X-energy wins US approval to build its first four small modular reactors

Permit covers four reactors in Texas

Nuclear startup X-energy announced on Monday that it has received a construction permit from the US Nuclear Regulatory Commission, the federal agency that oversees civilian nuclear power, according to TechCrunch. The permit covers its first four commercial reactors, which will be built in Texas.

The reactors are linked to a project with the chemicals company Dow. X-energy says the reactors will not be operational until the early 2030s.

Why small reactors are seen as a faster path

Small modular reactors, or SMRs, are compact nuclear reactors built from factory-made parts rather than assembled entirely on site. Supporters of the technology argue that building reactors at a smaller size will make construction faster and cheaper than for traditional nuclear plants.

Those advantages have not yet been demonstrated. No small modular reactor is currently operating in the United States, and the first reactors remain years away from service. The permit is a significant milestone for the industry, but it marks the start of a long construction process rather than the finish line.

Safety questions raised by experts

X-energy says its design, which passes helium gas over fuel pellets containing uranium, is safer than many existing reactors. The Union of Concerned Scientists has questioned both that claim and the speed of the permitting process.

The group's director of nuclear power safety, Edwin Lyman, said in a statement that the NRC had only achieved the approval by deferring safety questions that he argued should have been fully resolved before construction was allowed to begin. The concerns have not yet been addressed in the permit process, so readers should treat both the company's safety claims and the criticisms as contested.

Tech money and a choppy stock market debut

The nuclear sector has attracted strong interest from large technology companies that need more electricity for data centres. Amazon's Climate Pledge Fund led X-energy's $500 million Series C-1 funding round, and Amazon has also committed to buying 5 gigawatts of capacity from the company.

X-energy held an initial public offering in April 2026 that raised $1 billion. Investor enthusiasm has cooled since then. The permit approval gave the shares a small lift, but only enough to recover the previous week's losses, and the stock still trades at less than half its offering price.

The caution is understandable. Nuclear plants are expensive and slow to build, and while X-energy aims to reduce both cost and construction time, its first reactors are likely to be costly.

What the permit means for readers

The approval shows that US regulators are willing to license new small reactor designs, which could clear the way for similar projects. For data centre operators and companies with net-zero commitments, it adds another potential source of low-carbon power, though not until the early 2030s.

The project will still need to prove that small reactors can be built on time and on budget. Until then, the technology's promise rests largely on claims that have yet to be tested in the field.