Abstract: This disclosure describes various configurations and components for bimetallic and trimetallic claddings for use as a wall element separating nuclear material from an external environment. The cladding materials are suitable for use as cladding for nuclear fuel elements, particularly for fuel elements that will be exposed to sodium or other coolants or environments with a propensity to react with the nuclear fuel.

Abstract: This disclosure describes fuel-cladding chemical interaction (FCCI) resistant nuclear fuel elements and their manufacturing techniques. The nuclear fuel elements include two or more layers of different materials (i.e., adjacent barriers are of different base materials) provided on a steel cladding to reduce the effects of FCCI between the cladding and the nuclear material. Depending on the embodiment, a layer may be the structural element (i.e., a layer thick enough to provide more than 50% of the strength of the overall component consisting of the cladding and the barriers) or may be more appropriately described as a liner or coating that is applied in some fashion to a surface of the structural component (e.g., to the cladding, or to a structural form of the fuel).

Abstract: A computerized system for modeling reactor fuel element and fuel design to determine the thermo-mechanical performance thereof includes a processor coupled to memory, the memory configuring the processor to execute a fuel element analysis and an output configured to communicate data that describes the thermo-mechanical performance of the fuel element and fuel design based on the fuel element performance analysis. The processor is configured to estimate the mechanical behavior of a fuel by creating separate variables for the open and closed porosity components, conducting a routine for the open and closed porosity components that processes the current state of the fuel and updates the current state and forces of each of the open and closed porosity components, and combining the updates for the current state and forces according to a weighting; and estimate the creep and swelling behavior of a cladding.

Abstract: Disclosed embodiments include fuel assemblies, fuel element, cladding material, methods of making a fuel element, and methods of using same.

Abstract: The thermochemical conversion of biomass material to one or more reaction products includes generating thermal energy with at least one heat source, providing a volume of feedstock, providing a volume of supercritical fluid, transferring a portion of the generated thermal energy to the volume of supercritical fluid, transferring at least a portion of the generated thermal energy from the volume of supercritical fluid to the volume of feedstock, and performing a thermal decomposition process on the volume of feedstock with the thermal energy transferred from the volume of supercritical fluid to the volume of the feedstock in order to form at least one reaction product.

Abstract: Disclosed embodiments include nuclear fission reactors, nuclear fission fuel pins, methods of operating a nuclear fission reactor, methods of fueling a nuclear fission reactor, and methods of fabricating a nuclear fission fuel pin.

Abstract: Targetry coupled separation refers to enhancing the production of a predetermined radiation product through the selection of a target (including selection of the target material and the material's physical structure) and separation chemistry in order to optimize the recovery of the predetermined radiation product. This disclosure describes systems and methods for creating (through irradiation) and removing one or more desired radioisotopes from a target and further describes systems and methods that allow the same target to undergo multiple irradiations and separation operations without damage to the target. In contrast with the prior art that requires complete dissolution or destruction of a target before recovery of any irradiation products, the repeated reuse of the same physical target allowed by targetry coupled separation represents a significant increase in efficiency and decrease in cost over the prior art.

Abstract: Disclosed embodiments include fuel ducts, fuel assemblies, methods of making fuel ducts, methods of making a fuel assembly, and methods of using a fuel assembly.

Abstract: A gas-cooled pressure tube nuclear reactor is described that uses a room temperature and pressure gas as a primary coolant and a liquid moderator as a secondary coolant. The primary coolant, which may be maintained in a supercritical state, is circulated through fuel columns in a pool of the liquid moderator. The primary coolant removes the heat generated by fission from the nuclear fuel. The heated primary coolant is then passed to one or more turbines to generate power. The primary coolant is then repressurized by one or more compressors using some of the generated power from the turbines. Several modified Brayton cycle configurations are described that are uniquely suited to the operating conditions of the gas-cooled pressure tube reactor.

Abstract: This disclosure describes various configurations and components for bimetallic and trimetallic claddings for use as a wall element separating nuclear material from an external environment. The cladding materials are suitable for use as cladding for nuclear fuel elements, particularly for fuel elements that will be exposed to sodium or other coolants or environments with a propensity to react with the nuclear fuel.

