3 Nuclear Startups That Have Breakthrough Why It Matters – and Why It Doesn’t

Three startups are: Providing fireworks for the Department of Energy’s Fourth of July celebrations by achieving a major nuclear milestone. They have commissioned new reactors as part of a pilot program aimed at launching what Energy Secretary Chris Wright calls an “American nuclear renaissance” to develop and deploy the next generation of atomic energy.

Other companies in the pilot program have indicated they may reach criticality — a term used to describe a nuclear reactor that maintains a chain reaction, a key step in saving energy — shortly after the Fourth of July, after the deadline set by President Donald Trump in an executive order last year. But experts say that while the pilot project represents good public relations for the industry, there is still a long way to go before new reactor designs become a commercial reality.

“These prototypes mean everything and nothing,” says Adam Stein, director of the Nuclear Energy Innovation Program at the Breakthrough Institute. “It does a lot for companies that get to the point of importance, but even for those companies, they’re not commercial products. They’re test reactors.”

For decades, the American nuclear landscape has been dominated by large light-water reactors, which use water to transfer heat and maintain the nuclear reaction. The dream of building smaller reactors of different, more innovative designs has long remained elusive, thanks in part to the sluggish regulatory environment and the enormous upfront cost required for small companies to develop new reactor designs.

“The industry has always been seen as stuck, with a nuclear reactor always being 10 years away,” says Stein. “The pilot shows that’s not true, if you intentionally move faster. It changes the narrative, it changes the perception. That means a lot to the investment community.”

A growing number of Silicon Valley investors and tech figures see smaller nuclear reactors, which can provide 24/7 carbon-free power to power data centers and other operations, as part of a new golden age of technology. The technology world has relied heavily on the Trump administration to cut regulations and speed up development of smaller nuclear designs. The administration has responded with a series of actions, including establishing the pilot program by executive order last year. In classic Trumpian fashion, the executive order, issued in May 2025, set an aggressive timetable for preparing at least three reactors, coinciding with the country’s 250th anniversary celebrations on the Fourth of July.

Last February, the Department of Energy quietly reduced a number of environmental and safety regulations for reactors operating under that department’s jurisdiction, including those being built as part of the pilot program. (Similar regulatory cuts are now in the works at the Nuclear Regulatory Commission, which approves reactors to be sold commercially.) Stine says shortening processes for requirements such as environmental impact statements, which can take years, has saved “significant time” for companies participating in the program.

The reactor designs in the pilot program not only benefited from reduced red tape. Many companies also get help from federally funded national laboratories. Valar Atomics reached criticality late last year at the Los Alamos National Laboratory site using a core with the startup’s fuel and key structural components provided by the laboratory. (The company reached criticality again with a second reactor at a state-funded laboratory site in Utah earlier this month.) Antares Nuclear and Deployable Energy — the other startups in the pilot program that met the July 4 deadline — have also reached criticality at national laboratories.

Matt Loszak, co-founder and CEO of Aalo Atomics, credits the government with prioritizing new reactor development for the speed at which his company has been able to move. His company is part of the pilot program and has not yet reached criticality, although it expects to do so soon.