NRC finishes its safety review of X-energy's Xe-100 plant for Dow's Long Mott site in Texas
Serguey Asael Shinder1 min readThe US Nuclear Regulatory Commission released on 30 October its Final Safety Evaluation Report for the construction permit application of the Long Mott Generating Station in Texas, a plant of four X-energy Xe-100 high-temperature gas-cooled reactors. The report records the NRC staff's conclusion that the proposed plant and site provide the safety basis to begin construction under US rules.
The environmental review was completed in May with an Environmental Assessment and a Finding of No Significant Impact, so both primary reviews for the permit are now done, X-energy said. On social media the regulator told followers to stay tuned for a construction permit announcement soon.
Long Mott Energy, a wholly owned subsidiary of Dow, applied in March 2025. The four reactors would produce 800 MWt or 320 MWe of electricity and process steam for Dow's Seadrift Operations, exporting any surplus to the grid; X-energy says that would make it the first grid-scale advanced reactor at an industrial facility in US history. It is also the first construction permit application for a high-temperature gas-cooled reactor under the NRC's technology-inclusive, risk-informed and performance-based framework.
What it means
A construction permit is not an operating licence; the plant still has to be built and licensed to run. But the review has gone from application to finished safety evaluation in about 19 months, and that timing is what other advanced reactor applicants will now plan against.