Are Small Nuclear Reactors the Future of Energy?

Could there come a time when, in addition to a Starbucks and a CVS, every neighborhood will have its own local nuclear reactor? One DC company thinks it could happen someday. Don’t freak out yet: That possibility is a long way off. But if Last Energy is correct, your home could one day run on electricity generated by a mini-reactor around the corner.

Founded in 2020 by tech entrepreneur Bret Kugelmass, Last Energy builds small modular reactors that can pump out enough electricity to power individual factories or small residential areas. “If anyone actually cares about solving climate change,” he says, “the only path forward, the only thing that makes even the smallest amount of logical sense, is to throw all of your weight behind nuclear.”

Last Energy builds and sells these reactors overseas, but its headquarters is in a sleek office space near U Street and Vermont Avenue, Northwest. Kugelmass left Silicon Valley for DC in 2017 because the location would put him near energy policymakers and visiting European leaders who make up most of his current customer base. “I moved here thinking, ‘Policy, climate, energy,’ ” he says. “I didn’t know anyone here, but I needed to get out of the Silicon Valley mindset.”

So far, all of Last Energy’s customers—in Poland, the Netherlands, and other countries—intend to use the modular reactors to power things like data centers and factories, not residential neighborhoods. The company has built life-size prototypes to promote the idea. The tech itself isn’t altogether new: a 20-megawatt light-water reactor partially buried underground in an easy-to-assemble modular steel structure. The challenge is convincing customers, regulators, and—obviously—the public that small-scale nukes are a good idea. That means people in our area are unlikely to have a reactor on the corner soon. But like any good tech CEO, Kugelmass is a relentless promoter of his concept. “Nuclear will be the only energy source that future civilizations use,” he insists.

Well, maybe. There is reason for caution when it comes to modular reactors, according to some experts. “It’s important to be skeptical of startups pushing nuclear as a panacea for climate change,” says Edwin Lyman, director of nuclear-power safety for the watchdog group Union of Concerned Scientists. Lyman points out that nuclear power still carries all of the well-known risks: carcinogenic waste, vulnerability to attacks, and the massive damage that could occur if there were to be an accident. “Frankly, when it comes to new nuclear-reactor designs,” he says, “you have to be very skeptical about claims they can be rapidly deployed and reliably operated and be economical and safe.”

This article appears in the December 2023 issue of Washingtonian.