First construction permit issued for BWRX-300 SMR in the US

The Nuclear Regulatory Commission (NRC) said its decision "paves the way for the nation's first commercial small modular reactor". It said it completed the review in 14 months, four months earlier than it had scheduled.

NRC Chairman Ho Nieh said: "Today's Clinch River decision demonstrates that the new NRC can make rigorous and credible safety decisions that enable major American nuclear projects to move forward."

Tennessee Valley Authority (TVA), which is a government-owned power company, said that although no construction date has been announced, it is now the first US utility permitted to construct the BWRX‑300 small modular reactor (SMR). It said it "continues negotiations with industry partners to ensure responsible cost sharing and financial accountability throughout design and construction".

Mike Skaggs, TVA Interim President and CEO, said: "This construction permit is more than a regulatory achievement, it's foundational for America's nuclear future." TVA's Chief Nuclear Officer Matt Rasmussen said: "The NRC's strong engagement with the industry is essential to support America's energy leadership and help build the foundation for the nation's advanced nuclear future."

TVA said that the Clinch River permit "establishes a clear, repeatable licensing pathway for future BWRX-300 SMR applicants, improving predictability, lowering barriers, and accelerating deployment timelines nationwide." And Skaggs added that the priority now was "ensuring the people of the Valley do not shoulder the costs of first‑of‑a‑kind technology that benefits the nation and world. Strategic partnerships enable shared responsibility, shared value, and shared progress as we deploy advanced nuclear infrastructure to meet our nation’s energy security and AI dominance goals".

_{Mike Skaggs, left, and Jeremy Bowen from the NRC (Image: GE Vernova Hitachi)}

Eric Gray, CEO of GE Vernova Power Segment, said: "This is a milestone for TVA and GE Vernova Hitachi Nuclear Energy, and an important moment for new nuclear in the United States. TVA has shown strong leadership in advancing new nuclear, a commitment bolstered by the collaborative efforts of the NRC and Department of Energy. Together, and in alignment with federal Executive Orders aimed at accelerating advanced reactors, we are grateful for this collaboration as we work to support the deployment of the first BWRX-300 in the country."

Jason Cooper, CEO of GE Vernova Hitachi Nuclear Energy, said: "Fleet deployment is essential to scaling nuclear energy in the United States. A standard design, combined with a predictable and efficient regulatory environment, allows us to apply common technology, licensing experience, supply chain capabilities and lessons learned from one project to the next. Clinch River brings us another step closer to making that fleet model a reality."

State Governor Bill Lee said: "The Clinch River project represents the next chapter in our state's legacy of innovation, strengthening America's energy security and creating opportunity for generations to come."

The NRC formally began its review in July 2025. It included a safety evaluation completed by the NRC staff in June, which found that TVA's construction permit application met all regulatory requirements. The NRC also held a public hearing in Oak Ridge, Tennessee, in August. 

The background

The Tennessee Valley Authority submitted its application for Clinch River to the NRC in May 2025, making it the first utility in the USA to submit a construction permit application for GE Vernova Hitachi Nuclear Energy's BWRX-300 technology.

Small modular reactors - SMRs - are reactors with a smaller and more modular design than the USA's currently operating commercial nuclear fleet. As well as offering safety enhancements, their smaller footprint and modular design means they can potentially be built more quickly, are easier to operate and better fit into the landscape due to their compact size, TVA said.

TVA already holds an early site permit for SMRs at the Clinch River site, certifying that the site near Oak Ridge, Tennessee, is suitable for the construction of a nuclear power plant from the point of view of site safety, environmental impact and emergency planning. It has also completed and submitted an Environmental Report for the project to the Nuclear Regulatory Commission.

The BWRX-300 design is a 300 MWe water-cooled, natural circulation SMR with passive safety systems that leverages the design and licensing basis of the ESBWR boiling water reactor developed by GEH. The first BWRX-300 unit is currently under construction in Canada, the first of four of the SMRs planned at the Darlington New Nuclear Project site.

In September 2026, Blue Energy submitted the first part of its construction permit application to the NRC for a BWRX-300 planned for its gas-plus-nuclear project in Texas. There are also projects advancing for fleet deployment of BWRX-300 units in Poland and the UK.