolutions for each slice. Decoder, in one embodiment, is a decoder chip or a FET controller as known in the art. Decoder includes a plurality of output and control lines coupled to switch arrays 80 and 82 and DAS 32. In one embodiment defined as a 16 slice mode, decoder enables switch arrays 80 and 82 so that all rows of the photodiode array 52 are activated, resulting in 16 simultaneous slices of data for processing by DAS 32. Of course, many other slice combinations are possible. For example, decoder may also select from other slice modes, including one, two, and four-slice modes. As shown in FIG. 5, by transmitting the appropriate decoder instructions, switch arrays 80 and 82 can be configured in the four-slice mode so that the data is collected from four slices of one or more rows of photodiode array 52. Depending upon the specific configuration of switch arrays 80 and 82, various combinations of photodiodes 60 can be enabled, disabled, or combined so that the slice thickness may consist of one, two, three, or four rows of scintillator array elements 57. Additional examples include, a single slice mode including one slice with slices ranging from 1.25 mm thick to 20 mm thick, and a two slice mode including two slices with slices ranging from 1.25 mm thick to 10 mm thick. Additional modes beyond those described are contemplated. Referring now to FIG. 6, a CT detector having an integrated scintillator and collimator is schematically shown. The detector 20 includes a photodiode array 52 coupled to receive light emissions from a scintillator array 56 of scintillation elements 57. Cast directly onto the scintillation array or pack is a plurality of collimator plates 86. The collimator plates 86 are precisionally aligned with reflector lines 88 disposed between the scintillator elements 57. By casting the collimator plates directly onto the scintillator pack, the air gap discussed with reference to FIG. 10 is eliminated thereby improving the collimation achieved by collimator plates 86. As will be described in greater detail below, each of the collimator plates is formed by a combination or mixture of tungsten and epoxy. Casting the collimator plates directly onto a top reflective surface 90 of the scintillator pack improves the rigidity of the scintillator/collimator structure thereby improving the detector's response to loads induced by a rotating gantry during CT data acquisition. That is, the collimator plates of a CT detector 1 similar to that shown in FIG. 10 are susceptible to gravitational and rotational forces induced movement as a result of the collimator plates being separated from the scintillator array by the previously discussed air gap. The CT detector illustrated in FIG. 6, however, has reduced susceptibility to the aforementioned gravitational forces as a result of the collimator plates being directly cast onto the scintillator pack. Referring now to FIG. 7, a tooling assembly 92 for manufacturing an array of integrated scintillators and collimators is shown. The tooling assembly includes a tooling base 94 designed to support a scintillator array cast pack 96 that is positioned within the lower mold cavity 98. The lower mold cavity 98 is aligned with an upper mold housing 100 such that the pack 96 and mold 102 are properly aligned with respect to one another. To ensure proper and precisioned alignment, tooling assembly 92 includes a dowel pin alignment assembly 104. Other dowel pins and alignment tools such as bore datums (not shown) are contemplated and applicable with the illustrated assembly. In the illustrated embodiment, mold 102 includes a series of cavities 106 that is uniformly aligned in parallel relative to cast pack 96. Further, each cavity 106 has a height equal to the desired height of a collimator plate and extends to the top surface 108 of scintillator array cast pack 96. Assembly 92 further includes an evacuation gate 110 that is connected to a vacuum pump 112. The vacuum pump is controlled by a CPU 114 to remove air from each cavity 106. When the mold is positioned atop the scintillator pack, air fills cavities 106. This air must be removed for proper formation of the collimator, as will be described hereinafter. As such, pump 112 is used to remove air from cavities 106. After a vacuum is formed within the mold housing 100, a collimator mixture is injected by injector 116 through fill gate 118 such that each of the cavities 106 is filled with collimator mixture. The collimator mixture may directly injected by injector 116 or drawn into the mold cavity by the vacuum created in the cavity upon removal of air from within the cavity. The collimator mixture is preferably a combination of tungsten and epoxy. Additionally, the collimation is preferably a powder. However, other combinations, mixtures, and combinations and in non-powder forms may be equivalently used. The collimator mixture is cured at room temperature or elevated temperatures within the mold housing 100. Once cured, the mold housing is removed thereby leaving a series of collimator plates integrally formed with a top surface of the scintillator pack. Referring now to FIG. 8, a manufacturing process 120 for manufacturing an integrated scintillator and collimator array begins at 122 with a series of diced slices of scintillator material undergoing a hot setting process at 124. After undergoing the hot setting process 124, a mold or fence is installed at 126. The mold is used to properly dispose reflector material between each scintillation element. The material used to form the reflector layer is allowed to cast and cure 128 whereupon the mold is removed at 130. The resulting scintillator array cast pack having the reflector lines integrated therewith is milled at 132. Following milling of the top reflective layer of the cast pack, a collimator cavity is positioned about the milled scintillator pack at 134. As stated above, the mold cavity is used during aligning of the scintillator pack relative to the collimator mold. Once the mold cavity and scintillator pack are properly positioned on a tooling base, a collimator mold is positioned or installed relative to the scintillator pack and mold cavity at 136. The collimator mold cavity and scintillator pack are properly aligned using a dowel pin alignment assembly and a series of bore datums, as was previously described. Once the mold, cavity, and block are properly aligned, the air contained in each of the cavities, as a result of the positioning of the mold on the scintillator pack, is removed using a vacuum pump. Once a vacuum is created within the mold, the collimator mixture or powder is introduced into each of the cavities 138. The injected mixture is then allowed to cure 140 thereby resulting in a series of collimator plates being formed integrally with a top surface of the scintillator pack. The mold assembly is then disassembled at 142 resulting in an array of integrated scintillators and collimators. The resulting assembly then undergoes a grinding, inspection, and testing stage 144 to ensure proper alignment and fabrication of the integrated scintillator and collimator array 144. The present invention has been described with respect to fabrication of integrated scintillator and collimator for a CT detector of a CT imaging system. CT detectors incorporating an integrated scintillator and collimator in accordance with the present invention may be used in medical imaging systems as well as parcel inspections systems similar to those illustrated in FIG. 9. Referring to FIG. 9, package/baggage inspection system 150 includes a rotatable gantry 152 having an opening 154 therein through which packages or pieces of baggage may pass. The rotatable gantry 152 houses a high frequency electromagnetic energy source 156 as well as a detector assembly 158 having arrays of integrated scintillator/collimator cells similar to that shown in FIG. 6 and fabricated using an assembly apparatus similar to that described with respect to FIG. 7. A conveyor system 160 is also provided and includes a conveyor belt 162 supported by structure 164 to automatically and continuously pass packages or baggage pieces 166 through opening 154 to be scanned. Objects 166 are fed through opening 154 by conveyor belt 162, imaging data is then acquired, and the conveyor belt 162 removes the packages 166 from opening 164 in a controlled and continuous manner. As a result, postal inspectors, baggage handlers, and other security personnel may non-invasively inspect the contents of packages 166 for explosives, knives, guns, contraband, etc. The present invention has been described with respect to fabricating an integrated scintillator and collimator for a CT based imaging system. Further, fabrication of a rectangular shaped scintillator/collimator combination has been described. However, the present invention contemplates additional patterns or shaped cells being fabricated. Additionally, the present invention envisions numerous collimator material combinations beyond the tungsten/epoxy mixture previously described. Additionally, the high precision alignment and tooling aspects of the present invention may be used to support different “molding” processes such as extrusion, injection molding, and the like. The high precision alignment and tooling aspects could be also applied to electronics packaging application to provide x-ray shielding of sensitive components. Additionally, the present invention has been described with respect to an integrated scintillator whereupon the collimator plates are cast along one dimensional, i.e., the z-axis. However, integrated scintillators and collimators may be formed using the aforementioned methods of manufacturing along an x and z axis thereby rendering a “checkerboard” full two-dimensional (2D) arrangement of integrated scintillators and collimators. The present invention may be implemented to create a partial 2D array of integrated scintillator and collimators. That is, the collimator mold may be constructed such that the collimator cavities have different heights when filled with the collimator mixture. As a result, the collimator plates along one axis, i.e., the z-axis, may have a greater height than collimator plates along another axis, i.e., the x-axis. Therefore, in accordance with one embodiment of the present invention, a method of manufacturing a detector having an integrated scintillator and collimator is provided. The method includes the steps of positioning an array of scintillator elements or pack on a tooling base and positioning a collimator mold housing having a collimator mold cavity therein on the block. As a result, the mold cavity will be very accurately aligned to the scintillator array pattern. A collimator mixture is then disposed into the mold cavity and allowed to cure to form an integrated scintillator and collimator. In accordance with another embodiment of the present invention, a detector for a CT system includes an array of scintillation elements arranged to convert received x-rays to light. A plurality of collimator elements is integrally formed in a top surface of the array of scintillation elements and operates to attenuate off-angle scattered x-rays from being detected by scintillator elements. The detector further includes an array of photodiode elements arranged to receive light emissions from the array of scintillation elements. According to another embodiment of the present invention, an integrated scintillator and collimator array is formed by the steps of placing an array of pixilated scintillators on a tooling base and positioning a collimator mold defining a plurality of cavities that extend to a top surface of the array adjacent the array. A collimator material is then disposed within the plurality of cavities and cured so as to form the integrated scintillator and collimator array. In accordance with yet another embodiment of the present invention, an apparatus for manufacturing an integrated scintillator and collimator includes a tooling base designed to support a block of scintillating material and a mold to be positioned on the block of scintillating material. An alignment mechanism is provided to align the block in the mold in an aligned arrangement as well as a mold evacuator designed to remove air cavities within the mold. A collimator mixture supply is also provided to supply collimator material to the mold. According to yet another embodiment of the present invention, a system to manufacture an integrated scintillator/collimator includes means for positioning a block of scintillator pack on a tooling base as well as means for positioning a collimator mold over the block. Means for aligning the block and the collimator mold is provided as well as means for removing air cavities from the mold. The system also includes means for disposing collimator material into a volume previously occupied by the removed air cavities and means for curing the collimator material to form an integrated scintillator and collimator. The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.
	claims	1. A voltaic cell, comprising:a radioactive layer comprising a radioactive material, said radioactive layer having first and second sides oppositely disposed;a first n-type semiconductor layer overlying said first side of said radioactive layer;a first p-type semiconductor layer overlying said second side of said radioactive layer;a first dielectric layer overlying said first n-type semiconductor layer, said first dielectric layer comprising a plurality of quantum dots;a second dielectric layer overlying said first p-type semiconductor layer, said second dielectric layer comprising a plurality of quantum dots;a first conductor layer overlying said first dielectric layer; anda second conductor layer overlying said second dielectric layer. 2. The voltaic cell according to claim 1, further comprising:a second n-type semiconductor layer positioned between said first conductor layer and said first dielectric layer; anda second p-type semiconductor layer positioned between said second conductor layer and said second dielectric layer. 3. The voltaic cell according to claim 2, wherein said second p-type semiconductor layer comprises a material selected from the group consisting of amorphous hydrogenated silicon, crystalline hydrogenated silicon, amorphous hydrogenated silicon carbide, crystalline hydrogenated silicon carbide, diamond-like carbon, amorphous hydrogenated carbon, crystalline hydrogenated carbon, crystalline silicon, germanium, carbon, gallium-arsenide, indium-gallium-arsenide, gallium-nitride, indium-arsenide, zinc-selenium, zinc-sulfide, silicon-carbide, indium-selenide and aluminum-indium-gallium-phosphorous. 4. The voltaic cell according to claim 3, wherein said second p-type semiconductor layer is doped with an element selected from the group consisting of boron, aluminum, gallium, indium and combinations thereof. 5. The voltaic cell according to claim 2, further comprising:a first tunnel junction layer positioned between said second n-type semiconductor layer and said first conductor layer;a third p-type semiconductor layer positioned between said first tunnel junction layer and said first conductor layer;a third n-type semiconductor layer positioned between said third p-type semiconductor layer and said first conductor layer. 6. The voltaic cell according to claim 5, wherein said first tunnel junction layer comprises a p-n junction. 7. The voltaic cell according to claim 5, further comprising:a second tunnel junction layer positioned between said second p-type semiconductor layer and said second conductor layer;a fourth n-type semiconductor layer positioned between said second tunnel junction layer and said second conductor layer;a fourth p-type semiconductor layer positioned between said fourth n-type semiconductor layer and said second conductor layer. 8. The voltaic cell according to claim 6, wherein said second tunnel junction layer comprises a p-n junction. 9. The voltaic cell according to claim 1, wherein said radioactive layer comprises a material selected from the group consisting of amorphous hydrogenated silicon, crystalline hydrogenated silicon, amorphous hydrogenated silicon carbide, crystalline hydrogenated silicon carbide, diamond-like carbon, amorphous hydrogenated carbon, crystalline hydrogenated carbon, crystalline silicon, germanium, carbon, gallium-arsenide, indium-gallium-arsenide, gallium-nitride, indium-arsenide, zinc-selenium, zinc-sulfide, silicon-carbide, indium-selenide and aluminum-indium-gallium-phosphorous. 10. The voltaic cell according to claim 9, wherein said radioactive material is selected from the group consisting of tritium, carbon 14, magnesium 23, germanium 76, silicon 32, cadmium 113, indium 115 rubidium 87, potassium 40 and combinations thereof. 11. The voltaic cell according to claim 1, wherein said first n-type semiconductor layer comprises a material selected from the group consisting of amorphous hydrogenated silicon, crystalline hydrogenated silicon, amorphous hydrogenated silicon carbide, crystalline hydrogenated silicon carbide, diamond-like carbon, amorphous hydrogenated carbon, crystalline hydrogenated carbon, crystalline silicon, germanium, carbon, gallium-arsenide, indium-gallium-arsenide, gallium-nitride, indium-arsenide, zinc-selenium, zinc-sulfide, silicon-carbide, indium-selenide and aluminum-indium-gallium-phosphorous. 12. The voltaic cell according to claim 11, wherein said first n-type semiconductor layer is doped with an element selected from the group consisting of phosphorous, nitrogen, arsenic, antimony and combinations thereof. 13. The voltaic cell according to claim 1, wherein said first p-type semiconductor layer comprises a material selected from the group consisting of amorphous hydrogenated silicon, crystalline hydrogenated silicon, amorphous hydrogenated silicon carbide, crystalline hydrogenated silicon carbide, diamond-like carbon, amorphous hydrogenated carbon, crystalline hydrogenated carbon, crystalline silicon, germanium, carbon, gallium-arsenide, indium-gallium-arsenide, gallium-nitride, indium-arsenide, zinc-selenium, zinc-sulfide, silicon-carbide, indium-selenide and aluminum-indium-gallium-phosphorous. 14. The voltaic cell according to claim 13, wherein said first p-type semiconductor layer is doped with an element selected from the group consisting of boron, aluminum, gallium, indium and combinations thereof. 15. The voltaic cell according to claim 2, wherein said second n-type semiconductor layer comprises a material selected from the group consisting of amorphous hydrogenated silicon, crystalline hydrogenated silicon, amorphous hydrogenated silicon carbide, crystalline hydrogenated silicon carbide, diamond-like carbon, amorphous hydrogenated carbon, crystalline hydrogenated carbon, crystalline silicon, germanium, carbon, gallium-arsenide, indium-gallium-arsenide, gallium-nitride, indium-arsenide, zinc-selenium, zinc-sulfide, silicon-carbide, indium-selenide and aluminum-indium-gallium-phosphorous. 16. The voltaic cell according to claim 15, wherein said second n-type semiconductor layer is doped with an element selected from the group consisting of phosphorous, nitrogen, arsenic, antimony and combinations thereof. 17. The voltaic cell according to claim 1, wherein at least one of said first and second conductor layers comprise a metal. 18. The voltaic cell according to claim 17, wherein said metal is selected from the group consisting of gold, silver, copper, aluminum and combinations thereof. 19. The voltaic cell according to claim 1, wherein at least one of said first and second dielectric layers comprises a material selected from the group consisting of silicon oxide and silicon nitride. 20. The voltaic cell according to claim 1, wherein said quantum dots comprise silicon. 21. The voltaic cell according to claim 1, wherein said quantum dots have a size from about 1 nm to about 10 nm. 22. The voltaic cell according to claim 1, wherein said quantum dots are disbursed throughout at least one of said first and second dielectric layers at a density of about 1021 cm−3. 23. The voltaic cell according to claim 1, wherein said quantum dots are disbursed throughout at least one of said first and second dielectric layers at a density from about 108 cm−2 to about 1011 cm−2. 24. The voltaic cell according to claim 1, wherein said quantum dots are arranged in a three-dimensional array in at least one of said first and second dielectric layers. 25. The voltaic cell according to claim 1, wherein said quantum dots are arranged substantially at the surface of at least one of said first and second dielectric layers. 26. The voltaic cell according to claim 1, wherein said quantum dots have a substantially spherical shape. 27. The voltaic cell according to claim 1, wherein said quantum dots have a substantially pyramidal shape. 28. The voltaic cell according to claim 1, wherein said quantum dots are sized and spaced apart from one another within said dielectric layers so as to promote quantum mechanical tunneling of charge carriers from said radioactive layer to said conductor layers. 29. The voltaic cell according to claim 28, wherein said charge carriers have energies from about 1 eV to about 5 eV. 30. The voltaic cell according to claim 1, further comprising a plurality of first dielectric layers positioned between said first n-type semiconductor layer and said first conductor layer. 31. The voltaic cell according to claim 30, comprising at least three of said first dielectric layers. 32. The voltaic cell according to claim 30, wherein said quantum dots of at least one of said first dielectric layers are of a different size from said quantum dots of at least one other of said first dielectric layers. 33. The voltaic cell according to claim 30, wherein said quantum dots of at least one of said first dielectric layers are spaced apart from one another at a different spacing from said quantum dots of at least one other of said first dielectric layers. 34. The voltaic cell according to claim 1, further comprising a plurality of second dielectric layers positioned between said first p-type semiconductor layer and said second conductor layer. 35. The voltaic cell according to claim 34, comprising at least three of said second dielectric layers. 36. The voltaic cell according to claim 34, wherein said quantum dots of at least one of said second dielectric layers are of a different size from said quantum dots of at least one other of said second dielectric layers. 37. The voltaic cell according to claim 34, wherein said quantum dots of at least one of said second dielectric layers are spaced apart from one another at a different spacing from said quantum dots of at least one other of said second dielectric layers. 38. A battery comprising a plurality of voltaic cells according to claim 1. 39. A voltaic cell, comprising:a semiconductor layer having a p-type region and an n-type region forming a first p-n junction;a radioactive layer positioned within said semiconductor layer between said p-type region and said n-type region;at least a first dielectric layer overlying said n-type region, said first dielectric layer comprising a plurality of quantum dots;at least a second dielectric layer overlying said p-type region, said second dielectric layer comprising a plurality of quantum dots;an n-type semiconductor layer overlying said first dielectric layer;a p-type semiconductor layer overlying said second dielectric layer;a first conductor layer overlying said n-type semiconductor layer;a second conductor layer overlying said p-type semiconductor layer. 40. The voltaic cell according to claim 39, further comprising:a plurality of said first dielectric layers overlying said n-type region;a plurality of said second dielectric layers overlying said p-type region. 41. The voltaic cell according to claim 40, further comprising:a second p-n junction having a p-type region and an n-type region, said second p-n junction being positioned between said n-type semiconductor layer and said first conductor layer, said p-type region of said second p-n junction being adjacent to said n-type semiconductor layer;a first tunnel junction layer positioned between said p-type region of said second p-n junction and said n-type semi-conductor layer;a third p-n junction having a p-type region and an n-type region, said third p-n junction being positioned between said p-type semiconductor layer and said second conductor layer, said n-type region of said third p-n junction being adjacent to said p-type semiconductor layer;a second tunnel junction layer positioned between said n-type region of said third p-n junction and said p-type semi-conductor layer. 42. The voltaic cell according to claim 39, further comprising:a second p-n junction having a p-type region and an n-type region, said second p-n junction being positioned between said n-type semiconductor layer and said first conductor layer, said p-type region of said second p-n junction being adjacent to said n-type semiconductor layer;a first tunnel junction layer positioned between said p-type region of said second p-n junction and said n-type semi-conductor layer;a third p-n junction having a p-type region and an n-type region, said third p-n junction being positioned between said p-type semiconductor layer and said second conductor layer, said n-type region of said third p-n junction being adjacent to said p-type semiconductor layer;a second tunnel junction layer positioned between said n-type region of said third p-n junction and said p-type semi-conductor layer. 43. The voltaic cell according to claim 42, wherein at least one of said tunnel junction layers comprises a p-n junction. 44. The voltaic cell according to claim 39, wherein said radioactive layer comprises a material selected from the group consisting of amorphous hydrogenated silicon, crystalline hydrogenated silicon, amorphous hydrogenated silicon carbide, crystalline hydrogenated silicon carbide, diamond-like carbon, amorphous hydrogenated carbon, crystalline hydrogenated carbon, crystalline silicon, germanium, carbon, gallium-arsenide, indium-gallium-arsenide, gallium-nitride, indium-arsenide, zinc-selenium, zinc-sulfide, silicon-carbide, indium-selenide and aluminum-indium-gallium-phosphorous. 45. The voltaic cell according to claim 39, wherein said radioactive layer comprises a material selected from the group consisting of tritium, carbon 14, magnesium 23, germanium 76, silicon 32, cadmium 113, indium 115 rubidium 87, potassium 40 and combinations thereof. 46. The voltaic cell according to claim 39, wherein said n-type region comprises a material selected from the group consisting of amorphous hydrogenated silicon, crystalline hydrogenated silicon, amorphous hydrogenated silicon carbide, crystalline hydrogenated silicon carbide, diamond-like carbon, amorphous hydrogenated carbon, crystalline hydrogenated carbon, crystalline silicon, germanium, carbon, gallium-arsenide, indium-gallium-arsenide, gallium-nitride, indium-arsenide, zinc-selenium, zinc-sulfide, silicon-carbide, indium-selenide and aluminum-indium-gallium-phosphorous. 47. The voltaic cell according to claim 46, wherein said n-type region is doped with an element selected from the group consisting of phosphorous, nitrogen, arsenic, antimony and combinations thereof. 48. The voltaic cell according to claim 39, wherein said p-type region comprises a material selected from the group consisting of amorphous hydrogenated silicon, crystalline hydrogenated silicon, amorphous hydrogenated silicon carbide, crystalline hydrogenated silicon carbide, diamond-like carbon, amorphous hydrogenated carbon, crystalline hydrogenated carbon, crystalline silicon, germanium, carbon, gallium-arsenide, indium-gallium-arsenide, gallium-nitride, indium-arsenide, zinc-selenium, zinc-sulfide, silicon-carbide, indium-selenide and aluminum-indium-gallium-phosphorous. 49. The voltaic cell according to claim 48, wherein said p-type region is doped with an element selected from the group consisting of boron, aluminum, gallium, indium and combinations thereof. 50. The voltaic cell according to claim 39, wherein said n-type semiconductor layer comprises a material selected from the group consisting of amorphous hydrogenated silicon, crystalline hydrogenated silicon, amorphous hydrogenated silicon carbide, crystalline hydrogenated silicon carbide, diamond-like carbon, amorphous hydrogenated carbon, crystalline hydrogenated carbon, crystalline silicon, germanium, carbon, gallium-arsenide, indium-gallium-arsenide, gallium-nitride, indium-arsenide, zinc-selenium, zinc-sulfide, silicon-carbide, indium-selenide and aluminum-indium-gallium-phosphorous. 51. The voltaic cell according to claim 50, wherein said n-type semiconductor layer is doped with an element selected from the group consisting of phosphorous, nitrogen, arsenic, antimony and combinations thereof. 52. The voltaic cell according to claim 39, wherein said p-type semiconductor layer comprises a material selected from the group consisting of amorphous hydrogenated silicon, crystalline hydrogenated silicon, amorphous hydrogenated silicon carbide, crystalline hydrogenated silicon carbide, diamond-like carbon, amorphous hydrogenated carbon, crystalline hydrogenated carbon, crystalline silicon, germanium, carbon, gallium-arsenide, indium-gallium-arsenide, gallium-nitride, indium-arsenide, zinc-selenium, zinc-sulfide, silicon-carbide, indium-selenide and aluminum-indium-gallium-phosphorous. 53. The voltaic cell according to claim 52, wherein said p-type semiconductor layer is doped with an element selected from the group consisting of boron, aluminum, gallium, indium and combinations thereof. 54. The voltaic cell according to claim 39, wherein at least one of said first and second conductor layers comprises a metal. 55. The voltaic cell according to claim 54, wherein said metal is selected from the group consisting of gold, silver, copper, aluminum and combinations thereof. 56. The voltaic cell according to claim 39, wherein at least one of said first and second dielectric layers comprises a material selected from the group consisting of silicon oxide and silicon nitride. 57. The voltaic cell according to claim 39, wherein said quantum dots comprise silicon. 58. The voltaic cell according to claim 39, wherein said quantum dots have a size from about 1 nm to about 10 nm. 59. The voltaic cell according to claim 39, wherein said quantum dots are disbursed throughout at least one of said first and second dielectric layers at a density of about 1021 cm−3. 60. The voltaic cell according to claim 39, wherein said quantum dots are disbursed throughout at least one of said first and second dielectric layers at a density from about 108 cm−2 to about 1011 cm−2. 61. The voltaic cell according to claim 39, wherein said quantum dots are arranged in a three-dimensional array in at least one of said first and second dielectric layers. 62. The voltaic cell according to claim 39, wherein said quantum dots are arranged substantially at the surface of at least one of said first and second dielectric layers. 63. The voltaic cell according to claim 39, wherein said quantum dots have a substantially spherical shape. 64. The voltaic cell according to claim 39, wherein said quantum dots have a substantially pyramidal shape. 65. The voltaic cell according to claim 39, wherein said quantum dots are sized and spaced apart from one another within at least one of said dielectric layers so as to promote quantum mechanical tunneling of charge carriers from said radioactive layer to said conduction layers. 66. The voltaic cell according to claim 65, wherein said charge carriers have energies from about 1 eV to about 5 eV. 67. The voltaic cell according to claim 39, further comprising a plurality of first dielectric layers positioned between said n-type semiconductor layer and said first conductor layer. 68. The voltaic cell according to claim 67, comprising at least three of said first dielectric layers. 69. The voltaic cell according to claim 67, wherein said quantum dots of at least one of said first dielectric layers are of a different size from said quantum dots of at least one other of said first dielectric layers. 70. The voltaic cell according to claim 67, wherein said quantum dots of at least one of said first dielectric layers are spaced apart from one another at a different spacing from said quantum dots of at least one other of said first dielectric layers. 71. The voltaic cell according to claim 39, further comprising a plurality of second dielectric layers positioned between said p-type semiconductor layer and said second conductor layer. 72. The voltaic cell according to claim 71, comprising at least three of said second dielectric layers. 73. The voltaic cell according to claim 71, wherein said quantum dots of at least one of said second dielectric layers are of a different size from said quantum dots of at least one other of said second dielectric layers. 74. The voltaic cell according to claim 71, wherein said quantum dots of at least one of said second dielectric layers are spaced apart from one another at a different spacing from said quantum dots of at least one other of said second dielectric layers. 75. A battery comprising a plurality of voltaic cells according to claim 39. 76. A voltaic cell, comprising:a radioactive layer comprising a radioactive material and a semiconductor having energy band gaps from about 1 eV to about 4 eV, said radioactive layer having first and second sides oppositely disposed;a first n-type semiconductor layer overlying said first side of said radioactive layer;a first p-type semiconductor layer overlying said second side of said radioactive layer;a first dielectric layer overlying said first n-type semiconductor layer, said first dielectric layer comprising a plurality of quantum dots;a second dielectric layer overlying said first p-type semiconductor layer, said second dielectric layer comprising a plurality of quantum dots;a first conductor layer overlying said first dielectric layer; anda second conductor layer overlying said second dielectric layer. 77. The voltaic cell according to claim 76, further comprising:a second n-type semiconductor layer positioned between said first conductor layer and said first dielectric layer; anda second p-type semiconductor layer positioned between said second conductor layer and said second dielectric layer. 78. The voltaic cell according to claim 77, further comprising:a first tunnel junction layer positioned between said second n-type semiconductor layer and said first conductor layer;a third p-type semiconductor layer positioned between said first tunnel junction layer and said first conductor layer;a third n-type semiconductor layer positioned between said third p-type semiconductor layer and said first conductor layer. 79. The voltaic cell according to claim 78, further comprising:a second tunnel junction layer positioned between said second p-type semiconductor layer and said second conductor layer;a fourth n-type semiconductor layer positioned between said second tunnel junction layer and said second conductor layer;a fourth p-type semiconductor layer positioned between said fourth n-type semiconductor layer and said second conductor layer. 80. The voltaic cell according to claim 76, wherein said quantum dots have a size from about 1 nm to about 10 nm. 81. The voltaic cell according to claim 76, wherein said quantum dots are disbursed throughout at least one of said first and second dielectric layers at a density of about 1021 cm−3. 82. The voltaic cell according to claim 76, wherein said quantum dots are disbursed throughout said first and second dielectric layers at a density from about 108 cm−2 to about 1011 cm−2. 83. The voltaic cell according to claim 76, wherein said quantum dots are arranged in a three-dimensional array in said first and second dielectric layers. 84. The voltaic cell according to claim 76, wherein said quantum dots are arranged substantially at the surface of at least one of said first and second dielectric layers. 85. The voltaic cell according to claim 76, wherein said quantum dots have a substantially spherical shape. 86. The voltaic cell according to claim 76, wherein said quantum dots have a substantially pyramidal shape. 87. The voltaic cell according to claim 76, wherein said quantum dots are sized and spaced apart from one another within said dielectric layers so as to promote quantum mechanical tunneling of charge carriers from said radioactive layer to said conduction layers. 88. The voltaic cell according to claim 87, wherein said charge carriers have energies from about 1 eV to about 5 eV. 89. The voltaic cell according to claim 76, further comprising a plurality of first dielectric layers positioned between said first n-type semiconductor layer and said first conductor layer. 90. The voltaic cell according to claim 89, wherein said quantum dots of at least one of said first dielectric layers are of a different size from said quantum dots of at least one other of said first dielectric layers. 91. The voltaic cell according to claim 89, wherein said quantum dots of at least one of said first dielectric layers are spaced apart from one another at a different spacing from said quantum dots of at least one other of said first dielectric layers. 92. The voltaic cell according to claim 89, further comprising a plurality of second dielectric layers positioned between said first p-type semiconductor layer and said second conductor layer. 93. The voltaic cell according to claim 92, wherein said quantum dots of at least one of said second dielectric layers are of a different size from said quantum dots of at least one other of said second dielectric layers. 94. The voltaic cell according to claim 92, wherein said quantum dots of at least one of said second dielectric layers are spaced apart from one another at a different spacing from said quantum dots of at least one other of said second dielectric layers. 95. A battery comprising a plurality of voltaic cells according to claim 76.
