Abstract: The invention refers to a nuclear fuel, a fuel element, a fuel assembly and a method of manufacturing a nuclear fuel. The nuclear fuel is adapted for use in a water cooled nuclear reactor, including light water reactors LWR, such as Boiling Water Reactors BWR and Pressure Water Reactors PWR. The nuclear fuel comprises an uranium-containing compound consisting of UN. The uranium content of the uranium-containing compound comprises less than 10% by weight of the isotope 235U. The nuclear fuel comprises an additive substantially consisting of at least one element, in elementary form or as a compound, selected from the group consisting of Zr, Mo, Si, Al, Nb and U.

Abstract: A nuclear fuel composition includes a transuranic fuel and a neutron moderator mixed with transuranic fuel. The neutron moderator includes at least one of hafnium or zirconium.

Abstract: A sintered fuel pellet for a water nuclear reactor fuel rod including a peripheral wall extending along a central axis and two end faces. At least one of the end faces includes at least a first chamfer extending from the peripheral wall towards the central axis with a first non-zero slope with respect to a plane perpendicular to the central axis and a second chamfer extending from the first chamfer towards the central axis with a second non-zero slope with respect to a plane perpendicular to the central axis, wherein the first slope is different from the second slope.

Abstract: A nuclear fuel element including a uranium-molybdenum alloy that provides an enhanced reactivity in research, test and radioisotope production nuclear reactors. In this uranium-molybdenum alloy, the uranium is enriched in the isotope 235-U, while the molybdenum is depleted in the isotope 95-Mo. The thus obtained enhanced reactivity provides, depending on the exact use of the fuel element, a requirement for less uranium in the fuel and the use of the fuel elements during a longer period in the reactor.

Abstract: The invention concerns an alloy containing equally 0.02 to 0.07% wt. % of the total iron, of chromium or vanadium, 0.8 to 1.3 wt. % of niobium, 100 ppm or less of tin, 1100 to 1700 ppm of oxygen, less than 100 ppm of carbon, 10 to 30 ppm of sulphur and less than 50 ppm of silicon.

Abstract: A nuclear fuel element including a uranium-molybdenum alloy that provides an enhanced reactivity in research, test and radioisotope production nuclear reactors. In this uranium-molybdenum alloy, the uranium is enriched in the isotope 235-U, while the molybdenum is depleted in the isotope 95-Mo. The thus obtained enhanced reactivity provides, depending on the exact use of the fuel element, a requirement for less uranium in the fuel and the use of the fuel elements during a longer period in the reactor.

Abstract: The present invention provides a nuclear fuel assembly, where a boron-containing compound is used as a burnable poison and is distributed in a majority of the rods in the assembly. The assembly comprises a plurality of fuel rods, each fuel rod containing a plurality of nuclear fuel pellets, wherein at least one fuel pellet in more than 50% of the fuel rods in the fuel assembly comprises a sintered admixture of a metal oxide, metal carbide or metal nitride and a boron-containing compound.

Abstract: Among fuel rods constituting a fuel assembly, Gd compound oxide is added to low Gd containing fuel rods that containing uranium dioxide of which enrichment exceeds 5 wt %. The Gd compound oxide is oxide of gadolinium and rare earth element A except for gadolinium and is expressed as a chemical formula A1-xGdxO2-0.5x or a chemical formula A1-xGdxO1.5. As the rare earth element A, cerium Ce, lanthanum La or erbium Er can be used.

Abstract: The present invention relates to a fuel rod of a nuclear fuel assembly having a vase-like compression spring adapted to increase the internal volume thereof wherein when the vase-like compression spring is inserted into a cladding tube, it has a relatively smaller volume occupied inside the fuel rod when compared with the existing coil type compression spring, such that the vase-like compression spring can ensure a sufficient space portion receiving the fission gases generated during the operation of the fuel rod, thereby increasing the burn-up performance of the fuel rod and the mechanical integrity thereof.

Abstract: A tool to slide a channel on a nuclear reactor fuel bundle assembly, the tool includes: a plate having a slot to receive a handle of the fuel bundle and a lower surface that engages an upper edge of the channel; at least one post extends up from the plate, and an arm is attached to a pivot on the post and includes a first end to receive a downward force and a second end adapted to engage the handle of the fuel bundle to apply an upward force to the handle and push down on the channel.

