A new generation of reactors will start producing power in the next few years. They're comparatively tiny—and may be key to hitting our climate goals. //

NuScale uses a light water reactor—by far the most common type of reactor in commercial nuclear power plants—but that’s about where the similarities end. NuScale’s reactor is 65 feet tall and 9 feet in diameter, and is housed in a containment vessel only slightly larger. About the size of two school buses stacked end to end, you could fit around 100 of them in the containment chamber of a large conventional reactor. Yet this small reactor can crank out 60 megawatts of energy, which is about one-tenth the smallest operational reactor in the US today. //

They’re safer, in part because they are small enough to sit in underground pools of water. If a reactor leaks, the heat can slowly diffuse into the pool. That also means the reactors could be built closer to the places where their power is needed, without the 10-mile safety buffer a conventional plant must have.

The Nuclear Regulatory Commission has been reviewing NuScale’s design since 2016; if the commission gives its blessing, the company can finally start building the first commercial reactor of its kind. The review process is brutal—NuScale submitted a 12,000 page technical application—and will likely stretch on for at least another year. But the company has already secured permission to build its first 12-reactor plant at the Idaho National Laboratory //

The Department of Energy is also interested in microreactors, a “plug and play” nuclear plant that usually generates less than 50 megawatts of power. Whereas small modular reactors are better suited to industrial processes and other large power loads, microreactors are ideal for smaller needs like powering a remote military base or keeping the lights on in an isolated Alaskan community //

In the US, the push for small reactors has prompted some changes to the regulatory environment to help companies get a first small reactor online at a federal facility by 2027. But small reactors will still need to prove they can be cost-competitive,