NRC Issues First-Ever US Small Modular Reactor Construction Permit to TVA

The US Nuclear Regulatory Commission on 29 September 2026 issued a construction permit to the Tennessee Valley Authority for its Clinch River Nuclear Site in Roane County, Tennessee. The permit authorises construction of a GE Vernova Hitachi BWRX-300 boiling-water reactor with approximately 300 megawatts of generating capacity — making it the first commercial small modular reactor to receive a US construction permit.

The NRC completed its review in roughly 14 months after docketing TVA's application in July 2025. The agency described the decision as a milestone for advancing nuclear innovation and strengthening US energy leadership. The BWRX-300 is an advanced light-water design that uses natural circulation for cooling, simplifying the plant layout compared to conventional reactors.

The permit is explicitly limited to construction. TVA must still secure a separate Combined Operating License before any fuel loading or power generation can proceed, and the NRC has attached conditions and unresolved action items to the current authorisation. TVA has not announced a construction start date.

The decision arrives amid growing bipartisan support for nuclear energy in the US, driven partly by the electricity demands of AI data centres and a broader push for carbon-free baseload power. Several other SMR projects are progressing through various stages of NRC review, but Clinch River is now the first to clear the construction hurdle. Whether SMRs can deliver on their promise of faster builds and lower costs compared to conventional nuclear plants remains an open question that this project will begin to answer.