Abstract: A uranium oxide fuel pellet having an inner region and an outer rim region about the inner region, and that the fuel pellet is cylindrical and the inner region and outer rim region are coaxial cylindrical regions. The outer rim region has an excess of oxygen in comparison to the inner region, wherein high burnup structure (HBS) formation will be suppressed or delayed. Preferably, the excess oxygen is obtained by a chemical treatment by immersing the pellet in hydrogen peroxide (H2O2) or potassium permanganate (KMnO4) in solution.

Abstract: A fuel assembly for a nuclear reactor, a fuel rod of the fuel assembly, and a ceramic nuclear fuel pellet of the fuel rod are disclosed. The fuel pellet includes a first fissile material of UB2, The boron of the UB2 is enriched to have a concentration of the isotope 11B that is higher than for natural B.

Abstract: A uranium oxide fuel pellet having an inner region and an outer rim region about the inner region, and that the fuel pellet is cylindrical and the inner region and outer rim region are coaxial cylindrical regions. The outer rim region has an excess of oxygen in comparison to the inner region , wherein high burnup structure (HBS) formation will be suppressed or delayed. Preferably, the excess oxygen is obtained by a chemical treatment by immersing the pellet in hydrogen peroxide (H2O2) or potassium permanganate (KMnO4) in solution.

Abstract: A fuel assembly for a nuclear reactor, a fuel rod of the fuel assembly, and a ceramic nuclear fuel pellet of the fuel rod are disclosed. The fuel pellet includes a first fissile material of UB2, The boron of the UB2 is enriched to have a concentration of the isotope 11B that is higher than for natural B.

Abstract: A tubular ceramic component is provided for being used in a nuclear reactor. The component comprises an inner layer of silicon carbide, an intermediate layer of silicon carbide fibres in a fill material of silicon carbide, and an outer layer of silicon carbide. The intermediate layer adjoins the inner layer. The outer layer adjoins the intermediate layer. The silicon carbide of the inner layer, the fill material and the outer layer is doped and comprises at least one dopant in solid solution within crystals of the silicon carbide.

Abstract: A cladding tube for a fuel rod to be used in a nuclear fission reactor, and a method of manufacturing the cladding tube are disclosed. The cladding tube encloses fissile nuclear fuel and comprises a tubular base layer of a zirconium based alloy, and a coating layer. The coating layer is applied onto an outer border of the tubular base layer. The coating layer is formed of an amorphous alloy comprising zirconium and a further element.

Abstract: The present invention relates to nuclear fuel compositions including uranium dioxide with integral fuel burnable absorber, and triuranium disilicide and a composite of uranium mononitride and triuranium disilicide with or without integral fuel burnable absorber, and methods of sintering these compositions. The sintering is conducted using SPS/FAST apparatus and techniques. The sintering time and temperature is reduced using SPS/FAST as compared to conventional sintering methods for nuclear fuel compositions. The nuclear fuel compositions of the present invention are particularly useful in light water reactors.

Abstract: Disclosed are a sintered nuclear fuel pellet, a fuel rod, a fuel assembly and a method of manufacturing the nuclear fuel pellet. The pellet comprises a matrix of UO2 and particles dispersed in the matrix. The particles comprises a uranium-containing material. Each of the particles is encapsulated by a metallic coating. The uranium-containing material has a uranium density that is higher than the uranium density of UO2. The metallic coating consists of at least one metal chosen from the group of Mo, W, Cr, V and Nb.

Abstract: A method of making a nuclear fuel pellet for a nuclear power reactor. The method includes: providing a nuclear fuel material in powder form, the nuclear material is based on UO2; providing an additive; forming a green pellet, wherein said additive is added either to said nuclear fuel material or to the green pellet; and sintering the green pellet, wherein said additive causes larger grains in the nuclear fuel pellet, and wherein said additive is made of or includes a substance which causes the larger grains and which substantially leaves at least an outer portion of the pellet before and/or during the sintering step, wherein said substance is made of, or comprises, B and/or Cr.

Abstract: A method of providing an end-capped tubular ceramic composite for containing nuclear fuel (34) in a nuclear reactor involves the steps of providing a tubular ceramic composite (40), providing at least one end plug (14, 46, 48), applying (42) the at least one end plug material to the ends of the tubular ceramic composite, applying electrodes to the end plug and tubular ceramic composite and applying current in a plasma sintering means (10, 50) to provide a hermetically sealed tube (52). The invention also provides a sealed tube made by this method.

