The Nuclear Regulatory Commission has approved a construction permit for X-energy to build four small modular reactors at a Dow chemical plant in Texas, the nuclear startup announced Monday. The permit marks the first approval for an advanced nuclear reactor at an industrial site in the United States. Each of the four Xe-100 reactors will be capable of generating 80 megawatts of electricity and 200 megawatts of heat, though the reactors are not expected to be operational until the early 2030s.
The nuclear industry has positioned small modular reactors as a faster and cheaper alternative to traditional nuclear plants, though those advantages remain unproven. No small modular reactor currently operates in the United States. X-energy says its design flows helium gas over uranium-containing fuel pellets, which the company claims is safer than many existing reactors.
Safety advocates criticized the approval process. Edwin Lyman, director of nuclear power safety for the Union of Concerned Scientists, said in a statement that the NRC achieved the approval "by pushing consideration of critical safety questions to a later date—issues the NRC should've fully resolved before green lighting construction."
X-energy has attracted significant backing from technology companies seeking electricity sources for data centers. Amazon's Climate Pledge Fund led the company's $500 million Series C-1 funding round, and Amazon has committed to buying 5 gigawatts of capacity from the startup. X-energy raised $1 billion in an April initial public offering, but investor enthusiasm has cooled. The company's shares are trading at less than half their initial offering price.