Abstract: It is an object of the present invention to provide a method for producing an electrode for an electrochemical element, which can easily adjust a capacity and can produce the electrochemical element at low cost. The method for producing an electrode for an electrochemical element of the present invention includes a thickness adjustment step of compressing an aluminum porous body having continuous pores to adjust the thickness of the aluminum porous body to a predetermined thickness, and a filling step of filling the aluminum porous body, the thickness of which is adjusted, with an active material.

Abstract: A device for supporting nuclear fuel plates (4) with a longitudinal axis (X) including a bottom (6) forming a lower longitudinal end of the supporting device and a lid (8) forming an upper longitudinal end of the supporting device, the bottom (6) and the lid (8) being rigidly connected to each other through a central connecting means and peripheral connecting means, a plurality of upper means (18) for supporting the plates (4) attached to the lid (8), and a plurality of lower means (16) for supporting the plates (4) attached to the bottom (6), ensuring elastic support of the longitudinal ends of the plates (4) in a direction of the width (R) of the plate (4) and allowing free deformation of said longitudinal ends in the direction of the thickness (T) of the plate.

Abstract: A neutron absorbing insert for use in a fuel rack and method of manufacturing the same. In ones aspect, the invention is a neutron absorbing apparatus for insertion into a fuel rack comprising: a sleeve having a first wall and a second wall, the first and second walls forming a chevron shape; and the first and second wall being a single panel of a metal matrix composite having neutron absorbing particulate reinforcement bent into the chevron shape along a crease.

Abstract: A new nuclear fuel element has been developed to be used in particular in fourth generation gaseous heat exchanger reactors working with a fast neutron flow. With a composite plate structure, the element (1) according to the invention comprises a network of cells (8), more preferably of honeycomb shape, in each of which is placed a nuclear fuel pellet (10). Radial and axial gaps are provided in each cell (8) to compensate for the differential expansion between fissile materials and structural materials inherent in the operation of the plate (1).

Abstract: Disclosed is a breeding nuclear fuel mixture including metallic thorium useable in a nuclear power plant, prepared by mixing uranium dioxide (UO2) or plutonium dioxide (PuO2) having ceramic properties with metallic thorium (Th), in order to enable thorium breeding by neutrons released during nuclear fission of U or Pu and conversion of the bred thorium into a novel nuclear fissile material, i.e., U-233, thereby ensuring continuous nuclear fission. The foregoing nuclear fuel mixture may be burned at a reactor core of a nuclear power plant through thorium breeding over a long period of time. Therefore, when the inventive breeding nuclear fuel mixture is employed in a nuclear power plant, utilization of the nuclear power plant may be increased while maximizing conservation of limited uranium resources.

Abstract: A device for supporting nuclear fuel plates (4) with a longitudinal axis (X) including a bottom (6) forming a lower longitudinal end of the supporting device and a lid (8) forming an upper longitudinal end of the supporting device, the bottom (6) and the lid (8) being rigidly connected to each other through a central connecting means and peripheral connecting means, a plurality of upper means (18) for supporting the plates (4) attached to the lid (8), and a plurality of lower means (16) for supporting the plates (4) attached to the bottom (6), ensuring elastic support of the longitudinal ends of the plates (4) in a direction of the width (R) of the plate (4) and allowing free deformation of said longitudinal ends in the direction of the thickness (T) of the plate.

Abstract: A new nuclear fuel element has been developed to be used in particular in fourth generation gaseous heat exchanger reactors working with a fast neutron flow. With a composite plate structure, the element (1) according to the invention comprises a network of cells (8), more preferably of honeycomb shape, in each of which is placed a nuclear fuel pellet (10). Radial and axial gaps are provided in each cell (8) to compensate for the differential expansion between fissile materials and structural materials inherent in the operation of the plate (1).

Abstract: A lips-type multi-purposed spacer grid for supporting fuel rods within a nuclear fuel assembly is disclosed. In the spacer grid, the fuel rods are in contact with dimples and water strider-type springs in an equiangular surface contact manner. The spacer grid distributes load, applied to the springs, to the entire structure of its inner strips, thus reducing peak stress at the contact surfaces between the fuel rods and the springs and diminishing vibration of the fuel rods, and thereby reducing possible fretting wear of the fuel rods due to hydraulic vibration of the fuel rods. The spacer grid also enlarges the allowable elastic range of the springs, and allows the springs to soundly support the fuel rods by using residual spring force. The spacer grid has mixing blades capable of minimizing pressure loss and flow interference, so that the fuel rod cooling efficiency of the nuclear fuel assembly is improved.

Abstract: A single piece fuel element and fast spectrum boiling water reactor using such a single piece fuel element. The single piece fuel element is formed from coated fissile particles embedded in a matrix made from a material such as SiC that is inert to all fissile and fertile heavy nuclei and to the coolant fluid circulating in and around this element. Furthermore, the fuel element includes parallel plates delimiting spaces between them. A ratio between the thickness of the plates and the width of the spaces is set so that the fuel element can be put in fast spectrum or thermal spectrum at will. An application of the single piece fuel element to a fast spectrum boiling water nuclear reactor operating with natural circulation in which the above mentioned ratio is approximately equal to 1 enables a high consumption of plutonium.

