How hot salt could transform nuclear power

Kairos is making progress on construction, too. The company received approval in December from the NRC to build Hermes-1, its first nuclear test reactor. Hermes-1 will produce about 35 megawatts of thermal power (today’s commercial reactors typically produce around 1,000 megawatts of electricity). It’s planned for completion as soon as 2026.

Several other companies are also using molten salt or TRISO fuel in their advanced nuclear designs. X-energy, based in Maryland, is developing a gas-cooled reactor that uses TRISO fuel, and TerraPower and GE Hitachi Nuclear Energy are developing a sodium-cooled reactor that uses molten salt to store energy. 

There’s still a long road ahead before Kairos’s design and other advanced reactors can make it onto the grid. The company plans to build at least two more large-scale test cooling systems before putting the pieces together for Hermes-1, Blandford says. 

The company will also need to win an operating license for Hermes-1, the second of two major regulatory steps it’ll go through with the NRC. Next comes Hermes-2, which will include two reactors that are similar in scale and design to Hermes-1, plus a system to transform the heat generated into electricity. Finally, the company will move on to larger, commercial-scale reactors.

All of that will take some time, but Kairos and others feel the result will be worth it. “With our technology, it is unique,” Blandford says, “and it does open up unique opportunities to explore spaces that other technologies have not.”