Three startups are providing the fireworks for the Department of Energy’s Fourth of July celebrations by reaching a major nuclear milestone. They commissioned new reactors as part of a pilot program to revive what Energy Secretary Chris Wright calls “America’s Nuclear Renaissance” to develop and deploy the next generation of atomic energy.
Other companies participating in the pilot program have indicated that they could reach criticality— a term used to describe a nuclear reactor sustaining a chain reaction, a key step in providing electricity — shortly after July 4, following a deadline set by President Donald Trump in an executive order last year. But experts say that while the pilot project is good communication for the industry, there is still a long way to go before the 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. “They do a lot for companies that reach the critical level, but even for those companies, these are not commercial products. They are test reactors.”
For decades, the U.S. nuclear landscape was dominated by large light-water reactors, which use water to move heat and sustain the nuclear reaction. The dream of building smaller reactors with different, more innovative designs has long remained out of reach, in part because of a slow regulatory environment and the enormous upfront costs required for small companies to develop new reactor designs.
“The industry was considered stuck for a long time: a nuclear reactor was always 10 years away,” says Stein. The pilot program “shows that it’s not true if you intentionally go faster. It changes the narrative and the perception. It means a lot to the investment community.”
A growing number of Silicon Valley investors and tech figures see smaller nuclear reactors, capable of providing carbon-free energy 24/7 to power data centers and other operations, as part of a new golden age of technology. The world of technology has leaned heavily on the Trump administration to reduce regulations and accelerate the development of smaller nuclear designs. The administration responded with a series of actions, including creating the pilot program via an executive order last year. In classic Trump fashion, the executive order, issued in May 2025, set an ambitious timeline for making at least three reactors critical, coinciding with the country’s launch. 250th anniversary celebrations on July 4th.
In February, the Ministry of Energy quietly cut a number of environmental and safety regulations for reactors operated under the responsibility of this ministry, including those under construction under the pilot program. (Similar regulatory reductions are currently being worked out at the Nuclear Regulatory Commission, which approves reactors to be sold commercially.) Stein says shortening processes for requirements like environmental impact statements, which can take years, has created a “significant time savings” for companies participating in the program.
The pilot program’s reactor designs have not only benefited from reduced red tape. Several companies also benefit from help from federally funded national laboratories. Valar Atomics has reached critical level at the end of last year on-site at Los Alamos National Laboratory using a core with the startup’s fuel and key structural components provided by the lab. (The company reached critical level again with a second reactor at a state-funded lab in Utah earlier this month.) Antares Nuclear and Deployable Energy — the other startups in the pilot program that met the executive order’s July 4 deadline — also reached critical level at national labs.
Matt Loszak, co-founder and CEO of Aalo Atomics, credits the government’s prioritization of new reactor development for the speed with which his company has been able to scale. Her business is part of the pilot program and has not yet reached critical level, although she hopes to get there soon.
“Before, you’d try to get a signature, and maybe it would sit on someone’s desk for five weeks,” he says. “Now it’s like it’s done the next day, because it’s a priority for the nation.”
Reaching the criticality level does not mean that these reactors necessarily produce electricity: the Aalo reactor, for example, does not contain the sodium component that the company’s last commercial reactor will contain. (Thursday, the design of the Valar reactor powered (an Nvidia chip in a short demonstration, becoming the first advanced reactor in the United States to provide electricity.) And just proving that criticality can occur in the lab — which many college campuses across the country are doing — doesn’t mean a small reactor is ready to be connected to the grid or deployed to power a data center.
Commercial products will still need to go through authorization with the Nuclear Regulatory Commission, a process that traditionally takes years. (The Trump administration’s regulatory cuts could significantly shorten the process; Wright told CNBC that the NRC is working with his agency to create a “rapid” timeline for bringing the program’s reactors to market.) Stein says supply chains, particularly for fuel, could also pose a major obstacle for companies in the pilot program seeking to commercialize their products. This is especially true for some of the companies that have received help from the Department of Energy to procure fuel.
“It’s an incredible achievement to bring critical new reactors and deploy new reactor technology in 2026,” says Brett Rampal, senior director of nuclear and energy strategy at Veriten, an investment and strategy firm. (Aalo is a Veriten customer.) But Rampal cautions that some in the industry may overly romanticize the idea of a new golden age for nuclear power without fully recognizing the financial realities that plants remain expensive and time-consuming to build.
“If you look at all the nuclear power plants we’ve built across the country, on average they were over cost and over budget,” he says.