	abstract	An improved 3He nuclear reactor with provision for direct electric conversion of a relativistic proton stream into useable electric power at a voltage level compatible with the national power grid (one million V DC). Various embodiments include multiple collector cages for extracting relativistic protons of various energy levels, diverter wires for deflecting high-energy proton streams to either side of lower energy cages to avoid unwanted impact. Other embodiments include arrangements for dividing multi-megavolt voltages down to a useable one megavolt level compatible with the national power grid. Further embodiments comprise guiding the proton stream by the cusps of magnetron cavities to permit conversion of the relativistic proton energies into microwave power. A proposal is also made for harvesting 3He from the Moon to supply earth-bound and space-bound reactors. A solution to the problem of charging a potential well-forming anode in an electrostatic fusion reactor without electrical arcing is further disclosed.
052727424	abstract	An upper end fitting for a nuclear fuel assembly. A main body portion that is square in section has a base rigidly attached thereto. A combined pedestal and holddown spring assembly received in the main body portion is formed from leaf springs attached together by a bolt and nut. The leaf springs are bolted together such that the exterior radius or convex surface of the springs face each other. The bolt and nut are sized and shaped to serve as the pedestal for the control assembly of the reactor. A spring retainer movably received in the main body portion retains the springs inside the main body portion. The retainer is also provided with a bore therethrough sized to allow the bolt/pedestal to extend therethrough.
	summary
	abstract	A method for analysing the effect of temperature on at least one nuclear fuel rod, a rod comprising packed zones completely filled with fuel and intermediate zones partially filled with fuel, comprises: acquiring at least two count profiles, a first count profile being associated with a non-migrating isotope and a second count profile being associated with a migrating isotope; locating the intermediate zones by using the first count profile; determining an indicator Ki_1 indicative of the depth in the first profile of a measurement dip located at an intermediate zone i; determining an indicator Ki_2 indicative of the depth in the second profile of a measurement dip located at the intermediate zone i; determining for this intermediate zone i an indicator Δi by comparing the indicators Ki_1 and Ki_2.
	claims	1. An image forming method for scanning a two-dimensional area on a sample with a charged particle beam and forming an image of the scanned area, the image forming method comprising the steps of:scanning a first scanning line;scanning a second scanning line;scanning a third scanning line between the first scanning line and the second scanning line;scanning an area having two sections, defined by the first, second, and third scanning lines, by sequentially scanning positions between the first and third scanning lines and scanning positions between the third and second scanning lines so as to reduce the area in stages; andrepeatedly scanning for a center by scanning lines between the first scanning line and the third scanning line, and scanning lines between the third scanning line and the second scanning line until scanning of the two-dimensional area is complete. 2. An image forming method according to claim 1, wherein said third scanning line is disposed at equidistance from said first and second scanning lines. 3. An image forming method according to claim 1, wherein scanning line disposed at the center of said plurality of scanning lines is a fourth scanning line which is scanned next to said third scanning line. 4. An image forming method according to claim 1, wherein said first and second scanning lines are disposed at the edge of said two-dimensional area or a part of area of said two-dimensional area. 5. A charged particle beam apparatus including a deflector for scanning charged particle beam on a sample and a control apparatus for controlling said deflector, wherein:said control apparatus controls said deflector to:scan a first scanning line and second scanning line on a two-dimensional area on said sample;scan a third scanning line between said first and second scanning lines;scanning an area having two sections, defined by the first second, and third scanning lines, by sequentially scanning positions between the first and third scanning lines and scanning positions between the third and second scanning lines so as to reduce the area in stages; andrepeatedly scanning for a center by scanning lines between the first scanning line and the third scanning line, and scanning lines between the third scanning line and the second scanning line until scanning of the two-dimensional area is complete. 6. A charged particle beam scanning apparatus according to claim 5, wherein:said control apparatus controls said deflector such that positioning said third scanning line at equidistance to said first and second scanning lines. 7. A charged particle beam apparatus according to claim 5, wherein:said control apparatus renders scanning line disposed at center of said plurality of scanning lines as a fourth scanning line which is scanned next to said third scanning line. 8. A charged particle beam apparatus according to claim 5, wherein:said control apparatus positions said first and second scanning lines at an edge of said two-dimensional are or part of area of said two-dimensional area. 9. A charged particle beam apparatus according to claim 5, wherein:said control apparatus controls said deflector such that structuring said two-dimensional are on said sample as a single or divided plural areas, and scanning said first, second and third scanning lines at each area. 10. A charged particle beam apparatus according to claim 9, wherein:said two-dimensional area is divided into any one of two parts, four parts, eight parts, sixteen parts, thirty-two parts and sixty-four parts. 11. An image forming method for scanning a two-dimensional area on a sample with a charged particle beam and forming an image of scanning area, the image forming method comprising the steps of:scanning a first scanning line at upper portion of said two-dimensional area on said sample, a second scanning line at lower part, and third scanning line between said first and second scanning lines and at the center of said two-dimensional area; andthen, further scans scanning lines between said first and third scanning lines and between said second and third scanning lines,wherein said further scanning of said scanning lines repeat scanning of new scanning lines at a center of scanning lines which already scanned, such that narrowing distance between said scanning lines already scanned and scanning lines newly scanned, andwherein scanning is repeatedly performed for a center by scanning between the first scanning line and the third scanning line, and scanning lines between the third scanning line and the second scanning line until scanning of the two-dimensional area is complete. 12. An image forming method according to claim 11, wherein:said scanning of said new scanning lines scans scanning line newly for narrowing distance of scanning lines which is already scanned, after scanning at the center between scanning lines haying a same scanning line distance is said two-dimensional area. 13. An image forming method according to claim 11, wherein:said second scanning line scans at far most position from said first scanning line in said two-dimensional area. 14. A charged particle beam apparatus including deflector for scanning charged particle beam on a specimen and a control apparatus for controlling said deflector, wherein:said control apparatus scans a first scanning line at an upper portion of two-dimensional area on said specimen scans, a second scanning line at a lower part of said two-dimensional area, scans a third scanning line at the center of said two-dimensional area, and scans scanning lines between said first and said third scanning lines, and between said second and said third scanning lines,wherein said further scanning of said scanning lines controls said deflector such that repeat scanning of new scanning lines at a center of scanning lines which already scanned, and narrowing distance between said scanning lines already scanned and scanning lines newly scanned, andwherein scanning is repeatedly performed for a center by scanning between the first scanning line and the third scanning line, and scanning lines between the third scanning line and the second scanning line until scanning of the two-dimensional area is complete. 15. A charged particle beam apparatus according to claim 14, wherein:said control apparatus controls said deflector such that scans said new scanning lines for narrowing distance of scanning lines already scanned, after scanning at the center of scanning lines having a same scanning line distance in said two-dimensional area. 16. A charged particle beam apparatus according to claim 14, wherein:said control apparatus controls said deflector such that said second scanning line is scanned at far most position from said first scanning line in said two-dimensional area. 17. A pattern dimension measurement method for scanning two-dimensional area on a specimen with a charged particle beam and for forming an image of scanning area, and measuring dimension of pattern formed on said specimen based on said image, said method comprising steps of:as said two-dimensional area of said specimen, scanning a first and second scanning lines and scanning a third scanning line between said first and second scanning lines, then, scanning a plurality of scanning lines between said first and third and scanning lines and between said second and third scanning lines so that forming image of said two-dimensional area, and measuring said pattern by setting measuring direction in a different direction of line direction of each scanning lines on said image;scanning an area having two sections, defined by the first, second, and third scanning lines, by sequentially scanning positions between the first and third scanning lines and scanning positions between the third and second scanning lines so as to reduce the area in stages; andrepeatedly scanning for a center by scanning lines between the first scanning line and the third scanning line, and scanning lines between the third scanning line and the second scanning line until scanning of the two-dimensional area is complete. 18. An image forming method for scanning a two-dimensional area on a sample with a charged particle beam and forming an image of scanning area, the image forming method comprising the steps of:as to area including two-dimensional area in said sample, scanning a first and second scanning lines, scanning a third scanning line between said first and second scanning lines, then, by scanning a plurality of scanning lines between said first and third scanning lines, between second and third scanning lines, rendering to charge area including two-dimensional area of said sample,forming an image of said scanning area by scanning said charged particle beam onto said charged two-dimensional area,scanning an area haying two sections, defined by the first, second, and third scanning lines, by sequentially scanning positions between the first and third scanning lines and scanning positions between the third and second scanning lines so as to reduce the area in stages; andrepeatedly scanning for a center by scanning lines between the first scanning line and the third scanning line, and scanning lines between the third scanning line and the second scanning line until scanning of the two-dimensional area is complete. 19. A charged particle beam apparatus for deflecting charged particle beam irradiated on a specimen in a spot like shape, a deflector, and control apparatus for controlling said deflector, wherein:said control apparatus controls said deflector such that deflects said charged particle beam so that said charged particle beam is irradiated at a first irradiating position positioned at four corners of said two-dimensional area on said specimen, then deflects said charged particle beam so that a second irradiating position is positioned at the center of said first irradiating positions, then scans an area having two sections, defined by a first scanning line, a second scanning line, and a third scanning line between the first and second scanning lines, by sequentially scanning positions between the first and third scanning lines and scanning positions between the third and second scanning lines so as to reduce the area in stages, and repeatedly scans for a center by scanning lines between the first scanning line and the third scanning line, and scanning lines between the third scanning line and the second scanning line until scanning of the two-dimensional area is complete.
	claims	1. A spacer for a fuel assembly of a boiling water reactor having a fuel assembly channel with an inner side, the spacer comprising:a frame formed with outer webs and inner webs oriented crossways with respect to one another, said outer webs having an outer side facing towards the inner side of the fuel assembly channel in an assembled state;gills formed on said outer side of said outer webs and projecting outward to a given extent from said outer side, said gills each including an opening in said outer web defining an upper edge of said opening and an adjoining wall region of said outer webs both being pre-curved outward;a plurality of projections each formed by an outward bulge in a wall of said outer webs, said projections each having a lower edge extending to and being identical with a lower edge of a respective one of said outer webs and projecting outwardly to a greater extent than said given extent of said gills, said projections each being disposed in a region of a respective one of said inner webs; anda deflector lug formed integrally on a lower edge of said projections. 2. The spacer according to claim 1, wherein said projections are formed below said gills. 3. The spacer according to claim 1, wherein said inner web has a lateral edge and a first supporting section integrally formed on and laterally projecting beyond said lateral edge, wherein said first supporting section extends into and is connected to said projection. 4. The spacer according to claim 3, wherein said inner web has a lower edge and a second supporting section integrally formed on said lower edge, said second supporting section having an inclined edge and a deflector lug supported against said inclined edge. 5. The spacer according to claim 3, wherein said projection has an outer side formed with a recess, said recess extends in an axial direction and having formed therein a slot with said first supporting section at least partially penetrating through said slot. 6. The spacer according to claim 1, wherein said projections project outwardly to a greater extent than said given extent of said gills to prevent said gills from coming into contact with a channel of the fuel assembly.
H00002097	abstract	Disclosed is a discharge assembly for allowing elongate pins to be discharged from an area of relatively low pressure to an area of relatively greater pressure. The discharge assembly includes a duck valve having a lip piece made of flexible material. The flexible lip piece responds to a fluctuating pressure created downstream by an aspirator. The aspirator reduces the downstream pressure sensed by the duck valve when the discharge assembly is in the open position. This allows elongate pins to be moved through the duck valve with no backflow because the aspirator pressure is less than the pressure in the low pressure area from which the pins originate. Closure of the assembly causes the aspirator static pressure to force the flexible duck valve lip piece into a tightly sealed position also preventing backflow. The discharge assembly can be easily controlled using a single control valve which blocks the flow of aspirator gas and closes the pin passageway extending through the assembly.
	summary
050531891	claims	1. A system for providing control rod guidance support with restricted rod coolant flow in a nuclear reactor pressure vessel having a fuel core with an outlet plenum for core heated coolant located thereabove and with an upper head plenum located above the outlet plenum and receiving a portion of return core coolant flow, a plurality of externally driven control rod assemblies each having a drive rod coupled to a depending control rod and extending vertically through the upper plenum and outlet plenum spaces for control rod movement into and out of the core to control the nuclear reaction, said control rod guidance support system comprising: a generally solid upper horizontal support plate secured to the vessel above the fuel core between the upper head plenum and the outlet plenum; a control rod guide tube assembly for each control rod assembly having an upper guide tube located in the upper plenum above the upper support plate and lower guide tube means located in the outlet plenum and aligned with the upper guide tube through an opening in the upper support plate and further aligned with a fuel assembly located in the core therebelow; said upper guide tube and said lower guide tube means housing the control rod when it is withdrawn from the fuel core and having a plurality of horizontal support cards secured therein at vertically spaced locations and provided with openings therethrough to provide guided support of the control rod when it is positioned and as it moves along its vertical path operation; said upper guide tube having a top enclosure plate with a drive rod opening therethrough sized to provide a predetermined clearance space between said drive rod and said top enclosure plate and to direct coolant flow between said upper and outlet plenums and through said guide tube assembly; means for restricting coolant flow through said top plate clearance space to reduce control rod wear; coupling means for securing the drive and control rods in end-to-end relation within the guide tube assembly and located just below said top enclosure plate with the control rod fully withdrawn; said coolant restricting means including at least a flow restrictor located above and secured to said top enclosure plate and having an upper portion disposed about and spaced from the drive rod to provide a flow gap having a flow area substantially equal to said clearance space and otherwise structured to provide at least one contraction-expansion loss above said top guide tube plate for guide tube coolant flow; said coolant restricting means further includes a sleeve disposed about and secured to said coupling means and having a portion thereof extending upwardly over the drive rod so that said sleeve reduces the flow area in said clearance space when the control rod is fully withdrawn; and means providing a total bypass area between said upper and outlet plenums that takes up at least some of the restricted flow from the upper control rod guide tubes. a generally solid upper horizontal support plate secured to the vessel above the fuel core between the upper head plenum and the outlet plenum; a control rod guide tube assembly for each control rod assembly having an upper guide tube located in the upper plenum above the upper support plate and lower guide tube means located in the outlet plenum and aligned with the upper guide tube through an opening in the upper support plate and further aligned with a fuel assembly located in the core therebelow; said upper guide tube and said lower guide tube means housing the control rod when it is withdrawn from the fuel core and having a plurality of horizontal support cards secured therein at vertically spaced locations and provided with openings therethrough to provide guided support of the control rod when it is positioned and as it moves along its vertical path operation; said upper guide tube having a top enclosure plate with a drive rod opening therethrough sized to provide a predetermined clearance space between said drive rod and said top enclosure plate and to direct coolant flow between said upper and outlet plenums and through said guide tube assembly; means for restricting coolant flow through said top plate clearance space to reduce control rod wear; coupling means for securing the drive and control rods in end-to-end relation within the guide tube assembly and located just below said top enclosure plate with the control rod fully withdrawn; said coolant restricting means including at least a flow restrictor located above and secured to said top enclosure plate and having an upper portion disposed about and spaced from the drive rod to provide a flow gap having a flow area substantially equal to said clearance space and otherwise structured to provide at least one contraction-expansion loss above said top guide tube plate for guide tube coolant flow; wherein said clearance space is defined by the distance from an inner side of said flow restrictor and the normal outer diameter of said drive rod; and said drive rod having a lower portion with a relatively enlarged diameter to reduce the flow area within said flow restrictor when the control rod is fully withdrawn; and means providing a total bypass flow area between said upper and outlet plenums that takes up at least some of the restricted flow from the upper control rod guide tubes. a generally solid supper horizontal support plate secured to the vessel above the fuel core between the upper head plenum and the outlet plenum; a control rod guide tube assembly for each control rod assembly having an upper guide tube located in the upper plenum above the upper support plate and lower guide tube means located in the outlet plenum and aligned with the upper guide tube through an opening in the upper support plate and further aligned with a fuel assembly located in the core therebelow; said upper guide tube and said lower guide tube means housing the control rod when it is withdrawn from the fuel core and having a plurality of horizontal support cards secured therein at vertically spaced locations and provided with openings therethrough to provide guided support of the control rod when it is positioned and as it moves along its vertical path operation; said upper guide tube having a top enclosure plate with a drive rod opening therethrough sized to provide a predetermined clearance space between said drive rod and said top enclosure plate and to direct coolant flow between said upper and outlet plenums and through said guide tube assembly; means for restricting coolant flow through said top plate clearance space to reduce control rod wear; coupling means for securing the drive and control rods in end-to-end relation within the guide tube assembly and located just below said top enclosure plate with the control rod fully withdrawn; said coolant restricting means including at least a flow restrictor located above and secured to said top enclosure plate and having an upper portion disposed about and spaced from the drive rod to provide a flow gap having a flow area substantially equal to said clearance space and otherwise structured to provide at least one contraction-expansion loss above said top guide tube plate for guide tube coolant flow; wherein said top enclosure plate has a relatively enlarged opening and said flow restrictor further includes a lower portion extending downwardly from said upper portion through said top plate opening into said upper guide tube to define a coolant flow gap with the drive rod substantially equal to said clearance space and otherwise being structured to provide at least three cascaded contraction-expansion for guide tube coolant flow, and said upper flow restrictor structure is otherwise structured too provide at least three cascaded contraction-expansion for guide tube coolant flow; and means providing a total bypass flow area between said upper and outlet plenums that takes up at least some of the restricted flow from the upper control rod guide tubes. a generally solid upper horizontal support plate secured to the vessel above the fuel core between the upper head plenum and the outlet plenum; a control rod guide tube assembly for each control rod assembly having an upper guide tube located in the upper plenum above the upper support plate and lower guide tube means located in the outlet plenum and aligned with the upper guide tube through an opening in the upper support plate and further aligned with a fuel assembly located in the core therebelow; said upper guide tube and said lower guide tube means housing the control rod when it is withdrawn from the fuel core and having a plurality of horizontal support cards secured therein at vertically spaced locations and provided with openings therethrough to provide guided support of the control rod when it is positioned and as it moves along its vertical path operation; said upper guide tube having a top enclosure plate with a drive rod opening therethrough sized to provide a predetermined clearance space between said drive rod and said top enclosure plate and to direct coolant flow between said upper and outlet plenums and through said guide tube assembly; means for restricting coolant flow through said top plate clearance space to reduce control rod wear; coupling means for securing the drive and control rods in end-to-end relation within the guide tube assembly and located just below said top enclosure plate with the control rood fully withdrawn; said coolant restricting means including at least a flow restrictor located above and secured to said top enclosure plate and having an upper portion disposed about and spaced from the drive rod to provide a flow gap having a flow area substantially equal to said clearance space and otherwise structured to provide at least one contraction-expansion loss above said top guide tube plate for guide tube coolant flow; wherein said top enclosure plate has a relatively enlarged opening and said flow restrictor further includes a lower portion extending downwardly from said upper portion through said top plate opening into said upper guide tube to define a coolant flow gap with the drive rod substantially equal to said clearance space and otherwise being structured to provide two contraction-expansions of guide tube coolant flow; and means providing a total bypass flow area between said upper and outlet plenums that takes up at least some of the restricted flow from the upper control rod guide tubes. a generally solid upper horizontal support plate secured to the vessel above the fuel core between the upper head plenum and the outlet plenum; a control rood guide tube assembly for each control rod assembly having an upper guide tube located inn the upper plenum above the upper support plate and lower guide tube means located in the outlet plenum and aligned with the upper guide tube through ann opening in the upper support plate and further aligned with a fuel assembly located in the core therebelow; said upper guide tube and said lower guide tube means housing the control rod when it is withdrawn from the fuel core and having a plurality of horizontal support cards secured therein at vertically spaced locations and provided with openings therethrough to provide guided support to the control rod when it is positioned and as it moves along its vertical path operation; said upper guide tube having a top enclosure plate with a drive rod opening therethrough sized to provide a predetermined clearance space between said drive rod and said top enclosure plate and to direct coolant flow between said upper and outlet plenums and through said guide tube assembly; coupling means for securing the drive and control rods in end-to-end relation within the guide tube assembly and located just below said top enclosure plate with the control rod fully withdrawn; means for restricting coolant flow through said top plate clearance space too reduce control rod wear, located above and secured to said top enclosure plate and having an upper portion disposed about and spaced from the drive rod to provide a flow gap having a flow area substantially equal to said clearance space and otherwise structured to provide at least one contraction-expansion loss above said top guide tube plate for guide tube coolant flow; and said coolant restricting means further including a sleeve disposed about and secured to said coupling means and having a portion thereof extending upwardly over the drive rod so that said sleeve reduces the flow area in said clearance space when the control rod is fully withdrawn. 2. A control rod support system as set forth in claim 1 wherein means are provided for securing the upper end of said flow restricting sleeve to the drive rod. 3. A control rod support system as set forth in claim 1 wherein said bypass flow means includes a plurality of distributed openings through said upper support plate. 4. A control rod support system as set forth in claim 3 wherein said bypass openings are distributed in accordance with, the radial pressure profile across the outlet plenum. 5. A control rod support system as set forth in claim 3 wherein said upper support plate includes a plurality of control rod openings of which preselected ones are employed for said control rod assemblies, orifice plate means for closing other ones of said control rod openings and forming said bypass flow means, and cover plate means for closing any remaining ones of said control rod openings. 6. A control rod support system as set forth in claim 1 wherein said flow restrictor has a bottom portion forming a flange that is bolted to said top enclosure plate and further having an upwardly extending tubular portion defining an expansion chamber above said top plate and about said drive rod and having a top end portion extending about the drive rod and said sleeve and defining a contraction for top entering coolant and further defining a gap with said sleeve substantially equal to said clearance space less the sleeve thickness. 7. A control rod support system as set forth in claim 6 wherein said top enclosure plate is formed to provide a coolant contraction path for coolant entering from its top side and a coolant expansion path for coolant outletting from its bottom side. 8. A control rod support system as set forth in claim 1 wherein said top enclosure plate has a relatively enlarged opening and said flow restrictor further includes a lower portion extending downwardly from said upper portion through sad top plate opening into said upper guide tube to define a coolant flow gap with said sleeve substantially equal to said clearance space less the sleeve thickness and otherwise being structured to provide at least one additional contraction-expansion for guide tube coolant flow. 9. A control rod support system as set forth in claim 8 wherein aid flow restrictor lower portion is otherwise structured to provide three cascaded contraction-expansions for guide tube coolant flow. 10. A control rod support system as set forth in claim 1 wherein said horizontal guiding support plates are provided with a plurality of vertically aligned openings for a plurality of elongated control rodlets that depend from a top spider, and said coupling means is secured to said spider. 11. A system for providing control rood guidance support with restricted rod coolant flow in a nuclear reactor pressure vessel having a fuel core with an outlet plenum for core heated coolant located thereabove and with an upper head plenum located above the outlet plenum and receiving a portion of return core coolant flow, a plurality of externally driven control rod assemblies each having a drive rod coupled to a depending control rod and extending vertically through the upper plenum and outlet plenum spaces for control rod movement into and out of the core to control the nuclear reaction, said control rod guidance support system comprising: 12. A system for providing control rod guidance support with restricted rod coolant flow in a nuclear reactor pressure vessel having a fuel core with ann outlet plenum for core heated coolant located thereabove and with an upper head plenum located above the outlet plenum and receiving a portion of return core coolant flow, a plurality of externally driven control rod assemblies each having a drive rod coupled to a depending control rod and extending vertically through the upper plenum and outlet plenum spaces for control rod movement into and out of the core to control the nuclear reaction, said control rod guidance support system comprising: 13. A system for providing control rod guidance support with restricted rood coolant flow in a nuclear reactor pressure vessel having a fuel core with an outlet plenum for core heated coolant located thereabove and with an upper head plenum located above the outlet plenum and receiving a portion of return core coolant flow, a plurality of externally driven control rod assemblies each having a drive rood coupled to a depending control rod and extending vertically through the upper plenum and outlet plenum spaces for control rod movement into and out of the core to control the nuclear reaction, said control rod guidance support system comprising: 14. In a nuclear reactor pressure vessel having a fuel core with an outlet plenum for core heated coolant located thereabove and with an upper head plenum located above the outlet plenum and receiving a portion of return core coolant flow, a plurality of externally driven control rod assemblies each having a drive rod coupled to a depending control rod and extending vertically through the upper plenum and outlet plenum spaces for control rod movement into and out of the core to control the nuclear reaction, a system of providing control rod guidance support with restricted rod coolant flow comprising: 15. The nuclear reactor as set forth in claim 14 wherein means are provided for securing the upper end of said flow restricting sleeve to the drive rod. 16. The nuclear reactor as set forth in claim 14 wherein said clearance space is defined by the distance from an inner side of said flow restrictor and the normal outer diameter of said drive rod; and said drive rod having a lower portion with a relatively enlarged diameter too reduce the flow area within said flow restrictor when the control rod is fully withdrawn. 17. The nuclear reactor as set forth in claim 14 wherein said flow restrictor has a bottom portion forming a flange that is bolted to said top enclosure plate and further having an upwardly extending tubular portion defining an expansion chamber above said top plate and about said drive rod and having a top end portion extending about the drive rod and said sleeve and defining a contraction for top entering coolant and further defining a gap with said sleeve substantially equal to said clearance space less the sleeve thickness. 18. The nuclear reactor as set forth in claim 17 wherein said top enclosure plate is formed too provide a coolant contraction path for coolant entering from its top side and a coolant expansion path for coolant outletting from its bottom side. 19. The nuclear reactor as set forth in claim 14 wherein said top enclosure plate has a relatively enlarged opening and said flow restrictor further includes a lower portion extending downardly from said upper portion through said top plate opening into said upper guide tube to define a coolant flow gap with said sleeve substantially equal to said clearance space less the sleeve thickness and otherwise being structured to provide at least one additional contraction-expansion for guide tube coolant flow. 20. The nuclear reactor as set forth in claim 19 wherein said flow restrictor lower portion is otherwise structured to provide three cascaded contraction-expansions for guide tube coolant flow.
