US regulator approves first SMR site licence

18 December 2019

The US Nuclear Regulatory Commission (NRC) has authorised the issuance of an early site permit (ESP) to Tennessee Valley Authority (TVA) for the potential construction of small modular reactors at its Clinch River site near Oak Ridge, Tennessee. TVA has yet to decide whether to actually construct such reactors at the site and, if so, what technology it would use.

The Clinch River site in Tennessee (Image: TVA)

An ESP certifies that a site is suitable for the construction of a nuclear power plant from the point of view of site safety, environmental impact and emergency planning, but does not specify the choice of technology. The permit is valid for 10 to 20 years, renewable for an additional 10 to 20 years.

TVA submitted its 8000-page ESP application for the Clinch River site to the NRC in May 2016. The application was for two or more small modular reactor (SMR) modules of up to a combined capacity of 800 MWe at the 935 acre (378 hectare) site near the Department of Energy's Oak Ridge National Laboratory. The proposed site hosted the former Clinch River Breeder Reactor Project. The NRC accepted the application for regulatory review in December of that year. It was the first SMR-related application of any type to be received by the NRC. The regulator published a final environmental impact statement for the permit in April this year, followed in June by its final safety evaluation report on TVA's application.

The Commission has now authorised the agency's Office of Nuclear Reactor Regulation to issue the ESP to TVA. The NRC said the permit is expected to be issued in the next few days.

The permit, the NRC said, includes additional provisions - including approved analysis methods - that deal with the NRC's emergency preparedness regulations. This could allow a future licence applicant at the Clinch River site to request an emergency preparedness zone smaller than those found at current US nuclear power plants.

SMR units, typically with a capacity of 300 MWe equivalent or less, are designed using modular technology and factory fabrication. This allows for economies of series production and short construction times. Multiple units can be installed at one location to provide the total required capacity. Such reactors are seen as potentially offering improved safety and security, as well as more standardisation, more site options and lower financing costs compared to conventional light-water reactors.

Dan Stout, director of nuclear technology innovation at TVA, said: "Although we have no plans to build at this time, this permit will give TVA flexible options to prepare for future energy needs."

TVA Chief Nuclear Officer Tim Rausch added: "The decision to build will be based on energy needs and economic factors - we want to make the best decision for the people of the Valley."

Should TVA decide to build SMRs at Clinch River, it would need to apply separately for an NRC licence to build and operate them.

Researched and written by World Nuclear News