The Natrium technology of Bellevue, Wash.-based TerraPower has been accepted into the United Kingdom’s Generic Design Assessment process Feb. 19.
The Generic Design Assessment is the process used by U.K. nuclear and environmental regulators to evaluate new nuclear projects. TerraPower announced its intention to enter into the process in April 2025 and submitted the application in October 2025.
The UK Office of Nuclear Regulation said in its Feb. 19 release that it, along with the Environment Agency and Natural Resources Wales, had asked to begin assessing TerraPower’s reactor technology design. It follows the UK Department of Energy Security and Net Zero’s (DESNZ) readiness review of TerraPower’s application.
The UK nuclear regulator said that GDA will begin “once the necessary arrangements around timescales and resources have been put in place.”
TerraPower’s Natrium technology includes a 345-megawatt sodium-cooled fast reactor with a molten, salt-based energy storage system that can increase output to 500 megawatts of power when needed.
“We are incredibly pleased to have our application accepted into the UK’s Generic Design Assessment (GDA) process,” TerraPower President and CEO Chris Levesque said in a Feb. 19 statement. “We look forward to working with the Department for Energy Security and Net Zero (DESNZ), Office for Nuclear Regulation (ONR), and Environment Agency (EA) in the coming months, and ultimately advancing our efforts to bring a Natrium reactor to the United Kingdom.”
In the United States, TerraPower has already begun the non-nuclear construction of its first Natrium reactor plant in Kemmerer, Wyo. For the company’s construction permit application, submitted in March 2024, the Nuclear Regulatory Commission (NRC) has completed its review of TerraPower’s final safety evaluation and environmental impact statement.
NRC said there are no more safety aspects left that would prevent the issuance of the construction permit. TerraPower is currently awaiting a decision on the permit.