	claims	1. A system comprising:a processor;a permanent monitor operably coupled to a load connected to an energy distribution system, wherein the permanent monitor produces base load values indicative of an energy-related parameter associated with the load and transmits the base load values to the processor, the base load values being collected over a period of time sufficient to capture an operational range of the load;a temporary monitor operably coupled to the load, wherein the temporary monitor produces, at substantially the same time as the permanent monitor, temporary load values indicative of the energy-related parameter or a different energy-related parameter associated with the load and transmits the temporary load values to the processor, the temporary load values being collected over the period of time without having to disconnect the load from the energy distribution system, and wherein each of the permanent monitor and the temporary monitor is configured to measure values of the energy distribution system to produce the base load values and the temporary load values, respectively, the temporary monitor being capable of monitoring (a) more advanced measurements of the value than the permanent monitor is capable of or (b) more accurate measurements of the value relative to the permanent monitor;wherein the processor generates at least one load model indicative of a relationship between the transmitted base load values and the transmitted temporary load values, wherein, responsive to the temporary monitor being disconnected from the load, (a) the permanent monitor produces a new base load value indicative of the energy-related parameter associated with the load and (b) the processor calculates an estimated load value based on the new base load value and the load model, wherein the load model incorporates known characteristics of the load provided by the manufacturer of the load, and wherein the processor determines a confidence interval for the estimated load value to determine an estimation range for the load model, the estimation range corresponding to a range within which the estimated load value approximates at least one of the temporary load values. 2. The system of claim 1, wherein the temporary monitor is coupled to the load for a period of time sufficient to capture an operational range of the load. 3. The system of claim 1, wherein the temporary monitor and the permanent monitor are coupled to the processor by a communication network. 4. The system of claim 1, wherein the permanent monitor and the temporary monitor are synchronized to substantially simultaneously measure the base load value and the temporary load value. 5. The system of claim 4, wherein the temporary monitor and the permanent monitor are synchronized with an external time source. 6. The system of claim 4, wherein one of the permanent monitor and the temporary monitor acts as a master device and transmits a synchronization signal. 7. A method comprising:establishing, using a processor, a load model that utilizes a measurement of an energy distribution system from a second monitor to estimate a value taken by a first monitor operably coupled to a load connected to the energy distribution system;collecting, using the processor, from the first monitor base load values indicative of an energy-related parameter associated with the load over a period of time sufficient to capture an operational range of the load;collecting, using the processor, from the second monitor temporary load values indicative of the energy-related parameter or a different energy-related parameter associated with the load over the period of time without having to disconnect the load from the energy distribution system, the second monitor being capable of monitoring (a) more advanced measurements than the permanent monitor is capable of or (b) more accurate measurements relative to the permanent monitor, the base load values and the temporary load values being produced at substantially the same time;responsive to the second monitor being disconnected from the load, collecting a new base load value indicative of the energy-related parameter associated with the load and calculating, using the processor, an estimated load value by applying the load model to the new base load value, wherein the load model incorporates known characteristics of the load provided by the manufacturer of the load;storing the estimated load value in a memory device coupled to the processor; anddetermining, using the processor, a confidence interval for the estimated load value to determine an estimation range for the load model, the estimation range corresponding to a range within which the estimated load value approximates at least one of the temporary load values. 8. The method of claim 7, wherein the step of determining yields a second load model. 9. The method of claim 7, wherein the step of collecting the plurality of temporary load values and the step of collecting the plurality of the base load values are synchronized. 10. The method of claim 7, wherein the step of collecting the plurality of temporary load values and the step of collecting the plurality of the base load values is synchronized by a master monitor. 11. The method of claim 7, wherein the steps of collecting occurs over a period of time sufficient to capture an operational range of the load. 12. The method of claim 7, wherein an estimation range is determined for the load model. 13. The method of claim 7, wherein the step of establishing utilizes at least one external specification for the load. 14. The method of claim 7, wherein the step of establishing comprises utilizing a pre-defined load model. 15. The method of claim 7, wherein the load model is determined by a regression method. 16. A computer program product, comprising one or more non-transitory computer-readable media, wherein information embodied on the non-transitory computer-readable media is configured to cause a processor to implement a method comprising:establishing a load model that utilizes a measurement of an energy distribution system from a second monitor to estimate a value taken by a first monitor operably coupled to a load connected to the energy distribution system;collecting from the first monitor base load values indicative of an energy-related parameter associated with the load over a period of time sufficient to capture an operational range of the load;collecting from the second monitor temporary load values indicative of the energy-related parameter or a different energy-related parameter associated with the load over the period of time without having to disconnect the load from the energy distribution system, the second monitor being capable of monitoring (a) more advanced measurements than the permanent monitor is capable of or (b) more accurate measurements relative to the permanent monitor, the base load values and the temporary load values being produced at substantially the same time;responsive to the second monitor being disconnected from the load, collecting a new base load value indicative of the energy-related parameter associated with the load and calculating an estimated load value by applying the load model to the new base load value, wherein the load model incorporates known characteristics of the load provided by the manufacturer of the load;storing the estimated load value in a memory device; anddetermining a confidence interval for the estimated load value to determine an estimation range for the load model, the estimation range corresponding to a range within which the estimated load value approximates at least one of the temporary load values.
062467417	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel assembly which is used in a pressurized water reactor. 2. Description of Related Art A conventional fuel assembly used in a pressurized water reactor, which includes, a lower nozzle disposed on a lower core plate of the pressurized water reactor, an upper nozzle having a hold-down spring for holding down the lower nozzle against the lower core plate, a plurality of control rod guide thimbles for guiding control rods extending through the upper nozzle toward the lower core plate, a plurality of supporting grids mounted on the control rod guide thimbles, and a number of fuel rods held by the supporting grids in parallel with the control rod guide thimbles, is disclosed in a pamphlet published by FRAMATOME Co. entitled "SNE97-La Coruna-Nov. 5-7, 1997". In a fuel assembly such as mentioned above, when the control rods, detached from the control rod driving unit upon emergency shutdown of the nuclear reactor, fall within the control rod guide thimbles without being decelerated, the upper nozzle of the fuel assembly may be subjected to an excessively large impact force. Consequently, dashpots of a thin-tube configuration are formed within the control rod guide thimbles so that the speed at which the control rods fall within the control rod guide thimbles is decreased to thereby dampen the impact force applied to the upper nozzle. However, in a conventional fuel assembly such as described above, the dashpot has a length ranging from 0.16 L to 0.18 L, wherein L represents the entire length of a control rod guide thimble. Consequently, flexural deformation may take place in the dashpot under compression loads acting in the axial direction of the control rod guide thimble, giving rise to problems in that insertability of the control rod may be impaired due to the flexural deformation of the dashpot. SUMMARY OF THE INVENTION In the light of the state of the art described above, it is an object of the present invention to provide a fuel assembly of a structure such that the dashpot can be positively protected against flexural deformation under the compression loads acting in the axial direction of the control rod guide thimble. In view of the above and other objects, which will become apparent as the description proceeds, there is provided according to a general aspect of the present invention a fuel assembly for a pressurized water reactor which includes, a lower nozzle disposed on a lower core plate of the pressurized water reactor, an upper nozzle having hold-down spring means for holding down the lower nozzle against the lower core plate, a plurality of control rod guide thimbles for guiding control rods extending through the upper nozzle toward the lower core plate, a plurality of supporting grids mounted on the control rod guide thimbles, a number of fuel rods held by the supporting grids in parallel with the control rod guide thimbles, and dashpots each formed in a thin tubular shape in each of the control rod guide thimbles for reducing thee falling speed of the control rods. Each dashpot is comprised of a large diameter section which has a diameter substantially equal to that of the control rod guide thimble and which is formed at a lower portion of the dashpot and a small diameter section which has a diameter smaller than that of the large diameter section and which is formed at an upper portion of the dashpot, wherein the small diameter section has an effective length selected so as to fall within a range of 0.03 L to 0.1 L where L represents a length of the control rod guide thimble. In a preferred mode of the present invention, the effective length of the small diameter section may be selected so as to fall within a range of from 0.04 L to 0.06 L In another preferred mode, the length of the dashpot may be dimensioned so as to fall within a range of from 0.16 L to 0.18 L, while the length of the large diameter section may be so selected as to fall within a range of from 0.06 L to 0.15 L and more preferably within a range of from 0.10L to 0.14 L. In yet another preferred mode for carrying out the invention, another small diameter section may be additionally provided in a lower end portion of the large diameter section. The above and other objects, features and attendant advantages of the present invention will be more easily understood by reading the following description of the preferred embodiments, to be taken only by way of example, in conjunction with the accompanying drawings.
	summary
056132441	abstract	A process for preparing radioactive and other hazardous liquid wastes for treatment by the method of vitrification or melting is provided for.
	abstract	A two-part integrated head assembly (100) is disclosed wherein the lower portion (110) attaches to, and is supported by, the reactor vessel closure head (90), and the upper portion (160) is fluidly connected to the lower portion, but is supported externally from the reactor vessel closure head. In the disclosed embodiment, the upper portion includes transverse support beams (170) that engage containment walls (92), for example steam generator walls, to support the upper portion. A duct (150) releasably connects a fan plenum (165) in the upper portion with an annular plenum in the lower portion, such that fans (166) can draw heated air from around the CEDMs (95). In one embodiment, a chiller (168) is provided in the fan plenum to cool the air prior to expelling it in containment. A missile shield (169) is also provided in the upper portion.
051480409	claims	1. A shield for use with a radiation detecting probe to effect the detection, localization, imaging or mapping of radiation in a first, internal portion of the body of a living being by use of a radiation detecting probe, said probe having a field of view, said shield comprising a sheet formed of a radiation blocking material and sized to be readily located within a space in the body of the being so that said first, internal portion is interposed between remainder said shield and said probe, with said shield filling up a substantial portion of the field of view, thereby blocking radiation from sources behind said shield. 2. The shield of claim 1 wherein the surface of said shield which comes into contact with any portion of the body of said being is non-toxic. 3. The shield of claim 2 wherein said shield is formed of a material in the group comprising pure tungsten, tungsten alloys, tungsten powder suspended in gold, pure gold, gold alloys, pure platinum, and platinum-iridium alloys. 4. The shield of claim 3 wherein said tungsten, tungsten alloys, and tungsten powder suspended in gold, when used to form said shield are chrome plated. 5. The shield of claim 1 wherein said sheet is approximately 3 inches (7.62 cm) wide by 3.5 inches (8.89 cm) high. 6. The shield of claim 5 wherein said material is tungsten and said sheet is approximately 1/8 inch (0.32 cm) thick. 7. The shield of claim 1 additionally comprising means to mount said shield on said probe. 8. The shield of claim 7 wherein said last mentioned means is adjustable to vary the spacing of said shield from said probe. 9. The shield of claim 8 wherein said sheet is approximately 3 inches (7.62 cm) wide by 3.5 inches (8.89 cm) high. 10. The shield of claim 9 wherein said material is tungsten and said sheet is approximately 1/8 inch (0.32 cm) thick. 11. The shield of claim 7 wherein said sheet is approximately 3 inches (7.62 cm) wide by 3.5 inches (8.89 cm) high. 12. The shield of claim 11 wherein said material is tungsten and said sheet is approximately 1/8 inch (0.32 cm) thick. 13. The shield of claim 7 wherein the surface of said shield which comes into contact with any portion of the body of said being is non-toxic. 14. The shield of claim 13 wherein said shield is formed of a material in the group comprising pure tungsten, tungsten alloys, tungsten powder suspended in gold, pure gold, gold alloys, pure platinum, and platinum-iridium alloys. 15. The shield of claim 14 wherein said tungsten, tungsten alloys, and tungsten powder suspended in gold, when used to form said shield are chrome plated. 16. The shield of claim 8 wherein the surface of said shield which comes into contact with any portion of the body of said being is non-toxic. 17. The shield of claim 16 wherein said shield is formed of a material in the group comprising pure tungsten, tungsten alloys, tungsten powder suspended in gold, pure gold, gold alloys, pure platinum, and platinum-iridium alloys. 18. The shield of claim 17 wherein said tungsten, tungsten alloys, and tungsten powder suspended in gold, when used to form said shield are chrome plated. 19. A method of effecting the detection, localization, imaging or mapping of radiation in a first, internal portion of the body of a living being by use of a radiation detecting probe, said probe having a field of view, said method comprising introducing a shield into the body of said being, said shield comprising a sheet formed of a radiation blocking material and sized to be readily located within a space in the body of the being so that said first, internal portion is interposed between said shield and said probe, with said shield filling up a substantial portion of the field of view, whereupon said shield blocks radiation from sources behind said shield. 20. The method of claim 19 wherein said shield is mounted on said probe. 21. The method of claim 20 wherein the position of said shield with respect to said probe is adjustable via means mounting the shield on the probe.
	summary
	abstract	A Y-shaped carbon nanotube atomic force microscope probe tip and methods comprise a shaft portion; a pair of angled arms extending from a same end of the shaft portion, wherein the shaft portion and the pair of angled arms comprise a chemically modified carbon nanotube, and wherein the chemically modified carbon nanotube is modified with any of an amine, carboxyl, fluorine, and metallic component. Preferably, each of the pair of angled arms comprises a length of at least 200 nm and a diameter between 10 and 200 nm. Moreover, the chemically modified carbon nanotube is preferably adapted to allow differentiation between substrate materials to be probed. Additionally, the chemically modified carbon nanotube is preferably adapted to allow fluorine gas to flow through the chemically modified carbon nanotube onto a substrate to be characterized. Furthermore, the chemically modified carbon nanotube is preferably adapted to chemically react with a substrate surface to be characterized.
047145820	description	DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1 and 2, an actuating device for moving a cluster constitutes part of the mechanism for controlling a set of two clusters of vertically movable control elements and engaging them more or less deeply in a same fuel assembly of a reactor. Hereafter, that one of the two clusters which is moved by the device will be called "lower cluster" and the other "upper cluster". However, under certain operating conditions, the so-called upper cluster may be situated below the other. The upper cluster (not shown) may typically comprise elongated elements or rods containing a neutron poison and be used for adjusting the power of the reactor. The upper cluster is carried by a tubular drive shaft 10 slidably received in a tube (not shown) projecting through the cover of the reactor vessel. Shaft 10 is controlled by drive means which may have a number of different constructions. The drive means may for example be one of those described in French Pat. Nos. 2,537,764, 2,232,820, 2,106,373 to which reference may be made. The lower cluster is arranged for connection to and disconnection from a drive shaft 12, coaxial with shaft 10. As shown in FIG. 2, the lower cluster comprises four sub-clusters 14 (this number not being limitative) of sixteen elements each. Each of the sub-clusters 14 cooperates with associated gripping means formed by a nipper or gripper 16 fixed to an arm of a cross piece 18 fixed to the shaft 12 (FIGS. 1 and 2). The nature of the elongated elements forming the sub-clusters will depend on the contemplated use. The elements may contain a high proportion of neutron absorbing material, when the lower cluster is shutting down the reactor. The cluster may also comprise moderating or neutron-transparent material, when it is desired for example to modify the moderation ratio of the reactor during the life of this latter. They may contain fertile material in place of or in addition to other materials. The drive shaft 12 has at its lower part a resilient shock damper 20, which comes into contact with the upper core plate 22 during downward movement of shaft 12 supporting the clusters and which slows down the end travel in case of free fall of the shaft. Each set of two clusters associated with a fuel assembly, such as the assembly whose upper end piece or nozzle 24 is shown in FIG. 1, is associated with stationary retaining and guide means belonging to the internals of the reactor. The guide means comprise a guide tube 26 fixed to the upper core plate of the reactor (which is part of the upper internals of the reactor) and having an upper structure 28 in which are formed housings 30 each for receiving a grab 32. In the embodiment as described, the upper core plate forms a lower structure supporting the cross piece 18 and the sub-clusters 14 when they are in their lower position. The actuating device comprises a grab 32 for each sub-cluster 14. Each grab may have the construction as shown in FIGS. 3 to 6. The elongated elements of the sub-clusters are suspended from radial arms of the tubular body 34 of the grab. The top part of the tubular body 34 is split up, by slits 37 parallel to the axis and spaced apart at regular intervals, into flexible fingers 38. Each flexible finger has two projections 40 and 42 separated by an intermediate groove 44. The lower part of the body 34 slidably receives a stop member 36 carried by a pin 46 limiting downward movement of the stop away from a transverse partition 48 of the body. A return spring 50 urges stop 36 towards the lower position in which it is shown in FIGS. 1 and 3. Spring 50 is thus retained under a prestress, so calibrated that the spring contracts and allows stop 36 to move with respect to body 34 only when subjected to a force greater than the weight of the sub-cluster and to the snap engagement force of the body 34 of the sub-cluster 32 in housing 30. The housing 30 for receiving each grab in the upper structure 28 has a rotational symmetry. It comprises, from bottom to top, an entrance chamfer 52, an internal flange 54, a recess or counterbore 56 and a shoulder 58 connecting with a portion 60 of a smaller diameter than that of flange 54. Grooves 62, four in number as illustrated, divide up flange 54 at regular angle intervals. Their depth is such that their bottom is in alignment with that of the recess 56 and their function will be discussed further on. The axial dimension of recess 56 is such that it may receive both projections 40 and 42 together, as shown in FIG. 3. Each of the nippers 16, carried by arms of the cross piece 18, comprises four rigid blades 64 whose dimensions and mutual spacing are such that they may engage grooves 62 of housing 30 during upward movement of the nipper. Each of blades 64 ends with a latching lip 66 arranged for passing between the arms of the grab 32 and for: abutment with the projection 42, for supporting the grab 32, insertion into the intermediate groove 44 of the grab so as to connect the nipper 16 to grab 32, when the nipper is raised into the grab while the grab is in its upper abutment condition. The bottom wall of nipper 16 is formed with several holes 68 distributed about the vertical axis of the nipper, opposite the tubular body 34 of the grab. Holes 68 are located for providing a passage for fingers 70 arranged for forcibly disengaging the nipper. In the embodiment shown in FIG. 6, fingers 70 are carried by the end nozzle 24 of the fuel assembly which forms the lower fixed structure of the device. However, other arrangements are possible. Fingers 70 have a sufficient length for retaining the body 34 of grab 32 against axial movement when the latter is pulled downwardly by nipper 16 engaged with fingers 38. The operation of the device during the different possible phases is as follows. Locking of the grab in top position First, the upper cluster should be moved to its top "over travel" position, i.e. to a position which is above the top position in which it will later be retained. Locking of the grab in the top position automatically occurs by snap action upon upwardly moving the nipper 16 on which the grab simply rests (FIG. 1). The projections 40 of fingers 38 first engage the entrance chamfer 52. Upon continued upward movement of the nipper 16, the force transmitted from the nipper to the grab through stop 36 and spring 50 is sufficient for bending fingers 38 inwardly while projections 40 slide over the chamfer. As soon as projections 40 and 42 confront the recess 56, the fingers revert to their original shape and the projections snap into position and lock the grab. Upward movement of nipper 16 is then stopped. Cross piece 18 may then be moved down (FIG. 3) to its lower position, thus completely freeing the path of the other cluster. Grabs 32 and the sub-clusters 14 remain in their top position. Unlocking and lowering In order to bring the cluster to the low position, the cross piece 18 is raised. Lips 66 engage projection 42 and the bottom wall of nipper 16 comes into abutment against stop 36. Upon further upward movement of nipper 16, spring 50 is compressed and simultaneously fingers 38 are forced radially inwardly by the rigid blades 64 guided by recess 56 and grooves 62. Lips 66 snap into groove 44 whose depth is such that the projections 40, still in abutment against shoulder 58, have a size less than the passage area left free by flange 54 (FIG. 4). If then shaft 12 and cross piece 18 are lowered, they then carry the grab 32 engaged with nippers 16 and the sub-clusters 14 (Figure 5). The cross piece may thus be lowered as far as the lower position defined by abutment of the tubular body 34 of grab 32 on pins 70. Disconnection and raising When it is desired to move the sub-clusters 14 back to their top position, grabs 32 are first of all disengaged from nippers 16. Disconnection is effected by moving shaft 12 down by an additional extent. The body 34 of grab 32 is then retained by the fixed pins 70 and lips 66 escape downwardly, while temporarily bending the resilient fingers 38. As soon as the lips have left grooves 34, spring 50 raises the grab which comes into the position shown in FIG. 6, bearing on lips 66 and through stop 36, on the bottom of the nipper. Stop 36, arranged to rest on the bottom wall of nipper 16, fulfils two functions: When the grab is engaged with the nipper (FIG. 5) the stop holds the grab in a well defined position with respect to the nipper, since the compression force of the spring is less than the resilient locking force. The stop takes up possible lost motion and avoids shocks and fatigue effects. The resilient stop in addition relieves pins 70 when two-way connection changes to a simple bearing contact. In fact, spring 50 whose precompression force is greater than the weight of the sub-cluster, assists pins 70 in their action. It will be appreciated that the device moves the sub-clusters into their upper connection position. They may leave them and bring them back to the lower position, so making the sub-clusters completely independent of the movement of an additional cluster consisting of neutron absorbing control elements. It is important to note that the whole of the engaging and disengaging, locking and unlocking operations is controlled solely by movements of the nipper, without any auxiliary member. The control mechanisms may therefore be very simple and may be of existing types which provide a largely sufficient positioning accuracy for blindly effecting the different operations required.
