3 Nuclear Startups Hit a Milestone: What It Means and What It Doesn't

Three nuclear startups—Valar Atomics, Antares Nuclear, and Deployable Energy—have reached a significant milestone by achieving criticality in their reactors as part of a Department of Energy pilot program. The program, established by a Trump executive order, set a July 4 deadline to kickstart what Energy Secretary Chris Wright calls “America’s nuclear renaissance.” Other companies, including Aalo Atomics, are expected to reach criticality soon.

Experts caution that these achievements are only a first step. “These prototypes mean everything and nothing,” says Adam Stein of the Breakthrough Institute. “They do a lot for the companies reaching criticality, but even for those companies, they’re not commercial products. They’re test reactors.”

Commercial reactors will still need to go through Nuclear Regulatory Commission licensing, a process that traditionally takes years. While the Trump administration slashed environmental and safety regulations to speed things up, supply chains—especially for fuel—remain a major hurdle. Valar Atomics achieved criticality at Los Alamos National Laboratory and later at a state lab in Utah. In a brief demonstration, Valar's reactor powered an Nvidia chip, marking the first time an advanced U.S. reactor generated electricity.

Despite the progress, industry experts urge realism. “It’s an amazing achievement to bring new reactors critical and deploy new reactor technology in 2026,” says Brett Rampal of Veriten, an investing firm. “But if you go back and look at all the nuclear power plants we built throughout the country, on average, they were over cost and over budget.” He warns against romanticizing a new golden age for nuclear without acknowledging financial realities.