TerraPower’s advanced Natrium nuclear reactor design has been accepted into the United Kingdom’s Generic Design Assessment (GDA) process.
The Natrium technology is developed through a collaboration between TerraPower and GE Vernova Hitachi Nuclear Energy, combining next-generation reactor design with established nuclear engineering expertise.
The decision follows TerraPower’s formal application submission in October 2025, and represents the company’s first international regulatory filing for the sodium-cooled reactor technology. TerraPower President and CEO Chris Levesque welcomed the move, stating the company is “incredibly pleased to have our application accepted into the UK’s Generic Design Assessment (GDA) process… and ultimately advancing our efforts to bring a Natrium reactor to the United Kingdom.”
At its core, Natrium integrates a 345 MWe sodium fast reactor with a molten salt energy storage system, enabling steady baseload generation while ramping output to 500 MWe during periods of peak demand. This load-following capability distinguishes it from conventional nuclear plants, offering grid flexibility to complement growing renewable penetration while providing firm, dispatchable, zero-carbon power for industrial users and hydrogen production.
The GDA entry builds on progress in the United States, where TerraPower is advancing its lead project in Kemmerer, Wyoming, where non-nuclear site works began in June 2024 under a public-private partnership with the US Department of Energy. Once operational, the project is expected to become the first utility-scale advanced reactor in the country, helping validate the design for deployment in export markets such as the UK.
The UK’s DESNZ has set a target of up to 24 GW of nuclear capacity by 2050 to strengthen energy security and achieve net zero goals. Successful completion of the GDA process could streamline subsequent site-specific licensing, positioning Natrium as a potential contributor to the UK’s long-term nuclear ambitions.
