TerraPower

TerraPower is a nuclear innovation company headquartered in Bellevue, WA, founded in 2008 by Bill Gates, Nathan Myhrvold, and John Gilleland. The company designs and develops advanced nuclear reactor technologies aimed at delivering safe, affordable, and carbon-free energy at scale. Its flagship product is the Natrium® reactor - a 345 MW sodium-cooled fast reactor integrated with a molten salt energy storage system that allows for flexible, dispatchable power output. This innovative design decouples electricity generation from the thermal output of the reactor, enabling the plant to store energy and release it on demand, making it highly compatible with grids that carry variable renewable energy loads.

TerraPower's most prominent project is the Natrium® Demonstration Plant in Kemmerer, Wyoming, being built on the site of a retiring coal plant. The NRC issued a construction permit for the project in March 2026, and full utility-scale construction officially commenced in April 2026 - marking it as America's first utility-scale advanced nuclear power plant. The company has also submitted the Natrium® reactor for regulatory review in the United Kingdom and signed commercialization agreements with South Korean partners SK and KHNP. Beyond reactors, TerraPower operates TerraPower Isotopes®, a division producing Actinium-225 for targeted alpha therapy cancer treatments, including a new manufacturing facility breaking ground in Philadelphia.

TerraPower is a critical node in the US energy supply chain as the nation's most advanced sodium fast reactor developer with active government and private backing. It received a major award under the DOE's Advanced Reactor Demonstration Program (ARDP) and has secured over $1.48B in private fundraising rounds (including $750M in August 2022, $830M in November 2022, and $650M in June 2025), alongside strategic investments from Korea Hydro & Nuclear Power (KHNP). The company's work on HALEU fuel (in partnership with Framatome and Centrus Energy), domestic supply chain contracts, and international deployment agreements position it as a cornerstone of the next generation of US nuclear energy infrastructure.