The US Nuclear Regulatory Commission on July 10 accepted the Tennessee Valley Authority's construction permit application to build what could be the first utility-scale small modular nuclear reactor in the country.
The Tennessee Valley Authority (TVA) is the first utility applying to build GE-Hitachi Nuclear Energy Inc.'s BWRX-300 design in the US and could clear the path for other utilities looking to deploy the same small modular reactor (SMR) technology. The NRC set a 17-month schedule to review the permit application. (Docket No. 50-0615)
The TVA submitted its construction permit application in May for the Clinch River Nuclear SMR Project near Oak Ridge, Tennessee. The federal power authority already secured the nation's first and only early site permit for an SMR.
The next step is a full safety review of the reactor design before it is cleared for construction, according to a July 10 announcement by the US Energy Department. The safety review supports issuance of a final safety evaluation report by Dec. 14, 2026, or about 17 months from docketing, according to a July 9 letter from the NRC to Scott Hunnewell, the TVA's vice president of the new nuclear program.
"This is an exciting step to bringing the nation's first utility-led SMR online," TVA President and CEO Don Moul said in a statement. "This will create a path for other utilities to deploy the reactor — ensuring energy security and reliable electricity for all."
The BWRX-300 is the only boiling-water SMR design under development in the US.
The 300-MW light water system — a smaller, simplified version of GE Vernova Hitachi's licensed Economic Simplified Boiling Water Reactor — will leverage established supply chains that could speed up development, the DOE said.
The TVA partnered with Ontario Power Generation (OPG) in 2023 to expedite development of the BWRX-300 design for use in the US and Canada. Four BWRX-300 reactors were recently cleared for construction in Clarington, Ontario, with commercial operation expected by the end of 2029 at OPG's Darlington nuclear site.
Timeline in flux
The TVA expects preliminary site preparation work at Clinch River could begin as early as next year while the NRC reviews the construction permit application.
The 17-month review timeline could change, however, the NRC noted in its letter to the TVA. Timelines for resolution of complex technical issues, unanticipated changes to the scope of the review, and design changes are among the potential factors.
The TVA also expects to submit further technical information needed to support a construction permit between September and November.
The TVA is "nowhere near" ordering long-lead-time parts for the project, Moul said in May. The TVA has not yet fully signed off on the project. The agency's board would have to do that, and the board does not now have a quorum and has been unable to conduct business since the Trump administration fired the chair and another member.
The president announced four nominees to the board July 1, though the US Senate must confirm the nominees.
The TVA led an application filed in January for $800 million in federal grant funds to help pay for the BWRX-300 project at Clinch River, alongside Duke Energy Corp., American Electric Power Co. Inc. and others. The DOE in March reissued the solicitation for SMRs, with $900 million available, and the TVA-led group has reapplied.
Receiving the federal funding could accelerate construction by two years, with commercial operation planned in 2033.
Tennessee's two US senators urged the TVA in March to accelerate efforts to develop the SMR at Clinch River, saying the federal power authority could lead a nuclear energy "revival" necessary to meet growing electricity demand.
The TVA has invested $200 million in the Clinch River project so far, and its board has authorized another $150 million.
