Texas Project Secures First US Gas-Cooled Nuclear Reactor Permit in Decades
The US Nuclear Regulatory Commission has authorized a construction permit for the Long Mott Generating Station in Texas. As reported by Interesting Engineering, this milestone represents the first approval for a high-temperature gas-cooled reactor in nearly 60 years and the agency’s first ever permit for a multi-module facility utilizing advanced pebble-bed technology.
Context from Industry Pulse
The approval of the Long Mott facility highlights a shift toward integrating nuclear energy directly into industrial supply chains. By utilizing high-temperature steam, the project aims to replace fossil-fuel-based heat sources in manufacturing. This transition is supported by the Department of Energy’s Advanced Reactor Demonstration Program, which focuses on next-generation technologies like the Xe-100. Simultaneously, other large-scale infrastructure projects are advancing in Texas, such as the 46,000-square-foot B-21 stealth bomber hub, reflecting a broader trend of significant industrial and defense investments within the state during late 2026. The NRC's streamlined 18-month review process for this multi-module site suggests an evolving regulatory landscape for small modular reactors.
The Long Mott Generating Station, located in Calhoun County, Texas, will utilize four Xe-100 small modular reactors. Developed by X-energy, these units are designed to integrate directly with industrial manufacturing. According to Interesting Engineering, the facility is being spearheaded by Long Mott Energy, a subsidiary of the chemical producer Dow, to serve its Seadrift Operations site. The primary purpose of the installation is to provide high-temperature steam for energy-intensive industrial processes, though it will also generate electricity for the local grid.
The technical specifications for the site include a combined thermal capacity of 800 megawatts and an electrical capacity of 320 megawatts. Each of the four modules is capable of producing 80 megawatts of electricity alongside heat for industrial use. Interesting Engineering notes that the Xe-100 design utilizes helium as a coolant and graphite pebbles containing tri-structural isotropic fuel particles. This pebble-bed configuration allows for online refueling, meaning the reactor does not need to shut down to add new fuel.
The regulatory process for this project set several precedents. Interesting Engineering reports that the Nuclear Regulatory Commission completed its safety evaluation within an 18-month window, finishing ahead of the original schedule. The review utilized the Licensing Modernization Project framework, which is designed to be technology-inclusive and risk-informed. This marks the third construction permit for an advanced reactor issued by the agency in 2026.
While the permit is a critical step, it does not allow for immediate operation or the loading of nuclear fuel. According to Interesting Engineering, a separate operating license will be required before the plant can begin service. Dow has indicated that it must still complete further engineering work and receive board approval before making a final investment decision. If the project proceeds, construction is expected to start later this decade with a target operational date in the early 2030s.
The Industry Pulse Bottom Line
This permit establishes a regulatory blueprint for high-temperature gas reactors in the US, potentially decoupling industrial heat requirements from fossil fuels while testing the commercial viability of pebble-bed, online-refueling technology at scale.