Bill Gates-founded company begins Step 1 of generic design assessment process
US nuclear technology company TerraPower has announced major milestones in its UK reactor deployment programme with the formal commencement of the UK regulatory review for its Natrium plant, and the launch of its UK subsidiary, TerraPower UK Ltd.
TerraPower, which was co-founded by Bill Gates, said these regulatory and commercial activities mark the company’s most significant steps to date towards deploying a fleet of Natrium reactors in the UK.
Chris Levesque, TerraPower president and chief executive officer, said: “TerraPower is entering the UK market with a long-term commitment to supporting the nation’s clean energy future and establishing ourselves as a serious and reliable deployment partner.”
The company has begun Step 1 of the three-step regulatory review process, known as the generic design assessment, or GDA.
The company submitted its GDA application in October 2025, its first international regulatory filing for the Natrium technology. In February the UK announced its readiness to begin the GDA process for the Natrium reactor after the company’s application was accepted for review.
The voluntary GDA process is used by the UK’s joint nuclear regulators to assess new nuclear power station designs. It allows the regulators to assess the safety, security and environmental implications of new reactor designs, separately from applications to build them at specific sites.
The start of Step 1 of the GDA process marks a significant step toward Natrium advanced reactor deployment in the UK, TerraPower said.
“Confirming arrangements is an important enabling step for ONR to engage with and assess TerraPower’s Natrium design,” it said.
Diego Fernandez Lisbona, the UK Office of Nuclear Regulation’s head of regulation for the TerraPower Natrium GDA and advanced nuclear technologies, said: “Interactions in 2025, through our framework for early engagement, have provided early design familiarity and we will continue to engage closely with TerraPower and broader stakeholders as GDA progresses.”
De-Risking Future Natrium Projects
The GDA’s purpose is to de-risk future Natrium projects by ensuring that environmental protection is built into the design from the start.
Alan McGoff, the Environment Agency’s policy lead for new nuclear build, said: “This is the first GDA where we can take advantage of our arrangements for enhanced cooperation between international regulators following the UK and US governments’ signing last year of the Atlantic Partnership for Advanced Nuclear Energy.”
TerraPower UK will serve as the company’s operational base for all UK activities including GDA engagement. It is the company’s first office outside the US.
Ian Hudson has been appointed head of TerraPower UK. He brings more than 30 years of leadership experience in the nuclear industry.
TerraPower has been working through regulatory requirements in the US, where the first Natrium plant is being built at a former coal site in Kemmerer, Wyoming. That project is expected to be completed in 2030 and will be the first utility-scale advanced nuclear power plant in the US.
The US work includes recent approval by the US Nuclear Regulatory Commission to begin building the plant. The UK’s GDA process will expand on the company’s experience and efforts in the US and will allow TerraPower to establish deployment timelines for Natrium sites in the country.
The Natrium Reactor Technology
TerraPower says its Natrium technology is well positioned to support rapidly increasing energy demand. The Natrium plant design features a 345 MW sodium-cooled fast reactor with a patented molten salt-based energy storage system.
The storage technology can boost the system’s output to 500 MW of power when needed because it is designed to keep base output steady, ensuring constant reliability, and can quickly ramp up when demand peaks. It is the only advanced reactor design with this unique feature.
TerraPower said it is rapidly commercialising the Natrium technology, including an agreement with Meta for up to eight Natrium plants in the US by 2035.