Abstract: A method of making a nuclear fuel pellet for a nuclear power reactor. The method includes providing a nuclear fuel material in powder form, providing an additive, forming a so-called green pellet, wherein said additive is added either to said nuclear fuel material in powder form or to the green pellet, sintering the green pellet, wherein said additive is such that it causes larger grains in the nuclear fuel pellet, and wherein said additive is made of or includes a substance which causes the larger grains and which substantially leaves at least an outer portion of the pellet before and/or during the sintering step.

Abstract: A method of providing an end-capped tubular ceramic composite for containing nuclear fuel (34) in a nuclear reactor involves the steps of providing a tubular ceramic composite (40), providing at least one end plug (14, 46, 48), applying (42) the at least one end plug material to the ends of the tubular ceramic composite, applying electrodes to the end plug and tubular ceramic composite and applying current in a plasma sintering means (10, 50) to provide a hermetically sealed tube (52). The invention also provides a sealed tube made by this method.

Abstract: A control rod for a nuclear boiling water reactor is described. The control rod has a longitudinal centre axis and control rod blades, each control rod blade having a first and a second side and being substantially parallel to the longitudinal center axis. Each control rod blade comprises an absorber material which extends from a first absorber end to a second absorber end, the distance between the first absorber end and the second absorber end defining an active length. The control rod blades are provided with distance means on the first and second sides of the control rod blades, the distance means extending a distance of at least a third of the active length of the control rod blade.

Abstract: A method of providing an end-capped tubular ceramic composite for containing nuclear fuel (34) in a nuclear reactor involves the steps of providing a tubular ceramic composite (40), providing at least one end plug (14, 46, 48), applying (42) the at least one end plug material to the ends of the tubular ceramic composite, applying electrodes to the end plug and tubular ceramic composite and applying current in a plasma sintering means (10, 50) to provide a hermetically sealed tube (52). The invention also provides a sealed tube made by this method.

Abstract: The invention concerns a control rod configured for a nuclear power light water reactor of the BWR or PWR kind. The control rod contains absorber material. At least 50%, with respect to weight, of the absorber material that is in the control rod is in the form of hafnium hydride. The invention also concerns the use of such a control rod during operation in a nuclear power light water reactor of the BWR or PWR kind.

Abstract: A fuel assembly for a nuclear boiling water reactor is provided. The reactor comprises a plurality of such fuel assemblies and a plurality of control rods. Each control rod is insertable between the fuel assemblies. The fuel assembly has a longitudinal center axis and includes a plurality of elongated fuel rods and an elongated channel box. The channel box has inner sides, facing the fuel rods, and outer sides. Each inner and outer side has a longitudinal center line extending in parallel with the center axis and along the length of the channel box. A number of protrusions are distributed along the center line of at least two of the outer sides. The protrusions are configured to ensure a minimum distance between the outer side and an adjacent control rod and to enable the control rod to easily slide over and on top of the protrusions.

Abstract: A method of providing an end-capped tubular ceramic composite for containing nuclear fuel (34) in a nuclear reactor involves the steps of providing a tubular ceramic composite (40), providing at least one end plug (14, 46, 48), applying (42) the at least one end plug material to the ends of the tubular ceramic composite, applying electrodes to the end plug and tubular ceramic composite and applying current in a plasma sintering means (10, 50) to provide a hermetically sealed tube (52). The invention also provides a sealed tube made by this method.

Abstract: The invention relates to a final, ready to use, spacer grid for a nuclear boiling water reactor. The final spacer grid comprises: i) a spacer grid structure made of an alloy that has been formed and assembled such that it constitutes a spacer grid, and ii) an outer oxide coating on the surface of the spacer grid structure. Said alloy is a Ni base alloy that consists of the following: (table) The invention also relates to a method of manufacturing the final spacer grid according to the invention.

Abstract: The invention relates to a fuel component and a method for manufacturing of a fuel component. The fuel component is adapted to be used in fission reactors. The fuel component comprises a core consisting of a first material, and a layer consisting of a second material. The layer encloses at least partly the core. The first material comprises a fissile substance. The fuel component comprises an intermediate layer between the core and the layer. The intermediate layer has a material gradient that comprises a decrease of the concentration of the first material from the core to the layer and an increase of the concentration of the second material from the core to the layer.

Abstract: The invention regards a neutron absorbing component (1) and a method for manufacturing a neutron absorbing component. The neutron absorbing component comprises a core (2) consisting of a first material, a layer (3) consisting of a second material. The layer encloses a least partly the core and is adapted to protect the core from an outer surrounding. The first material has a higher neutron absorption capability than the second material. The neutron absorbing component is manufactured by sintering in such a way that an intermediate layer (4) is formed between the core and the layer. The intermediate layer has a material gradient that comprises a decrease of the concentration of the first material from the core to the layer and an increase of the concentration of the second material from core to the layer.