Abstract: Methods and systems for stabilizing spent fuel assemblies from sodium-cooled nuclear reactors using Zamak are described herein. It has been determined that there is a synergism between Zamak and sodium that allows Zamak to form thermally-conductive interface with the sodium-wetted surfaces of the fuel assemblies. In the method, one or more spent fuel assemblies are removed from the sodium coolant pool and placed in a protective sheath. The remaining volume of the sheath is then filled with liquid Zamak. To a certain extent Zamak will dissolve and alloy with sodium remaining on the fuel assemblies. Excess sodium that remains undissolved is displaced from the sheath by the Zamak fill. The Zamak is then cooled until solid and the sheath sealed. The resulting Zamak-stabilized spent fuel assembly is calculated to have sufficient internal thermal conductivity to allow it to be stored and transported without the need for liquid cooling.

Abstract: A nuclear reactor is constructed in sub-modules and super modules which are manufactured, packaged, and shipped to a construction site. At least some of the modules are packaged in suitable shielding containers or portions of containers, which may be steel. The modules are assembled on-site, and some of the modules remain within their respective shipping containers after assembly. One or more of the shipping containers may be used as concrete forms to support the pouring of concrete in between selected modules. The concrete may be used for structural support, shielding, or both.

Abstract: Methods and systems for stabilizing spent fuel assemblies from sodium-cooled nuclear reactors using Zamak are described herein. It has been determined that there is a synergism between Zamak and sodium that allows Zamak to form thermally-conductive interface with the sodium-wetted surfaces of the fuel assemblies. In the method, one or more spent fuel assemblies are removed from the sodium coolant pool and placed in a protective sheath. The remaining volume of the sheath is then filled with liquid Zamak. To a certain extent Zamak will dissolve and alloy with sodium remaining on the fuel assemblies. Excess sodium that remains undissolved is displaced from the sheath by the Zamak fill. The Zamak is then cooled until solid and the sheath sealed. The resulting Zamak-stabilized spent fuel assembly is calculated to have sufficient internal thermal conductivity to allow it to be stored and transported without the need for liquid cooling.

Abstract: A nuclear reactor includes a heat exchanger that transfers thermal energy from a primary reactor coolant to a secondary coolant. The heat exchanger is a compact plate heat exchanger and more than one heat exchanger may be spaced about the reactor vessel. A plurality of heat exchangers may be spaced vertically, radially, and/or circumferentially about the reactor vessel. A first heat exchanger may be in fluid communication with a second heat exchanger. Two or more heat exchangers may share a thermal load and therefore share thermal stresses. The heat exchanger may have a third fluid flow path and a third fluid. The third fluid may be used to remove fission products, be used for leak detection, create an oxidation layer to inhibit migration of activation products, and/or provide additional heat transfer.

Abstract: A nuclear reactor is constructed in sub-modules and super modules which are manufactured, packaged, and shipped to a construction site. At least some of the modules are packaged in suitable shielding containers or portions of containers, which may be steel. The modules are assembled on-site, and some of the modules remain within their respective shipping containers after assembly. One or more of the shipping containers may be used as concrete forms to support the pouring of concrete in between selected modules. The concrete may be used for structural support, shielding, or both.

Abstract: A nuclear reactor is designed to allow efficient packing of components within the reactor vessel, such as by offsetting the core, and/or vertically stacking components. The in-vessel storage system can be separate from the support cylinder and these components can be fabricated and shipped separately and coupled together at the construction site. Furthermore, the in-vessel storage system can be located adjacent to the core rather than being located circumferentially around it, and may also be located beneath the heat exchanger to further improve packing of components within the vessel. Through these, and other changes, the delicate components can be manufactured in a manufacturing facility, assembled, and shipped by commercial transportation options without exceeding the shipping envelope.

Abstract: This disclosure describes various configurations and components of a molten fuel fast or thermal nuclear reactor in which one or more primary heat exchangers are located above the reactor core of the nuclear reactor.

Abstract: An integrated energy system includes a nuclear thermal plant situated on a nuclear site. The nuclear thermal plant produces thermal energy that is transported to a thermal energy storage system located outside the nuclear site. The thermal storage system is thermally coupled to a power generation system which is also remote to the nuclear site. By this arrangement, the nuclear thermal plant is isolated and decoupled from the power generation system. The nuclear thermal plant may supply thermal energy upwards of 800° C. or more to be stored at the thermal energy storage system until needed such as for industrial heat, power generation, or other uses. The thermal storage system is source agnostic, and one or more additional thermal energy generators, such as additional nuclear reactors, solar thermal plants, or other thermal energy generators can be coupled to a common thermal storage system and power generation system.

Abstract: This disclosure describes various configurations and components of a molten fuel fast or thermal nuclear reactor in which one or more primary heat exchangers are located above the reactor core of the nuclear reactor.

Abstract: This disclosure describes various configurations and components of a molten fuel fast or thermal nuclear reactor in which one or more primary heat exchangers are located above the reactor core of the nuclear reactor.

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: This disclosure describes various configurations and components of a molten fuel fast or thermal nuclear reactor in which one or more primary heat exchangers are located above the reactor core of the nuclear reactor.

Abstract: A duct for a nuclear fuel assembly includes a tubular body and an elongated member. The tubular body has a sidewall with an inner face and an outer face and is configured to contain nuclear fuel within a fuel region. The elongated member extends from the outer face along at least a portion of the fuel region and has a contact surface configured to stabilize the duct during operation of the nuclear fuel assembly.

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: A duct for a nuclear fuel assembly includes a tubular body and an elongated member. The tubular body has a sidewall with an inner face and an outer face and is configured to contain nuclear fuel within a fuel region. The elongated member extends from the outer face along at least a portion of the fuel region and has a contact surface configured to stabilize the duct during operation of the nuclear fuel assembly.