US-based TerraPower has submitted its construction permit application to the US Nuclear Regulatory Commission (NRC) for the Natrium reactor demonstration project. This is the first application to NRC for construction of a commercial advanced reactor.

TerraPower says it has been working closely with NRC in pre-application meetings and is confident in its application. Non-nuclear construction will begin on the Natrium reactor demonstration project this summer and nuclear construction will begin only after the application is approved by NRC.

“We will continue working closely with local stakeholders, elected officials and regulatory partners as we begin non-nuclear construction this year while working through this application process with the NRC,” said Chris Levesque, President & CEO of TerraPower. “This milestone is one of many that paves the way toward clean, reliable and flexible power for the grid and long-term jobs for the Kemmerer community.”

In November 2021, TerraPower, founded by Bill Gates, announced an ageing coal plant owned by US PacifiCorp, in Kemmerer, Wyoming, as the preferred site for the Natrium reactor demonstration project. Natrium is a TerraPower and GE-Hitachi technology and is one of two competitively-selected Advanced Reactor Demonstration Program (ARDP) projects supported by the US Department of Energy (DOE).

The Natrium technology is a TerraPower and GE-Hitachi technology featuring a 345 MWe sodium-cooled fast reactor with a molten salt-based energy storage system. The storage technology is intended to boost the system’s output to 500 MWe for more than five and a half hours when needed to integrate with variable renewable energy sources. Along with PacifiCorp and GE Hitachi Nuclear Energy, members of the demonstration project team include engineering and construction partner Bechtel, Energy Northwest, Duke Energy and nearly a dozen additional companies, universities and national laboratory partners.

In March, NRC issued new guidance documents to facilitate the licensing of non-light water reactor designs. The guidance is expected to significantly reduce the regulatory uncertainty for new reactor concepts that differ from conventional reactor technologies. DOE said this was good news for advanced reactor vendors, including two DOE demonstration projects with TerraPower and X-energy. Both companies are applying this guidance to their construction permit applications. Both projects are being managed through DOE’s Office of Clean Energy Demonstrations.

TerraPower has received significant and constant DOE support for its Molten Chloride Fast Reactor (MCFR) project. In 2016, DOE awarded a five-year, $40m cost-share award for continued R&D that resulted in a new public-private MCFR project development partnership including TerraPower, Southern Company, Oak Ridge National Laboratory, the Electric Power Research Institute, and Vanderbilt University.

In 2019, the MCFR design team reported a major milestone with 1,000 hours of isothermal loop operations. The MCFR technology will utilise liquid salt as both fuel and coolant in the reactor core. This fully pumped molten salt loop tested key components including pumps, heaters, freeze valves, flanges, and instrumentation over time.

In 2020, DOE selected the Molten Chloride Reactor Experiment (MCRE) proposal, with Southern Company as the lead, as a winner of the ARDP risk-reduction pathway. DOE awarded TerraPower $80m in initial funding to demonstrate its Natrium technology. In February 2022, TerraPower and Southern Company finalised an agreement to design, construct and operate the MCRE at Idaho National Laboratory under the ARDP.

Southern Company and TerraPower are working on an Integrated Effects Test (IET) to learn how the MCFR technology will scale and behave at larger, commercially relevant sizes. The IET was commissioned and began operating in TerraPower’s Everett, Washington, facility in October 2023.

TerraPower’s demonstration plant, planned for Kemmerer is intended to validate the design, construction, and operational features of the Natrium technology. However, in December 2022, TerraPower postponed the expected start date of the reactor by at least of two years.

The company had originally hoped to commission the plant in 2028 using Russian-supplied high-assay low-enriched uranium (HALEU) fuel to get the demonstration unit up and running by 2028. The conflict in Ukraine, however, has made continuing Russian HALEU deliveries unlikely and the US has yet to develop its own supplies. The projected commissioning date is now 2030. Volume 2 of the IRP comprises more than 400 pages of appendices. The Appendix on regulatory compliance includes the following comment: “Finally, we acknowledge the inherent complexities with the Natrium project and direct the Company to continue to assess the risks of technology viability and potential delays with Natrium and plan accordingly.”

Nevertheless, US PacifiCorp, owner of the Kemmerer site, in its 2023 Integrated Resource Plan (IRP) considered the possible addition of two more Natrium units to the company’s generation resource mix by 2033, under certain circumstances. These could be sited in Utah near currently operating coal-fired facilities. TerraPower says it remains confident that the US supply chain will be ready to support up to five more reactors of the same design in Wyoming and Utah by 2035.

Image: Chris Lebeque (front row, 3rd from the right), CEO of TerraPower, stands alongside NRC and TerraPower officials and the official application for an SMR construction permit (courtesy of TerraPower)

Date: Wednesday, 03 April 2024
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