TRISO-X, a wholly-owned subsidiary of X-Energy, has announced that its TX-1 fuel fabrication facility is progressing to the interior buildout phase. This stage involves the installation of fuel fabrication equipment and continued construction of supporting facilities. The TX-1 facility is projected to produce approximately 700,000 TRISO-X fuel pebbles annually, which is equivalent to five tonnes of uranium and can fuel up to 11 Xe-100 reactors. This production capacity is initially intended to support X-energy's proposed deployment of the Xe-100 advanced 
small modular reactor at Dow Inc.’s UCC Seadrift Operations manufacturing site in Texas.
Earlier this year, the US Nuclear Regulatory Commission granted TRISO-X a 40-year Special Nuclear Material License for the facility. This license permits the commercial manufacturing of fuel using high-assay low-enriched uranium (HALEU) at its first two commercial facilities, TX-1 and TX-2. Joel Duling, President of TRISO-X, stated that the transition from core and shell construction to interior utilities, manufacturing equipment installation, and key support capabilities marks a significant step towards establishing a domestic source of advanced nuclear fuel.
In July, TRISO-X received an USD11 million grant from the State of Tennessee. This funding is designated to support the ongoing development of its fuel fabrication campus in Oak Ridge, which includes plans for a potential second commercial fuel facility and a dedicated research and development center. The campus is designed to establish domestic, commercial-scale manufacturing and research capabilities for TRISO-X fuel, which is the company's proprietary tristructural isotropic (TRISO) fuel for advanced nuclear reactors.
The campus will comprise three facilities: TX-1, TX-2, and TX-L. TX-1 is the initial commercial facility. TX-2, a larger facility, is anticipated to significantly expand capacity with enhanced automation and production efficiency, leveraging operational experience from TX-1. TX-L, a dedicated fuel fabrication laboratory, will focus on fuel innovation, testing, and continuous improvement of TRISO manufacturing processes. These facilities are the culmination of nearly a decade of fuel development and qualification efforts by X-energy and TRISO-X, which began in 2016 with a pilot facility at Oak Ridge National Laboratory aimed at optimizing TRISO manufacturing processes for commercial scale.
In 2025, TRISO-X fuel became the first advanced nuclear fuel form fabricated for commercial use to undergo irradiation testing at Idaho National Laboratory's Advanced Test Reactor. Testing is ongoing to qualify TRISO-X fuel for use in the Xe-100 and to expand the performance envelope for TRISO fuels. TRISO fuel consists of small spheres of enriched uranium coated with multiple layers of carbon and ceramic materials, forming a robust shell designed to withstand high temperatures. HALEU contains between 5% and 20% fissile uranium-235, which is a higher enrichment level than the 3.5% to 5% U-235 typically found in fuel used in current commercial reactors.
