Clinch River BWRX-300 — construction permit issued

Operator and regulator research, October 11, 2026

The NRC’s Federal Register notice confirms construction permit CPAR-2 for TVA’s Clinch River Nuclear Unit 1 was issued September 28, 2026. It authorizes construction of the reactor facility in Roane County, Tennessee. A construction permit does not establish an operating licence or prove construction has started.^[2]

NRC application page provides project and review context; its earlier fall-2026 target is superseded by the issued permit notice.^[3]

Earlier pin evidence / inventory snapshot

• On 29 September 2026 the NRC issued TVA a construction permit for a BWRX-300 small modular reactor at the Clinch River Nuclear Site in Oak Ridge, Tennessee, the first such permit for the design in the United States and, in the Breakthrough Institute's words, "the first construction authorization for a commercial small modular reactor in the United States"^[1][7]
• The NRC completed its review in 14 months, four months ahead of schedule, helped by the Early Site Permit TVA already held for Clinch River, which sets a combined limit of 800 MWe; it is the NRC's second major new-reactor construction approval of 2026 after TerraPower's Natrium in March^[7]
• TVA submitted its construction permit application in April 2025; the BWRX-300 is a 300 MW boiling-water SMR from GE Vernova Hitachi Nuclear Energy, and the site sits within the Oak Ridge nuclear ecosystem near the Department of Energy's Oak Ridge National Laboratory^[1]
• The permit allows TVA to build but not to run the reactor: TVA must complete construction and win a separate NRC operating licence before it can load fuel^[5][7]
• No construction start date has been announced; TVA says it "continues negotiations with industry partners to ensure responsible cost sharing", plans as many as four 300 MW units at the site, and had projected the first BWRX-300 in revenue service by 2032 without committing to a firm date^[6]
• Bechtel was selected to lead construction and Sargent & Lundy the detailed design; the NRC staff's safety evaluation recommended the permit in the summer of 2026^[6][8]

Additional August 2026 inventory evidence

GEM August 2026 snapshot: mixed phases. 1200 MW sum of published phase ratings (ratings may mix solar DC/AC). Technologies: Nuclear.^[4]

Compare phase coverage and AC/DC, nameplate and net ratings before combining source figures. This inventory view is not extra capacity to add to the existing project total.

Inventory unit details — gem-L100000500282

Additional source view; compare phase coverage and rating conventions before combining figures.

• 1 (G100000500652): reported rating 300 MW; boiling water reactor; status pre-construction; reported year 2033; solar rating not specified/not applicable.^[4]
• 2 (G100001054578): reported rating 300 MW; boiling water reactor; status announced; reported year None; solar rating not specified/not applicable.^[4]
• 3 (G100001054579): reported rating 300 MW; boiling water reactor; status announced; reported year None; solar rating not specified/not applicable.^[4]
• 4 (G100001054580): reported rating 300 MW; boiling water reactor; status announced; reported year None; solar rating not specified/not applicable.^[4]