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: A fast neutron nuclear reactor contains a nuclear reactor core having an array of device locations. Some device locations in the nuclear reactor core contain fissile and fertile nuclear fuel assembly devices. One or more other device locations in the nuclear reactor core contain Doppler reactivity augmentation devices that amplify the negativity of the Doppler reactivity coefficient within the nuclear reactor core. In some implementations, a Doppler reactivity augmentation device can also reduce the coolant temperature coefficient within the nuclear reactor core. Accordingly, a Doppler reactivity augmentation device contributes to a more stable nuclear reactor core.

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: A fast neutron nuclear reactor contains a nuclear reactor core having an array of device locations. Some device locations in the nuclear reactor core contain fissile and fertile nuclear fuel assembly devices. One or more other device locations in the nuclear reactor core contain Doppler reactivity augmentation devices that amplify the negativity of the Doppler reactivity coefficient within the nuclear reactor core. In some implementations, a Doppler reactivity augmentation device can also reduce the coolant temperature coefficient within the nuclear reactor core. Accordingly, a Doppler reactivity augmentation device contributes to a more stable nuclear reactor core.

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

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 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: Annular metal fuel and fuel rods are described that have improved performance over uranium oxide fuel rods. The annular metal fuel can be made out of porous metal nuclear fuel and will generate more power and operate at a much lower temperature than uranium oxide fuel. The annular metal fuel rods may be used in traveling wave reactors and other fast reactors. Pressurized water reactors may also be retrofit with annular metal fuel rods to improve reactor performance.

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

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

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 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: This disclosure describes new high temperature, radiation-resistant, ferritic-martensitic steel compositions. The new steels generally contain 9.0-12.0 wt. % Cr, 0.001-1.0 wt. % Mn, 0.001-2.0 wt. % Mo, 0.001-2.5 wt. % W, and 0.1-0.3 wt. % C, with the balance being primarily Fe. More specifically, steels having from 10.0-12.0 wt. % Cr are considered particularly advantageous. Small amounts of N, Nb, V, Ta, Ti, Zr, and B may or may not also be present, depending on the particular embodiment. Impurities may be present in any embodiment, in particular impurities of less than 0.01 wt. % S, less than 0.04 wt. % P, less than 0.04 wt. % Cu, less than 0.05 wt. % Co, and less than 0.03 wt. % As are contemplated. Examples of these steels exhibit improved fracture toughness and reduced thermal creep and swelling.

Abstract: An end cap for a nuclear fuel rod and methods of welding the end cap to a cladding tube, particularly an HT9 end cap to an HT9 cladding tube, such as by resistance pressure welding or pressure resistance welding. The end cap includes an annular shoulder and an angled recess. Also provided are welding techniques and techniques for classifying fuel rod welds.