Kairos test reactor passes NRC safety review

Earlier this year, the agency’s Advisory Committee on Reactor Safeguards independently reviewed safety-related aspects of the Kairos application, and on May 16, recommended approval.

According to the June 15 announcement, staff will provide the safety evaluation and the final environmental impact statement—which is on track to be completed in September—to the commissioners for the mandatory hearing phase of the licensing process. During the mandatory hearing, expected later this year, the commissioners will examine whether the staff’s review supports the findings necessary to issue the permit, the NRC said.

Should the permit be issued, Kairos will need to submit a separate application for a Hermes operating license.

The official words: “The staff thoroughly reviewed this first-of-a-kind advanced reactor in 18 months, well ahead of schedule,” said Andrea Veil, director of the NRC’s Office of Nuclear Reactor Regulation. “This reflects the NRC’s commitment to maintaining safety, by applying risk-informed approaches, while improving efficiency.”

Background: Kairos submitted the permit application in two parts in September and October 2021. Hermes is a 35-MWth fluoride salt–cooled high-temperature reactor intended to demonstrate complete nuclear systems, advance Kairos’s manufacturing capabilities for critical components, test the supply chain, and facilitate licensing certainty for the technology. The company expects Hermes to be operational in 2026 and to lead to the development of its commercial-scale version, a 140-MWe reactor dubbed the KP-X.

In December 2020, Kairos received a Department of Energy Advanced Reactor Demonstration Program award for risk-reduction funding to support the development, construction, and commissioning of Hermes in collaboration with Oak Ridge National Laboratory, Idaho National Laboratory, Materion Corporation, and the Electric Power Research Institute. The total award value is $629 million over seven years, with the DOE contributing $303 million.

Kairos has also established a cooperative development agreement with the Tennessee Valley Authority to provide defined engineering, operations, and licensing services for Hermes.