Abstract: A nuclear fission reactor device including a core having an array of fissile material and which is capable of being transported to and from the place of operation using conventional transportation vehicles. In a first embodiment, the fissile material is a uranium hydride enriched 15%-to-20% with U-235. In a second embodiment, the fissile material is a uranium oxide enriched to 18% to 20% with U-235.

Abstract: A pellet including a nuclear fuel material for applications in reactors. The pellet has an elongated shape along an axis (z) and includes on an outer radial surface at least one privileged breaking area (R2) for promoting a breaking in a plane substantially perpendicular to the axis (z). During a temperature rise of the pellet, the pellet is broken along the privileged breaking areas into several fragments having a smaller slenderness ratio than that of the entire pellet, which contributes to lessen the stresses on the sheath housing such pellets.

Abstract: A method for production of a fuel cladding tube for a nuclear reactor, characterized by the preparation of an ingot of an alloy of zirconium with the following composition by weight %: 0.8%?Nb?2.8%, traces?Sn?0.65%, 0.015%?Fe?0.40%, C?100 ppm, 600 ppm?O?2300 ppm, 5 ppm?S?100 ppm, Cr+V?0.25%, Hf?75 ppm and F?1 ppm the remainder being zirconium and impurities arising from production. The ingot is then subjected to forging, a hardening and thermomoechanical treatments comprising cold laminations separated by intermediate annealing, all intermediate annealings being carried out at a temperature below the ???+? transition temperature of the alloy, finishing with a recrystallization annealing and resulting in the production of a tube, whereupon an optional external cleaning of the tube is carried out and a mechanical polishing of the external surface of the tube is carried out to give a roughness Ra less than or equal to 0.5 ?m. The invention further relates to a fuel cladding tube obtained thereby.

Abstract: The invention concerns a method of producing a cladding tube for nuclear fuel for a nuclear boiling water reactor. According to the method, a tube is formed which comprises an outer cylindrical component (10) mainly containing zirconium and an inner cylindrical component (20) metallurgically bonded to the outer component (10), wherein also the inner component (20) at least mainly contains zirconium. The inner component (20) has a lower recrystallization temperature than the outer component (10). The cladding tube is final annealed at a temperature and during a time such that the inner component (20) substantially completely recrystallizes and such that the outer component (10) partly recrystallizes but to a lower extent than the inner component (20). The invention also concerns a cladding tube, a fuel assembly for a boiling water reactor as well as the use of a cladding tube.

Abstract: A fuel channel for housing a fuel rod bundle in a boiling water nuclear reactor includes an expanded section to create an increased flow area at a top of the fuel channel and thereby reduce a pressure drop through the fuel channel. The expanded section eliminates a need for channel spacers and a fastener guard.

Abstract: Direct nuclear energy conversion into electricity device based on nano-hetero-structures with applications in nuclear reactors and radioisotope batteries. The nano structure may be made by a repeated customized sequence of nano-layers generically called “CIci” The structure may also be made by a series of structures evolved from CIci as nanoplasmon, nanowire, nano-tube. The Structure relies on knock on electron avalanche produced by stopping radiation that is generated by the high electron density conductor material “C” that tunnels through insulator “I” and accumulates in the low density conductor “c”. The “C” material is producing no electrons to cross the associate insulator “i” therefore remains negatively charged by the electron shower, and discharges through a resistor connected to th “C” later. The nanoplasmon structure exhibits thermal direct conversion properties by radiation switched mechanism that is generated by the plasmon-phonon resonance.

Abstract: A nuclear fuel assembly having a tube-in-tube control rod guide tube design that incorporates an end plug that extends axially upward to an elevation above the lower most grid where it is sealed at its upper end to the lower end of the control rod guide tube. The guide tube lower end plug has a threaded recess in its upper surface that mates with a corresponding dashpot end plug threaded extension that is formed as an insert in the lower end of the guide tube. A hole formed through the outer wall of the guide tube end plug at the elevation of the lower portion of the recess provides a positive inspection port for assuring the proper seating of the dashpot. A method of manufacture of such a fuel assembly is also disclosed.

