DOE-supported project becomes first advanced nuclear facility approved for construction at a U.S. industrial site.
November 13, 2026
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The U.S. Nuclear Regulatory Commission (NRC) approved a construction permit on November 9 for Dow and X-energy’s proposed Long Mott Generating Station at Dow’s Seadrift Operations site in Texas.
The approval marks the first advanced nuclear facility authorized for construction at a U.S. industrial site, the first NRC construction permit for a high-temperature gas-cooled reactor in more than 50 years, and the first-ever NRC approval for a pebble-bed core design.
This project is supported by the U.S. Department of Energy’s (DOE) Advanced Reactor Demonstration Program, which aims to accelerate commercial deployment of advanced nuclear reactor technologies in the United States.
Nuclear Power for American Industry
The proposed Long Mott Generating Station would deploy four X-energy Xe-100 small modular reactors to provide reliable electricity and high-temperature steam to Dow’s Seadrift manufacturing operations.
Each Xe-100 reactor is designed to produce 80 megawatts of electricity or 200 megawatts of thermal energy. Together, the four reactors could provide up to 320 megawatts of electricity while supporting the site’s industrial steam needs for 60 years.
The project demonstrates how advanced nuclear reactors could support energy-intensive manufacturing operations by providing both electricity and process heat directly where they are needed.
“This milestone marks a significant step forward for the Department of Energy’s Advanced Reactor Demonstration Program and our efforts to bring next-generation nuclear technologies to market,” said Principal Deputy Assistant Secretary for Nuclear Energy Mike Goff. “The NRC’s approval demonstrates meaningful progress toward deploying advanced reactors that can deliver reliable power and industrial heat, strengthen American energy leadership and expand the role of nuclear energy in meeting our nation’s growing energy demands.”
Meet the Next Generation
X-energy’s Xe-100 is a high-temperature gas-cooled reactor that uses TRISO-X fuel, a form of tri-structural isotropic (TRISO) coated particle fuel that uses high-assay, low-enriched uranium (HALEU), and is designed to retain radioactive materials under extreme conditions beyond any credible accident scenario.
The Xe-100 combines the robust characteristics of TRISO fuel with advanced safety features for a flexible design that enables a dramatically smaller footprint than conventional light-water reactors.
DOE has supported decades of research and development on high-temperature gas-cooled reactors and TRISO fuel technologies, helping establish the technical foundation for today's advanced reactor designs.
TRISO-X, a wholly owned subsidiary of X-energy, completed vertical construction in September 2026 on its TX-1 fuel fabrication facility in Oak Ridge, Tennessee, to produce TRISO-X fuel “pebbles” for the Xe-100. The facility is the first commercial-scale HALEU fuel fabrication facility in the United States to receive NRC approval, and the first new U.S. fuel facility licensed in over 50 years.
What’s Next?
The construction permit allows X-energy and Dow to advance the project toward construction readiness, including finalizing the Xe-100 design, strengthening the supply chain for long-lead components, and preparing an operating license application for NRC review.
If completed, Long Mott Generating Station would demonstrate a new application for advanced nuclear energy in the United States, providing dependable electricity and industrial steam directly to a major manufacturing facility that helps nuclear technology expand beyond conventional power, and into the industries powering our country forward.
The project is targeting initial energy delivery in the early 2030s.