TerraPower, LLC

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.

Sodium-tin and sodium-tin-lead compositions have been identified and created that exhibit better reactivity characteristics (i.e., are less reactive) than sodium metal under the same conditions, making these compositions safer alternatives to sodium metal for use as a coolant. These compositions include compositions having at least 90% sodium (Na), from 0-10% lead (Pb) and the balance being tin (Sn).

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.

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.

A vaporizer includes an outer tube configured to receive a flow of heated gas and an inner tube disposed at least partially within the outer tube. The inner tube is spaced apart from the outer tube such that the flow of heated gas is channeled through an annular space therebetween. The vaporizer also includes a crucible disposed at least partially within the inner tube. The crucible is extendable and retractable relative to the inner tube and within the outer tube. The crucible is configured to hold a molten metal such that a surface area of the molten metal exposed to the flow of heated gas is adjustable based on the position of the crucible relative to the inner tube. A heater is configured to vaporize the molten material and the vapor mixes with the flow of heated gas.

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

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 (CO 2 ) atmosphere. The system includes a recuperating and condensing circuit that removes dissolved pyrolysis products from the supercritical CO 2 atmosphere and then recovers CO 2 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.

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.