This startup is getting closer to bringing next-generation nuclear to the grid

MIT Technology Review released our list of 15 Climate Tech Companies to Watch less than two months ago. Since then, awardee Kairos Power has had three big announcements about its progress toward building next-generation nuclear reactors. 

Each of these bits of news represents an interesting aspect of the process. So let’s dig into the announcements and what they mean for where nuclear technology is going.

First, a quick refresher on Kairos Power: While nuclear plants today overwhelmingly use pressurized water to keep reactors cool, Kairos is using molten salt. The idea is that these reactors (which are also smaller than those typically built today) will help generate electricity in a way that’s safer and more efficient than conventional nuclear power.

When it comes to strategy, Kairos is taking small steps toward the ultimate goal of full-size power plants. Construction began earlier this year on Hermes, the company’s first nuclear test reactor. That facility will generate a small amount of heat—about 35 megawatts’ worth—to demonstrate the technology.

Last week, the company announced it received a construction permit for the next iteration of its system, Hermes 2. This plant will share a location with Hermes, and it will include the infrastructure to transform heat to electricity. That makes it the first electricity-producing next-generation nuclear plant to get this approval in the US.

While this news wasn’t a huge surprise (the company has been working with the Nuclear Regulatory Commission for years), “any day that you’re getting a permit or a license from the NRC is an unusual and special day,” Kairos CEO Mike Laufer told me in an interview.  

The company is developing a plan to work on construction for both Hermes and Hermes 2 at the same time, he added. When I asked if Hermes is still on track to start up in 2027 (as we reported in our profile of the company in October), Laufer said that’s an “aggressive timeline.”

While construction on test reactors is rolling, Kairos is forging ahead with commercial deals—in October, it announced an agreement with Google to build up to 500 megawatts’ worth of power plants by 2035. Under this agreement, Kairos will develop, construct, and operate plants and sell electricity to the tech giant.