US TerraPower has submitted a letter to the UK Department for Energy Security & Net Zero (DESNZ) announcing its intention to enter the UK Generic Design Assessment (GDA) process. This is the first step in efforts to deploy the Natrium technology in the international market.

TerraPower’s regulatory milestones with its first Natrium plant, currently being developed in the United States, will be used as the basis of its GDA application. These include:

  • Pre-application meetings with the US Nuclear Regulatory Commission (NRC);
  • Submission and acceptance of a construction permit application (CPA) to NRC;
  • More than a year of review with NRC on the company’s CPA and Topical Report Submittals, with the NRC recently announcing they are ahead of schedule on the review, and
  • The award of a state-level construction permit from the State of Wyoming; where the first Natrium project is being built.

The Natrium technology features a 345 MWe sodium-cooled fast reactor with a molten salt-based energy storage system. The storage technology can boost the system’s output to 500 MWe for more than five and a half hours when needed. TerraPower broke ground on the first Natrium project in 2024 in Kemmerer, Wyoming.

“I am incredibly excited to begin of the process of licensing the Natrium technology in the UK,” said Chris Levesque, TerraPower President and CEO. “TerraPower is committed to deploying Natrium units globally and has been in active discussions in the UK for years. There is immense interest and opportunity for the United States and United Kingdom to cooperate on deploying advanced nuclear plants over the coming decade.”

GDAs have previously been completed for the EDF/Areva UK EPR, the Westinghouse AP1000, the Hitachi-GE UK ABWR and the CGN/EDF/GNI UK HPR1000 designs. GDAs are ongoing for Rolls-Royce SMR’s small modular reactor design, GE Hitachi Nuclear Energy’s BWRX-300 and Holtec International’s SMR-300. The Westinghouse AP300 was accepted for a GDA review in August 2024, and France-based reactor developer Newcleo submitted an application for its LFR-AS-200 small modular lead-cooled fast reactor to begin the process in December.