The Nuclear Regulatory Commission is set to issue only its second construction permit for a novel type of nuclear reactor in decades, giving the Tennessee Valley Authority the go-ahead to begin building what could be the nation’s first commercial small modular reactor. The 300-megawatt unit at the federally-owned utility’s Clinch River site represents a milestone for third-generation SMR deployment, a technology based on existing large-scale reactors but shrunken down to force developers to buy more and help the industry bring down the cost of atomic power through repeatedly building the same design. The permit comes six months after the NRC gave TerraPower, the Bill Gates-backed fourth-generation nuclear developer, the green light to start constructing its liquid sodium-cooled reactor at the site of an old coal plant in Kemmerer, Wyoming.
The unit planned at Clinch River is a BWRX-300, a boiling water reactor from GE Vernova Hitachi Nuclear Energy that borrows from the technology behind roughly a third of the American nuclear fleet. Boiling water reactors, pioneered by General Electric in the mid-20th century, traditionally represented a competitor to the more dominant pressurized water reactor invented by Westinghouse. The project is one of two the Department of Energy is financing to support deployment of third-generation SMRs; the second is Holtec’s expansion of the Palisades nuclear plant in Michigan. TVA has said it plans to bring its debut BWRX-300 online by the end of 2033 at the latest. Yet, despite the forthcoming permit, no start date for construction has been announced.
The evidence for this development comes from a single full-text source, Heatmap News, a secondary outlet covering climate and energy. The report frames the permit within a broader permitting-reform moment: Senate negotiators reached a bipartisan agreement on a package of federal permitting reforms, locking in what Politico described as “the contours of long-sought legislation to speed up approvals for new energy projects in the U.S.” Democratic negotiators Senators Martin Heinrich of New Mexico and Sheldon Whitehouse of Rhode Island said they were withholding endorsements of a final deal as “the last five yards” of the agreement are hammered out. Whitehouse cautioned that he needed “more clarity from the Trump administration” on what their easing of the blockade on wind and solar approvals would mean. Neither Democrats nor Republicans released text of the bill, which both parties said should come out this week.
For the nuclear sector, the Clinch River permit signals incremental but meaningful regulatory momentum. By the time Clinch River comes online, North America may already have its first BWRX-300 in operation in Canada, where Ontario Power Generation is building the first reactor at its Darlington plant. The NRC has also sought to advance plans to restart the functional reactor at Constellation Energy’s Christopher Crane Clean Energy Center, the facility formerly known as Three Mile Island; last week, the agency issued an environmental assessment finding no significant impact from plans to begin generating electricity there. These actions suggest a regulatory environment increasingly willing to move on both new builds and restarts, though the source does not provide cost figures, financing terms, or construction timelines beyond TVA’s 2033 target.
The report leaves several material questions unanswered. No construction start date has been announced for Clinch River, and the source does not specify the dollar amount of DOE financing for the project or the expected total cost. The permitting-reform deal referenced in the same article remains textless and unendorsed by key Democratic negotiators, meaning its impact on future nuclear approvals is uncertain. Readers should treat the permit as a regulatory step rather than a financial or construction commitment, and watch for the release of the permitting bill text and any TVA announcement on a construction start date as the next evidence-bounded signals.