NRC Approves Construction Permit for TVA’s 300 MW Clinch River SMR
The NRC approved TVA's construction permit for a 300 MW BWRX-300 reactor at Clinch River in Tennessee, while a separate operating license will still be required.
The Nuclear Regulatory Commission has approved a construction permit for Tennessee Valley Authority to build a 300-megawatt BWRX-300 small modular reactor at its Clinch River site near Oak Ridge, Tennessee. The September 28, 2026 decision clears a federal licensing threshold for what NRC describes as the nation’s first commercial small modular reactor construction permit.
NRC formally began its review in July 2025 and completed the decision in 14 months. The agency issued a final safety evaluation in June 2026 and held a mandatory public hearing in Oak Ridge in August. TVA previously received an early site permit for Clinch River in 2019.
Construction permission is not an operating license
The permit authorizes construction under NRC requirements, but TVA will need a separate operating license before loading fuel and starting the reactor. That distinction keeps design verification, construction quality, testing and operating-readiness reviews ahead of the project.
The proposed unit uses GE Vernova Hitachi’s BWRX-300 design, a boiling-water reactor rated at approximately 300 megawatts electric. NRC’s project page records completion of the environmental review in April 2026 and the final safety evaluation in June.
What it means
Analysis: The decision is a major regulatory milestone because it converts a long-running advanced-reactor proposal into an authorized construction project. It does not settle the final investment schedule, procurement strategy or operating approval. Those steps will determine how quickly the project becomes a functioning power asset.
The 14-month review also establishes a benchmark for later applications, although future schedules will depend on design maturity and site-specific issues. Standardization matters to the small-reactor business model because repeated designs can reduce engineering changes and licensing uncertainty.
For TVA’s system, a 300 MW unit would be large enough to affect resource planning but smaller than a conventional gigawatt-scale reactor. That scale can support phased additions, provided financing, supply-chain and construction performance match the modular premise.
Sources
- NRC construction-permit announcement, September 28, 2026
- NRC Clinch River application and milestone page, updated September 2026
Representative nuclear-energy photograph; Clinch River is not pictured. Photo: John Swarey (Jbs666), CC BY-SA 3.0. No editorial alterations; WordPress may resize or crop for display.
