Construction is underway on a new nuclear power plant in Tennessee – the first officially approved fourth-generation nuclear reactor in the U.S.

Kairos Power has begun building the Hermes Low-Power Demonstration Reactor in Oak Ridge, the first Gen IV reactor approved for construction by the U.S. Nuclear Regulatory Commission. The Hermes reactor utilizes a fluoride salt-cooled, high-temperature reactor design, differing from conventional light-water reactors. //

The reactor is set to employ TRISO-coated particle fuel and high-purity fluoride salt coolant, known as FLiBe, a mixture of lithium fluoride and beryllium fluoride. This design is intended to produce affordable nuclear heat rather than electricity, showcasing the potential of a factory-built small modular reactor to revolutionize nuclear construction.

"Kairos will combine the molten salt coolant... with a novel form of nuclear fuel called TRISO, where the fuel is in tiny (<1 mm) particles coated in layers of graphite (both as a moderator and to give the fuel strength and structure)," said Peel.