050531913	abstract	A cantilevered hold-down spring (68) for a nuclear fuel assembly (10), comprising an elongated metal bar including a substantially straight long leg portion (66) having one end adapted to be mounted (38) to a fuel assembly, an arcuate transition portion (70) at the other end of the long leg, and a straight short leg portion (76) extending from the transition portion at an acute included angle with the long leg portion, and a load transfer means (64) projecting from the straight leg intermediate the transition portion and the long leg first end. As the load on the primary loading point (80) on the transition portion increases, the load is transferred to the projection (64), thereby effectively shortening and stiffening the spring.
	abstract	A nuclear reactor in one embodiment includes a cylindrical body having an internal cavity, a nuclear fuel core, and a shroud disposed in the cavity. The shroud comprises an inner shell, an outer shell, and a plurality of intermediate shells disposed between the inner and outer shells. Pluralities of annular cavities are formed between the inner and outer shells which are filled with primary coolant such as demineralized water. The coolant-filled annular cavities may be sealed at the top and bottom and provide an insulating effect to the shroud. In one embodiment, the shroud may comprise a plurality of vertically-stacked self-supported shroud segments which are coupled together.
	abstract	A patient alignment system for a radiation therapy system. The alignment system includes multiple external measurement devices which obtain position measurements of components of the radiation therapy system which are movable and/or are subject to flex or other positional variations. The alignment system employs the external measurements to provide corrective positioning feedback to more precisely register the patient and align them with a radiation beam. The alignment system can be provided as an integral part of a radiation therapy system or can be added as an upgrade to existing radiation therapy systems.
044908369	claims	1. A shut-off valve comprising a housing defining a valve chamber; a cover mounted on said housing and defining a cylinder; a valve stem having a lid at one end and a piston at an opposite end slidably disposed in said cylinder to divide said cylinder into a first chamber on one side of said piston and a second chamber on an opposite side of said piston; a first duct extending from said first chamber through said cover; a second duct of fixed minimum cross-section extending from said second chamber through said cover; a third duct extending from said valve chamber through said cover to said first chamber; a fixed throttle means in said first duct; at least one control valve in said third duct; a first connecting line extending from said first duct; a second connecting line extending from said second duct; a third connecting line extending from said control valve for controlling said control valve; a low pressure chamber connected to said first connecting line and to said second connecting line; a first closing valve in said first connecting line to selectively connect said first chamber to said low pressure chamber; and a second closing valve in said second connecting line to selectively connect said second chamber to said low pressure chamber. a wall of a nuclear reactor plant; a shut-off valve within said wall, said shut-off valve comprising a housing defining a valve chamber; a cover mounted on said housing and defining a cylinder; a valve stem having a lid at one end and a piston at an opposite end slidably disposed in said cylinder to divide said cylinder into a first chamber on one side of said piston and a second chamber on an opposite side of said piston; a first duct extending from said first chamber through said cover; a second duct of fixed minimum cross-section extending from said second chamber through said cover; a third duct extending from said valve chamber through said cover to said first chamber; a fixed throttle means in said first duct; at least one control valve in said third duct; a first connecting line extending from said first duct through said wall; a second connecting line extending from said second duct through said wall; a third connecting line extending from said control valve through said wall for controlling said control valve; a low-pressure chamber outside said wall and connected to said first connecting line and said second connecting line; a first closing valve in said first connecting line adjacent and within said wall to selectively connect said first chamber to said low-pressure chamber; and a second closing valve in said second connecting line adjacent and within said wall to selectively connect said second chamber to said low-pressure chamber. 2. A shut-off valve as set forth in claim 1 which further comprises a non-return valve in said third duct between said valve chamber and said control valve, a fourth connecting line connected to said cover in communication with said first chamber for delivering an external pressure medium into said first chamber, a closing valve in said fourth connecting line for controlling flow therethrough, and a non-return valve in said cover in communication with said fourth connecting line to prevent a return flow into said fourth connecting line. 3. A shut-off valve as set forth in claim 2 which further comprises a non-return valve in said fourth connecting line located near said first closing valve and said second closing valve, and wherein each of said closing valves is remotely-controlled. 4. A shut-off valve as set forth in claim 1 which further comprises a redundant control valve in said third duct and a cylindrical insert within said cover containing said control valves in coaxial relation to each other. 5. A shut-off valve as set forth in claim 1 which further comprises a third closing valve in said third connecting line for controlling a flow of a control medium therethrough. 6. In combination, 7. The combination as set forth in claim 6 wherein each said closing valve is remotely-controlled. 8. The combination as set forth in claim 6 which further comprises a remote-controlled third closing valve in said third connecting line adjacent and within said wall to selectively connect said control valve to a pressure medium. 9. The combination as set forth in claim 6 which further comprises a non-return valve in said third duct between said valve chamber and said control valve, a fourth connecting line extending through said wall and connected to said cover in communication with said first chamber for delivering an external pressure medium into said first chamber, a closing valve in said fourth connecting line and outside said wall for controlling flow therethrough, and a non-return valve in said cover in communication with said fourth connecting line to prevent a return flow into said fourth connecting line. 10. The combination as set forth in claim 9 which further comprises a non-return valve in said fourth connecting line adjacent and within said wall.
	summary
	abstract	In a scintillator panel, a glass substrate with the thickness of not more than 150 μm serves as a support body, thereby achieving excellent radiotransparency and flexibility and also relieving a problem of thermal expansion coefficient. Furthermore, in this scintillator panel, an organic resin layer is formed so as to cover a one face side and a side face side of the glass substrate. This reinforces the glass substrate, whereby the edge part thereof can be prevented from chipping or cracking. Furthermore, stray light can be prevented from entering the side face of the glass substrate, while transparency is ensured for light incident to the other face side of the glass substrate because the organic resin layer is not formed on the other face side of the glass substrate.
	summary
044217145	description	DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a partial section of the closure head 1 of a nuclear reactor pressure vessel (not shown), which is provided with a through-hole 2, shaped as stepped boreholes 3, 4 at its opposite ends. The closure consists of a ferritic material with a heat expansion coefficient of 13.times.10.sup.-6 and is provided with a plating 5 on its inner side, which extends to stepped borehole 3 of cover 1. A nozzle 6 comprised of a nonferrous base alloy of the DIN designation Ni Cr 15 Fe with a thermal expansion coefficient of 14.times.10.sup.-6 is inserted into through-hole 2 and projects at its end provided with a thread into the area of stepped borehole 3. A compensating ring 8 made of austenitic material with a thermal expansion coefficient of 17.times.10.sup.-6 is placed on contact surface 7 formed by stepped borehole 4, and nozzle 6 is braced on this ring by means of its shoulder 9. The nozzle is fastened in the cover by nut 10 engaging in the thread of support 6, which nut comes into contact with surface 11 of stepped borehole 3. With a weld seam 12 serving only for tightness purposes, nozzle 6 is connected to plating 5 with the interposing of a packing ring 13. Nut 10 consists of a ferritic material, which has the same thermal expansion coefficient as the closure material. If the distance denoted "1" between shoulder 9 and the tension coupling amounts to 80 mm in the above-named materials, then the height "h" of the compensating ring 8 must be 20 mm. An elongation of 0.336 mm is produced for the nozzle in the region of the 80-mm long distance upon heating to approximately 300.degree. C. This value is also obtained together with nut 10, projection 14, and compensating ring 8. In this way it is assured that no heat stresses occur in the region of the tension coupling. In the example of embodiment according to FIG. 2, nozzle 6 is screwed directly into the through-hole 2 provided with an inside threading. A compensating ring 8 is placed on contact surface 7, in the same way as in the embodiment example according to FIG. 1, and nozzle 6 is braced by its shoulder 9 on this ring. In this case also, the height "h" and the material of compensating ring 8 are selected in such a way that the elongation of the nozzle in the region of length "l" is equal to the elongation of projection 14 plus the height of compensating ring 8 upon a change in temperature. If a specific difference in stress is desired, then this can be accomplished by changing height "h" or the material composition of compensating ring 8. The heat stresses in the region of the tension coupling can be successfully controlled with the nozzle penetration according to the invention. The above description and drawings are illustrative of two embodiments which achieve the objects, features and advantages of the present invention, and is not intended that the present invention be limited thereto. Any modification of the present invention which comes within the spirit and scope of the following claims is considered part of the present invention.
	abstract	The invention comprises a system for controlling a charged particle beam shape and direction relative to a controlled and dynamically positioned patient and/or an imaging surface, such as a scintillation plate of a tomography system and/or a first two-dimensional imaging system coupled to a second two-dimensional imaging system. Multiple interlinked beam/patient/imaging control stations allow safe zone operation and clear interaction with the charged particle beam system and the patient. Both treatment and imaging are facilitated using automated sequences controlled with a work-flow control system.
	summary
048719110	abstract	An electron beam apparatus comprising a semiconductor electron emitter whose emissive surface dimensions are determined by dimensions of a p-n junction provided in the semiconductor element. By optimizing the dimensions of the emissive surface in relation to the electron-optical properties of the apparatus, an emitter is realized which combines optimum beam formation or imaging with a sufficiently large beam current and a high beam current density as required by the apparatus.
062394304	abstract	A particle beam apparatus that can be used, in particular in an electron microscope, has a dispersively imaging energy filter in the illumination beam path. A higher energy sharpness of the particles contributing to the further particle-optic imaging, and hence a reduction of the effect of chromatic aberrations, is attained by means of the energy filter. So that voltage fluctuations of the applied high voltage also bring about no drift of the image of the beam producer in spite of the dispersion present after complete passage through the filter, the beam producer is imaged, enlarged, in a plane of the filter that is imaged achromatically by the filter into an output image plane. Because of the high dispersion of the dispersive filter as against non-dispersive filters, the particle beam apparatus can be operated at a higher particle energy within the filter, so that the influence of the Boersch effect is reduced in comparison with non-dispersive filters.
056423900	claims	1. A uranium-containing nuclear-fuel sintered pellet containing UO.sub.2, comprising a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound UB.sub.x with at least one number x from a number set 2; 4 and 12, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 2. A uranium-containing nuclear-fuel sintered pellet containing (U, Pu)O.sub.2, comprising a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, Pu)B.sub.x with at least one number x from a number set 2; 4 and 12, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 3. A uranium-containing nuclear-fuel sintered pellet containing (U, Th)O.sub.2, comprising a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, Th)B.sub.x with at least one number x from a number set 4 and 6, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 4. A uranium-containing nuclear-fuel sintered pellet containing (U, RE)O.sub.2 (RE=rare earth), comprising a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, RE)B.sub.x with at least one number x from a number set 4; 6 and 12, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 5. A uranium-containing nuclear-fuel sintered pellet containing (U, Pu, Th)O.sub.2, comprising a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, Pu, Th)B.sub.x with at least one number x from a number set 2; 4; 6 and 12, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 6. A uranium-containing nuclear-fuel sintered pellet containing (U, Pu, RE)O.sub.2 (RE=rare earth), comprising a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, Pu, RE)B.sub.x with at least one number x from a number set 2; 4; 6 and 12, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compounds. 7. A uranium-containing nuclear-fuel sintered pellet containing (U, Th, RE)O.sub.2 (RE=rare earth), comprising a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, Th, RE)B.sub.x with at least one number x from a number set 4 and 6, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 8. A uranium-containing nuclear-fuel sintered pellet containing (U, Pu, Th, RE)O.sub.2 (RE=rare earth), comprising a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, Pu, Th, RE)B.sub.x with at least one number x from a number set 4 and 6, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 9. The uranium-containing nuclear-fuel sintered pellet according to claim 1, including at least 90% by volume of the chemical boron compounds in the sintered-pellet surface, and at most 2% by volume of the chemical boron compounds in the remainder of the sintered pellet. 10. The uranium-containing nuclear-fuel sintered pellet according to claim 2, including at least 90% by volume of the chemical boron compounds in the sintered-pellet surface, and at most 2% by volume of the chemical boron compounds in the remainder of the sintered pellet. 11. The uranium-containing nuclear-fuel sintered pellet according to claim 3, including at least 90% by volume of the chemical boron compounds in the sintered-pellet surface, and at most 2% by volume of the chemical boron compounds in the remainder of the sintered pellet. 12. The uranium-containing nuclear-fuel sintered pellet according to claim 4, including at least 90% by volume of the chemical boron compounds in the sintered-pellet surface, and at most 2% by volume of the chemical boron compounds in the remainder of the sintered pellet. 13. The uranium-containing nuclear-fuel sintered pellet according to claim 5, including at least 90% by volume of the chemical boron compounds in the sintered-pellet surface, and at most 2% by volume of the chemical boron compounds in the remainder of the sintered pellet. 14. The uranium-containing nuclear-fuel sintered pellet according to claim 6, including at least 90% by volume of the chemical boron compounds in the sintered-pellet surface, and at most 2% by volume of the chemical boron compounds in the remainder of the sintered pellet. 15. The uranium-containing nuclear-fuel sintered pellet according to claim 7, including at least 90% by volume of the chemical boron compounds in the sintered-pellet surface, and at most 2% by volume of the chemical boron compounds in the remainder of the sintered pellet. 16. The uranium-containing nuclear-fuel sintered pellet according to claim 8, including at least 90% by volume of the chemical boron compounds in the sintered-pellet surface, and at most 2% by volume of the chemical boron compounds in the remainder of the sintered pellet. 17. The uranium-containing nuclear-fuel sintered pellet according to claim 1, including at least 98% by volume of the chemical boron compound in the sintered-pellet surface layer, and at most 1% by volume of the chemical boron compound in the remainder of the sintered pellet. 18. The uranium-containing nuclear-fuel sintered pellet according to claim 2, including at least 98% by volume of the chemical boron compound in the sintered-pellet surface layer, and at most 1% by volume of the chemical boron compound in the remainder of the sintered pellet. 19. The uranium-containing nuclear-fuel sintered pellet according to claim 3, including at least 98% by volume of the chemical boron compound in the sintered-pellet surface layer, and at most 1% by volume of the chemical boron compound in the remainder of the sintered pellet. 20. The uranium-containing nuclear-fuel sintered pellet according to claim 4, including at least 98% by volume of the chemical boron compound in the sintered-pellet surface layer, and at most 1% by volume of the chemical boron compound in the remainder of the sintered pellet. 21. The uranium-containing nuclear-fuel sintered pellet according to claim 5, including at least 98% by volume of the chemical boron compound in the sintered-pellet surface layer, and at most 1% by volume of the chemical boron compound in the remainder of the sintered pellet. 22. The uranium-containing nuclear-fuel sintered pellet according to claim 6, including at least 98% by volume of the chemical boron compound in the sintered-pellet surface layer, and at most 1% by volume of the chemical boron compound in the remainder of the sintered pellet. 23. The uranium-containing nuclear-fuel sintered pellet according to claim 7, including at least 98% by volume of the chemical boron compound in the sintered-pellet surface layer, and at most 1% by volume of the chemical boron compound in the remainder of the sintered pellet. 24. The uranium-containing nuclear-fuel sintered pellet according to claim 8, including at least 98% by volume of the chemical boron compound in the sintered-pellet surface layer, and at most 1% by volume of the chemical boron compound in the remainder of the sintered pellet. 25. The uranium-containing nuclear-fuel sintered pellet according to claim 1, wherein the remainder of the sintered pellet is without a detectable boron content. 26. The uranium-containing nuclear-fuel sintered pellet according to claim 2, wherein the remainder of the sintered pellet is without a detectable boron content. 27. The uranium-containing nuclear-fuel sintered pellet according to claim 3, where in the remainder of the sintered pellet is without a detectable boron content. 28. The uranium-containing nuclear-fuel sintered pellet according to claim 4, wherein the remainder pellet sintered pellet is without a detectable boron content. 29. The uranium-containing nuclear-fuel sintered pellet according to claim 5, wherein the remainder of the sintered pellet is without a detectable boron content. 30. The uranium-containing nuclear-fuel sintered pellet according to claim 6, wherein the remainder of the sintered pellet is without a detectable boron content. 31. The uranium-containing nuclear-fuel sintered pellet according to claim 7, wherein the remainder of the sintered pellet is without a detectable boron content. 32. The uranium-containing nuclear-fuel sintered pellet according to claim 8, wherein the remainder of the sintered pellet is without a detectable boron content. 33. The nuclear-fuel sintered pellet according to claim 1, wherein the boron-containing sintered-pellet surface layer has a thickness of from 2 to 40 .mu.m. 34. The nuclear-fuel sintered pellet according to claim 2, wherein the boron-containing sintered-pellet surface layer has a thickness of from 2 to 40 .mu.m. 35. The nuclear-fuel sintered pellet according to claim 3, wherein the boron-containing sintered-pellet surface layer has a thickness of from 2 to 40 .mu.m. 36. The nuclear-fuel sintered pellet according to claim 4, wherein the boron-containing sintered-pellet surface layer has a thickness of from 2 to 40 .mu.m. 37. The nuclear-fuel sintered pellet according to claim 5, wherein the boron-containing sintered-pellet surface layer has a thickness of from 2 to 40 .mu.m. 38. The nuclear-fuel sintered pellet according to claim 6, wherein the boron-containing sintered-pellet surface layer has a thickness of from 2 to 40 .mu.m. 39. The nuclear-fuel sintered pellet according to claim 7, wherein the boron-containing sintered-pellet surface layer has a thickness of from 2 to 40 .mu.m. 40. The nuclear-fuel sintered pellet according to claim 8, wherein the boron-containing sintered-pellet surface layer has a thickness of from 2 to 40 .mu.m. 41. The nuclear-fuel sintered pellet according to claim 1, wherein the boron-containing sintered-pellet surface layer has a thickness of from 5 to 20 .mu.m. 42. The nuclear-fuel sintered pellet according to claim 2, wherein the boron-containing sintered-pellet surface layer has a thickness of from 5 to 20 .mu.m. 43. The nuclear-fuel sintered pellet according to claim 3, wherein the boron-containing sintered-pellet surface layer has a thickness of from 5 to 20 .mu.m. 44. The nuclear-fuel sintered pellet according to claim 4, wherein the boron-containing sintered-pellet surface layer has a thickness of from 5 to 20 .mu.m. 45. The nuclear-fuel sintered pellet according to claim 5, wherein the boron-containing sintered-pellet surface layer has a thickness of from 5 to 20 .mu.m. 46. The nuclear-fuel sintered pellet according to claim 6, wherein the boron-containing sintered-pellet surface layer has a thickness of from 5 to 20 .mu.m. 47. The nuclear-fuel sintered pellet according to claim 7, wherein the boron-containing sintered-pellet surface layer has a thickness of from 5 to 20 .mu.m. 48. The nuclear-fuel sintered pellet according to claim 8, wherein the boron-containing sintered-pellet surface layer has a thickness of from 5 to 20 .mu.m. 49. The nuclear-fuel sintered pellet according to claim 1, wherein an isotope B.sub.10 in boron of the chemical boron compound is enriched relative to a natural isotopic composition. 50. The nuclear-fuel sintered pellet according to claim 2, wherein an isotope B.sub.10 in boron of the chemical boron compound is enriched relative to a natural isotopic composition. 51. The nuclear-fuel sintered pellet according to claim 3, wherein an isotope B.sub.10 in boron of the chemical boron compound is enriched relative to a natural isotopic composition. 52. The nuclear-fuel sintered pellet according to claim 4, wherein an isotope B.sub.10 in boron of the chemical boron compound is enriched relative to a natural isotopic composition. 53. The nuclear-fuel sintered pellet according to claim 5, wherein an isotope B.sub.10 in boron of the chemical boron compound is enriched relative to a natural isotopic composition. 54. The nuclear-fuel sintered pellet according to claim 6, wherein an isotope B.sub.10 in boron of the chemical boron compound is enriched relative to a natural isotopic composition. 55. The nuclear-fuel sintered pellet according to claim 7, wherein an isotope B.sub.10 in boron of the chemical boron compound is enriched relative to a natural isotopic composition. 56. The nuclear-fuel sintered pellet according to claim 8, wherein an isotope B.sub.10 in boron of the chemical boron compound is enriched relative to a natural isotopic composition. 57. A nuclear-reactor fuel assembly, comprising a fuel rod having a cladding tube; and a uranium-containing nuclear-fuel sintered pellet in said cladding tube, said uranium-containing nuclear-fuel sintered pellet containing UO.sub.2 and having a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound UB.sub.x with at least one number x from a number set 2; 4 and 12, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 58. A nuclear-reactor fuel assembly, comprising a fuel rod having a cladding tube; and a uranium-containing nuclear-fuel sintered pellet in said cladding tube, said uranium-containing nuclear-fuel sintered pellet containing (U, Pu)O.sub.2 and having a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, Pu)B.sub.x with at least one number x from a number set 2; 4 and 12, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 59. A nuclear-reactor fuel assembly, comprising a fuel rod having a cladding tube; and a uranium-containing nuclear-fuel sintered pellet in said cladding tube, said uranium-containing nuclear-fuel sintered pellet containing (U, Th)O.sub.2 and having a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, Th)B.sub.x with at least one number x from a number set 4 and 6, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 60. A nuclear-reactor fuel assembly, comprising a fuel rod having a cladding tube; and a uranium-containing nuclear-fuel sintered pellet in said cladding tube, said uranium-containing nuclear-fuel sintered pellet containing (U, RE)O.sub.2 (RE=rare earth) and having a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, RE)B.sub.x with at least one number x from a number set 4; 6 and 12, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 61. A nuclear-reactor fuel assembly, comprising a fuel rod having a cladding tube; and a uranium-containing nuclear-fuel sintered pellet in said cladding tube, said uranium-containing nuclear-fuel sintered pellet containing (U, Pu, Th)O.sub.2 and having a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, Pu, Th)B .sub.x with at least one number x from a number set 2; 4; 6 and 12, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 62. A nuclear-reactor fuel assembly, comprising a fuel rod having a cladding tube; and a uranium-containing nuclear-fuel sintered pellet in said cladding tube, said uranium-containing nuclear-fuel sintered pellet containing (U, Pu, RE)O.sub.2 (RE =rare earth) and having a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, Pu, RE)B.sub.x with at least one number x from a number set 2; 4; 6 and 12, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compounds. 63. A nuclear-reactor fuel assembly, comprising a fuel rod having a cladding tube; and a uranium-containing nuclear-fuel sintered pellet in said cladding tube, said uranium-containing nuclear-fuel sintered pellet containing (U, Th, RE)O.sub.2 (RE=rare earth) and having a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, Th, RE)B.sub.x with at least one number x from a number set 4 and 6, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 64. A nuclear-reactor fuel assembly, comprising a fuel rod having a cladding tube; and a uranium-containing nuclear-fuel sintered pellet in said cladding tube, said uranium-containing nuclear-fuel sintered pellet containing (U, Pu, Th, RE)O.sub.2 (RE=rare earth) and having a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound (U, Pu, Th, RE)B.sub.x with at least one number x from a number set 4 and 6, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. 65. A nuclear fuel sintered pellet, comprising an oxide of a uranium containing metal and at least one boride of the uranium containing metal, a surface layer being formed of at least 80% by volume of said at least one boride of the uranium containing metal, and a remainder being formed of at most 5% by volume of said at least one boride of the uranium containing metal. 66. A nuclear fuel sintered pellet, comprising: an oxide of a uranium containing metal and at least one boride of the uranium containing metal, said at least one boride of the uranium containing metal forming at least 80% by volume of a surface layer of the sintered pellet and at most 5% by volume of a remainder of the sintered pellet. 67. The nuclear fuel sintered pellet according to claim 66, wherein said oxide of the Uranium containing metal is UO.sub.2, and said at least one boride is UB.sub.x wherein x is at least one number from a number set 2, 4 and 12. 68. The nuclear fuel sintered pellet according to claim 66, wherein said oxide of the uranium containing metal is (U, Pu)O.sub.2, and said at least one boride is (U, Pu)B.sub.x wherein x is at least one number from a number set 2, 4 and 12. 69. The nuclear fuel sintered pellet according to claim 66, wherein said oxide of the uranium containing metal is (U, Th)O.sub.2, and said at least one boride is (U, Th)B.sub.x wherein x is at least one number from a number set 4 and 6. 70. The nuclear fuel sintered pellet according to claim 66, wherein said oxide of the Uranium containing metal is (U, RE)O.sub.2 (RE=rare earth), and said at least one boride is (U, RE)B.sub.x wherein x is at least one number from a number set 4, 6 and 12. 71. The nuclear fuel sintered pellet according to claim 66, wherein said oxide of the uranium containing metal is (U, Pu, Th)O.sub.2, and said at least one boride is (U, Pu, Th)B.sub.x wherein x is at least one;number from a number set 2, 4, 6 and 12. 72. The nuclear fuel sintered pellet according to claim 66, wherein said oxide of the uranium containing metal is (U, Pu, RE)O.sub.2 (RE=rare earth), and said at least one boride is (U, Pu, RE)B.sub.x wherein x is at least one number from a number set 2, 4, 6 and 12. 73. The nuclear fuel sintered pellet according to claim 66, wherein said oxide of the Uranium containing metal is (U, Th, RE)O.sub.2 (RE=rare earth), and said at least one boride is (U, Th, RE)B.sub.x wherein x is at least one number from a number set 4 and 6. 74. The nuclear fuel sintered pellet according to claim 66, wherein said oxide of the Uranium containing metal is (U, Pu, Th, RE)O.sub.2 (RE=rare earth) and said at least one boride is (U, Pu, Th, RE)B.sub.x wherein x is at least one number from a number set 4 and 6. 75. The nuclear fuel sintered pellet according to claim 66, wherein said at least one boride of the uranium containing metal forms at least 90% by volume of said surface layer and at most 2% by volume of said remainder. 76. The nuclear fuel sintered pellet according to claim 66, wherein said at least one boride of the uranium containing metal forms at least 98% by volume of said surface layer and at most 1% by volume of said remainder. 77. The nuclear fuel sintered pellet according to claim 66, wherein said remainder is without a detectable boron content. 78. The nuclear fuel sintered pellet according to claim 66, wherein said surface layer has a thickness of from 2 to 40 .mu.m. 79. The nuclear fuel sintered pellet according to claim 90, wherein said surface layer has a thickness of from 5 to 20 .mu.m. 80. The nuclear fuel sintered pellet according to claim 66, wherein an isotope B.sub.10 in boron of said at least one boride is enriched relative to a natural isotopic composition. 81. A nuclear reactor fuel assembly, comprising: a fuel rod having a cladding tube; a nuclear fuel sintered pellet contained in said cladding tube; and said sintered pellet containing an oxide of a uranium containing metal and at least one boride of the uranium containing metal, said at least one boride of the uranium containing metal forming at least 80% by volume of a surface layer of said sintered pellet and at most 5% by volume of a remainder of said sintered pellet.