Abstract: Examples of a flexible pyrolysis system are provided that include at least one reaction chamber capable of pyrolyzing a combination of coal in a supercritical carbon dioxide (CO2) atmosphere. The system includes a recuperating and condensing circuit that removes dissolved pyrolysis products from the supercritical CO2 atmosphere and then recovers CO2 for reuse in the reaction chamber. The recuperating and condensing circuit includes multiple stages of recuperators and collectors that can be independently controlled in order to selectively fractionate the pyrolysis products. In addition, the pyrolysis reaction may be controlled to alter the pyrolysis products generated.

Abstract: This disclosure describes systems and methods for using pyrolysis tail gas as the source for additional hydrogen to be used in the pyrolysis reaction. Tail gas is separated from the pyrolysis products and a portion of the tail gas is converted into formic acid (HCOOH). The formic acid is then injected into the pyrolysis reactor where it becomes the donor of two monohydrogen atoms and is ultimately converted into CO2 under reaction conditions. In this fashion, a closed loop pyrolysis hydrogen donor system may be created utilizing a generally non-toxic intermediary derived from the pyrolysis reaction products. This disclosure also describes using a ruthenium catalyst supported on particles of activated carbon to improve the yield of pyrolysis reactions.

Abstract: This disclosure describes methods for improving the performance and consistency of steels by closely controlling the initial homogenization of steel compositions prior to hot working. Experimental data is provided illustrating that the traditional austenitization techniques do not take into account diffusion of the various components within a steel composition and, as such, may not completely homogenize the steel composition. In the methods described in this disclosure, the initial step of austenitizing the steel ingot is altered to achieve a more homogenous distribution of the different components throughout the ingot. The improved method includes heating the steel composition to a temperature within the upper half of the pure austenitic phase temperature range and maintaining the steel composition at that temperature for a period of time determined based on the diffusivity in the austenitic phase of the steel composition of at least one constituent of the steel.

Abstract: This disclosure describes various configurations and components for bimetallic and trimetallic claddings for use as a wall element separating nuclear material from an external environment. The cladding materials are suitable for use as cladding for nuclear fuel elements, particularly for fuel elements that will be exposed to sodium or other coolants or environments with a propensity to react with the nuclear fuel.

Abstract: This disclosure describes various configurations and components for bimetallic and trimetallic claddings for use as a wall element separating nuclear material from an external environment. The cladding materials are suitable for use as cladding for nuclear fuel elements, particularly for fuel elements that will be exposed to sodium or other coolants or environments with a propensity to react with the nuclear fuel.

Abstract: Illustrative embodiments provide methods and systems for migrating fuel assemblies in a nuclear fission reactor, methods of operating a nuclear fission traveling wave reactor, methods of controlling a nuclear fission traveling wave reactor, systems for controlling a nuclear fission traveling wave reactor, computer software program products for controlling a nuclear fission traveling wave reactor, and nuclear fission traveling wave reactors with systems for migrating fuel assemblies.

Abstract: A cable management system has an outer rotating plug. An inner rotating plug is disposed off-center from and within the outer rotating plug. The inner rotating plug is rotatable independent of a rotation of the outer rotating plug. A tower extends from the inner rotating plug and has an arm pivotally connected to the tower which defines a cable guide.

Abstract: This disclosure describes various configurations and components of a molten fuel fast or thermal nuclear reactor for managing the operating temperature in the reactor core. The disclosure includes various configurations of direct reactor auxiliary cooling system (DRACS) heat exchangers and primary heat exchangers as well as descriptions of improved flow paths for nuclear fuel, primary coolant and DRACS coolant through the reactor components.

Abstract: A nuclear fuel includes a volume of a nuclear fuel material defined by a surface, the nuclear fuel material including a plurality of grains, some of the plurality of grains having a characteristic length along at least one dimension that is smaller than or equal to a selected distance, wherein the selected distance is suitable for maintaining adequate diffusion of a fission product from a grain interior to a grain boundary in some of the grains, the nuclear fuel material including a boundary network configured to transport the fission product from at least one grain boundary of some of the grains to the surface of the volume of the nuclear fuel material.

Abstract: Sodium-cesium detection systems and methods for the simultaneous detection of both sodium (Na) and cesium (Cs) in gas are provided. The detection systems include two non-identical ionization chambers each having an anode and a cathode that ionize Na and Cs in gas. Each ionization chamber generates a current proportional to the Na and Cs concentration and based on the current, Na concentration and Cs concentration in the gas is determined.