X-Energy, a developer of advanced nuclear reactors and fuel technology, and Dow, through its wholly-owned subsidiary Long Mott Energy, on Nov. 9 announced that the U.S. Nuclear Regulatory Commission has approved the Construction Permit Application for the proposed construction of four Xe-100 advanced small modular reactors at Dow’s UCC Seadrift Operations site in Texas.
The CPA approval makes Long Mott Generating Station the first advanced nuclear facility approved for an industrial site in the United States, "a historic milestone achieved under the U.S. Department of Energy’s Advanced Reactor Demonstration Program," x-Energy said.
Approval of the construction permit enables X-energy and Dow to continue advancing the proposed project toward construction readiness, finalizing and standardizing the Xe-100 design, maturing the supply chain for long-lead components and materials, and developing an Operating License application for submission to the NRC, x-Energy said.
"This supports Dow’s consideration of the proposed project’s next phases, ensuring the design, equipment, and materials are in place before allocating major capital for full-scale construction, consistent with Dow’s proven global project management practices. For a first-of-a-kind project, this reduces schedule and cost risk once work begins on site, and is aligned to the Company’s established timeline of first delivery in the early 2030s," x-Energy added.
The issuance marks the first NRC CPA approval of a high-temperature gas-cooled reactor in nearly 60 years, the first-ever pebble-bed HTGR approval and the first-ever for a nuclear industrial deployment.
The NRC’s review found that the Xe-100 design can be safely sited and constructed within an operating industrial site.
The proposed plant is intended to provide both electricity and high-temperature steam to Dow’s site, replacing existing energy and steam assets near their end-of-life. The four first-of-a-kind Xe-100s deployed at Seadrift are expected to provide power to the site for 60 years.
The NRC completed its review in alignment with its established schedule, evaluating the safety and environmental impacts of the proposed Xe-100 facility against the global benchmark for safe, responsible operation of nuclear technology.
"Across both parts of the review, the intrinsic safety characteristics of the design and extensive pre-application engagement supported an efficient, thorough, independent review that met or exceeded the NRC’s high standard, supported by decades of U.S. Department of Energy research on HTGRs and TRISO fuel, and strengthened by the passage of the bipartisan ADVANCE Act in 2024," x-Energy said. "CPA approval by the NRC builds on this body of work, and positions future Xe-100 applications for enhanced efficiency in commercial nuclear licensing by incorporating learnings from Long Mott’s review."
Since 2018 and 2023, X-energy and Dow, respectively, have worked with the NRC through extensive pre-application engagement to demonstrate the safety profile of the Xe-100 and its TRISO-X fuel, directly cited by the NRC as a contributor to the application’s efficient review, x-Energy said.
The companies "intend to carry this same discipline and rigor into the next phase of the project, ensuring construction and commercial readiness before major site work begins to reduce cost and schedule risk. Dow is expected to consider a preliminary investment decision in 2027."
Full-scale nuclear construction would begin following Dow’s final investment decision.
