NRC Hands Dow and X-energy a Construction Permit for Four Texas Reactors

The NRC issued the construction permit on Nov. 9 for four X-energy Xe-100 reactors at Dow's Seadrift chemical manufacturing site in Texas. The proposed Long Mott Generating Station would replace electricity and steam assets that Dow says are nearing the end of their lives. According to the NRC, the plant would mainly make steam for industrial use, with surplus electricity sent to the grid.

The permit covers construction only. Long Mott Energy, Dow's wholly owned subsidiary developing the project, needs a separate NRC operating license before it can load fuel or fire up the reactors. And Dow has not made a final call on building the plant at all.

The four-module design is listed at 800 megawatts thermal and 320 megawatts electric. Each module can produce 80 megawatts of electricity or roughly 200 megawatts thermal of steam — a setup where industrial heat, not just power, is the point.

The NRC called it the first U.S. construction permit for a high-temperature gas-cooled reactor in nearly 60 years, and its first approval of a multimodule advanced reactor facility. Chairman Ho K. Nieh said the agency hit its 18-month review schedule.

What's left is a lot of work. Dow said engineering and design finalization plus board review still stand between the permit and shovels in the ground. Construction could start later this decade with startup in the early next decade, and X-energy said Dow is expected to weigh a preliminary investment decision in 2027, with full-scale nuclear construction following a final investment decision.

X-energy says Long Mott can serve as a reference plant for later Xe-100 applications, with approved generic technical reports reusable for subsequent customers — its pipeline includes the Cascade Advanced Energy Facility with Amazon and Energy Northwest. Each of those would still get its own review. Edward Stones, Dow's business vice president for Energy & Climate, said the company will weigh “competitiveness, execution readiness, and capital affordability” before deciding whether to construct.