TerraPower

TerraPower is an American nuclear reactor design and development engineering company headquartered in Bellevue, Washington. TerraPower is developing a class of nuclear fast reactors termed traveling wave reactors (TWR).

TWR places a small core of enriched fuel in the center of a much larger mass of non-fissile material, in this case depleted uranium. Neutrons from fission in the core "breeds" new fissile material in the surrounding mass, producing Plutonium-239. Over time, enough fuel is bred in the area surrounding the core that it can undergo fission, sending neutrons further into the mass and continuing the process while the original core expires. Over a period of decades, the reaction moves from the core of the reactor to the outside, thus "travelling wave".

In September 2015, TerraPower signed an agreement with state-owned China National Nuclear Corporation to build a prototype 600 MWe reactor unit at Xiapu in Fujian province, China, from 2018 to 2025. Commercial power plants, generating about 1150 MWe, were planned for the late 2020s. However, in January 2019 it was announced that the project had been abandoned due to technology transfer limitations placed by the Trump administration.

In October 2020, the company was chosen by the United States Department of Energy as a recipient of a matching grant totaling between $400 million and $4 billion over the ensuing 5 to 7 years to build a demonstration reactor using their "Natrium" design. Natrium uses liquid sodium as a coolant (reducing the cost using an ambient pressure primary loop). It then transfers that heat to molten salt, which can be stored in tanks and used to generate steam on demand, enabling the reactor to run continuously at constant power, while allowing dispatchable electricity generation.