Clinch River nuclear project is nearing a major US regulatory milestone for its planned 300MW small modular reactor. The Nuclear Regulatory Commission could issue the construction permit on September 29. The approval would allow Tennessee Valley Authority to advance construction of Unit 1. The project sits at TVA’s Clinch River Nuclear Site near Oak Ridge, Tennessee
The planned reactor will use GE Vernova Hitachi Nuclear Energy’s BWRX-300 technology. TVA is also evaluating up to four reactors at the wider site. However, the expected permit covers only the initial 300MW unit.
The project has an estimated construction value of up to $5.4 billion. Bechtel, Sargent & Lundy and GE Hitachi support TVA with planning and evaluation work.
Clinch River nuclear project reaches licensing milestone
The NRC received TVA’s first application section in April 2025. TVA submitted the second and final section on May 20, 2025. The submission covered the proposed BWRX-300 construction permit application.
The NRC subsequently conducted detailed environmental and technical reviews. It issued the final supplemental environmental impact statement in April 2026. The document assessed construction and operation impacts for Unit 1.
NRC staff also recommended issuing the construction permit following their safety evaluation. The review found TVA’s application met key regulatory and technical requirements.
The regulator held a mandatory public hearing on August 13. Public comments remained open through August 27, according to the NRC.
Therefore, the anticipated permit would mark a significant step toward nuclear construction at Clinch River.
Clinch River nuclear project advances BWRX-300 construction
The BWRX-300 will generate approximately 300MW using boiling-water reactor technology. Its design uses natural circulation and passive safety systems.
The reactor also uses a modular construction approach. Manufacturers can produce components in factories before assembling them at the project site.
That approach aims to reduce construction complexity, project duration and costs. However, the technology remains relatively unproven commercially outside limited deployments.
Ontario Power Generation began construction of the first BWRX-300 in Canada last year. Meanwhile, only two small modular reactors remain under construction outside China and Russia.
The US project would become only the second commercial small modular reactor to receive a US construction permit. TerraPower received the first such approval for its Wyoming project in March.
The Hermes 2 nuclear reactor project in Oak Ridge is also advancing with support from Samsung C&T and a $100 million investment package. The development adds to Tennessee’s growing pipeline of advanced nuclear projects, alongside the Clinch River nuclear project, which is approaching a separate federal construction approval milestone.
Clinch River nuclear project targets early 2030s operation
TVA expects the initial reactor could enter commercial service in the early 2030s. Earlier project planning has identified 2032 as the potential operating target.
The Clinch River property covers about 1,200 acres along the Watts Bar Reservoir. The designated nuclear site occupies approximately 935 acres.
The site already benefits from existing transmission infrastructure and highway access. TVA also secured the nation’s first early site permit for SMR development there in December 2019.
TVA’s Board has authorized $350 million for Clinch River-related development activities. The Department of Energy separately selected TVA for up to $400 million in federal cost-shared funding.
The federal support will help advance the reactor and strengthen domestic supply-chain capabilities. TVA also plans to work with several nuclear manufacturing and supply-chain companies.
If approved, Clinch River would provide a major US construction test for factory-oriented nuclear technology. The project could also establish a model for subsequent BWRX-300 deployments.
Project Fact Sheet
Project: Clinch River Nuclear Site Unit 1.
Location: Oak Ridge and Roane County, Tennessee, United States.
Type: Small modular nuclear reactor construction.
Reactor technology: GE Vernova Hitachi BWRX-300.
Generation capacity: 300MW electric.
Technology type: Boiling-water small modular reactor.
Construction value: Up to $5.4 billion.
Wider site area: Approximately 1,200 acres.
Designated nuclear site: Approximately 935 acres.
Construction permit application: Submitted to the NRC in May 2025.
NRC environmental review: Final supplemental environmental impact statement issued April 2026.
NRC safety review: Staff recommended construction permit approval.
Early site permit: Issued by the NRC in December 2019.
Potential commercial operation: Early 2030s.
Potential operating target: 2032.
Federal support: Up to $400 million through the US Department of Energy.
TVA authorization: Up to $350 million for Clinch River development activities.
Development objective: Demonstrate deployment of the BWRX-300 in the United States.
Wider development plan: TVA is evaluating up to four BWRX-300 reactors.
Project Team
Owner and project developer: Tennessee Valley Authority (TVA).
Nuclear regulator: US Nuclear Regulatory Commission (NRC).
Reactor technology provider: GE Vernova Hitachi Nuclear Energy.
Project planning and construction partner: Bechtel.
Engineering partner: Sargent & Lundy.
Federal funding partner: US Department of Energy.
Nuclear supply-chain partners: Scot Forge, North American Forgemasters and BWX Technologies.
Additional supply-chain partner: Aecon.
Licensing responsibility: Tennessee Valley Authority and the Nuclear Regulatory Commission.
Site management: Tennessee Valley Authority.
Reactor technology: GE Vernova Hitachi BWRX-300.
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