Advanced nuclear power engineer and developer Kairos Power LLC has begun construction on the Hermes Low Power Demonstration Reactor, which it says is the first and only next-generation nuclear reactor that the US Nuclear Regulatory Commission has authorized to build and the first to use no Light water technology will be allowed in the US in more than 50 years.
The demonstration molten salt reactor is part of the Alameda, California company’s “rapid iterative development approach” to developing and commercializing nuclear power plant designs based on fluorine salt-cooled high-temperature reactor technology, he said. Hermes, a 35 MWth thermal reactor, is set to “demonstrate Kairos Power’s ability to produce affordable nuclear heat,” the developer said, noting that it will not initially produce electricity.
Barnard Construction Co. Inc., Bozeman, Mont. has begun construction in Oak Ridge, Tenn., for the developer, which aims to complete the project by 2027 as a “critical step” in commercializing its technology.
Kairos Power, founded in 2016, anticipates a commercial reactor could be operational by the early 2030s.
The company pointed to its investment of about $100 million in the plant and supporting infrastructure, and an infusion last year from the US Department of Energy of up to $300 million. ENR could not confirm by publication of the time whether the total cost of the project was higher and whether it had additional sources of investment.
The agency will pay Kairos in installments for the demonstration project, established under a technology investment agreement, which will be based on milestones such as construction progress and the application of a future license federal operation.
Barnard and Kairos Power are also collaborating to build a third engineering test unit in Oak Ridge, which the developer says is a “non-nuclear” facility “that will generate supply chain, construction and operational experience to inform the Hermes project”. Two other test units have been built at research and test sites operated by Kairos Power in Albuquerque, NM and Elmore, Ohio, which the firm says will “inform the design, construction and operation of the Hermes reactor.”
Both will be built using modular construction techniques, with reactor modules fabricated at the Albuquerque site and shipped to Oak Ridge for assembly, “demonstrating the potential of a factory-built small modular reactor design to transform construction conventional nuclear,” said Kairos Power.
Kairos Power was the first to apply to the federal nuclear regulator for a proof-of-concept for its technology, the company said, adding that it seeks to reduce technical risk “through a novel approach to the iteration of evidence that is often lacking in the nuclear space.”
The facility is designed to operate at high temperatures and near-atmospheric pressure, using a special particulate fuel along with a molten fluoride salt coolant, the company told the commission in a 2023 filing. combination of extremely high temperature tolerant fuel and low-pressure, single-phase, chemically stable reactor coolant eliminates entire classes of potential fuel damage scenarios, greatly simplifying the design and reducing the number of safety systems,” said Peter Hastings . , Kairos Power Vice President of Regulatory Affairs and Quality,
“This historic initiative presents a critical opportunity to transform the way we generate energy in the US, as well as an opportunity to expand economic and employment opportunities for the greater Tennessee area,” said Quincy Anderson, vice president and director of Barnard operations.
The firm also plans to develop the next iteration, Hermes 2, also at Oak Ridge, which will include two 35 MWh test reactors. It will use the same fuel but is planned to produce a combined 20 MWe of electrical power through an integrated steam-powered conversion system, Kairos Power said, adding that the project will “de-risk the technology, construction, supply chain and the licenses for a multi-reactor plant”.
In July, the commission completed its final safety assessment for Hermes 2, “almost four months ahead of schedule,” the regulator noted.
The Tennessee Valley Authority is now preparing a construction permit application for a GE Hitachi BWRX-300 small modular nuclear reactor at its 935-acre Clinch River site, located near Oak Ridge, and is weighing additional sites in its large service area for other possible deployments.
