Molten Salt/pebble bed, designed to avoid catastrophy even with earthquakes, etc. Glad it's finally moving forward. The world needs it now more than ever with all of the new AI datacenters sucking up power like there's no tomorrow.
Tennessee-based Kairos Power’s nuclear plant design features a graphite-moderated pebble-bed reactor with fluoride salt as its coolant. It uses tri-structural ISOtropic (TRISO) particle fuel, which is “randomly packed” in pebble form inside the reactor.
...
With the recent approval, the NRC has given Kairos the go-ahead to build a power plant that will eventually supply power to the grid. Dubbed Hermes 2, the power plant will be sited next to Hermes 1 and will feature two 35-MWth reactors with a combined generation capacity of 20 MWe. Hermes 2 will replicate complete plant architecture at a reduced scale while supplying carbon-free energy to the grid.