A methodology is disclosed for compaction of a ceramic matrix of certain nuclear fuels incorporating neutron poisons, whereby those poisons aid in reactor control while aiding in fuel fabrication. Neutronic poisons are rare-earth oxides that readily form eutectics suppressing fuel fabrication temperature, of particular importance to the fully ceramic microencapsulated fuel form and fuel forms with volatile species.

Disclosed is a nuclear fuel rod including at least one or more fuel pellets, a cladding tube surrounding the fuel pellets, and burnable absorber inside the cladding tube. The burnable absorber comprises a burnable absorber material and a cladding material surrounding the burnable absorber material. The burnable absorber has a disk shape, and the cladding material is an alloy comprising zirconium.

The present invention relates to a sintered nuclear fuel pellet wherein one or more consolidated bodies of a burnable absorber are inserted inside, wherein the one or more consolidated bodies of the burnable absorber do not include nuclear fuel which includes UO.sub.2, and the one or more consolidated bodies of the burnable absorber are inserted into a radially central region of the sintered nuclear fuel pellet, such that the one or more consolidated bodies are surrounded by the nuclear fuel pellet without being exposed to an outside of the sintered nuclear fuel pellet. The present invention can optimize the regulation of excess reactivity by optimizing the self-shielding and the burning speed of the burnable absorber using one or more consolidated bodies the burnable absorber.

Provided is a nuclear-fuel sintered pellet based on oxide in which a plate-type fine precipitate material in a base of a sintered pellet of uranium dioxide, used as nuclear fuel in nuclear power plants, is uniformly dispersed in a matrix of uranium dioxide fuel thereof so as to form a donut-shaped precipitate cluster, and to a method of manufacturing the same. The plate-type fine precipitate material is uniformly precipitated in a tissue thereof or forms a donut-shaped precipitate cluster having a two-dimensional structure through dispersion to improve thermal and physical performance of the nuclear-fuel sintered pellet of uranium dioxide, whereby the creep deformation rate and thermal conductivity of the sintered pellet are improved. The nuclear-fuel sintered pellet based on oxide can reduce the Pellet-Clad Interaction (PCI) failure and the core temperature of nuclear fuel when an accident occurs, thereby significantly improving the safety of a nuclear reactor.

A method is described that includes the steps of making a thin walled Zr alloy tube, loading nuclear fuel pellets into the tube, compressing the tube onto the fuel pellets to substantially reduce free space around the fuel pellets, positioning end plugs at each of two ends of the tube, filling the tube with a heat transferring gas, and coating the compressed tube with a corrosion resistant material using a thermal deposition process, such as cold spray, before inserting the tube into a pre-formed SiC composite cover having at least one closed end.

A method for manufacturing a nuclear fuel compact is provided. The method includes forming an additive structure, consolidating a fuel matrix around the additive structure, and thermally processing the fuel matrix to form a fuel compact in which the additive structure is encapsulated therein. The additive structure optionally includes a vertical segment and a plurality of arm segments that extend generally radially from the vertical segment for conducting heat outwardly toward an exterior of the fuel compact. In addition to improving heat transfer, the additive structure may function as burnable absorbers, and may provide fission product trapping.

Disclosed is a nuclear fuel rod including at least one or more fuel pellets, a cladding tube surrounding the fuel pellets, and burnable absorber inside the cladding tube. The burnable absorber comprises a burnable absorber material and a cladding material surrounding the burnable absorber material. The burnable absorber has a disk shape, and the cladding material is an alloy comprising zirconium.

Fuel pellets and fuel pellet arrangements include thermally-conductive inserts within a fuel. The inserts have at least one portion of a thermally-conductive material, such as radially-extending fins. The inserts are configured to dissipate heat during use of the fuel pellets, while minimizing the amount of the total volume of the fuel pellet that is occupied by non-fissile material. The inclusion of heat-dissipating inserts enables the fuel pellets to exhibit improved thermal performance over the lifetime of the fuel, including a relatively low peak temperature and relatively low integrated average temperatures, while the minimal volume of the inserts avoids significantly decreasing the percent of enrichment achievable.

An optical counter is used in a method and system for producing a nuclear fuel element having a known volume of homogeneously distributed nuclear material. The method includes feeding nuclear fuel particles along a channel having a conveyer configured to transmit the nuclear fuel particles to an exit; driving the conveyer until a target number of nuclear fuel particles exits the channel through the exit; and counting a number of nuclear fuel particles which pass through the exit of the channel with an optical counter. The conveyer is stopped after the target number of nuclear fuel particles exits the channel. The target number of nuclear fuel particles are fed into a mold for shaping the nuclear fuel element, and void space remaining in the mold is filled with a particulate matrix material so as to homogeneously distribute the target number of nuclear fuel particles within the particulate matrix material. The particulate matrix material is then converted into a solid matrix material.

Embodiments of the invention are directed to a method for production of a nuclear fuel pellet by spark plasma sintering (SPS), wherein a fuel pellet with more than 80% TD or more than 90% TD is formed. The SPS can be performed with the imposition of a controlled uniaxial pressure applied at the maximum temperature of the processing to achieve a very high density, in excess of 95% TD, at temperatures of 850 to 1600 C. The formation of a fuel pellet can be carried out in one hour or less. In an embodiment of the invention, a nuclear fuel pellet comprises UO.sub.2 and a highly thermally conductive material, such as SiC or diamond.