Abstract: A core of a light water reactor having a plurality of fuel assemblies, which are loaded in said core, having nuclear fuel material containing a plurality of isotopes of transuranium nuclides, an upper blanket zone, a lower blanket zone, and a fissile zone, in which the transuranium nuclides are contained, disposed between the upper blanket zone and the lower blanket zone; wherein a ratio of Pu-239 in all the transuranium nuclides contained in the loaded fuel assembly is in a range of 40 to 60% when burnup of the fuel assembly is 0; sum of a height of the lower blanket zone and a height of the upper blanket zone is in a range of 250 to 600 mm; and the height of said lower blanket zone is in a range of 1.6 to 12 times the height of the upper blanket zone.

Abstract: The present invention is directed to a plutonium-based nuclear fuel that is suitable for burning weapon-grade and reactor-grade plutonium in a light water reactor, thereby reducing the amount of such material that could potentially be used to manufacture a weapon. In one embodiment, the fuel is comprised of plutonium, zirconium hydride, and thorium, with the zirconium hydride comprising more than about 20% by weight of the fuel.

Abstract: The invention relates to a metal polymer composite having properties that are enhanced or increased in the composite. Such properties include color, magnetism, thermal conductivity, electrical conductivity, density, improved malleability and ductility and thermoplastic or injection molding properties.

Abstract: A nuclear fuel and a method to produce a nuclear fuel wherein a porous uranium dioxide arrangement is provided, the arrangement is infiltrated with a precursor liquid and the arrangement is thermally treated such the porous uranium dioxide arrangement is infiltrated with a precursor liquid, followed by a thermal treating of the porous uranium dioxide arrangement with the infiltrated precursor liquid such that the precursor liquid is converted to a second phase.

Abstract: In a nuclear fuel rod a cladding tube is provided having a closed inner space and manufactured from at least one of the materials in the group zirconium and a zirconium-based alloy, and a pile of nuclear fuel pellets arranged in the inner space in the cladding tube. The nuclear fuel pellets fill part of the inner space. A fill gas is arranged in the closed inner space to fill the rest of the inner space. The internal pressure of the fill gas in the nuclear fuel rod amounts to at least 2 bar (abs) or at least 10 bar (abs). The fill gas contains a proportion of inert gas a proportion of carbon monoxide that is greater than 3 volume percent of the fill gas or greater than 2 volume percent of the fill gas.

Abstract: Exemplary embodiments provide automated nuclear fission reactors and methods for their operation. Exemplary embodiments and aspects include, without limitation, re-use of nuclear fission fuel, alternate fuels and fuel geometries, modular fuel cores, fast fluid cooling, variable burn-up, programmable nuclear thermostats, fast flux irradiation, temperature-driven surface area/volume ratio neutron absorption, low coolant temperature cores, refueling, and the like.

Abstract: In a nuclear power installation a nuclear reactor (R) and other parts or components which are hazardous because of radioactivity or other hazard factors are placed in a lower part (12) of the installation which is located at a level deep below the ground level, whereas a ground-level part (11) of the installation comprises equipment for making the energy produced by the reactor useful. The deep-level part (12) of the installation includes a storage site (19) for spent nuclear fuel (29). These two pans (11, 12) of the installation are interconnected by a passageway which is suitably formed by one or more shafts.

Abstract: A nuclear fuel assembly having a tube-in-tube control rod guide tube design that incorporates an end plug that extends axially upward to an elevation above the lower most grid where it is sealed at its tipper end to the lower end of the control rod guide tube. The guide tube lower end plug has a threaded recess in its upper surface that mates with a corresponding dashpot end plug threaded extension that is formed as an insert in the lower end of the guide tube. A hole formed through the outer wall of the guide tube end plug at the elevation of the lower portion of the recess provides a positive inspection port for assuring the proper seating of the dashpot. A method of manufacture of such a fuel assembly is also disclosed.

Abstract: In a method for heat treating a fuel assembly channel made of zircaloy, the channel is continuously moved relative to a heat-treatment device and, longitudinal sections of it are heated to the beta phase range in an inductive heating zone. The longitudinal section of the channel heated in this manner is than cooled in a cooling zone to a temperature within an alpha phase range. The heat treatment is effected by at least two heating devices, which are spaced apart from one another, operate independently of each other, and each contain at least one induction coil and together form a heating zone. The channel section is first heated using a first heating device and then heat-treated using a second heating device which has less power and in that cooling is effected using a stream of inert gas applied to the outer surface of the channel.

Abstract: A fuel channel fastener having a body with a hole, a bolt inserted into the hole, at least two anti-rotation supports attached to the body, a spring configured to attach to the body and to extend away from the body down the sides of a fuel assembly fuel channel, and at least two spring anti-rotation pads connected to the body.