058617019	claims	1. A charged-particle powered battery, comprising at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; and a plurality of electrically connected cells, each cell comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, wherein a plurality of said secondary emitters intercepts at least a portion of said primary charged particles from at least one said primary energy source, and wherein said primary charged particles have maximum kinetic energy preferably equivalent to at least twice a predetermined maximum cell potential. at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; and a plurality of electrically connected cells, each cell comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, wherein a plurality of said secondary emitters intercepts at least a portion of said primary charged particles from at least one said primary energy source, and wherein said kinetic energy of each said primary charged particle is incrementally reduced on passage of said particle through a cell, at least a portion of said increment of kinetic energy being imparted to a plurality of said secondary electrons. at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; and a plurality of electrically connected cells, each cell comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, wherein a plurality of said secondary emitters intercepts at least a portion of said primary charged particles from at least one said primary energy source, and wherein within a cell, said emitter and collector plates are distinguished by a relatively higher yield from said emitter of secondary electrons having imparted kinetic energies at least equivalent to a predetermined cell electrical potential following cell interception of a plurality of said primary charged particles. at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; and a plurality of electrically connected cells, each cell comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, wherein a plurality of said secondary emitters intercepts at least a portion of said primary charged particles from at least one said primary energy source, and wherein probability of emitter plate interaction with primary charged particles is maximized and emitter plate self absorption of secondary electrons is minimized. at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; and a plurality of electrically connected cells, each cell comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, wherein a plurality of said secondary emitters intercepts at least a portion of said primary charged particles from at least one said primary energy source, and wherein probability of collector plate interaction with primary charged particles is minimized and collector plate self absorption of secondary electrons is maximized. at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; and a plurality of electrically connected cells, each cell comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, wherein a plurality of said secondary emitters intercepts at least a portion of said primary charged particles from at least one said primary energy source, and wherein maximum cell potential between said collector plate and said secondary electron emitter plate of each said cell does not exceed about 50 V. at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; and a plurality of electrically connected cells, each cell comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, wherein a plurality of said secondary emitters intercepts at least a portion of said primary charged particles from at least one said primary energy source, and wherein maximum cell potential between said collector plate and said secondary electron emitter plate of each said cell does not exceed about 10 V. at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; and a plurality of electrically connected cells, each cell comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, wherein a plurality of said secondary emitters intercepts at least a portion of said primary charged particles from at least one said primary energy source, and wherein maximum cell potential between said collector plate and said secondary electron emitter plate of each said cell does not exceed about 3 V. at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; and a plurality of electrically connected cells, each cell comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, wherein a plurality of said secondary emitters intercepts at least a portion of said primary charged particles from at least one said primary energy source, and wherein collector Fermi energy levels exceed emitter Fermi energy levels. at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; and a plurality of electrically connected cells, each cell comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, wherein a plurality of said secondary emitters intercepts at least a portion of said primary charged particles from at least one said primary energy source, and wherein collector material work functions exceed emitter material work functions. at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; and a plurality of electrically connected cells, each cell comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, wherein a plurality of said secondary emitters intercepts at least a portion of said primary charged particles from at least one said primary energy source, and wherein collector material work functions exceed emitter material work functions and collector Fermi energy levels exceed emitter Fermi energy levels. providing at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; arranging a plurality of electrically connected cells proximate each said primary energy source, each cell comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, a plurality of said secondary emitters intercepting at least a portion of said primary charged particles from at least one said primary energy source; choosing a preferred cell potential for each cell of said plurality of cells; and establishing a composition for each said primary energy source such that, with each cell of said plurality of cells having a cell potential substantially equal to said preferred cell potential, at least a portion of said primary charged particles have kinetic energy sufficient to impinge on at least two of said secondary emitter plates. providing at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; arranging a plurality of electrically connected cells proximate each said primary energy source, each cell comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, a plurality of said secondary emitters intercepting at least a portion of said primary charged particles from at least one said primary energy source; and choosing a preferred cell potential for each cell of said plurality of cells such that at least a portion of said primary charged particles impinge on at least two of said secondary emitter plates. arranging a plurality of electrically connected cells proximate each said primary energy source, each cell having a cell potential and comprising a secondary emitter plate for producing secondary electrons spaced apart from a collector plate for collecting secondary electrons emanating from said secondary emitter plate, at least two said secondary emitter plates intercepting at least a portion of said primary charged particles from at least one said primary energy source. choosing materials for each said collector plate and each said emitter plate so that cell collector Fermi energy levels exceed cell emitter Fermi energy levels for each said cell. choosing materials for each said collector plate and each said emitter plate so that cell collector material work functions exceed cell emitter material work functions for each said cell. choosing materials for each said collector plate and each said emitter plate so that cell collector Fermi energy levels exceed cell emitter Fermi energy levels for each said cell and cell collector material work functions exceed cell emitter material work functions for each said cell. 2. A charged-particle powered battery, comprising 3. A charged-particle powered battery, comprising 4. A charged-particle powered battery, comprising 5. A charged-particle powered battery, comprising 6. A charged-particle powered battery, comprising 7. A charged-particle powered battery, comprising 8. A charged-particle powered battery, comprising 9. A charged-particle powered battery, comprising 10. A charged-particle powered battery, comprising 11. A charged-particle powered battery, comprising 12. The charged-particle powered battery of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11 in which at least one primary energy source is spaced apart from said collector and emitter plates. 13. A method of making a charged-particle powered battery, the method comprising 14. The method of claim 13 wherein at least a portion of said primary charged particles have kinetic energy which is incrementally reduced on interaction with at least one secondary emitter plate. 15. The method of claim 13 wherein said preferred cell potential is chosen to be less than about 10 V. 16. A method of making a charged-particle powered battery, the method comprising 17. The method of claim 16 wherein at least a portion of said primary charged particles have kinetic energy which is incrementally reduced on interaction with at least one secondary emitter plate. 18. The method of claim 16 wherein said preferred cell potential is chosen to be less than about 10 V. 19. A method of making a charged-particle powered battery, the method comprising providing at least one primary energy source for producing a plurality of primary charged particles having kinetic energy; and 20. The method of claim 19 wherein at least a portion of said primary charged particles have kinetic energy which is incrementally reduced on interaction with at least one secondary emitter plate. 21. The method of claim 19 comprising the additional step of 22. The method of claim 19 comprising the additional step of 23. The method of claim 19 comprising the additional step of
	description	X-ray inspection systems are often used to inspect objects that may be difficult to inspect using optical or other inspection techniques. For example, x-ray inspection systems are particularly useful in the inspection of objects that are embedded within, or are otherwise visually blocked by, other objects. X-ray inspection involves the capture of projected images of an object under inspection by one or more x-ray sensors. In this regard, one or more x-ray sources generate x-rays that may illuminate one or more sensors as attenuated by an intervening object under inspection. During image acquisition, the quality of the images captured by the one or more sensors may be limited due to the presence of x-ray scatter, which can result in loss of dynamic range in a captured image, thus reducing the system's inspection capability. To reduce interference from x-ray scatter, a collimator may be placed between an x-ray source and the object space. As used herein, the term “collimator” refers to a device that produces directed beams from one or more x-ray sources. For example, a collimator may collimate x-rays from one or more x-ray sources into one or more fan beams. As used herein, the term “fan beam” refers to an x-ray beam having a constant ratio of major to minor dimension at any transverse cross section. To reduce x-ray scatter in an X-ray inspection system, a collimator may be used to collimate the x-rays generated by the x-ray source(s) into a number of fan beams, each directed at a respective sensor along a respective controlled solid angle. For example, a collimator may be configured to produce one or more fan beams having respective ratios of major to minor dimensions that substantially match respective ratios of major to minor dimensions of corresponding sensor areas—thus, the x-rays substantially illuminate only the sensing area of the sensor(s) located in the imaging plane. To obtain the advantages of X-ray collimation, very precise tapered windows must be machined into material that is an effective attenuator of X-rays. Tungsten (W) is generally the material of choice for an application where precision, strength and X-ray attenuation are required, although any x-ray attenuating material may be used. However, the manufacture of Tungsten collimators is very expensive due to the miniscule complex shapes that must be created. Although Tungsten is quite pliant in its purest form, it typically contains small concentrations of carbon and oxygen, which gives tungsten metal its considerable hardness and brittleness. Given these properties, collimators made from Tungsten or other hard materials are typically created using Electrical Discharge Machining (EDM) techniques. In EDM metal is removed by producing a rapid series of repetitive electrical discharges between an electrode and a metal workpiece. The electrical discharges actually remove small amounts of material and allow the electrode to be moved through the metal. The path of the electrode is typically controlled by a computer, which allows extremely intricate contours or delicate cavities that would be difficult to produce with a grinder or other cutting tools. Lead (Pb) and other softer X-ray attenuating materials can also be used to create lower cost X-ray collimators, but the window sizes must be increased and additional thickness is required compared to Tungsten collimators. Larger windows make a collimator less effective at attenuating scatter X-rays and the additional thickness required for equivalent attenuation reduces the allowable distance from the X-ray source to the object being imaged. Accordingly, a need exists for creating complex shaped 3-dimensional internal structures in hard materials such as Tungsten to allow the fabrication of effective X-ray collimators at a cost much lower than traditional methods of construction. An embodiment of a method for fabricating an x-ray collimator comprises identifying 3-dimensional structures and positions of the 3-dimensional structures in a collimator design, selecting a number of collimator layers, determining 2-dimensional shapes corresponding to the respective identified 3-dimensional structures for each layer, determining, in each collimator layer, positions of the 2-dimensional shapes corresponding to the respective identified 3-dimensional structures for each layer, forming apertures in at least one laminated layer to produce the selected number of collimator layers, each having apertures according to its respective determined 2-dimensional shapes at the respective determined positions, stacking the collimator layers in a position of alignment to form the identified 3-dimensional structures, and attaching the stacked and aligned collimator layers to form a composite collimator structure with the identified 3-dimensional structures therein. An embodiment of an x-ray collimator comprises a plurality of collimator layers, each collimator layer corresponding to a respective cross-section of the x-ray collimator and each collimator layer having at least one aperture, the plurality of collimator layers stacked and attached to form a composite collimator structure wherein the apertures of the respective collimator layers are aligned to form 3-dimensional hollow structures that direct x-rays generated by an x-ray source into x-ray beams. An embodiment of an x-ray collimator comprises a plurality of laminated layers having apertures therein, the plurality of laminated layers stacked and attached to form a composite collimator structure wherein the apertures of the respective laminated layers align to form 3-dimensional apertures that direct x-rays generated by an x-ray source into x-ray beams. Methods and apparatus for forming complex-shaped, 3-D internal structures in hard materials to fabricate x-ray collimators are described. For simplicity and illustrative purposes, the principles of the embodiments are described. Moreover, in the following detailed description, references are made to the accompanying figures, which illustrate specific embodiments. Electrical, mechanical, logical, and structural changes may be made to the embodiments without departing from the spirit and scope of the embodiments. Embodiments of the invention include methods which utilize a laminated stack of thin sheets to construct an X-ray collimator. The laminated sheets may comprise Tungsten or other X-ray attenuating materials. The 3-dimensional structures required to collimate x-rays according to the desired collimation function may be formed by creating apertures in laminated sheets and stacking the layers to form the required 3-dimensional structures in the composite collimator structure. FIG. 1 is a flowchart of an embodiment of a method for fabricating an x-ray collimator. The method includes identifying 3-dimensional structures and structure positions in a collimator design (step 101), selecting a number of collimator layers (step 102), determining 2-dimensional shapes corresponding to the respective identified 3-dimensional structures for each layer (step 103), determining, in each collimator layer, positions of the 2-dimensional shapes corresponding to the respective identified 3-dimensional structures for each layer (step 104), forming apertures in at least one laminated layer of x-ray attenuating material to produce the selected number of collimator layers, each having apertures according to its respective determined 2-dimensional shapes at the respective determined positions (step 105), stacking the collimator layers in a position of alignment to form the identified 3-dimensional structures (step 106), and attaching the stacked and aligned collimator layers to form a composite collimator structure with the identified 3-dimensional structures therein (step 107). The collimator layers may be created from as few as a single laminated layer. In one embodiment, a plurality of collimator layers are created from different sections of a single laminated sheet. The portions of the laminated sheet that outline each collimator layer and the collimator layer's corresponding apertures may be removed through a well-known photo-etching process, or through machine punching, laser-cutting, drilling, or any other material removal process. The individual collimator layers are removed from the laminated layer, and may then be stacked and aligned according to the process described previously. In the case where the collimator fabrication process creates sharp edges at the meeting points between collimator layers, the edges may be honed or smoothed through extrude honing (i.e., by pushing an abrasive at pressure through the 3-dimensional structures of the composite collimator structures) (step 108). This process may be used to smooth or knock off sharp edges within the 3-dimensional hollow structures in the composite collimator structure. Alternatively, the apertures of each photo-etched collimator layer may be honed prior to stacking and attaching the collimator layers (step 109). Embodiments of the invention allow creation of intricate shapes in a thin (for example, 0.001-0.010 inch) laminated sheet made from an X-ray attenuating material such as, but not limited to, Tungsten (W). By varying the sizes and/or shapes of the apertures in each collimator layer, a complex 3-dimensional internal shape can be created by stacking several layers together. The advantages include low raw material cost (for example, the cost of a thin laminated sheet versus a block of material) and low formation cost (for example, forming the layers using process such as photo-etching, punching, or laser-cutting, which are known to be lower cost that EDM techniques. This enables production of a complex X-ray collimator at an overall cost that is much less expensive than traditionally fabricated collimators. FIGS. 2A and 2B show a perspective view and a cross-sectional side view, respectively, of an embodiment of an exemplary image acquisition mechanism 200. In image acquisition mechanism 200, x-ray source 202 is employed to irradiate a planar array of sensors 205 that are sensitive to x-rays. The x-ray source 202 remains stationary relative to the array of sensors 205, projecting x-rays toward all of the sensors 205 simultaneously. A collimator 206 is employed to restrict x-ray exposure to the locations occupied by the sensors 205 and the intervening areas of the object under inspection in order to limit overall x-ray exposure of the object and to improve the dynamic range of the images captured by the sensors 205. To this end, the collimator 206 generates respective fan beams 203 directed at each of the respective sensors 205. A field block 208 may be positioned between the x-ray source 202 and the sensors 205 close to the array of sensors. The field block 208 may be an x-ray absorbing plate comprising a respective aperture located over each sensor 205. Each aperture is positioned to expose only the corresponding sensor to the source 202. Furthermore, the field block 208 is positioned a sufficient distance away from the sensor(s) (i.e., the imaging plane) so as to limit the field of view of the respective sensors mainly to that of the corresponding fan beam directed at it. The field block 208 is therefore configured to pass x-rays sourced directly by the x-ray source 202 to respective ones of the sensors 205 and to block detection of reflected or scatter x-rays by the respective sensors 205. In this system, the position of the object under inspection 204 is altered relative to the x-ray source 202, sensors 205, collimator 206, and field block 208, passing between the collimator 206 and field block 208. The collimator 206 is positioned close to the x-ray source 202 and configured to collimate x-rays generated by the x-ray source into one or more fan beams directed at corresponding ones of the sensors 205. In operation, an object 204 to be inspected (shown only in FIG. 2A) is moved between collimator 206 and field block 208 to positions that allow each of the sensors 205 to capture projection images of the object after the x-rays have transmitted through the object. Each of the sensors 205 are positioned relative to the x-ray source 202 so that the projection image of the object captured by each sensor 205 is acquired at a distinct angle relative to the x-ray source 202. In the embodiment shown in FIGS. 2A and 2B, a total of twelve sensors 205 are arranged in a circular configuration, resulting in a difference in viewing angle between adjacent sensors 205 of approximately 30 degrees. Each of the sensors 205 is stationary relative to each other and to the x-ray source 202 by way of attachment to a stable base 211. In order to generate the fan beams 203, the collimator 206 must be configured to direct x-rays from the source 202 into beams 203. FIG. 3 is a perspective view of an exemplary collimator design 300 for generating fan beams, such as for use in the example imaging system 200 of FIGS. 2A and 2B. Thus, a collimator implemented in accordance with the collimator design 300 may be used as the collimator 206 which generates the fan beams 203 of the imaging system 200. As shown in the design 300, the collimator design includes twelve 3-dimensional apertures 310. The 3-dimensional structures of the apertures 310 are narrow pyramidal structures. Each pyramidal structure is hollow, having a respective aperture 310 at the top of the respective pyramid though which x-rays generated by an x-ray point source may enter, and an aperture 312 which forms the hollow base of the pyramidal structure through which the rays exit. The dimensions of the base aperture 312 of its pyramidal 3-dimensional collimator aperture 310 dictates the fan beam coverage at the image plane. The angle of the pyramid with respect to both the x-ray source and the image plane dictates the direction of the fan beam. In one embodiment, the collimator design 300 may be implemented according to the steps of FIG. 1. In the fabrication of a collimator for the example collimator design 300 of FIG. 3, a number of collimator layers is selected. For illustrative purposes, assume the selected number of collimator layers is ten. Then, the respective 2-dimensional shapes and positions of the respective cross-sections of each 3-dimensional structure in each collimator layer are patterned on one or more laminated metal sheets, and portions of the laminate material are photo-etched, punched, laser-cut, or otherwise removed to create apertures in each collimator layer according to the collimator layer's respective aperture pattern. Thus, for the collimator design of FIG. 3, each layer requires twelve rectangular apertures in, from top to bottom of the collimator design, progressively larger and more spread out positions. FIG. 4 illustrates an example etching pattern 411, 412, 413, 414, 415, 416, 417, 418, 419, and 420 (shown in crosshatch) for ten different collimator layers 401, 402, 403, 404, 405, 406, 407, 408, 409, and 410 for the design 300 of FIG. 3. While each collimator layer may be formed from different respective laminated metal sheets, in one embodiment, a plurality of collimator layers 401, 402, 403, 404, 405, 406, 407, 408, 409, and 410 are simultaneously formed from as few as a single laminated metal sheet. For example, FIG. 4 illustrates the aperture patterns for all ten collimator layers on a single laminated sheet 450. After photo-etching, punching, laser-cutting, or otherwise, of the laminated sheet(s) 450 to produce the collimator layers 401, 402, 403, 404, 405, 406, 407, 408, 409, and 410, the collimator layers are stacked and attached such that corresponding 2-dimensional apertures of each layer are appropriately aligned to form the 3-dimensional internal structures according to the collimator design. For example, the collimator layers of FIG. 4 may be aligned and stacked as shown in FIG. 5 to produce the composite collimator structure 500 shown in FIG. 6. The collimator layers may be attached using adhesive, rivets, bolts, or other attachment techniques so long as the attachment technique does not interfere with the functionality of the internal 3-dimensional structures in x-ray collimation. In one embodiment, the edges at the meeting points between collimator layers are honed or smoothed through extrude honing (i.e., by pushing an abrasive at pressure through the 3-dimensional structures of the composite collimator structures) or other appropriate honing technique. In one embodiment, the apertures of each collimator layer are honed prior to stacking and attaching the collimator layers. Collimators fabricated according to the collimator fabrication technique described herein may be produced at much less cost than EDM techniques. Furthermore, once the etching patterns for each of the collimator layers are captured in artwork, collimators can be produced in high volume much more quickly than can be done using EDM techniques. Although embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
	description	This is a divisional of U.S. patent application Ser. No. 10/232,319, filed Aug. 29, 2002 now U.S. Pat. No. 7,280,883 in the name of Toru KITAMOTO, et al. and entitled SUBSTRATE PROCESSING SYSTEM MANAGING APPARATUS INFORMATION OF SUBSTRATE PROCESSING APPARATUS, which is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-270699 filed Sep. 6, 2001, Japanese Patent Application No. 2001-271599 filed Sep. 7, 2001, Japanese Patent Application No. 2001-270584 filed Sep. 6, 2001 and Japanese Patent Application No. 2001-271369 filed Sep. 7, 2001, the entire contents of which are incorporated herein by reference. 1. Field of the Invention The present invention relates to a network communication technique connecting a substrate processing apparatus performing prescribed processing on a semiconductor substrate, a glass substrate for a liquid crystal display, a glass substrate for a photomask or a substrate for an optical disk (hereinafter simply referred to as “substrate”) and a computer, with each other through a communication network. 2. Description of the Background Art A product such as a semiconductor device or a liquid crystal display is manufactured by performing a series of processing steps such as cleaning, resist coating, exposure, development, etching, formation of an interlayer dielectric film and thermal processing, on a substrate. In general, a substrate processing apparatus having a built-in resist coating processing, a built-in development processing unit etc., performs such processing steps. A transfer robot provided on the substrate processing apparatus successively transfers the substrate to the respective processing units thereby performing the series of processing steps on the substrate. Such substrate processing is automatically controlled, and the substrate processing apparatus stores application program data, set information etc. for the automatic control. In other words, the substrate processing apparatus is controlled through the application program according to the contents of the set information. The set information stored in the substrate processing apparatus includes basic information employed in common for the substrate processing apparatus and information intrinsic to the substrate processing apparatus. While the substrate processing apparatus is essentially controllable by basic information set by default, optimum control cannot be performed with the same set contents as a result of a differing set environment or a manufacturing error of the substrate processing apparatus. Therefore, the basic information must be corrected for performing control procedures, and each substrate processing apparatus accumulates this corrected information as intrinsic information. The intrinsic information is information intrinsic to every user and every substrate processing apparatus. In order to return a substrate processing apparatus having some fault, such as a hardware fault (with loss of accumulated information) to the state before the occurrence of the fault, it is necessary to periodically back up the set information. When the user changes the set information in a self-determined manner, past set information may be required. In order to operate the substrate processing apparatus with the past set information in this case, it is necessary to periodically back up the set information. In general, the user backs up the set information on a removable disk or the like in each substrate processing apparatus. However, it is extremely time-consuming to back up the set information of the substrate processing apparatus on the removable disk or the like, leading to a burden on the user. When a large number of substrate processing apparatuses are set, the backup operation particularly burdens the user. Further, it is necessary to minimize the interval for backup processing so that the backup data is effective. However, the burden of the backup processing is so heavy that it is impractical to require the user to frequently perform periodic backup processing. The aforementioned basic information of a set in the substrate processing apparatus in an initial stage, consists of an extremely large number of set items. The user or a member of a support staff, first sets the basic information in the substrate processing apparatus, thereby operating the substrate processing apparatus according to the basic information. The user then sets intrinsic information in response to the individual substrate processing apparatus. In other words, the user corrects the operation of the substrate processing apparatus set according to the basic information, with the intrinsic information thereby performing optimum control. As hereinabove described, the basic information to be set in the substrate processing apparatus consists of an extremely large number of set items. If the set information is erroneous with respect to some of the large number of items, the substrate processing apparatus cannot perform a planned operation. When a number of different substrate processing apparatuses are provided by operating staff with basic information the set contents of the basic information may vary with the substrate processing apparatuses due to introduced artificial errors. In this case, the same products cannot be produced even if the substrate processing apparatuses execute the same processing steps. When it is proven that the basic information set in each substrate processing apparatus includes a set error from the results of operation of the substrate processing apparatus, it is extremely difficult to find the erroneous set contents from the large number of set items. Components forming the aforementioned substrate processing apparatus also include consumables. For example, cleaning brushes provided in a cleaning processing unit for cleaning substrates or lamps provided in a lamp annealing apparatus for rapidly annealing substrates by photoirradiation are typical consumables. Further, belts, cylinders, motors etc. forming a driving mechanism for driving the transfer robot or the like are also consumables. Such consumables are consumed or deteriorate as used and become entirely unusable with excessive use. It is thus necessary to periodically order new components for replacement of the consumables. In general, new components are ordered and procured only after the consumables are consumed or rendered unusable. Therefore, processing time is wasted until arrival of the new components thereby disadvantageously reducing the working efficiency of the apparatus. While it is preferable to manage the usable life of the consumables in the substrate processing apparatus, a large number of substrate processing apparatuses are usually arranged in a single substrate processing factory and excessive effort is required for managing consumables of all substrate processing apparatuses. In addition, since a large number of such substrate processing apparatuses are arranged in a single substrate processing factory for manufacturing semiconductor devices or the like they are operated by a number of operators. It is accordingly necessary to properly educate inexperienced unskilled operators with respect to the method of operating the apparatuses. When specifications etc. of the apparatuses are changed, it is also necessary to instruct even skilled operators about the new operating method. The operators must divide into groups for attending a lecture about the apparatuses which lecture is repetitively delivered to the groups. Alternatively, the groups are gathered around a single substrate processing apparatus for getting a collective explanation thereof. Because lectures must be repeated, with the same contents or not all operators will not be sufficiently or properly trained, there is a marked disadvantageous inefficiency for both users and vendors of the substrate processing apparatuses. The present invention is directed to a substrate processing apparatus management system managing a substrate processing apparatus capable of communicating through a network. According to an aspect of the present invention, a substrate processing apparatus management system managing a substrate processing apparatus capable of communicating through a network, comprises a first storage element storing control information for controlling operation of the substrate processing apparatus, a duplicate information acquisition element acquiring duplicate information of the control information stored in the first storage element, and a storing element storing the duplicate information acquired by the duplicate information acquisition element in a second storage element comprised in an information storage computer connected to the substrate processing apparatus through the network. The storage element of the information storage computer connected through the network stores the control information for the substrate processing apparatus, whereby no backup operation to a recording medium is necessary. Thus, a user's burden related to backup operation can be remarkably abated. In a substrate processing apparatus management system connecting a substrate processing apparatus and a support computer with each other through a network according to another aspect of the present invention, the support computer comprises a first storage element storing basic information necessary in initialization of the substrate processing apparatus, and a basic information transmission element transmitting the basic information to the substrate processing apparatus through the network. The substrate processing apparatus comprises a second storage element storing the basic 1 information received from the support computer, and the initial state of the substrate processing apparatus is set up with the basic information stored in the second storage element. Initialization can be correctly and readily performed in introduction or resetting of the substrate processing apparatus. In a substrate processing apparatus management system having a substrate processing apparatus and a computer managing the substrate processing apparatus, both connected to a network, in still another aspect of the present invention, the substrate processing apparatus comprises a utilization consumption measuring element measuring utilization consumption of a component of the substrate