The US Nuclear Regulatory Commission (NRC) says it aims to complete its review by the end of 2025 on TerraPower’s construction permit application for Kemmerer Power Station unit 1 in Kemmerer, Wyoming. “Frequent and productive engagements with TerraPower, along with other efficiency gains”, mean the NRC can complete reviews by 31 December 2025, six months ahead of the current schedule. “The accelerated timeline depends on a continued commitment from TerraPower to resolve the remaining issues in a timely manner,” NRC noted.
TerraPower, through its subsidiary US SFR Owner, filed the application in March 2024, requesting a permit to build the sodium-cooled, advanced reactor design on a site near an existing coal-fired power plant. If the NRC issues the construction permit, TerraPower would need to submit a separate operating licence application.
Terrapower’s Natrium technology features a 345 MWe sodium-cooled fast reactor with a molten salt-based energy storage system. The storage technology can boost the system’s output to 500 MWe for more than five and a half hours when needed. TerraPower broke ground on the first Natrium project in Kemmerer in 2024.
NRC spokesman Scott Brunell told Cowboy State Daily. “The agency has looked at the available information and given the additional guidance that we have received through both the ADVANCE Act and from the recent Executive Orders, the agency determined that it would be appropriate to move up the timetable for completing our review. “
ADVANCE stands for the Accelerating Deployment of Versatile, Advanced Nuclear for Clean Energy Act of 2024. President Donald Trump’s Executive Orders signed in May support faster US deployment of advanced nuclear energy.
The schedule acceleration coincides with the start a public comment period on the draft environmental impact statement (EIS) for the Kemmerer project. The draft EIS, issued in June, evaluates the public health impacts of constructing the Natrium reactor. NRC is requesting public input until 4 August. NRC’s preliminary recommendation supports issuing the construction permit unless safety issues arise.
However, several technical issues will require resolution before a construction permit can be issued, including materials, design components and design for seismic and structural systems. “There is the responsibility on TerraPower as part to continue to answer any other questions we might have as completely and as quickly as possible,” Brunell said.
TerraPower has begun construction on non-nuclear portions of its Kemmerer facility that do not require NRC approval. In May, NRC granted an exemption allowing Terrapower to start work on the “energy island” – the non-nuclear components of the plant including the molten salt energy storage system
The Kemmerer project is supported by the Department of Energy’s Advanced Reactor Demonstration Program and with a stated completion date of 2030. However, while the TerraPower website provides some details of work done with molten salt, it contains very little information about the reactor technology. It is also notable that none of the contracts signed with suppliers relate to the reactor itself.
Basically, the Natrium reactor is a sodium-cooled fast reactor. Currently, the only commercially operating liquid metal-cooled fast reactors are in Russia, using sodium as the coolant. Development of these reactors took decades supported by full government support. In the US and Europe research on fast reactors took place in the 1960s and 1970s but by the early 1990s the US, the UK and Germany had closed down their programmes. France continued with projects for a few more years, finally closing Superphénix in 1998 and Phénix in 2009, In 2019, France also cancelled the Generation IV ASTRID sodium-cooled fast reactor demonstrator design project.
Although interest is now reviving in Europe and the USA, it remains at the early design phase and is probably decades away from implementation. As an example, India’s prototype sodium-cooled fast breeder reactor began fuel loading in March 2024. The Indira Gandhi Centre for Atomic Research (IGCAR) began to design the reactor in 1980 and construction only began in 2004, 24 years later. Technical and financial problems then caused further delays.
