TRISO-X is X-energy's fuel fabrication subsidiary and received the first ever NRC Category II licence enabling commercial-scale TRISO fuel manufacture at its co-located TX-1 and TX-2 facility sites in Oak Ridge, Tennessee in February 2026. This is the first commercial TRISO fuel manufacturing licence in US history. TRISO (Tristructural Isotropic) fuel pebbles contain uranium particles coated with three layers of carbon-based and silicon carbide materials — providing passive safety at temperatures up to 1,600°C, far exceeding any accident scenario. TRISO-X fuel is the fuel type used in the X-energy Xe-100, Kairos Power FHR, and Westinghouse eVinci microreactor.
X-energy shareholders (public after April 2026 IPO)