Abstract: A fuel channel fastener having a body with a hole, a bolt inserted into the hole, at least two anti-rotation supports attached to the body, a spring configured to attach to the body and to extend away from the body down the sides of a fuel assembly fuel channel, and at least two spring anti-rotation pads connected to the body.

Abstract: Illustrative embodiments provide nuclear fission igniters for nuclear fission reactors and methods for their operation. Illustrative embodiments and aspects include, without limitation, a nuclear fission igniter configured to ignite a nuclear fission deflagration wave in nuclear fission fuel material, a nuclear fission deflagration wave reactor with a nuclear fission igniter, a method of igniting a nuclear fission deflagration wave, and the like.

Abstract: A fuel element for a pressurized water reactor has fuel rods guided through a number of axially spaced spacers. The spacers form a square grid with mesh openings arranged in rows and columns. Support tubes that do not contain fuel pass through a number of the mesh holes and are joined to the meshes . The support tubes are spread out in positions within the grid with a predetermined number of support tubes and a distribution thereof within the grid, which is rotationally symmetric about 90° with regard to a rotation about the central axis of the spacer, the central axis is perpendicular to the grid plane, the number of rows and columns that do not contain any support tubes is minimal. Optionally, remaining inner rows and columns that do not contain any support tubes are not situated next to one another.

Abstract: A nuclear fuel assembly having a tube-in-tube control rod guide tube design that incorporates an end plug that extends axially upward to an elevation above the lower most grid where it is sealed at its tipper end to the lower end of the control rod guide tube. The guide tube lower end plug has a threaded recess in its upper surface that mates with a corresponding dashpot end plug threaded extension that is formed as an insert in the lower end of the guide tube. A hole formed through the outer wall of the guide tube end plug at the elevation of the lower portion of the recess provides a positive inspection port for assuring the proper seating of the dashpot. A method of manufacture of such a fuel assembly is also disclosed.

Abstract: A method for providing a nuclear fuel includes forming a uranium-molybdenum alloy that provides an enhanced reactivity in research, test and radioisotope production nuclear reactors. In this uranium-molybdenum alloy, the uranium is enriched in the isotope 235-U, while the molybdenum is depleted in the isotope 95-Mo. The thus obtained enhanced reactivity can have at least two advantages, depending on the exact use of the fuel element: a requirement for less uranium in the fuel and the use of the fuel elements during a longer period in the reactor.

Abstract: One object of the present invention is to provide a production method for a nuclear fuel assembly support grid that improves the corrosion resistance of welded parts without impairing the characteristics of the support grid so as to be able adequately withstand highly efficient operation. In order to achieve the object, the present invention provide a production method for a nuclear fuel assembly support grid comprising the steps of: assembling a plurality of straps in a grid form; welding intersections of each strap; and carrying out annealing thereafter to precipitate an intermetallic compound on the welded parts.

Abstract: The present invention relates to a zirconium alloy having excellent corrosion resistance and mechanical properties and a method for preparing a nuclear fuel cladding tube by zirconium alloy. More particulary, the present invention is directed to a zirconium alloy comprising Zr-aNb-bSn-cFe-dCr-eCu (a=0.05-0.4 wt %, b=0.3-0.7 wt %, c=0.1-0.4 wt %, d=0-0.2 wt % and e=0.01-0.2 wt %, provided that Nb+Sn=0.35-1.0 wt %), and to a method for preparing a zirconium alloy nuclear fuel cladding tube, comprising melting a metal mixture comprising of the zirconium and alloying elements to obtain ingot, forging the ingot at &bgr; phase range, &bgr;-quenching the forged ingot at 1015-1075° C., hot-working the quenched ingot at 600-650° C., cold-working the hot-worked ingot in three to five passes, with intermediate vacuum annealing and final vacuum annealing the worked ingot at 460-540° C.

Abstract: The method of determining the extent to which a nickel structure has been attacked by a halogen containing gas to which it has been exposed which comprises preparing a quantity of water substantially free from dissolved oxygen, passing ammonia gas through a cuprammonium solution to produce ammonia substantially free from oxygen, dissolving said oxygen-free ammonia in said water to produce a saturated aqueous ammonia solution free from uncombined oxygen, treating at least a portion of said nickel structure of predetermined weight with said solution to dissolve nickel compounds from the surface of said structure without dissolving an appreciable amount of said nickel and analyzing the resulting solution to determine the quantity of said nickel compounds that was associated with said said portion of said structure to determine the proportion of combined nickel in said nickel structure.

