Furthermore, Russia’s invasion of Ukraine in 2022 slammed the doors on supplies of Russian uranium, including the fuel with a higher concentration of uranium-235 that’s needed to make the pellets for Kairos’s efficient reactors. The US and Europe have since been scrambling to mobilize domestic production, but the process will take years. In the meantime, the DOE has agreed to supply Kairos and a few other US companies developing similar reactors with limited quantities of the specialized uranium for their near-term fuel needs.
Even with a regular supply, transporting that uranium to reactors won’t be straightforward. There isn’t yet a special container approved by the US Nuclear Regulatory Commission that could move it in any significant volume, and using existing containers could take thousands of shipments to fuel a single reactor. Kairos has said that it could potentially use a less enriched type of uranium to prove its technology’s viability while the supply of its desired version is tight.
Next steps
Kairos is now building three reactors simultaneously —two non-nuclear test units to validate its systems, and the Hermes experimental nuclear reactor. These facilities will prove the molten salt technology at full scale, without generating any usable power. Kairos will soon start work on another, Hermes 2, which will be the company’s first system to produce electricity.
When that 50-megawatt reactor comes online in 2030, Kairos will sell its power to the Tennessee Valley Authority, the US’s largest public power provider, and the associated clean energy credits to Google. Google has agreed to purchase up to 500 megawatts of generation capacity from Kairos by 2035 to help decarbonize its data centers. But take all those dates with a pinch of molten salt—nuclear power stations usually come in late and over budget.
