X-energy and its helium-cooled nuclear reactors
X-energy is developing small modular reactors to satisfy some of the planet’s most power-hungry users: industrial manufacturers that need high temperatures to produce billions of tons of concrete, plastics, fibers, and chemicals. Solar panels and wind turbines are great at producing electricity but what heavy industry also needs is raw heat—and lots of it.
Many industries, such as concrete, plastic, glass, steel, and chemical production, rely heavily on fossil fuels to generate the extreme heat needed for manufacturing. This heat is essential but difficult to replace with renewable energy sources like solar or wind, which primarily generate electricity. Industrial heating currently contributes to 18% of annual global greenhouse-gas emissions, with about half of this coming from high-temperature processes that are challenging to electrify. For example, producing cement alone accounts for roughly 8% of global CO₂ emissions, largely due to the heat required in kilns. Traditional methods use natural gas or coal, but these emit significant amounts of carbon dioxide. X-energy’s solution aims to address this by providing a cleaner alternative for industrial heat production.
X-energy is developing a small modular reactor (SMR) called the Xe-100, which uses helium gas as a coolant instead of water. Helium allows the reactor to operate at lower pressures and higher temperatures, making it more efficient for industrial applications. The reactor heats water to create super-heated steam, which can be used directly for industrial processes or to generate 80 megawatts (MW) of electricity via a turbine. This is about one-tenth the capacity of traditional nuclear reactors. The Xe-100 uses a modern uranium-based fuel called TRISO (tristructural-isotropic), which consists of tiny, corrosion-resistant fuel pebbles that flow slowly through the reactor. If temperatures rise uncontrollably, the nuclear reaction naturally slows and stops, enhancing safety.
The TRISO fuel used in the Xe-100 reactor is designed to be extremely safe and resistant to melting or corrosion. Each TRISO fuel pebble is about the size of a tennis ball and contains thousands of tiny uranium particles encased in multiple layers of carbon and ceramic materials. These layers act as a barrier, preventing the release of radioactive materials even in extreme conditions. TRISO fuel is also difficult to repurpose for weapons, making it a safer choice for nonproliferation. However, the Xe-100 may produce up to 10 times more spent nuclear fuel per unit of energy compared to existing reactors, though this waste is expected to be lower in radioactivity and require less sophisticated storage solutions.
The Xe-100 reactor is designed to serve two main purposes: providing high-temperature heat for industries like chemical manufacturing and generating electricity. For industries, the reactor can supply heat directly or produce 80 MW of electricity, which is enough to power a small city. In the fossil fuel industry, it could replace natural gas used to extract oil from tar sands or during oil refining. For electricity generation, the reactor’s small size allows it to be deployed in locations where larger nuclear plants are impractical, such as data centers. AI and data centers are the fastest-growing consumers of electricity in the US, with demand expected to double by 2030. X-energy proposes clustering up to 12 Xe-100 reactors to provide 24/7 power on-site at a lower cost than traditional nuclear plants.
While helium-cooled reactors are a proven technology, commercial-scale deployment remains limited. Currently, only China operates two helium-cooled reactors, and they have faced challenges in maintaining continuous operation. X-energy claims its vertically integrated fuel supply will ensure reliability, with reactors designed to last 60 years. However, the economic viability of SMRs is still unproven. The US Energy Information Administration estimates that electricity from SMRs could cost more than six times that of solar farms. Additionally, regulatory and funding environments in the US currently favor nuclear energy, but this could change over the long development timeline. Public perception and safety concerns also remain hurdles for widespread adoption.
X-energy has made progress in securing regulatory approvals for its technology. The US Nuclear Regulatory Commission issued a fuel fabrication license for TRISO-X pebbles to X-energy’s subsidiary, with the first factory expected to open in 2028. A proposed Xe-100 reactor to supply heat and power to a Dow chemical facility in Texas has cleared its first regulatory hurdle and could be operational by the early 2030s. X-energy is also collaborating with Amazon on a 320 MW cluster of four Xe-100 reactors in Richland, Washington, and plans a larger 6 GW fleet in the UK’s northeast, both targeting electricity generation in the 2030s. These projects highlight the growing interest in SMRs as a flexible and scalable energy solution.