processing apparatus, and the substrate processing apparatus management system comprises a utilization consumption information accumulation element accumulating the utilization consumption measured by the consumptiveness measuring element, and a utilization consumption information uploading element rendering the utilization consumption information accumulated in the utilization consumption information accumulation element accessible from the computer through the communication network. The utilization consumption of the component of the substrate processing apparatus can be efficiently managed. According to a further aspect of the present invention, the computer comprises an educational information distribution element distributing educational information related to operation of the plurality of substrate processing apparatuses through the communication network. Each of the plurality of substrate processing apparatuses comprises a receiving element receiving the educational information distributed from the computer, and a display element displaying the educational information received by the receiving element. The computer distributes the educational information related to operation of the plurality of substrate processing apparatuses through the communication network, whereby operational education can be efficiently given to operators. The present invention is also directed to a substrate processing apparatus management method for managing a substrate processing apparatus. The present invention is yet further directed to a substrate processing apparatus connected with a prescribed computer through a communication network. Accordingly, an object of the present invention is to provide a technique of readily backing up information stored in a substrate processing apparatus while alleviating the job burden on a user. Another object of the present invention is to provide a network system for readily and reliably setting initial operation of a substrate processing apparatus while reducing the job burden on a user or a support staff. Still another object of the present invention is to provide a technique capable of efficiently managing the utilization consumption of a component of a substrate processing apparatus. A further object of the present invention is to provide a substrate processing system capable of efficiently operationally educating an operator. The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. Embodiments of the present invention are now described with reference to the drawings. First, the outline of the overall substrate processing system 10 according to a first embodiment of the present invention is described. FIG. 1 schematically illustrates the structure of the substrate processing system 10. As shown in FIG. 1, a plurality of substrate processing apparatuses 1 and an information storage server 2 comprised in a substrate processing factory 4 and support computers 3 comprised in a support center 5 are connected with each other through a network 6 in the substrate processing system 10. Remote control staffs remote-controlling the substrate processing apparatuses 1 are posted on the support center 5. In the substrate processing factory 4, the substrate processing apparatuses 1 and the information storage server 2 are connected with each other through a LAN (local area network) 41. The LAN 41 is connected to a wide area network 61 such as the Internet through a connector 42 having functions of a router, a firewall and the like. The support center 5 also has a LAN 51 connected with the support computers 3, and this LAN 51 is also connected to the wide area network 61 through a connector 52 having functions of a router, a firewall and the like. Thus, the substrate processing apparatuses 1, the information storage server 2 and the support computers 3 can effect various types of data communication with each other. Throughout the specification, the LANs 41 and 51 and the wide area network 61 are generically referred to as a network 6. Referring to FIG. 1, the substrate processing factory 4 may alternatively comprise a single substrate processing apparatus 1 in place of the plurality of substrate processing apparatuses 1, and the support center 5 may also alternatively comprise a single support computer 3 in place of the plurality of support computers 3. Each of the substrate processing apparatus 1 arranged on the substrate processing factory 4 is now described. FIG. 2 is a schematic plan view of the substrate processing apparatus 1. This substrate processing apparatus 1 performs resist coating processing, development processing and subsequent thermal processing on substrates. The substrate processing apparatus 1 comprises an indexer ID delivering unprocessed substrates from a carrier while receiving processed substrates and storing the same in the carrier, coating processing units (the so-called spin coaters) SC dropping photoresist on the main surfaces of substrates while rotating the substrates for coating the photoresist thereto, development processing units (the so-called spin developers) SD supplying a developer to exposed substrates thereby performing development processing and a transfer robot TR transferring the substrates between the indexer ID and each processing unit. Thermal processing units (not shown) are arranged above the coating processing units SC and the development processing units SD through a fan filter unit. A heating unit (the so-called hot plate) heating the substrates and a cooling unit (the so-called cool plate) cooling the heated substrates to a constant temperature are provided as the thermal processing units. Throughout the specification, the coating processing units SC, the development processing units SD and the thermal processing units are generically referred to as processing units 110 performing prescribed processing on the substrates. FIG. 3 is a block diagram showing the structure of a control system for the substrate processing apparatus 1. As shown in FIG. 3, the control system for the substrate processing apparatus 1 is formed by a system control part 100 controlling the overall apparatus 1 and unit control parts 115 individually controlling the plurality of processing units 110. The system control part 100 controlling the overall apparatus 1 in a unified manner comprises a microcomputer. More specifically, the system control part 100 comprises a CPU 101 serving as a body part, a ROM 102 serving as a read-only memory storing a basic program and the like, a RAM 103 serving as a random-access memory mainly defining an arithmetic working area, a storage part 104 consisting of a hard disk or the like storing application program data and the like and a communication part 105 performing data communication with an external device, which are connected with each other by a bus line 190. The communication part 105 is connected to the network 6 through a network interface (not shown), so that the substrate processing apparatus 1 can transmit/receive various data to/from the information storage server 2, the support computers 3 and the like. While the communication part 105 may perform either wire communication or radio communication through the network 6, a wire communication system is employed in this embodiment. Along with the system control part 100 and the plurality of processing units 110, a display part 130 displaying various information, an operation part 140 accepting recipe input operation, command operation etc. from an operator, a reader 150 reading various data from a recording medium 91 such as a magnetic disk or a magnetooptic disk and the like are also electrically connected to the bus line 190. Thus, data can be transferred between the respective parts of the substrate processing apparatus 1 through the bus line 190 under control of the system control part 100. Each processing unit 110 comprises the unit control part 115 along with a substrate processing part 116 serving as a working part (a mechanism rotating the substrates, a mechanism discharging a processing solution to the substrates, a mechanism heating the substrates or the like, for example) processing the substrates in practice. The unit control part 115, individually controlling the processing unit 110, controls and monitors operation of the substrate processing part 116 of the processing unit 110 provided with this unit control part 115. In other words, the aforementioned system control part 100 takes charge of unified control of the overall substrate processing apparatus 1, while each unit control part 115 takes charge of control responsive to the processing contents of each substrate processing part 116. The unit control part 115 comprises a microcomputer similarly to the system control part 100. More specifically, the unit control part 115 comprises a CPU 111 serving as the body part, a ROM 112 serving as a read-only memory storing a basic program and the like, a RAM 113 serving as a random-access memory defining an arithmetic working area and a storage part 114 consisting of an SRAM backed up with a battery for storing various data. The storage part 104 of the system control part 100 stores a control program 152 serving as an application program for system control related to the overall apparatus 1, set information 151 for defining operation of the substrate processing apparatus 1 and the like (see FIG. 7). When the CPU 101 of the system control part 100 executes arithmetic processing according to the control program 152 and the set information 151, it follows that operation control and data processing are implemented on the overall substrate processing apparatus 1. The storage part 114 of the unit control part 115 stores a control program 153 serving as an application program for unit control responsive to the processing contents of the substrate processing part 116 of this processing unit 110. When the CPU 111 of the unit control part 115 executes arithmetic processing according to this control program 153, it follows that operation control and data processing are implemented on the substrate processing part 116. Thus, control information for controlling the operation of the substrate processing apparatus 1 includes the control programs 152 and 153 for controlling the substrate processing apparatus 1 and the set information 151 for defining the operation of the substrate processing apparatus 1, while the storage parts 104 and 114 form first storage means storing the control information. The information storage server 2 arranged on the substrate processing factory 4 and each support computer 3 arranged on the support center 5 are now described. The information storage server 2 and the support computer 3 are similar in hardware structure to a general computer. Therefore, each of the basic structures of the information storage server 2 and the support computer 3, which are similar to each other, is described with reference to FIG. 4. As shown in FIG. 4, each of the information storage server 2 and the support computer 3 is formed by connecting a CPU 21 or 31 (the CPU 21 for the information storage server 2 and the CPU 31 for the support computer 3: this also applies to the following description), a ROM 22 or 32 storing the basic program and a RAM 23 or 33 storing various information to a bus line. A hard disk 24 or 34 storing various information such as an application program, a display 25 or 35 displaying various information, a keyboard 26a or 36a and a mouse 26b or 36b accepting input operation from the operator, a reader 27 or 37 reading various data from the recording medium 91 such as an optical disk, a magnetic disk or a magnetooptical disk and a communication part 28 or 38 making communication with the external device through the network 6 are also connected to the bus line properly through interfaces (I/F) or the like. Each of the information storage server 2 and the support computer 3 can read data from the recording medium 91 through the reader 27 or 37 and store the same in the hard disk 24 or 34. Each of the information storage server 2 and the support computer 3 can also download data from another server through the network 6 and store the same in the hard disk 24 or 34. The CPU 21 or 31 executes arithmetic processing according to various programs stored in the hard disk 24 or 34 for performing various operation. The operation of the substrate processing apparatus 1 is controlled by the control program 152 or 153 stored in the storage part 104 or 114 according to the procedure of a previously described flow recipe. The control program 152 or 153 controls the substrate processing apparatus 1 according to the set information 151 stored in the storage part 104. FIG. 5 illustrates exemplary contents of the set information 151 stored in the storage part 104. The set information 151 includes set information related to total control of the substrate processing apparatus 1 and set information related to control of each processing unit 110, and it is assumed that the storage part 104 of the system control part 100 collectively stores the set information 151 including the same in this embodiment. Alternatively, the storage part 114 of each unit control part 115 may store the set information every processing unit 110. The set information 151 is data including recipe data 151a, apparatus basic data 151b and apparatus intrinsic data 151c. The operator input-controls these data 151a, 151b and 151c through the operation part 140 thereby updating the same with correction at need. Alternatively, the support computer 3 or the information storage server 2 may input-control the set information 151 by remote control. The recipe data 151a is data defining the procedure of the substrate processing apparatus 1. In other words, the transfer robot TR of the substrate processing apparatus 1 transfers the substrates to the target processing unit 110 according to a processing schedule described in the recipe data 151a. FIG. 6 illustrates an exemplary flow recipe described in the recipe data 151a. Referring to FIG. 6, each substrate transferred by the transfer robot TR in a circulatory manner is processed in the following sequence: Step 1: adhesion reinforcement processing in the hot plate; Step 2: cooling processing in the cool plate; Step 3: resist coating processing in any coating processing unit SC; Step 4: prebake processing in the hot plate; Thus, the recipe data 151a, which is information defining the procedure of the substrate processing apparatus 1, is stored as the know-how of a user. In other words, the user creates the recipe data 151a to be capable of performing most efficient processing, and controls the substrate processing apparatus 1 is controlled according to the recipe data 151a. The apparatus basic data 151b is set information common to the substrate processing apparatus 1, i.e., default set information for the substrate processing apparatus 1. While the substrate processing apparatus 1 includes a large number of working parts and control parts such as the transfer robot TR an each processing unit 110, the apparatus basic data 151b defines set values for driving the working parts and the control parts. The apparatus basic data 151b includes data such as robot basic data, temperature control data and the like, for example. The robot basic data defines the operation of the transfer robot TR. In other words, the robot basic data defines set values (a set value related to the distance of movement, a set value for the rotational angle of an arm etc.) for the operation of the transfer robot TR transferring the substrates to each processing unit 110, the indexer ID, the thermal processing units etc. The temperature control data sets the temperatures of the thermal processing units etc. in the substrate processing apparatus 1. The apparatus intrinsic data 151c is correction data intrinsically set for each of the plurality of substrate processing apparatuses 1. While the substrate processing apparatuses 1 can be basically controlled with the same set information, i.e., the apparatus basic data 151b, when the same are identical in structure to each other, the set information must be corrected every apparatus 1 in practice. This is because the structures of the substrate processing apparatuses 1 are dispersed in a strict sense, and because adjustment responsive to environment is required due to the difference between set positions or set environment of the substrate processing apparatuses 1. In other words, the set information must be corrected every apparatus 1 so that the substrate processing apparatuses 1 perform the same processing thereby bringing the same processing results. The apparatus intrinsic data 151c includes data such as teaching data and temperature control correction data. The teaching data is data for correcting the aforementioned robot basic data. The transfer robot TR may basically perform the same operation according to the same set information when the substrate processing apparatuses 1 are identical in structure to each other. However, the transfer robot TR including a large number of components and movable parts causes an error in the operation due to subtle difference between the structures. Therefore, the operation of the transfer robot TR is adjusted to be optimum, and set information for this adjustment is stored as the teaching data. Control of the transfer robot TR can be optimized by correcting the robot basic data with the teaching data. The temperature control correction data is data for correcting the temperature control data set by default in response to the difference between the set positions and the set environment of the substrate processing apparatuses 1. Thus, the recipe data 151a decides the sequence of processing steps for each substrate processing apparatus 1, while the apparatus basic data 151b set by default and the apparatus intrinsic data 151c which is correction data every apparatus 1 control the operation of the substrate processing apparatus 1. While the recipe data 151a stored as the user's know-how and the apparatus intrinsic data 151c intrinsic to each apparatus 1 are extremely important information, it is not easy to restore these data 151a and 151c. Therefore, the data 151a and 151c must be efficiently backed up, to be prevented from disappearance. While the hardware structures of the substrate processing system 10 and the substrate processing apparatus 1, the information storage server 2 and the support computer 3 forming the same and the contents of the set information 151 have been described, the functions and the processing contents of the substrate processing system 10 are now described. FIG. 7 is a functional block diagram showing the functional structure of the substrate processing system 10. Referring to FIG. 7, the CPU 101 of the system control part 100 runs a maintenance program 154 thereby implementing a local instruction part 121, a duplicate information acquisition part 122 and a restore processing part 123 as processing parts. The storage part 104 stores the maintenance program 154. Referring to FIG. 7, the CPU 21 of the information storage server 2 runs a maintenance program 252 thereby implementing a storing part 221 and a differential extraction part 222 as processing parts. The hard disk 24 stores the maintenance program 252. The CPU 31 of the support computer 3 runs a maintenance program 351 thereby implementing a remote instruction part 321 as a processing part. The hard disk 34 stores the maintenance program 351. The local instruction part 121 has a function of transmitting an instructional command of backup processing for the set information 151 and the control programs 152 and 153 to the duplicate information acquisition part 122 and a function of transmitting an instructional command of restore processing for the set information 151 and the control programs 152 and 153 to the restore processing part 123. The local instruction part 121 transmits the instructional command of the backup processing when determining the backup timing due to a schedule function provided therein. In addition to periodic backup processing according to the schedule function, the user may perform input operation through the operation part 140 of the substrate processing apparatus 1 for explicitly instructing backup processing for the set information 151 and the control programs 152 and 153. In other words, the set information 151 and the like are automatically backed up in a planned manner due to an instruction according to the schedule function. On the other hand, the user may instruct backup processing in order to preserve the current apparatus state at an arbitrary point of time such as before maintenance or before temporary stoppage of the apparatus 1. When the local instruction part 121 issues an instructional command for backup processing, the duplicate information acquisition part 122 generates duplicate information of the set information 151 and the control program 152 stored in the storage part 104 of the system control part 100 and the control program 153 stored in the storage part 114 of the unit control part 115 and transmits the generated duplicate information, i.e., the data of the set information 151 and the control programs 152 and 153, to the information storage server 2 through the LAN 41. The backup processing may be performed on all data of the set information 151 and the control programs 152 and 153 or only individual data. As shown in FIG. 8, the local instruction part 121 comprises a schedule control part 121a. The schedule control part 121a is a functional part setting the schedule for the backup processing, and the local instruction part 121 transmits the instructional command for the backup processing according to the schedule set in the schedule control part 121a. Schedule setting shows which information is backed up at what timing. For example, it is possible to schedule the backup processing to back up the set information 151 every week while backing up the control programs 152 and 153 every month. It is also possible to set whether to back up all data or to back up differential data, as described later. For example, it is possible to set a schedule to back up all data every week as to the set information 151 while backing up differential data every day. The user can set the schedule through the operation part 140. It is more convenient to display a guidance menu on the display part 130 so that the user can set the schedule according to the menu. The duplicate information transmitted from the duplicate information acquisition part 122 is transferred to the storing part 221 of the information storage server 2 so that the storing part 221 stores the duplicate information in the hard disk 24 serving as second storage means. FIG. 7 shows the duplicate information stored in the hard disk 24 as backup data 251. In order to back up differential data, i.e., when the schedule control part 121a specifies backup operation of the differential data or the user explicitly instructs to back up the differential data, the duplicate information acquisition part 122 adds information indicating backup of the differential data to the duplicate information and transmits the same to the storing part 221. While the storing part 221 can store the set information 151 and the control programs 152 and 153 in the hard disk 24 as full data, the differential extraction part 222 extracts differential data of backup object data and thereafter stores duplicate information in the hard disk 24 when receiving the information instructing to back up the differential data. In other words, the differential extraction part 222 compares the duplicate information received from the duplicate information acquisition part 122 with the backup data 251 stored in the hard disk 24, and extracts the differential data. For example, when periodically performing backup processing according to the schedule function of the local instruction part 121, the quantity of the backup data 251 stored in the hard disk 24 is markedly increased in a method of storing full data each time. Not only the latest data but also data backed up in the past may be required as the backup data 251. For example, a request for returning the set information for the apparatus 1 to a state of several weeks ago may be received. Further, a request for returning the flow recipe changed by trial and error to that of two months ago may be received. Therefore, it is effective to leave the backup data 251 at a large number of points over a long period, though the capacity of the hard disk 24 is not unlimited. Therefore, the differential extraction part 222 extracts the differential data between the duplicate information and precedent backup data 251 and stores only the differential data in the hard disk 24. Thus, the substrate processing system 10, according to the first embodiment, periodically stores the set information 151 for controlling the operation of the substrate processing apparatus 1 and the control programs 152 and 153 in the information storage server 2 connected with the substrate processing apparatus 1 through the network 6 as the backup data 251, so that the user need not perform complicated backup operations. In particular, the substrate processing apparatus 1 has the recipe data 151a updated according to the user's know-how. The apparatus intrinsic data 151c adjusts the apparatus 1 while working the same on the actual set position, and hence it is important to periodically back up these data 151a and 151c, for preventing loss. While the substrate processing apparatus 1 is set in a clean room, data stored by backup processing can be maintained outside of the clean room when the information storage server 2, connected through the network 6, is set outside the clean room. While the user can manually perform the backup processing through the operation part 140 of the substrate processing apparatus 1, in this embodiment, the information server 2 may alternatively transmit an instructional command for the backup processing through the network 6. Thus, the instructional command for the backup processing can be transmitted from outside the clean room. The information storage server need not necessarily be set in the substrate processing factory 4. Alternatively, a system management center may be set in the vicinity of the substrate processing factory 4 for transferring the backup data 251 through a private line. According to the aforementioned processing, the information storage server 2 saves the backup data 251 of the set information 151, and the control programs 152 and 153, periodically or at arbitrary times. The restore processing part 123 in the system control part 100 fetches the backup data 251 from the hard disk 24 for restoring the set information 151 and the control programs 152 and 153. The set information 151 and the control programs 152 and 153 may be restored at any timing. For example, the set information 151 and the control programs 152 and 153 may be lost due to a hardware fault, or the user may erroneously lose data during maintenance operation. While the data are restored at abnormality restoration timing in this case, the user may request to return the set information 151 and the control programs 152 and 153 to past backup data. For example, the user may request to return the recipe data 151a updated for operating the substrate processing apparatus 1 to previous recipe data 151a. Further, the user newly finely controlling the operation of the transfer robot TR and updating the teaching data may request to return the teaching data to the previous state. In this case, the user inputs an instruction for restore processing through the operation part 140 of the substrate processing apparatus 1. More specifically, the user instructs restore processing by specifying information as to the data to be restored, the target of restoration and the like. Thus, the local instruction part 121 transmits a restore instructional command to the restore processing part 123. The restore processing part 123 refers to the backup data 251 stored in the hard disk 24 of the information storage server 2, extracts necessary information and performs restore processing. When the set information 151 and the control programs 152 and 153 specified as the object of the restore processing are reserved as full data, the restore processing part 123 extracts the full data as such and stores the same in the storage part 104 of the system control part 100 or the storage part 114 of the unit control part 115. When the set information 151 and the control programs 152 and 153 specified as the object of the restore processing are reserved as differential data, the restore processing part 123 extracts data obtained by accumulating full data backed up before the date of backup of the differential data and differential data from the date of backup of the full data and the specified date. Thus, the restore processing part 123 restores full data also as to the backup data 251 stored as differential data. In the substrate processing system 10 according to the first embodiment, the information storage server 2 connected with each substrate processing apparatus 1 through the network 6 stores backed-up data, whereby restore operation can be readily performed through the network 6 also in the restore processing. Thus, the restore operation can be completed in a short time, thereby improving the working efficiency of the substrate processing apparatus 1. As hereinabove described, the local instruction part 121 of the system control part 100 transmits a processing command thereby executing backup processing. The local instruction part 121 transmits the backup processing command according to the schedule function or when the user inputs an instruction through the operation part 140 of the substrate processing apparatus 1. In the system structure according to the first embodiment, each support computer 3 of the support center 5 is connected to the substrate processing apparatus 1 through the wide area network 61, and it is also possible to execute backup processing by remote control from the support computer 3. When a staff remote-controlling each substrate processing apparatus 1 inputs an instruction for backup processing in the support computer 3 in the support center 5, the remote instruction part 321 transmits a backup processing command through the network 6. When the backup processing command is transferred to the duplicate information acquisition part 122 in the substrate processing apparatus 1, processing similar to the above is performed. When the support center 5 performs backup processing by remote control, a more hospitable user support system can be provided. The backup data 251 may be transferred to the support center 5. A second embodiment of the present invention is now described. The overall schematic structure of a substrate processing system 10 according to the second embodiment is identical to that shown in FIG. 1. The hardware structure of a substrate processing apparatus 1 is identical to that of the first embodiment described with reference to FIGS. 2 and 3. The hardware structure each of an information storage server 2 and a support computer 3 is also identical to that of the first embodiment described with reference to FIG. 4. Similarly to the first embodiment, the operation of the substrate processing apparatus 1 is controlled by control programs 152 and 153 stored in storage parts 104 and 114 according to the procedure of a previously described flow recipe. The control programs 152 and 153 control the substrate processing apparatus 1 according to set information 151 stored in the storage part 104. The contents of the set information 151 are identical to those of the first embodiment shown in FIG. 5. However, apparatus basic data 151b include an extremely large number of data species in addition to those illustrated with reference to the first embodiment. While these are information initialized every substrate processing apparatus 1, the substrate processing apparatus 1 cannot perform planned operation when the contents of partial data are erroneously set among the large number of data. While it is possible to correct the operation of the substrate processing apparatus 1 with apparatus intrinsic data 151c, such correction is extremely complicated or impossible if the apparatus basic data 151b is not reliably set as basic information. The apparatus basic data 151b must be correctly set in the introduction or resetting of the substrate processing apparatus 1. FIG. 9 is a functional block diagram showing the functional structure of the substrate processing system 10 according to the second embodiment. Referring to FIG. 9, a CPU 101 of a system control part 100 runs a maintenance program 154 thereby implementing a basic data request part 1121, a version acquisition part 1122 and a basic data registration part 1123 as processing parts. The storage part 104 stores the maintenance program 154. Referring to FIG. 9, a CPU 21 of the information storage server 2 runs a maintenance program 252 thereby implementing a basic data request part 1221 as a processing part. A hard disk 24 stores the maintenance program 252. Referring to FIG. 9, a CPU 31 of the support computer 3 rums a maintenance program 351 thereby implementing a basic data set part 1321 as a processing part. A hard disk 34 stores the maintenance program 351. The basic data request part 1121 is a functional part transmitting a transmission request for the apparatus basic data 151b from the substrate processing apparatus 1 to the support center 5. The user instructs acquisition of the apparatus basic data 151b through an operation part 140 provided on the substrate processing apparatus 1. In response to input of this instruction, the basic data request part 1121 requests the basic data set part 1321 of the support computer 3 to transmit the apparatus basic data 151b. In order to simplify the input operation by the operator, a display part 130 may display a menu for acquiring the apparatus basic data 151b. When the input operation is enabled according to guidance, the burden on the operator can be reduced. If the support center 5 has a plurality of support computers 3 and the support computer 3, requested to transmit the apparatus basic data 151b is not fixed, the operator specifies the support computer 3 for transmitting the apparatus basic data 151b by input operation. The version acquisition part 1122 is a functional part detecting the software version of the control program 152 controlling the overall substrate processing apparatus 1. While the substrate processing apparatus 1 requests the support computer 3 to transmit the apparatus basic data 151b, the set contents of the apparatus basic data 151b vary with the software version of the control program 152 controlling the substrate processing apparatus 1. Therefore, the substrate processing apparatus 1 posts the software version of the control program 152 therefor to the support computer 3, thereby requesting transmission of the apparatus basic data 151b corresponding to the software version. The basic data request part 1221 comprised in the information storage server 2 also basically comprises a function similar to that of the basic data request part 1121 comprised in the substrate processing apparatus 1. When the operator inputs a request instruction for basic data through a keyboard 26a or a mouse 26b in the information storage server 2, the basic data request part 1221 transmits a transmission request instruction for the apparatus basic data 151b. However, it is assumed that operation for specifying the substrate processing apparatus 1 registering the apparatus basic data 151b is performed when the information storage server 2 requests transmission of the apparatus basic data 151b. Thus, the information storage server 2 can transmit a transmission request for the apparatus basic data 151b as to all substrate processing apparatuses 1 set in substrate processing factory 4. The basic data request part 1221 requests acquisition of the software version to the version acquisition part 1122 of the substrate processing apparatus 1 through a LAN 41. Thus, the basic data request part 1221 transmits the transmission request for the apparatus basic data 151b to the support computer 3, after specifying the software version. FIG. 10 shows apparatus basic data 151b of various versions stored in the hard disk 34 of the support computer 3. The version of each apparatus basic data 151b corresponds to the software version of the control program 152 for the substrate processing apparatus 1. The apparatus basic data 151b is managed in correspondence to the software version of the control program 152 controlling the overall substrate processing apparatus 1 according to the second embodiment, apparatus basic data corresponding to the control program 153 controlling each processing unit may also be managed. In this case, the version acquisition part 1122 of the system control part 100 also detects version information of the control program 153 stored in the storage part 114 of a unit control part 115. When receiving a transmission request instruction for the apparatus basic data 151b from the basic data request part 1121 (or the basic data request part 1221), the basic data set part 1321 of the support computer 