The US Nuclear Regulatory Commission (NRC) has formally completed its landmark safety review for the initial deployment of X-energy’s Xe-100 high-temperature gas-cooled reactor (HTGR). The issuance of the Final Safety Evaluation Report (FSER) marks the completion of the core regulatory reviews needed for a construction permit under 10 CFR Part 50.
The proposed initial deployment will take place at chemical company Dow’s UCC Seadrift Operations facility in Long Mott, Texas. It is slated to become the first grid-scale advanced nuclear reactor operating at an industrial site in the US.
While future applications will face individual evaluations, this review establishes vital regulatory precedents, creating a “replicable pathway” to drastically improve the efficiency of future X-energy Xe-100 SMR licensing.
The Xe-100 design leverages passive physics safety and Tri-structural Isotropic (TRISO) particle fuel. This allows for a compact 400-metre emergency planning zone compared with the 10-mile radius mandated for traditional light-water reactors. This footprint enables placement directly inside industrial perimeters or closer to populations.
The project was developed under the US Department of Energy’s Advanced Reactor Demonstration Program (ARDP). Each reactor produces 80 MWe of or 200 MW of high-temperature process heat for industrial manufacturing.
Amazon is a major anchor investor and shareholder in X-energy, holding roughly a 23% stake in the company. Its involvement goes far beyond simple financial backing, acting as a primary driver for the deployment of the Xe-100 reactors to power its booming artificial intelligence data centre infrastructure.
With both environmental (completed in May) and safety reviews finalised, the independent Advisory Committee on Reactor Safeguards has endorsed the findings, pushing the project into the final stages of construction permit approval. X-energy is also scaling its fuel supply chain, building a specialised TRISO fuel fabrication facility in Oak Ridge, Tennessee.
The technology is also expanding globally, having recently entered the Generic Design Assessment process to begin formal licensing deployment pathways in the UK.