Abstract: A fuel assembly for a pressurized-water reactor includes fuel rods held in cells of spacers, control rod guide tubes, and a headpiece and a foot piece, by which it is fixed to upper and lower core grids, respectively. A spacer having a first part, which lies on a radially outer side with respect to a longitudinal center axis of the fuel assembly, and a second part, which lies on a radially inner side and is completely surrounded by the first part are included to reduce the size of gaps between fuel assemblies. The second part is formed of Zircaloy. The first part is made of a metallic material, and when compared to the Zircaloy of the second part, has a lower growth in the radial direction, caused by neutron radiation and a higher coefficient of thermal expansion.

Abstract: The rod contains substantially cylindrical oxide nuclear fuel pellets based on enriched uranium oxide. The H/D ratio of the height over the diameter of the pellets lies in the range 0.4 to 0.6. The initial diametral clearance between the pellets and the cladding does not exceed 200 &mgr;m.

Abstract: This disclosure describes a method for metallurgically bonding a complete leak-tight enclosure to a matrix-type fuel element penetrated longitudinally by a multiplicity of coolant channels. Coolant tubes containing solid filler pins are disposed in the coolant channels. A leak-tight metal enclosure is then formed about the entire assembly of fuel matrix, coolant tubes and pins. The completely enclosed and sealed assembly is exposed to a high temperature and pressure gas environment to effect a metallurgical bond between all contacting surfaces therein. The ends of the assembly are then machined away to expose the pin ends which are chemically leached from the coolant tubes to leave the coolant tubes with internal coolant passageways. The invention described herein was made in the course of, or under, a contract with the U.S. Atomic Energy Commission.

Abstract: A nuclear fuel assembly includes a fuel bundle resting on a lower tie plate. The lower tie plate includes a grid having raised bosses disposed in a rectilinear array for receiving the end plugs of the fuel rods and webs interconnecting the bosses. Between the raised bosses and the end plugs, there is disposed a filter plate having holes registering with the holes through the bosses for receiving the end plugs and apertures providing an approximate 40% open area through the filter plate. The webs of the tie plate grid are recessed from the upper edges of the bosses, facilitating flow through the apertures of the filter plate.

Abstract: A method for production of a nuclear fuel element with oxide base, in which the nuclear fuel with oxide base is mixed with Cr and sintered to a solid body. The amount of chrome oxide added is =>50 and <100 ppm with respect to the amount of nuclear fuel with oxide base added.

Abstract: A MOX nuclear fuel assembly employable either for a thermal neutron reactor employing UO2 as the nuclear fuel and light water as the moderator/coolant or for a thermal neutron reactor employing the MOX fuels as the nuclear fuel and light water as the moderator/coolant is provided with only one kind of MOX nuclear fuel rods each of which has relatively large magnitude of the enrichment grade of the fissionable Pu-s or Pu239 and Pu241, the quantity of the MOX nuclear fuel rods being relatively small.

Abstract: A fuel channel box manufacturing method processes a fuel channel box of a zirconium-base alloy by a beta-quench treatment that heats the fuel channel box by a heating coil. The distance between the heating coil and the opposite walls of the fuel channel box is controlled so that temperature differences between the opposite walls of the fuel channel box are reduced. The fuel channel box of a zirconium-base alloy is heated at a temperature in a temperature range including &bgr;-phase temperatures so that temperature difference between the opposite walls is 50° C. or below. The fuel channel box manufacturing method is capable of manufacturing a fuel channel box that is not subject to significant irradiated bow even if a deflection is produced therein originally when the same is manufactured and of manufacturing the fuel channel box at a high production efficiency.

Abstract: Disclosed is a method for manufacturing a tube and a sheet of niobium-containing zirconium alloys for the high burn-up nuclear fuel. The method comprises melting Nb-added zirconium alloy to ingot; forging the ingot at &bgr; phase range; &bgr;-quenching the forged ingot after solution heat-treatment at 1015-1075° C.; hot-working the quenched ingot at 600-650° C.; cold-working the hot-worked ingot in three to five passes, with intermediate vacuum annealing; and final vacuum annealing the cold-worked ingot at 440-600° C., wherein temperatures of intermediate vacuum annealing and final vacuum annealing after &bgr;-quenching are changed so as to attain the condition under which precipitates in the alloy matrix are limited to an average diameter of 80 nm or smaller and the accumulated annealing parameter (&Sgr;A) is limited to 1.

