The U.S. Nuclear Regulatory Commission (NRC) has just finished its Final Environmental Impact Statement (FEIS) on Kairos Power's application for a construction permit for the Hermes demonstration molten salt reactor at Oak Ridge, Tennessee. The NRC have recommended that the permit should be issued.
Kairos submitted it permit application in two parts in September and October of 2021. The company began extensive pre-application engagement with the NRC in 2018. The NRC accepted Kairos’ Hermes construction permit application (CPA) for review in November of 2021.
Last June, the NRC issued a Final Safety Evaluation Report (FSER) for the Kairos application. The NRC concluded that there were no safety aspects that would preclude issuing a construction permit for the Hermes reactor.
The NRC weighed the facility’s environmental, economic, technical, and other benefits against environmental and other impacts. The NRC staff have now issued the FEIS, also recommending that the permit should be issued.
Kairos said that “This is the final document from NRC staff to support the commission hearing planned later this year and marks the formal conclusion of the environmental review for the Hermes construction permit application.”
The NRC staff will provide the FEIS and FSER to the NRC for the mandatory hearing phase of the project. The hearing is expected to take place later this year. After the hearing, the NRC will vote on whether to authorize the staff to issue the permit.
Marty Bryan is the Kairos Site Licensing Manager. He said that “We are grateful to the NRC staff for their thorough review and comprehensive engagement with us and with local stakeholders.”
Darrell Gardner is the Senior Licensing Director at Kairos. He said, “The FEIS follows extensive engagement between Kairos Power and the NRC beginning in 2018. It builds upon selecting and characterizing an appropriate site for Hermes, engaging with the local community, and continuously communicating with stakeholders. We applaud the staff's steady progress toward closing out the Hermes CPA review and look forward to completing the mandatory hearing later this year.”
Kairos will have to submit a separate application for an operating license. It will have to receive approval from the NRC before operating the Hermes reactor.
Hermes is a thirty-five-megawatt thermal non-power version of the company’s fluoride salt-cooled high temperature reactor called the KP-FHR. It uses TRI-structural ISOtropic (TRISO) fuel pebbles with a low-pressure fluoride salt coolant. The demonstration Hermes reactor has been selected by the U.S. Department of Energy to receive six hundred and twenty-nine million dollars in cost-shared risk reduction funding over several years under the Advanced Reactor Demonstration Program. It is intended to provide operational data to support the development of a larger version for commercial deployment.
A site in the East Tennessee Technology Park in Oak Ridge has been selected for the demonstration reactor. The TRISO fuel pebbles will be produced at the Los Alamos National Laboratory's Low Enriched Fuel Fabrication Facility under an agreement announced in late 2022. Kairos has also commissioned a plant to produce a high-purity fluoride salt-coolant known as Flibe in partnership with the Materion Corporation.
Last month, Kairos submitted an application to the NRC for permission to construct the Hermes 2 plant next to the Hermes reactor at Oak Ridge. The Hermes 2 plant will consist of two thirty-five megawatt thermal reactors. Each of these reactors will be the same size as the original test reactor and they will share a power generation system. The Hermes 2 plant will generate and sell electricity. The NRC is currently assessing that application to determine if it is acceptable and complete enough to start the formal technical review process.