The Tennessee Valley Authority won approval for an early site permit from the Nuclear Regulatory Commission (NRC) to potentially build and operate small modular nuclear reactors.

The 20-year permit approves a 935-acre site near Oak Ridge, Tennessee, and the Clinch River for a nuclear facility with a generating capacity of up to 800 megawatts.

TVA said it has no plans to build a small modular reactor, also known as an SMR. The reactors are roughly one-third the size of a conventional reactor, and are intended to offer more standardization, reduced construction times and the ability to deploy in smaller increments.

Proposed rule change

In a related action, the NRC said it is seeking comment on a proposed rule and associated draft regulatory guide to apply "risk-informed, performance-based emergency preparedness requirements" to SMRs and other technologies, including non-light-water reactors and certain non-power production or utilization facilities.

The NRC said that its existing emergency preparedness program for nuclear power plants has focused on large, light-water cooled reactors. The proposed rule and related guidance consider advances in facility designs and safety research and their application to future operation of SMRs and other new technologies.

The NRC is proposing to amend its regulations to create an alternative emergency preparedness framework that would adopt a risk-informed, performance-based and technology-inclusive approach. The alternative requirements would include a scalable approach for determining the size of the emergency planning zone around each facility, based on the distance at which possible radiation doses could require protective actions.

TVA permit process

TVA applied for an early site permit in 2016, and the NRC began reviewing the application in January 2017. The application addressed the site safety, environmental and emergency preparedness requirements to determine approval of the site.

TVA will have up to 20 years to make a decision to pursue the construction of small modular reactors. Another NRC application would be required to build and operate a facility.