Pre-ceramic particle solutions can prepared by a Coordinated-PDC process, a Direct-PDC process or a Coordinated-Direct-PDC process. The pre-ceramic particle solution includes a polymer selected from the group consisting of (i) an organic polymer including a metal or metalloid cation, (ii) a first organometallic polymer and (iii) a second organometallic polymer including a metal or metalloid cation different from a metal in the second organometallic polymer, a plurality of particles selected from the group consisting of (a) a ceramic fuel particle and (b) a moderator particle, a dispersant, and a polymerization initiator. The pre-ceramic particle solution can be supplied to an additive manufacturing process, such as digital light projection, and made into a structure (which is pre-ceramic particle green body) that can then be debinded to form a polymer-derived ceramic sintered body. In some embodiments, the polymer-derived ceramic sintered body is a component or structure for fission reactors.

The present disclosure provides systems and methods for fast molten salt reactor fuel-salt preparation. In one implementation, the method may comprise providing fuel assemblies having fuel pellets, removing the fuel pellets and spent fuel constituents from the fuel assemblies, granulating the removed fuel pellets or process feed to a chlorination process, processing the granular spent fuel salt into chloride salt by ultimate reduction and chlorination of the uranium and associated fuel constituents chloride salt solution, enriching the granular spent fuel salt, chlorinating the enriched granular spent fuel salt to yield molten chloride salt fuel, analyzing, adjusting, and certifying the molten chloride salt fuel for end use in a molten salt reactor, pumping the molten chloride salt fuel and cooling the molten chloride salt fuel, and milling the solidified molten chloride salt fuel to predetermined specifications.

The present disclosure provides systems and methods for fast molten salt reactor fuel-salt preparation. In one implementation, the method may comprise providing fuel assemblies having fuel pellets, removing the fuel pellets and spent fuel constituents from the fuel assemblies, granulating the removed fuel pellets or process feed to a chlorination process, processing the granular spent fuel salt into chloride salt by ultimate reduction and chlorination of the uranium and associated fuel constituents chloride salt solution, enriching the granular spent fuel salt, chlorinating the enriched granular spent fuel salt to yield molten chloride salt fuel, analyzing, adjusting, and certifying the molten chloride salt fuel for end use in a molten salt reactor, pumping the molten chloride salt fuel and cooling the molten chloride salt fuel, and milling the solidified molten chloride salt fuel to predetermined specifications.

Nuclear fuel assemblies include fuel elements that are sintered or cast into billets and co-extruded into a spiral, multi-lobed shape. The fuel kernel may be a metal alloy of metal fuel material and a metal-non-fuel material, or ceramic fuel in a metal non-fuel matrix. The fuel elements may use more highly enriched fissile material while maintaining safe operating temperatures. Such fuel elements according to one or more embodiments may provide more power at a safer, lower temperature than possible with conventional uranium oxide fuel rods. The fuel assembly may also include a plurality of conventional UO2 fuel rods, which may help the fuel assembly to conform to the space requirements of conventional nuclear reactors.

Nuclear fuel assemblies include fuel elements that are sintered or cast into billets and co-extruded into a spiral, multi-lobed shape. The fuel kernel may be a metal alloy of metal fuel material and a metal-non-fuel material, or ceramic fuel in a metal non-fuel matrix. The fuel elements may use more highly enriched fissile material while maintaining safe operating temperatures. Such fuel elements according to one or more embodiments may provide more power at a safer, lower temperature than possible with conventional uranium oxide fuel rods. The fuel assembly may also include a plurality of conventional UO2 fuel rods, which may help the fuel assembly to conform to the space requirements of conventional nuclear reactors.

Systems and methods for manufacturing metal fuel are described. Methods for fabricating a metal-fuel-matrix cermet nuclear fuel may include crushed ceramic particles combined with metallic fast reactor fuel via bottom pour casting or injection casting, or a powdered metallurgical process. A maximum quantity of crushed ceramic particles added to the metallic fuel must not exceed that which would fail to yield a continuous matrix of metal fuel. After a short irradiation period, the microstructure of the fuel may be substantially identical to that of injection cast fuel, without crushed ceramic particles, irrespective of the fabrication process. Thus, the extensive existing database for injection cast fuel, without crushed ceramic particles, may be an excellent indicator of expected irradiation performance. Each of the processes may contribute to a solution of the spent nuclear fuel problem and may denature Pu239 during the process.

Systems and methods for manufacturing metal fuel are described. Methods for fabricating a metal-fuel-matrix cermet nuclear fuel may include crushed ceramic particles combined with metallic fast reactor fuel via bottom pour casting or injection casting, or a powdered metallurgical process. A maximum quantity of crushed ceramic particles added to the metallic fuel must not exceed that which would fail to yield a continuous matrix of metal fuel. After a short irradiation period, the microstructure of the fuel may be substantially identical to that of injection cast fuel, without crushed ceramic particles, irrespective of the fabrication process. Thus, the extensive existing database for injection cast fuel, without crushed ceramic particles, may be an excellent indicator of expected irradiation performance. Each of the processes may contribute to a solution of the spent nuclear fuel problem and may denature Pu239 during the process.

A system to determine position and/or heading may include a receiver including at least two antennas configured to be coupled to the vehicle and receive electromagnetic signals including at least one of microwaves or radio waves. The system may also include a navigation module configured to determine first and second locations associated with respective first and second transmitters that send respective first and second signals. The navigation module may also be configured to determine, based at least in part on the first signals, a first relative orientation of the receiver relative to the first transmitter, and determine, based at least in part on the second signals, a second relative orientation of the receiver relative to the second transmitter. The navigation module may also be configured to determine a position and/or heading of the vehicle based at least in part on the first and second relative orientations of the receiver.

Nuclear fuel assemblies include fuel elements that are sintered or cast into billets and co-extruded into a spiral, multi-lobed shape. The fuel kernel may be a metal alloy of metal fuel material and a metal-non-fuel material, or ceramic fuel in a metal non-fuel matrix. The fuel elements may use more highly enriched fissile material while maintaining safe operating temperatures. Such fuel elements according to one or more embodiments may provide more power at a safer, lower temperature than possible with conventional uranium oxide fuel rods. The fuel assembly may also include a plurality of conventional UO2 fuel rods, which may help the fuel assembly to conform to the space requirements of conventional nuclear reactors.

The invention relates to compositions and methods for coating a zirconium alloy cladding of a fuel element for a nuclear water reactor. The coating includes a first tier or layer and a second tier or layer. The first layer includes an elemental metal and the second layer is an oxidation-resistant layer that includes elemental chromium. The first layer serves as an intermediate layer between the zirconium alloy substrate and the second layer. This intermediate layer can be effective to improve adhesion of the second layer to the zirconium alloy substrate. The multilayer coating forms a protective layer which provides improved capability for the zirconium alloy cladding to withstand normal and accident conditions to which it is exposed in the nuclear reactor.