3 acquires the software version of the control program 152 included in the data of the transmission request instruction and extracts the apparatus basic data 151b corresponding to this software version from the hard disk 34. The basic data set part 1321 transmits the extracted apparatus basic data 151b to the substrate processing apparatus 1. In the substrate processing apparatus 1, the basic data registration part 1123 receives the apparatus basic data 151b transmitted from the support computer 3 and stores the same in the storage part 104. Thus, it follows that the substrate processing apparatus 1 is initialized in correspondence to the control program 152 for this substrate processing apparatus 1. FIG. 10 shows a state where a substrate processing apparatus 1A installed with a control program 152 of a version 1.0 stores apparatus basic data (Ver1.0) and a substrate processing apparatus 1B installed with a control program 152 of a version 2.0 stores apparatus basic data (Ver2.0). Thus, the substrate processing system 10 according to the second embodiment can readily acquire the apparatus basic data 152b which is basic information for controlling the substrate processing apparatus 1 through a network and reflect the same on the substrate processing apparatus 1, whereby it follows that stable initialization operation can be performed on the same substrate processing apparatus 1 controlled by the same software version. Also when performing initialization operation on a plurality of substrate processing apparatuses 1 controlled by the same software version, the substrate processing apparatuses 1 are initialized identically to each other. In other words, initialized states of a plurality of substrate processing apparatuses 1 can be synchronized with each other. Thus, it is possible to completely avoid dispersion in setting between the apparatuses 1 caused when the operator manually copies the apparatus basic data 151b. After the apparatus basic data 151b is registered in each substrate processing apparatus 1, each substrate processing apparatus 1 performs intrinsic tuning. It follows that each substrate processing apparatus 1 is optimally controlled according to the apparatus basic data 151b received from the support computer 3 and the apparatus intrinsic data 151c created every apparatus 2. The support computer 3 determines the software version of the control program 152 installed in the substrate processing apparatus 1 thereby transmitting the proper apparatus basic data 151b in the second embodiment. It is possible to transmit apparatus basic data 151b responsive to the types of respective substrate processing apparatuses 1 also when different substrate processing apparatuses 1 are present in combination if each substrate processing apparatus 1 posts the type thereof as information to the support computer 3. While the support computer 3 manages the apparatus basic data 151b set in common for the substrate processing apparatuses 1 in the second embodiment, the support computer 3 may alternatively manage the apparatus intrinsic data 151c. While the apparatus intrinsic data 151c is information intrinsic to each apparatus 1 as described above and hence the data 151c may not necessarily be directly utilizable in another apparatus, the user can use apparatus intrinsic data 151c set for a certain substrate processing apparatus 1 as know-how for another apparatus 1. While the version acquisition part 1122 comprised in the system control part 100 automatically detects the software version of the control program 152 in the second embodiment, this functional part is not essential. As hereinabove described, the user may specify the software version of the apparatus 1 when inputting the transmission request instruction for the apparatus basic data 151b through the operation part 140. In order to avoid an artificial error, however, it is more preferable that the version acquisition part 1122 automatically detects the software version. A third embodiment of the present invention is now described. FIG. 11 schematically illustrates the structure of a substrate processing system 10A according to the third embodiment. As shown in FIG. 11, the substrate processing system 10A has such a structure that a plurality of processing apparatuses 1C and an information storage server 2 comprised in a substrate processing factory 4, support computers 3 comprised in a support center 5 where support staffs for the substrate processing apparatuses 1C are posted and an order acceptance server 8 in a component center 7 supplying components of the substrate processing apparatuses 1 to the substrate processing factory 4 are connected with each other through a network 6. In the substrate processing system 10A, the information storage server 2 accumulates utilization consumption or deteriorating use information described as utilization consumption of consumables (hereinafter the term “components” indicates consumables) mounted on the substrate processing apparatuses 1C, so that the support computers 3 can read the stored utilization consumption information through the network 6. The order acceptance server 8 accepts orders for components through the network 6. In the substrate processing factory 4, the substrate processing apparatuses 1C and the information storage server 2 are connected with each other through a LAN (local area network) 41. The LAN 41 is connected to a wide area network 61 such as the Internet through a connector 42 having functions of a router, a firewall and the like. The support center 5 also has a LAN 51 connected with the support computers 3, and this LAN 51 is also connected to the wide area network 61 through a connector 52 having functions of a router, a firewall and the like. The component center 7 also has a LAN 71 connected with the order acceptance server 8, and this LAN 71 is also connected to the wide area network 61 through a connector 72 having functions of a router, a firewall and the like. Thus, various data communication can be made between the substrate processing apparatuses 1C, the information storage server 2, the support computers 3 and the order acceptance server 8. Throughout the specification, the LANS 41, 51 and 71 and the wide area network 61 are generically referred to as a network 6. Referring to FIG. 11, the substrate processing factory 4 comprising the plurality of substrate processing apparatuses 1C may alternatively comprise a single substrate processing apparatus 1C, and the support center 5 comprising the plurality of support computers 3 may also alternatively comprise a single support computer 3. Further, the component center 7 may alternatively comprise a plurality of order acceptance servers 8. Each of the substrate processing apparatuses 1C arranged on the substrate processing factory 4 is now described. FIG. 12 is a schematic plan view of the substrate processing apparatus 1C. This substrate processing apparatus 1C cleans front and back surfaces of substrates. The substrate processing apparatus 1C comprises an indexer ID delivering unprocessed substrates from a carrier while receiving processed substrates and storing the same in the carrier. Surface cleaning processing units SS bring cleaning brushes into contact with the surfaces of the substrates or approaching the former to the latter while rotating the substrates, thereby performing surface cleaning processing, back surface cleaning processing units SSR bring cleaning brushes into contact with the back surfaces of the substrates or cause approaching the former to the latter while rotating the substrates thereby performing back surface cleaning processing. A transfer robot TR transfer the substrates between the indexer ID and each cleaning processing unit. The substrate processing apparatus 1C also comprises a surface inversion unit (not shown). FIG. 13 schematically illustrates the structure of each surface cleaning processing unit SS. The surface cleaning processing unit SS is the so-called spin scrubber. A spin chuck 13 is the so-called vacuum chuck vacuum-sucking the back surface of a substrate W thereby horizontally holding the substrate W. A motor shaft 14 of an electric motor (not shown) is suspended on the center of the lower surface of the spin chuck 13. The electric motor rotates the spin chuck 13 through the motor shaft 14, thereby rotating the substrate W held by the same. A cup 15 is arranged around the substrate W for receiving and recovering a processing solution scattered from the rotated substrate W. The cup 15 is vertically movable by a hoist mechanism (not shown). When the hoist mechanism moves the cup 15 downward, the upper end of the cup 15 is located downward beyond the spin chuck 13. In this state, the transfer robot TR can introduce and discharge the substrate W into and from the spin chuck 13. When moved upward, the cup 15 encloses the substrate W held by the spin chuck 13 while the upper end of the cup 15 is located upward beyond the substrate W. The substrate W is cleaned while the cup 15 is moved upward. A cleaning brush 11 is mounted on the forward end of a brush arm 12. The brush arm 12 is vertically movable and swingable in a horizontal plane through a driving mechanism (not shown). When performing surface cleaning processing on the substrate W, the brush arm 12 is swung while bringing the cleaning brush 11 into contact with the surface of the substrate W or approaching the former to the latter and rotating the substrate W, thereby removing contaminants such as particles adhering to the surface of the substrate W. Each back surface cleaning processing unit SSR, which is substantially similar in structure to the surface cleaning processing unit SS, employs the so-called mechanical chuck grasping an edge of the substrate W thereby horizontally holding the substrate W as a spin chuck 13. In the third embodiment, the surface cleaning processing units SS and the back surface cleaning processing units SSR are generically referred to as processing units 110 performing prescribed processing on substrates. FIG. 14 is a block diagram showing the structure of a control system for the substrate processing apparatus 1C. As shown in FIG. 14, the control system for the substrate processing apparatus 1C is formed by a system control part 100 controlling the overall apparatus 1C and unit control parts 115 individually controlling a plurality of processing units 110. The system control part 100 controlling the overall apparatus 1C in a unific manner comprises a microcomputer. More specifically, the system control part 100 comprises a CPU 101 serving as a body part, a ROM 102 serving as a read-only memory storing a basic program and the like, a RAM 103 serving as a random-access memory mainly defining an arithmetic working area, a storage part 104 consisting of a hard disk or the like storing a software module and the like and a communication part 105 performing data communication with an external device, which are connected with each other by a bus line 190. The communication part 105 is connected to the network 6 through a network interface (not shown), so that the substrate processing apparatus 1C can transmit/receive various data to/from the information storage server 2, the support computers 3 and the like. While the communication part 105 may perform either wire communication or radio communication through the network 6, a wire communication system is employed in this embodiment. Together with the system control part 100 and the plurality of processing units 110, there is a display part 130 displaying various information, an operation part 140 accepting input operation of a recipe and command operation from an operator. A reader 150 reading various data from a recording medium 91 such as a magnetic disk or a magnetooptic disk and the like is also electrically connected to the bus line 190. Thus, data can be transferred between the respective parts of the substrate processing apparatus 1C through the bus line 190 under control of the system control part 100. Each processing unit 110 comprises the unit control part 115 along with a substrate processing part 116 serving as a working part (for example, a mechanism rotating substrates, a mechanism discharging a processing solution to the substrates, a mechanism driving the cleaning brush 11 or the like) processing the substrates in practice. The unit control part 115, individually controlling the processing unit 110, controls and monitors operation of the substrate processing part 116 of the processing unit 110 provided with this unit control part 115. In other words, the aforementioned system control part 100 takes charge of unified control on the overall substrate processing apparatus 1C, while each unit control part 115 takes charge of control responsive to the processing contents of each substrate processing part 116. The unit control part 115 comprises a microcomputer similarly to the system control part 100. More specifically, the unit control part 115 comprises a CPU 111 serving as the body part, a ROM 112 serving as a read-only memory storing a basic program and the like, a RAM 113 serving as a random-access memory defining an arithmetic working area and a storage part 114 consisting of an SRAM backed up with a battery for storing various data. Each processing unit 110 is further provided with a timer 117 and a counter 118. The timer 117 has a function of measuring the used time (time used for substrate processing after exchange to a new cleaning brush 11) of the component, such as the cleaning brush 11 of the processing unit 110. When the processing unit 110 is provided with a plurality of components, the timer 117 measures the used time every component. The counter 118 has a function of counting the number of substrates (the number of substrates processed after exchange to a new cleaning brush 11) processed with the component, such as the cleaning brush 11 of the processing unit 110. When the processing unit 110 is provided with a plurality of components, the counter 118 measures the number of processed substrates every component. The ROM 102 and the storage part 104 of the system control part 100 previously store system control programs related to the overall apparatus 1C. When the CPU 101 of the system control part 100 executes arithmetic processing according to the system control programs, it follows that operation control and data processing are implemented on the overall substrate processing apparatus 1C. The ROM 112 and the storage part 114 of the unit control part 115 previously store unit control programs responsive to the processing contents of the substrate processing part 116 of this processing unit 110. When the CPU 111 of the unit control part 115 executes arithmetic processing according to the unit control programs, it follows that operation control and data processing are implemented on the substrate processing part 116. These programs can be acquired and updated by reading from the recording medium 91 through the reader 150 or downloading from a prescribed server memory or the like through the network 6. Each program has a version, and version information such as a numerical value for identifying the version is changed when the program is updated. The storage part 104 of the system control part 100 stores the version information of each program run by the substrate processing apparatus 1C. The information storage server 2 arranged on the substrate processing factory 4, each support computer 3 arranged on the support center 5. The order acceptance server 8 arranged on the component center 7 are now described. The information storage server 2, the support computer 3 and the order acceptance server 8 are similar in hardware structure to a general computer. Each of the basic structures of the information storage server 2, the support computer 3 and the order acceptance server 8, which are similar to each other, is described with reference to FIG. 15. As shown in FIG. 15, each of the information storage server 2, the support computer 3 and the order acceptance server 8 is formed by connecting a CPU 21, 31 or 81 (the CPU 21 for the information storage server 2, the CPU 31 for the support computer 3 and the CPU 81 for the order acceptance server 8: this also applies to the following description), a ROM 22, 32 or 82 storing the basic program and a RAM 23, 33 or 83 storing various information to a bus line. A hard disk 24, 34 or 84 storing various information, a display 25, 35 or 85 displaying various information, a keyboard 26a, 36a or 86a and a mouse 26b, 36b or 86b accepting input from the operator, a reader 27, 37 or 87 reading various data from the recording medium 91 such as an optical disk, a magnetic disk or a magnetooptical disk and a communication part 28, 38 or 88 making communication with the external device through the network 6 are also connected to the bus line properly through interfaces (I/F) or the like. Each of the information storage server 2, the support computer 3 and the order acceptance server 8 can read a program from the recording medium 91 through the reader 27, 37 or 87 and store the same in the hard disk 24, 34 or 84. Each of the information storage server 2, the support computer 3 and the order acceptance server 8 can also download a program from another server through the network 6 and store the same in the hard disk 24, 34 or 84. The CPU 21, 31 or 81 executes arithmetic processing according to the program stored in the hard disk 24, 34 or 84 for performing operation. In other words, it follows that the information storage server 2 performs operation as the information storage server 2, the support computer 3 performs operation as the support computer 3 and the order acceptance server 8 performs operation as the order acceptance server 8 as a result of executing arithmetic operation according to the program. While the hardware structures of the substrate processing system 10A and the substrate processing apparatus 1C, the information storage server 2, the support computer 3 and the order acceptance server 8 forming the same have been described, the function and the processing contents of the substrate processing system 10A are now described. FIG. 16 is a functional block diagram showing the functional structure of the substrate processing system 10A. FIG. 17 is a flow chart showing the procedure in the substrate processing system 10A. Referring to FIG. 16, the CPU 21 of the information storage server 2 runs processing programs thereby implementing a utilization consumption information registration part 231 and an information uncasing part 236 as processing parts respectively, and the CPU 31 of the support computer 3 runs processing programs thereby implementing a WEB browser 312, a warning part 313 and an order signal transmission part 314 as processing parts respectively. At a step S1 in FIG. 17, utilization consumption of a component of the substrate processing apparatus 1C is measured. The utilization consumption is measured of every processing unit 110. According to this embodiment, the timer 117 measures the used time of the component such as the cleaning brush 11 as the utilization consumption. The unit control part 115 collects the measured utilization consumption of every processing unit 110 and transmits the same to the system control part 100. The system control part 100 collects the measured utilization consumption of every substrate processing unit 1C and transmits the utilization consumption of each component of the substrate processing apparatus 1C to the utilization consumption information registration part 231 of the information storage server 2 from the communication part 105 through the LAN 41. Then, the process advances to a step S2 in FIG. 17, so that the utilization consumption information registration part 231 registers the utilization consumption of each component of the substrate processing apparatus 1C in the hard disk 24. The hard disk 24 cumulatively stores the utilization consumption every component of each substrate processing apparatus 1C as utilization consumption information 241. FIG. 18 illustrates exemplary utilization consumption information 241. Referring to FIG. 18, the column of “apparatus” shows identification numbers assigned to the respective substrate processing apparatuses 1C, the column of “component” shows the names of the consumables, and the columns of “used time” and “number of processed substrates” show the utilization consumption. This embodiment employs the used time as the utilization consumption, and hence the utilization consumption information 241 describes no number of processed substrates. As shown in FIG. 18, the utilization consumption information 241 accumulates the utilization consumption of every component as to each of the substrate processing apparatuses 1C arranged on the substrate processing factory 4. As to a substrate processing apparatus 1C having an apparatus number “8101”, for example, the utilization consumption information 241 records that the used time of a cleaning brush 11 provided with a name “brush 2” is 12 hours. The timer 117 measures the used time of each component at a constant interval and the utilization consumption information registration part 231 sequentially registers the result of measurement in the hard disk 24 thereby constructing the utilization consumption information 241. The information uncasing part 236 uploads the utilization consumption information 241 accumulated in the hard disk 24 of the information storage server 2 to be readable through the network 6. The staff at the support center 5 can read the utilization consumption information 241 by acquiring the utilization consumption information 241 accumulated in the hard disk 24 from the information uncasing part 236 through the WEB browser 312 and displaying the same on the display 35 for confirming the utilization consumption of each component of the substrate processing apparatus 1C arranged on the substrate processing factory 4. Thus, the support center 5 can efficiently manage the utilization consumption of each component of the substrate processing apparatus 1C. The utilization consumption information 241 is regularly acquired through the WEB browser 312. The CPU 31 of the support computer 3 determines whether or not the utilization consumption of the component of the substrate processing apparatus 1C is in excess of a previously set prescribed value on the basis of the utilization consumption information 241 acquired through the WEB browser 312 (step S3). The CPU 31 makes this determination every component registered in the consumptiveness information 241, i.e., every component of the plurality of substrate processing apparatuses 1C. When the utilization consumption of any component exceeds the previously set prescribed value, i.e., when the used time exceeds the prescribed value, the process advances to a step S4 so that the warning part 313 gives a warning for prompting exchange of the component. In other words, the warning part 313 gives the warning for prompting exchange of the component when the utilization consumption of the component accumulated in the hard disk 24 reaches the prescribed value. The warning can be displayed on the display 35 or given as a sound, for example. The staff for maintaining the substrate processing apparatus 1C can recognize that the component approaches the end of its life through the warning for prompting exchange. When the utilization consumption of any component is in excess of the previously set prescribed value, the process advances to a step S5 so that the order signal transmission part 314 transmits an order signal for a new component to the order acceptance server 8 in the third embodiment. When the utilization consumption of the component accumulated in the hard disk 24 reaches the prescribed value, the order signal transmission part 314 transmits the order signal for the new component for exchanging for this component to the order acceptance server 8. When the order acceptance server 8 receives the order signal, the component center 7 immediately progresses processing of supplying the new component to the substrate processing factory 4. The steps S4 and S5 may be replaced with each other in order, or may be simultaneously carried out. According to the third embodiment, it follows that a new component is already prepared in the substrate processing factory 4 when any component of the substrate processing apparatus 1C is consumed or broken, whereby the component can be immediately exchanged and the stop time of the substrate processing apparatus 1C following this component exchange can be minimized so that the apparatus 1C can be inhibited from remarkable reduction of working efficiency. As the aforementioned prescribed value, therefore, it is preferable to set a value immediately before the component is consumed to an unusable state as a value requiring exchange. When any component becomes unusable after a lapse of a used time of 100 hours, for example, the period of 90 hours is set as the value requiring exchange. The life of each component may be experimentally obtained for calculating the value requiring exchange, or the value requiring exchange may be stochastically obtained from the utilization consumption information 241 accumulated in the aforementioned manner. More specifically, the utilization consumption information 241 records utilization consumption of every component, so that utilization consumption can be made known when the component becomes unusable. The life of each component can be obtained by knowing utilization consumption levels leading to unusable states as to a plurality of components and stochastically processing the same, so that the value (value requiring exchange) immediately before the component is consumed to an unusable state can be determined. While the information storage server 2 is arranged in the substrate processing factory 4 in the third embodiment, the present invention is not restricted to this. The information storage server 2 may be arranged anywhere so far as the same is connected to the network 6 to be capable of making communication with the substrate processing apparatus 1C and the support computer 3. While both of warning and transmission of the order signal are performed when the utilization consumption of any component is in excess of the previously set prescribed value in the third embodiment, only one may be performed. When only warning is performed the support staff of the support center 5 recognizing that any component approaches the end of its life orders a new component to the component center 7 with e-mail or the like. Hereafter, a new component is prepared in the substrate processing factory 4 when the component of the substrate processing apparatus 1C is consumed or broken, whereby the component can be immediately exchanged and the substrate processing apparatus 1C can be prevented from excessive reduction of working efficiency. Neither warning nor transmission of the order signal may be performed. In this case, the support staff of the support center 5 monitoring the utilization consumption information 241 determines the exchange period and orders a new component to the component center 7 by e-mail or the like. While the utilization consumption information 241 is configured so that the support computer 3 determines whether or not the utilization consumption of any component is in excess of the previously set prescribed value (value requiring exchange) in the third embodiment, the system control part 100 of the substrate processing apparatus 1C may alternatively directly transmit the utilization consumption of the component to the support computer 3 without constructing the utilization consumption information 241. While the used time is employed as the utilization consumption in the third embodiment, the number of processed substrates may alternatively be employed as the utilization consumption. When the number of processed substrates is employed as the utilization consumption, the counter 118 measures the number of substrates processed with any component such as the cleaning brush 11 as the utilization consumption. Handling of the measured utilization consumption is identical to that of the aforementioned used time. Also in this case, an effect similar to that in the case of employing the used time as the utilization consumption can be attained. Further alternatively, both of the used time and the number of processed substrates may be employed as the utilization consumption. In this case, warning may be given or an order signal for a new component may be transmitted when either the used time or the number of processed substrates is in excess of the previously set prescribed value. Further, instead of not the support computer 3 the substrate processing apparatus 1C or the information storage server 2 may have the warning function and the function of transmitting an order signal for a new component. FIG. 19 is a functional block diagram showing the functional structure of a substrate processing system 10A provided with a substrate processing apparatus 1C having a warning function and a function of transmitting a component order signal. Referring to FIG. 19, elements having the same functions as those in FIG. 16 are denoted by the same reference numerals. Referring to FIG. 19, a CPU 101 of a system control part 100 runs processing programs thereby implementing an order signal transmission part 108 and a warning part 109 as processing parts having roles identical to those of the order signal transmission part 314 and the warning part 313 shown in FIG. 16 respectively. In this case, the system control part 100 (in a strict sense, the CPU 101) determines whether or not utilization consumption measured by a timer 117 or a counter 118 is in excess of a previously set prescribed value (value requiring exchange) so that the warning part 109 gives warning from a display part 130 or the like. Alternatively, the order signal transmission part 108 transmits an order signal for a new component from a communication part 105 to an order acceptance server 8 through a network 6. An effect similar to that of the third embodiment can be also attained in this case. While it is assumed that the substrate processing apparatus 1C performs cleaning processing on substrates and the utilization consumption of the cleaning brush 11 forming the same is managed in the third embodiment, the present invention is not restricted to this but the technique according to the present invention can be applied also to a case such as managing utilization consumption of a lamp forming a lamp annealing apparatus heating substrates by photoirradiation. Further, the technique according to the present invention is also applicable to a case of managing utilization consumption of a belt, cylinder, a motor or the like for driving the transfer robot TR as a consumable. A fourth embodiment of the present invention is now described. The overall structure of a substrate processing system 10 according to the fourth embodiment is identical to that shown in FIG. 1. In the substrate processing system 10 according to the fourth embodiment, however, each support computer 3 distributes educational information related to operation of each substrate processing apparatus 1 to the substrate processing apparatus 1 through a network 6, and a staff delivering a lecture on the operation of the substrate processing apparatus 1 is posted at a support center 5. The hardware structure of the substrate processing apparatus 1 is identical to that in the first embodiment described with reference to FIGS. 2 and 3. Further, the hardware structure of each of an information server 2 and the support computer 3 is also identical to that in the first embodiment described with reference to FIG. 4. FIG. 20 is a functional block diagram showing the functional structure of the substrate processing system 10 according to the fourth embodiment. Referring to FIG. 20, a CPU 101 of a system control part 100 runs a control program thereby implementing a distribution request part 2108 as a processing part, and a CPU 31 of the support computer 3 runs a control program thereby implementing a distribution part 2315 as a processing part. A hard disk 34 comprised in the support computer 3 of the support center 5 stores an educational program 2341. The CPU 31 of the support center 3 reads and runs the educational program 2341, so that the distribution part 2315 can distribute educational information related to operation of each substrate processing apparatus 1 of a substrate processing factory 4 from a communication part 38 through a network 6. The technique of streaming distribution, for example, may be employed as the mode of distribution. A communication part 105 receives the educational information distributed from the support computer 3 and displays the same on a display part 130. As to the timing of distribution, educational information may be simultaneously be distributed to a plurality of substrate processing apparatuses 1 arranged on a certain substrate processing factory 4 regardless of presence/absence of distribution requests from the substrate processing apparatuses 1, or may be distributed only to a substrate processing apparatus 1 presenting a distribution request. More specifically, the distribution request part 2108 transmits a distribution request to the support computer 3 from the communication part 105 through the network 6 when a distribution request command is input from an operation part 140. The distribution part 2315 of the support computer 3 receiving the distribution request distributes the educational information to the substrate processing apparatus 1 from the communication part 38 through the network 6. In a case of simultaneously delivering a lecture on operation explanation to a large number of operators of the substrate processing factory 4, educational information may be simultaneously distributed to the plurality of substrate processing apparatuses 1. The large number of operators can learn the method of operating the apparatuses 1 by dispersing to each substrate processing apparatus 1 in small groups and observing the educational information displayed on the display parts 130. In a case of delivering a lecture on operation explanation to unskilled operators of the substrate processing factory 4, the operators may be posted to any substrate processing apparatus 1 which in turn presents a distribution request so that educational information is distributed only to this substrate processing apparatus 1. The operators can learn the method of operating the apparatus 1 by observing the educational information displayed on the display part 130. In either case, an apparatus vendor can deliver the lecture on operation explanation by simply creating the educational program 2341 and storing the same in the support computer 3, while a user can hold the lecture related to operation explanation repeatedly at desired timing for efficiently educating the operators with reference to the operation. While the support computer 3 stores the educational program 2341 so that the support center 5 distributes the educational information to the substrate processing apparatus 1 through the Internet in the fourth embodiment, the information storage server 2 may alternatively have the role of the support computer 3. FIG. 21 is a functional block diagram showing another exemplary functional structure of the substrate processing system 10 according to the fourth embodiment. Referring to FIG. 21, a CPU 21 of an information storage server 2 runs a control program thereby implementing a distribution part 2215 as a processing part. A hard disk 24 comprised in the information storage server 2 stores an educational program 2241. The CPU 21 of the information storage server 2 reads and runs this educational program 2241 so that the distribution part 2215 can distribute educational information related to operation of each substrate processing apparatus 1 of a substrate processing factory 4 from a communication part 28 through a LAN 41. The mode and the timing of distribution are similar to those of the aforementioned embodiment. When distributing the educational information through the LAN 41, an apparatus vendor can also deliver a lecture on operation explanation by simply creating the educational program 2241 and storing the same in the information storage server 2, while a user can hold the lecture related to operation explanation repeatedly at desired timing for efficiently educating operators with reference to the operation. The technique according to the present invention is applicable to any substrate processing apparatus, such as a lamp annealing apparatus heating substrates by photoirradiation, a cleaning apparatus performing cleaning processing of removing particles while rotating substrates or a dipping apparatus performing surface processing by dipping substrates in a processing solution such as hydrofluoric acid, for example, performing prescribed processing on substrates. While the invention has been shown and described in detail, the foregoing description is in all aspects illustrative and not restrictive. It is therefore understood that numerous modifications and variations can be devised without departing from the scope of the invention.
