The $2.4 billion Long Mott Generating Station Plant in Texas has moved to the final permitting stage. The US Nuclear Regulatory Commission released its Final Safety Evaluation Report for the project. Consequently, a construction permit announcement is expected soon.
The safety review covered the Xe-100 plant’s principal design criteria, preliminary design and safety analyses. It also examined the probabilistic risk assessment and research programmes. NRC staff concluded that the proposed plant and site provide the safety basis to begin construction under US nuclear regulations.
The regulator completed its environmental review in May, when it issued an Environmental Assessment and Finding of No Significant Impact. Both primary reviews are therefore complete. On its social media channels, the NRC told followers to “stay tuned for a construction permit announcement soon”.
Other Projects
Power projects such as the Long Matt Generating station are fundamental to the advancement of data center projects such as SpaceXAI’s Colossus 2 data center expansion project in Mississippi. SpaceXAI is focusing on expansion of its Colossus 2 data center across two additional campuses in Southaven, Mississippi. CEO Elon Musk announced the sites, dubbed Gun Range and Spam, in reference to their former uses. Both should run by the end of the year. Gun Range sits on a 55.9-acre parcel that once held a police and fire training center. It will host two single-story buildings and a high-performance AI training cluster. Spam occupies 53 acres and reuses a warehouse that once stored products from Hormel Foods, the maker of Spam. Musk said the company is optimising it for inference work.
Scope of implementation on the Long Mott Generating Station Plant
Long Mott Energy, a wholly owned subsidiary of The Dow Chemical Company, submitted the construction permit application in March 2025. The proposed plant consists of four Xe-100 high-temperature gas-cooled reactors. Together they generate 800 megawatts thermal, or 320 megawatts electrical. The plant will generate electricity and process steam for Dow’s Seadrift Operations. It will also export any excess power to the grid. X-energy says this makes it the first grid-scale advanced nuclear reactor at an industrial facility in US history.
The facility targets the production of more than 4 billion pounds of materials per year at the 4,700-acre Seadrift site. It will also replace aging, end-of-life energy and steam infrastructure there. In April 2026, X-energy signed an engineering, procurement and construction contract with Fluor Corporation to advance the plant layout.
The licensing effort draws on decades of work. X-energy began engaging with the NRC on its technology in 2018. Meanwhile, the Department of Energy has researched the reactor class for decades. Notably, the Xe-100 is the first HTGR construction permit application to use the NRC’s technology-inclusive, risk-informed, and performance-based licensing framework.
“Licensing a new reactor is earned through the quality of the application and the rigor of the regulator’s review,” said Dragan Popovic, Chief Global Operating Officer at X-energy. “The NRC’s completion of its safety review reflects years of disciplined work by our team and the NRC staff, establishing the foundations to support every Xe-100 application that follows on the path to scale.”
Outlook for the Long Mott Generating Station project
The project sits under the Department of Energy’s Advanced Reactor Demonstration Program, a 50/50 cost-share framework covering up to $2.4 billion in estimated development expenses. Dow became X-energy’s first major commercial offtaker in 2022. The two companies later signed a joint development agreement with $50 million for site-specific engineering.
However, the NRC permit only starts the clock. Construction, TRISO fuel supply from X-energy’s Oak Ridge facility, and first power all remain ahead. If the permit lands as expected, the reactors still need years of build-out before serving Dow’s Gulf Coast operations. Even so, the project stands first in line to prove advanced reactors can power heavy industry in the United States.
Project Overview
- Project Value: $2.4 billion estimated
- Location: Seadrift, Texas
- Developer: Long Mott Energy (Dow subsidiary)
- Technology: X-energy Xe-100 reactors
- Status: Final NRC permitting stage
Scope
- Four high-temperature gas-cooled reactors
- 800 megawatts thermal combined output
- 320 megawatts electrical capacity
- Electricity and steam for Dow
Project Highlights
- First advanced reactor at US industrial site
- First HTGR under new licensing framework
- Replaces end-of-life steam infrastructure
- Supports 4 billion pounds of production
Key Developments
- Permit application filed March 2025
- Environmental review completed May 2026
- Fluor EPC contract signed April 2026
- Safety report issued October 30, 2026
Key Challenges
- Construction permit still pending
- Construction phase not yet funded fully
- TRISO fuel supply must scale
- First power still years away
Outlook
- Permit announcement expected soon
- Grid-scale industrial nuclear first
- DOE cost-share covers $2.4 billion
- Excess power exports to grid
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