Abstract: In order to provide a boiling water type nuclear reactor use control rod with a guide use roller which improves corrosive environment at a clearance in the guide use roller and suppresses a generation of stress corrosion cracking while maintaining sliding function of the control rod by the guide use roller, at least one of a handle 5, a lower portion supporting plate 2a and a dropping speed limiter 2 is provided with the guide use roller, and a space which causes water flow in a clearance between a pin 9 and a pin hole 12 in the guide use roller is provided adjacent the clearance.

Abstract: Two embodiments of a high uranium fuel plate are disclosed which contain a meat comprising structured uranium compound confined between a pair of diffusion bonded ductile metal cladding plates uniformly covering the meat, the meat having a uniform high fuel loading comprising a content of uranium compound greater than about 45 Vol. % at a porosity not greater than about 10 Vol. %. In a first embodiment, the meat is a plurality of parallel wires of uranium compound. In a second embodiment, the meat is a dispersion compact containing uranium compound. The fuel plates are fabricated by a hot isostatic pressing process.

Abstract: A BWR fuel assembly has a hybrid fuel design composed of both rod-type fuel and plate-type fuel. An outer hollow tubular flow channel of the assembly surrounds the rod-type fuel being provided in the form of a plurality of fuel rods so as to direct flow of coolant/moderator fluid therealong. The assembly also includes a hollow central water cross extending through the channel and composed of radially extending panels dividing the fuel rods into separate fuel rod mini-bundles. The plate-type fuel is attached on the exterior of the water cross panels. This hybrid fuel design substantially avoids PCI constraints and failures.

Abstract: A flat or curved plate structure, to be used as fuel in a nuclear reactor, comprises elongated fissionable wires or strips embedded in a metallic continuous non-fissionable matrix plate. The wires or strips are made predominantly of a malleable uranium alloy, such as uranium silicide, uranium gallide or uranium germanide. The matrix plate is made predominantly of aluminum or an aluminum alloy. The wires or strips are located in a single row at the midsurface of the plate, parallel with one another and with the length dimension of the plate. The wires or strips are separated from each other, and from the surface of the plate, by sufficient thicknesses of matrix material, to provide structural integrity and effective fission product retention, under neutron irradiation. This construction makes it safely feasible to provide a high uranium density, so that the uranium enrichment with uranium 235 may be reduced below about 20%, to deter the reprocessing of the uranium for use in nuclear weapons.

Abstract: A plate-shaped high power nuclear fuel element containing low enrichment uranium (5 to 20 percent by weight uranium.sup.235 in the uranium component) as fissionable material, the fuel element essentially comprising a UAl.sub.4 plate provided with an aluminum sheath or a sheath of an Al alloy and impurities inherent in the manufacturing process. A process for producing such a UAl.sub.4 plate comprises (a) intimately mixing a powder of low enrichment uranium or uranium compound U.sub.6 Fe (5 to 20 percent by weight U.sup.235) having a particle size in the range from 0.1.mu. to 90.mu. with aluminum powder having a particle size in the range from 0.1.mu. to 100.mu. in a weight ratio range of uranium to aluminum between 1.1 U:1 Al and 2.

Abstract: This invention teaches an encapsulated fuel unit for a nuclear reactor, such as for an enriched uranium fuel plate of thin cross section of the order of 1/64 or 1/8 of an inch and otherwise of rectangular shape 1-2 inches wide and 2-4 inches long. The case is formed from (a) two similar channel-shaped half sections extended lengthwise of the elongated plate and having side edges butted and welded together to define an open ended tube-like structure and from (b) porous end caps welded across the open ends of the tube-like structure. The half sections are preferably of stainless steel between 0.002 and 0.01 of an inch thick, and are beam welded together over and within machined and hardened tool steel chill blocks. The porous end caps preferably are of T-316-L stainless steel having pores of approximately 3-10 microns size.

Abstract: For the production of plate shaped fuel elements for material testing and research reactors with highly enriched uranium recently there has been needed U.sub.3 O.sub.8 fuels which have a high density, high strength and a small open porosity. Such fuels are obtained if U.sub.3 O.sub.8 powder produced in known manner is first compressed mechanically to molded bodies of any shape, then processed to a granulate having a size of fuel grains below 200.mu. and subsequently sintered to high density particles, preferably at 1370.degree..+-.50.degree. C.

Abstract: An elongated absorber plate, which is stationarily mounted in a gap between two fuel assemblies in a reactor core, comprises a plurality of absorber channels which are filled with a burnable absorber material. The channels (5b) are formed by welding to each other two confronting sheet elements (2b, 3b), of which at least one is corrugated.

Abstract: A fuel element for a high temperature gas cooled nuclear reactor which aims at reducing the temperature difference between the fuel center and the coolant has a reduced thickness of heat transfer path and means for eliminating discontinuities therein. The fuel element has flat plates each having a inner fuel bearing sheet of coated nuclear fuel particles dispersed in a carbonaceous matrix material clad by preformed relatively thin artefacts of unfuelled carbonaceous material which have been platen pressed on to the external surfaces of the fuel sheet while both the fuel sheet and the artefacts are in the green state.