NederlandsSmall X-energy nuclear reactor passes safety review: construction permit for plant at Texas chemical site moves closer
The US nuclear regulator NRC has completed its safety review of the Xe-100, a small reactor cooled with helium gas. Four of these reactors are to supply power and steam to a Dow plant in Texas. The construction permit is the next step.
The US Nuclear Regulatory Commission (NRC), which oversees nuclear power plants, published its final safety report on the Xe-100 on 30 October 2026. This is a small nuclear reactor from the American company X-energy. The conclusion of the NRC staff: the design and the chosen site offer a safe basis to start building.
With this, both major reviews needed for a construction permit are complete. The environmental review was already finished in May 2026, when the NRC found no major impact on the surroundings. The NRC's independent advisory body on reactor safety has also looked at the report and supports the permit. On social media, the NRC said a decision on the construction permit will follow soon.
Four reactors next to a chemical plant
The application comes from Long Mott Energy, a subsidiary of the chemicals group Dow. Dow submitted it in March 2025. The plan: four Xe-100 reactors at Dow's plant in Seadrift, Texas. Together they supply 320 megawatts of electricity, or 800 megawatts of heat. Dow wants to use the power and the steam in its own plant; whatever is left goes to the electricity grid. According to X-energy, this will be the first new-generation, grid-scale nuclear reactor at an industrial site in the United States.
A chemical plant needs not only electricity but also a lot of hot steam. Today this is mostly made by burning gas. A reactor that runs very hot itself can supply that steam without CO2 emissions.
How the Xe-100 works
Ordinary nuclear power plants are cooled with water. The Xe-100 uses helium gas. This allows the reactor to run much hotter than a water-cooled reactor, which is exactly what a factory needs for its steam. Each reactor supplies 80 megawatts of electricity or 200 megawatts of heat.
The fuel is held in spheres the size of a billiard ball. Each sphere contains thousands of tiny grains of uranium, each wrapped in protective layers. These layers keep the radioactive material inside, even when it gets very hot in the reactor. Because the fuel consists of separate spheres, new ones can be added while the reactor keeps running.
According to X-energy, the design is so safe that the zone around the plant that needs an emergency plan is only 400 metres across. For ordinary nuclear power plants it is about 16 kilometres. This means such a reactor can stand closer to a factory.
A new way of reviewing
The Xe-100 is the first application for this type of reactor that the NRC reviews with a newer approach. In it, the regulator looks mainly at the real risks of a design, instead of at rules written for water-cooled reactors. X-energy has been talking to the NRC about the design since 2018. The project is supported by the US Department of Energy, which has been researching this type of reactor for decades. A review of the Xe-100 has also started in the United Kingdom.
According to Dragan Popovic, one of X-energy's senior executives, a company must earn such a permit with a good application, and the regulator must earn it with a strict review. In his view, the work of recent years lays the foundation for future Xe-100 projects.
The construction permit itself has not been granted yet and construction has not started. After construction, a separate licence is also needed to operate the reactors. Each future project will be assessed again.
What does this mean for the road to the singularity?
Powerful AI needs enormous amounts of electricity, and data centres and factories are looking for sources that deliver around the clock without CO2 emissions. Small nuclear reactors are one of the candidates, but new designs often get stuck on the years a licence takes. The fact that the NRC has completed this review shows that a new type of reactor can get through the assessment. If the construction permit and the building succeed, this could clear the way for more of these reactors, also at data centres: X-energy is already working with Amazon, among others.
What is the technological singularity? Read the explanation →