Abstract: A nuclear fuel assembly skeleton having a top nozzle and a bottom nozzle (10) interconnected by guide tubes (16) designed to receive control cluster rods and each containing, at its bottom end, a tubular cartridge (20), each of said tubes being provided with a bottom plug (22) that bears against the bottom nozzle (10) and that is pierced by a hole for passing a fixing screw (26). The cartridge (20) includes a bottom plug (28) bearing against the guidetube plug (22) and in that the facing faces of the two plugs (22, 28) present axial projections that co-operate with one another to lock the two plugs against relative rotation once said screw (26) has been screwed into a tapped hole (32) in the cartridge plug (28).

Abstract: A fuel channel box manufacturing method processes a fuel channel box of a zirconium-base alloy by a beta-quench treatment that heats the fuel channel box by a heating coil. The distance between the heating coil and the opposite walls of the fuel channel box is controlled so that temperature differences between the opposite walls of the fuel channel box are reduced. The fuel channel box of a zirconium-base alloy is heated at a temperature in a temperature range including P-phase temperatures so that temperature difference between the opposite walls is 50° C. or below. The fuel channel box manufacturing method is capable of manufacturing a fuel channel box that is not subject to significant irradiated bow even if a deflection is produced therein originally when the same is manufactured and of manufacturing the fuel channel box at a high production efficiency.

Abstract: An apparatus for succesively loading solid objects (19) into a tube (27), for instance, nuclear fuel pellets into a nuclear fuel tube, includes means (17) for feeding the objects towards one, open end (29) of the tube. A reduced pressure is induced between each solid object and the tube end prior to entry of the object into the tube.

Abstract: A nuclear reactor fuel assembly with a high burnup is provided. In order to increase the burnup potential of fuel assemblies, pellets with an impermissibly high level of enrichment are produced on production lines, which are constructed for processing large quantities of normally enriched fuel. The impermissible level of enrichment is compensated for by the fact that, as early as in a powder mixer at an entry to the production line, so much absorber material is mixed with the fuel that the reactivity of the poisoned mixture does not exceed the reactivity of an unpoisoned fuel mixture with a normal level of enrichment. Corresponding fuel assemblies then contain relatively large quantities of these poisoned pellets (or only such poisioned pellets), which can be produced in large numbers (and therefore economically) by using conventional plants.

Abstract: A sintered nuclear fuel body includes (U, Pu)O2 mixed crystals having a mean particle size in a range from 7.5 &mgr;m to 50 &mgr;m. This sintered nuclear fuel body has a high retention capacity for fission gas in a power reactor. In order to produce the sintered nuclear fuel body by sintering a body in a hydrogen-containing sintering atmosphere, a powered substance selected from the group consisting of aluminum oxide, titanium oxide, niobium oxide, chromium oxide, aluminum stearate, aluminum distearate and aluminum tristearate is added to the starting powder for the body. As an alternative or in addition, the body made from the starting powder is sintered during a holding period of 10 minutes to 8 hours at a sintering temperature of 1400° C. to 1800° C.

Abstract: A method for providing a leak-tight metal enclosure to a fuel matrix penetrated by coolant channels, wherein the mutually contacting surfaces of said metal enclosure and said fuel matrix are metallurgically bonded, comprising placing a metal cladding about the lateral surface of said fuel matrix; disposing metal coolant tubes within said coolant channels; placing a perforated header plate having tubular extensions at each end of the fuel matrix from which the coolant tube ends protrude, said coolant tubes passing through said perforated header plate and said tubular extensions and terminating even with the ends of said extensions; welding, under vacuum, said cladding to said header plates, and the ends of said coolant tubes to the ends of said tubular extensions; exposing the assembly comprising the fuel matrix and enclosure to a gas at high temperature and pressure; and machining said header plates to provide a finished fuel element.

Abstract: A corrosion and hydride resistant nuclear fuel rod having a highly corrosion resistant outer portion in which hydride precipitation is inhibited and an inner portion in which hydride precipitation is promoted.