X-energy LLC develops Generation IV high-temperature gas-cooled nuclear reactors and the advanced TRISO fuel to power them. The company's technical domains span high-temperature gas-cooled reactor (HTGR) design, high-temperature fuel design, and nuclear thermal propulsion, positioning it at the intersection of the energy and space exploration sectors.
Its primary products are the Xe-100 reactor and TRISO-X fuel. The Xe-100 is a high-temperature gas-cooled reactor design that achieves safety through physics-based passive systems, specifically negative temperature coefficients and passive heat dissipation, rather than relying on active safety mechanisms. TRISO-X is an advanced fuel capable of withstanding extreme temperatures well beyond those of conventional nuclear fuels.