Kairos Power begins Hermes 2 build, targets first non-LWR power by 2030

Kairos Power has broken ground on its Hermes 2 demonstration plant in Oak Ridge, Tennessee, after securing test reactor construction permits from the Nuclear Regulatory Commission (NRC) in November 2024. The project is expected to start operations by 2030 and could become the first NRC-licensed non–light water reactor to generate electricity.

The site event also marked progress at Kairos’s Oak Ridge campus. Officials highlighted the site’s transition from its role in the Manhattan Project to a cleaned-up location now supporting new nuclear development.

Hermes 2 was initially approved as a nonpower test facility with two 35-MWt molten salt–cooled reactors and 20 MWe output. Following a power purchase agreement involving the Tennessee Valley Authority (TVA) and Google, the planned capacity has been revised to 50 MWe.

Kairos is using a factory-based construction model, with reactor modules built in Albuquerque and assembled on-site. The project builds on lessons from the earlier Hermes unit and is intended to support future commercial reactor deployment.

Photo credit: Kairos Power