	summary
	summary
	description	The present invention relates to the field of safety devices used to protect apparatuses under pressure against excessive pressure and/or excessive vacuum. It deals more particularly with a novel rupture disk forming a device of this type. The implementation and the description of all the devices used to protect apparatuses under pressure against excessive pressure notably forms the subject of the French standard NF EN ISO 4126. A review of this standard shows that currently there are essentially four types of devices that can be itemized as follows: 1) rupture disks, 2) safety valves, 3) devices combining the use of rupture disks and of safety valves, 4) the so-called “controlled safety pressure relief systems” (CSPRS). The rupture disks, which are the subject of the standard NF EN ISO 4126-2 are devices actuated by differential pressure between the interior and the exterior of the apparatus that they protect and are designed to operate by rupture, that is to say by material tearing. More specifically, a rupture disk consists of a part which contains the pressure, which is sensitive to the pressure inside the apparatus under pressure and which is designed to open by rupturing at a determined pressure. This rupture makes it possible to release the gas contained in the apparatus under pressure and thus leads to a drop in the internal pressure thereof. Among the existing rupture disks, they can be distinguished according to their particular geometries, which constitute the majority of the market: the rupture disks of domed form, with a form domed outward from the apparatus under pressure that they protect, the rupture disks of inverse domed form, that is to say with a domed form toward the interior of the apparatus under pressure that they protect, the rupture disks of planar form. The existing rupture disks can be produced from a single material or multiple materials. They are all designed to rupture at a single pressure value P, which is the specified rupture pressure, for the intended use. The value of P is a function of the temperature but independent of the nature of the gas contained in the apparatus under pressure. In practice, the value of P is supplied by the manufacturer with a performance tolerance. Thus, the rupture disks make it possible, through a simple technical means, to protect apparatuses under pressure against excessive vacuum, or excessive pressure. In the latter case, as mentioned above, the rupture of the disk occurs as soon as pressure internal to the apparatus equals the specified rupture pressure, to within the tolerance value, and does so independently of the chemical nature of the gas contained in the apparatus. Hydrogen gas embrittlement of steels, often referred to by the acronym HE, is a phenomenon caused by the interaction between the hydrogen and the steels. The interaction consists of the adsorption of hydrogen at the surface of the steel and possibly the diffusion of the hydrogen in the volume thereof. Based on multiple parameters linked to the material, such as its microstructure, its mechanical characteristics, etc., and to its environment, such as the fugacity of the hydrogen, the temperature, etc., this interaction can result in a premature rupture of the steel, and therefore a clear rupture of the apparatuses concerned. This premature rupture, generically referred to by the term embrittlement, is generally reflected in terms of mechanical behavior of the steel by a reduction in its ductility. The scale of this reduction depends on the parameters cited previously. The literature on this subject very clearly shows the importance and the criticality of this phenomenon in many fields, such as petrochemicals, metallurgy or even the nuclear industry. Thus, the manufacturer of an apparatus under pressure, whose metal walls, generally of steel, can be effected by the embrittlement, must take this phenomenon into consideration. In particular, such an apparatus may be required to undergo, during its operation, and successively, the pressure of an inert gas followed by hydrogen. In this case, the manufacturer of the apparatus may want, through a safety measure, to lower the maximum allowable pressure under hydrogen compared to that under inert gas. Now, to date, there is no device for protecting apparatuses under pressure against excessive pressure designed, according to the chemical nature of the gas in the apparatus, to automatically accommodate the pressure value which leads to the rupture of the device. There is therefore a need to improve the protection devices of the apparatuses under pressure, notably in order to adapt them, according to the chemical nature of the gas in the apparatus, to automatically accommodate the pressure value which leads to their rupturing of the device. The general aim of the invention is to at least partly address this need. A particular aim is to propose a device which addresses the general aim, which is simple to produce, reliable and inexpensive. To do this, the subject of the invention is a rupture disk for a device for protecting against overpressures inside an apparatus, the disk consisting of a part of generally circular form comprising two planar faces substantially parallel to one another, and two scores each located on a circumference, the circumferences of the two scores being different to one another, the score located on the larger circumference being produced on one of the planar faces, called bottom face, whereas the score located on the smaller circumference is produced on the other of the planar faces, called top face. According to an advantageous embodiment, the score located on the top face is designed to rupture at a first pressure P0 whereas the score located on the bottom face is designed to rupture at a second pressure P1 different from P0. Regarding the placement of the rupture disk according to the invention, the bottom face of the disk which has the circumferential score of larger diameter is placed in direct contact with the pressure contained in the apparatus to be protected. The top face of the disk is not therefore subject to the pressure internal to the apparatus and is at atmospheric pressure under inert gas or air. Thus, the inventors of the present invention have thought shrewdly to differentiate the fracture initiation scores of a rupture disk according to the pressurized gases contained in the apparatus. They have also analyzed the possible location of these fracture initiation scores and have come to the conclusion that it was necessary to locate a fracture initiation score, or score, on each of the two planar faces of the disk. In effect, if the scores were both located on the top face of the disk intended not to be in direct contact with the pressure of the apparatus, then these scores would not be embrittled by the gas or gases, such as the hydrogen. Consequently, the main point of embrittlement of the disk would occur on its opposite face, i.e. the bottom face, at the level of its embedment with the bearing element of the protection device. The rupture pressure would then become extremely sensitive to the presence of defects (scratches) on the bottom face of the disk at the level of the embedment, and the rupture pressure under gas, such as the hydrogen, would therefore be very random. In other words, it would not be possible to guarantee a good reliability. On the other hand, if the scores were both located on the bottom face of the disk, it would be very difficult to manage to dimension the disk for the bottom of the two scores to be stressed by traction and not by compression. The embrittlement by the gas, such as the hydrogen, would then be transferred to the level of the embedment on the bottom face of the disk, and the same issue as previously of rupture pressure control would arise. It goes without saying that a person skilled in the art will take care to dimension the geometrical parameters of the disk, such as the thickness, the diameter, and those of the scores, such as the depth, the score bottom radius, the location in the disk, in order to obtain the desired rupture pressures. A person skilled in the art can perform this dimensioning using finite element computation software. This may be software called Cast3M developed by the applicant and commercially available. It may also be software with the commercial name Abaqus. Any other finite element computation software may be suitable. The inventors carried out the dimensioning of a rupture disk according to the invention using the Cast3M software according to the following procedure: firstly, an evaluation of the mechanical characteristics of the material of the rupture disk was carried out under inert gas, by performing traction and rupture mechanics tests, notably toughness tests, secondly, an evaluation of the sensitivity of the material to hydrogen gas embrittlement was conducted, by performing traction tests under various hydrogen pressures and for multiple rates of deformation. The aim of these tests under hydrogen pressures is to outline the general behavior of the material under hydrogen. A simulation via finite element software was then carried out on the disk with its scores, subjected to an increasing gas pressure on its bottom face. The changes with the gas pressure of the tapered stress and deformation fields of the two scores are analyzed. An iterative process of modification of the parameters of the geometry of the scored disk, such as the radius of the scores and their depth, is then carried out until the various geometrical parameters of the disk make it possible to obtain the rupture pressures desired under hydrogen and under inert gas. The inventors of the present invention have therefore defined a specific rupture disk geometry which allows an automatic adjustment of the rupture pressure of the disk as a function of the chemical nature of the pressurized gas in the apparatus. Thus, if the gas is an inert gas, the rupture pressure of the disk is equal to P0. If the gas is hydrogen, the rupture pressure is equal to P1. P0 is strictly greater than P1. The difference in absolute value between P0 and P1 is greater than the tolerance on the rupture pressure under inert gas. The accommodation of the value of the rupture pressure of the disk according to the chemical nature of the pressurized gas in the apparatus is done automatically without the need for intervention from a third party. One and/or the other of the scores may be continuous or discontinuous over its circumference. The part forming the rupture disk may advantageously be made of a steel chosen from the ferritic, martensitic, ferrito-bainitic, bainitic, ferrito-martensitic, ferrito-perlitic, preferably of API X80 grade, and perlitic steels. A rupture disk and its scores according to the invention may have the following preferred dimensions: the part has a thickness of 1 to 5 mm, the depth of the scores is less than or equal to a value corresponding to approximately 70% of the thickness of the part, the bottom radius of the scores is between 0.1 and 0.6 mm, the aperture angle of the scores being less than or equal to 500. These preferred dimensions are implemented advantageously, for rupture pressures under inert gas and H2 of between 250 and 550 bar, and for a part made of steel sensitive to HE, such as a steel chosen from the ferritic steels, certain martensitic steels, ferrito-perlitic steels. Also a subject of the invention, according to another of its aspects, is an apparatus, intended to contain, in succession, two gases of different chemical nature, such as helium and hydrogen, comprising: a wall in which an aperture is formed; a device protecting the apparatus against overpressures comprising: a rupture disk as described previously, whose bottom face is in direct contact with the pressure contained in the apparatus, at least one bearing element, designed to press the disk against the wall with the scores of the disk on the aperture. The device protecting the apparatus may advantageously comprise: sealing means arranged between the periphery of the disk and the wall around the aperture, at least one holding element, called closing cap, bearing against the bearing element, and fixed by tightening to the equipment so as to hold the bearing element and the rupture disk on the apparatus and guarantee the seal-tightness at the level of the sealing means. Preferably, the bearing element is a ring whose bottom face bears against the top face of the disk and whose aperture is arranged facing the aperture of the wall. The apparatus may also comprise sealing means arranged between the periphery of the ring and the closing cap. These sealing means preferably consist of one or more O-ring seals. According to a variant embodiment, the closing cap and the apparatus are pierced respectively with tapped holes facing one another to house the screws for tightening the closing cap on the apparatus. A final subject of the invention is the use of the apparatus described above to contain, under pressure, two gases of different chemical nature, such as helium (He) and hydrogen (H2). An advantageous use is that where the apparatus is a hydrogen production and storage apparatus. As illustrated in FIGS. 1 to 2A, the rupture disk 1 according to the invention is a circular part of diameter Ø whose planar face 10 is scored with a continuous score 12 of circular form C1, of aperture angle α1, of score bottom radius R1 and of score depth e1. The other planar face 11 of the disk 1 is also scored with a continuous score 13 of circular form C2, of aperture angle α2, of score bottom radius R2 and of score depth e2. The circumferences C1, C2 of the two scores 12, 13 are concentric and with a center that coincides with that of the disk 1. As an example, the dimensions are as follows: thickness of the disk e1+e2: 1.5 mm, diameter Ø: 58 mm. diameter C1: 18 mm, depth e1: 0.65 mm, bottom radius R1: 0.1 mm, aperture α1 of 30°. diameter C2: 12 mm, depth e2: 0.85 mm, bottom radius R2: 0.1 mm, aperture α2 of 30°. The disk 1 can advantageously be made of ferrito-perlitic steel for a use with hydrogen. The constituent material of the ring can be a steel of any microstructure. FIGS. 3 to 3B show a bearing ring 2 designed to press the rupture disk 1 according to the invention against a wall of an apparatus under pressure to be protected. This ring 2 is of circular section with a diameter Ø2, a thickness H2 and comprises a top face 20 and a bottom face 21. This bottom face 21 defines the plane making it possible to hold the top face 11 of the disk 1. The top face 20 is provided with a peripheral groove 22, of rectangular section of height H22 and of width L22. This groove 22 can house a sealing O-ring seal 6 designed to produce the final seal of the apparatus protection device as detailed hereinbelow. The ring 2 is pierced with a central aperture 23 also of circular section 23 of diameter Ø23 over most of its height H23, a connection in the form of a radius of curvature r23 being produced at the join with the bottom face 21. The diameter Ø23 and the radius of curvature r23 are to be dimensioned according to the rupture pressures desired for the disk under inert gas and under hydrogen. As an example, the dimensions are as follows: ring diameter Ø2: 58 mm, thickness H2: 9.25 mm, groove width L22: 4 mm, groove height H22: 2.4 mm, groove outer diameter Ø22: 45 mm diameter of the central aperture Ø23: 22.5 mm, height H23: 7.75 mm, radius of curvature r23: 1.5 mm. The ring 2 is made of type 316L stainless austenitic steel preferably with its surface nitrided. This surface treatment makes it possible to harden the steel at the surface and thus ensure that, in case of rupture of the disk 1, the ring 2 will not be damaged. Other materials may be considered for the production of the ring 2. Whatever the material considered for the ring, it is chosen such that the mechanical strength of the ring 2 is greater than that of the disk 1, that is to say that, at a given pressure, the disk 1 is deformed and under no circumstances the ring 2. FIGS. 4A and 4B show an example of fixing of a protection device 4 incorporating the rupture disk 1 and the ring 2 according to the invention, to an apparatus 5 intended to contain, successively, two gases of different chemical nature, namely helium and hydrogen. A wall of the apparatus 5 is pierced with a circular aperture 50 over which the bottom face 10 of the disk is positioned and held. The bottom face 10 with its score 12 is therefore in direct contact with the pressure inside the apparatus 5. The top face 11 of the disk 1 is held against the wall of the apparatus 5 around the aperture 50 by the ring 2. More specifically, the peripheral part 14 of the disk is embedded between the wall of the apparatus 5 and the ring 2 whereas the scores 12, 13 are centered on the aperture 50 of the wall and the central aperture 20 of the ring 2. The disk 1 and the ring 2 are held in place on the apparatus 5 to be protected by a closing cap 3 screwed into the wall of the apparatus. The closing cap 5, also of generally circular form, comprises a central aperture 30 positioned facing the central aperture 20 of the ring 2. Although not represented, the tightening screws are screwed into the tapped holes 31, 51 respectively produced in the closing cap 3 and the wall of the apparatus 5. The seal between the interior of the apparatus 5 and the exterior is produced via two O-ring seals 6. One of the seals 6 is positioned between the apparatus 5 under pressure and the rupture disk 1. As illustrated in FIGS. 4A and 4B, this seal 6 may be housed in a groove 52 provided for this purpose in the wall of the apparatus 5. The other of the seals 6 is positioned between the ring 2 and the closing cap 3. It is not essential to provide this other seal 6. If it proves necessary not to have any gas leak between the cap 3 and the ring 2, then installation of this other seal 6 between these two elements 2, 3 is vital. Such is the case for example if the apparatus 5 is located inside a building/structure/installation and if the gas must then be channeled in a pipe to be discharged outside. On the other hand, if for example the apparatus 5 is located outdoors, then the installation of this other seal 6 is not vital. Such is the case for example when the apparatus 5 is a gas storage tank placed in the open air. As illustrated in FIGS. 4A and 4B, this other seal 6 may be housed in the groove 22 of the ring 2. The seals 6 may be of elastomer. Advantageously, if the apparatus 5 is designed to remain for long periods under hydrogen pressure, at least the seal 6 between the rupture disk 1 and the apparatus 5 is made of indium. The tightening torque applied to the closing cap 3 makes it possible to ensure both that the protection device 4 is held against the apparatus 5 and that the seals 6 are tight. The inventors carried out validation tests on a protection device 4 according to the invention. It is specified here that, for these validation tests, the dimensions of the rupture disk 1 and of the ring 2 are those given by way of examples above. It is also specified that, for these validation tests, the rupture disk 1 was made of API X80 grade ferrito-perlitic steel and the ring 2 was made of 316L steel with its surface nitrided. The device 4 was validated by using a disk bursting cell, a test means originally developed by the applicant in its research center located in Valduc. The test scheme in this bursting cell is shown in FIG. 5. An increasing helium pressure with a rise in pressure rate of 20 bar/min, was applied under the disk 1 until its rupture. Three tests were carried out in succession on three different disks. Then, three new tests were performed under an increasing hydrogen pressure (99.9999% pure) on three different disks. The results of the tests are presented in the table below. TABLERupture pressureGasPR(bar)Location of the RuptureHelium487Score 13500516Hydrogen335Score 12296392 In this table, it emerges that the rupture pressure of the disk 1 under hydrogen is systematically significantly lower, by approximately 30%, than that observed under helium. Furthermore, under helium it occurs on the top score 13, whereas under hydrogen, the rupture always occurs at the bottom score 12. That is shown respectively in FIGS. 6A and 6B for the rupture under helium and in FIGS. 7A and 7B for the rupture under hydrogen, where the difference in size of the torn cappings 15 can be seen. Two additional tests were carried out under hydrogen in order to confirm that the preceding test results are independent of the rate of pressure rise of the gas. Thus, the two additional tests were as follows: a first test was carried out at 6.7×10−2 bar/min. The results are comparable to those obtained under hydrogen at 20 bar/min. a second test was carried out at 2400 bar/min. The results of the test are also comparable to those obtained under hydrogen at 20 bar/min. In conclusion, the protection device 4 according to the invention described above therefore does indeed make it possible to accommodate the maximum allowable pressure in the pressurized enclosure as a function of the nature of the gas contained, i.e. inert gas or hydrogen. The apparatus 5 intended to be protected by the protection device 4 may advantageously be an apparatus used in the field of hydrogen energy production and storage. Other variants and enhancements may be implemented without in any way departing from the scope of the invention which has just been described. According to a preferred use, an apparatus with a rupture disk according to the invention as overpressurization protection device is designed to successively contain helium (He) and hydrogen (H2). However, an apparatus with a rupture disk according to the invention may be used advantageously to contain all other existing inert gases. In particular, it may be used with all the gases containing a partial H2 pressure.
055966110	claims	1. A method of collecting a medical isotope from a fission product produced in a nuclear reactor, the method comprising: providing a reactor having a 100 to 300 kilowatt rating; using a uranyl nitrate solution as a homogeneous fissionable material in the reactor, the fissionable material producing fission products including Molybdenum-99 in the uranyl nitrate solution; passing a portion of the uranyl nitrate solution from the reactor to and through a column of alumina for fixing the fission products including Molybdenum-99 to alumina in the column; adding acid to the portion of the uranyl nitrate solution to achieve a pH of about 2 to about 5; passing the portion of the uranyl nitrate solution at pH of about 2 to about 5, back into the reactor; removing the fixed fission products from the alumina column through elution with a hydroxide; and precipitating the resulting elutriant with alpha-benzoinoxime for collecting the Molybdenum-99 as the medical isotope. a vessel containing a selected quantity of uranyl nitrate solution as a homogeneous fissionable material for producing fission products including Molybdenum-99 in the uranyl nitrate solution at a 100 to 300 kilowatt power rating; at least one alumina column, the fission products including Molybdenum-99 being fixable to alumina in the column; means for directing a portion of the solution through the alumina column and thereafter back to the vessel; means for adding acid to the portion of the solution before it is returned to the vessel and between the column and the vessel; means for supplying a hydroxide through the column for eluting the fission products fixed to the alumina; means for receiving the eluted fission products; and means for precipitating Molybdenum-99 from the fission products using alpha-benzoinoxime in the means for receiving the eluted fission products. 2. The method according to claim 1, wherein the uranyl nitrate solution is passed through the column of alumina for a period of time ranging from approximately 12 to 36 hours. 3. The method according to claim 1, wherein the solution contains U-235. 4. The method according to claim 1, wherein for about 20 liters of uranyl nitrate solution are in the reactor, the portion of the uranyl nitrate solution passing from the reactor being about 0.1 to 1.0 ml/per second. 5. The method according to claim 1, including washing the resulting elutriant with water before collecting the Molybdenum-99. 6. The method according to claim 1, wherein the hydroxide comprises one of sodium hydroxide and ammonium hydroxide. 7. The method according to claim 1, wherein for 20 liters of solution, the solution contains approximately 1,000 grams of U-235 in a 93% enriched uranium. 8. The method according to claim 1, wherein for 100 liters of solution, the solution contains about 2,300 grams of 20% enriched uranium-235. 9. The method according to claim 1, including passively cooling the reactor. 10. A system for collecting a medical isotope from a fission product produced in a nuclear reactor, comprising: 11. A system according to claim 10, including means for passively cooling the vessel. 12. A system according to claim 10, including means for washing the column. 13. A system according to claim 10, including an additional column and valve means connected to the first mentioned and additional column for supplying a stream of solution through only one of the columns at a time. 14. A system according to claim 10, wherein the vessel includes outwardly extending fins, the system including means for cooling the vessel comprising a pool of coolant fluid in which the vessel is immersed. 15. A system according to claim 10, wherein the selected amount of solution comprises 20 liters of solution, the solution containing approximately 1,000 grams of 93% enriched U-235. 16. A system according to claim 10, wherein the selected amount of solution comprises 100 liters containing about 1,000 grams of 20% enriched U-235.

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