Construction Starts On ‘Revolutionary’ US Nuclear Reactor

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.

“Generation IV nuclear power plant designs are revolutionary, in that they are planned to use a very different set of technologies than the reactors we use today,” Ross Peel, a professor with King’s College London’s Centre for Science and Security Studies told Newsweek.

“They have the potential to offer a range of benefits in terms of nuclear safety, security, non-proliferation, nuclear waste management, economics, and more, although so far it’s not at all clear if all of these benefits can be achieved at the same time – for instance, will it be truly possible to achieve safety improvements, minimize nuclear waste, and reduce operating costs within a single reactor design? This is currently not clear,” he added.

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 (

“Neither of these ideas are new, but they’ve never been commercialized. Kairos is quite unusual in bringing the molten salt and the TRISO fuel together – the commonly cited six Generation IV reactor types tend to use one or the other, but Kairos seems to be hoping to achieve the best of both worlds in one design.”

Construction of the Hermes reactor is taking place at the Heritage Center Industrial Park in Oak Ridge, Tennessee,…