US-based TRISO-X, a wholly-owned subsidiary of X-Energy, has been awarded an $11m economic development grant by the State of Tennessee’s Nuclear Energy Supply Chain Investment Fund established by Governor Bill Lee in 2023. The fund is intended to support nuclear investment, workforce development, and site development and to expand the State’s nuclear manufacturing ecosystem.
The grant will fund expansion of TRISO-X’s fuel fabrication campus on a 110-acre site at the Horizon Center Industrial Park campus in Oak Ridge where a commercial-scale fuel fabrication facility (TX-1) is already under construction.
The Horizon Center Industrial Park is located within the original boundary of the Oak Ridge Reservation (ORR), but it is no longer within the area of the ORR controlled by the Department of Energy (DOE). It is now owned and managed by the Oak Ridge Industrial Development Board (IDB) for private economic development.
The site has transitioned from a top-secret government buffer zone to a modern industrial hub. During the post WWII and cold war eras the land was a “greenfield” portion of the ORR. Unlike the nearby Heritage Center (the former K-25 enrichment site), the Horizon Center land was primarily used as a security and safety buffer.
The DOE-managed part of the ORR primarily houses three major, separate operating installations – the Oak Ridge National Laboratory (ORNL); Y-12 (nuclear weapons component production, dismantlement, and the storage of special nuclear materials); and the East Tennessee Technology Park (ETTP), formerly the K-25 uranium enrichment site now undergoing environmental cleanup for use as a private-sector industrial and technology park.
TX-1 began vertical construction in late 2025 and is part of X-energy’s participation DOE’s Advanced Reactor Demonstration Program. The new funding will support development of TX-2, a second, larger fuel fabrication facility, currently in the design phase. This is anticipated to significantly expand capacity, with enhanced automation and production efficiency based on TX-1 operational experience, expected to create more than 1,000 permanent jobs.
TX-2 would significantly scale TRISO fuel production capacity to support X-energy’s planned commercial pipeline for its Xe-100 small modular reactor (SMR) as well as for other SMR developers. X-energy says full-scale production at TX-1 and TX-2 is expected to establish a stable commercial source of TRISO fuel for the first time in US.
As of late 2025, TRISO-X is expanding its pilot-scale footprint through the DOE’s Fuel Line Pilot Program with the aim of building an additional laboratory facility (TX-L) to support pilot-scale integration. This will strengthen the domestic supply chain for HALEU fuel testing and provide a “fast-track” for system validation and training before TX-1 becomes fully operational (targeted for late 2026/2027).
Together, TX-1, TX-2 and TX-L are designed to establish domestic, commercial-scale manufacturing and research capabilities for TRISO-X fuel. When completed, the campus is expected to establish one of the world’s largest commercial-scale nuclear fuel fabrication campuses, with the capacity to produce enough TRISO-X fuel to support approximately 55 of X-energy’s Xe-100 advanced small modular reactors.
In February 2026, TRISO-X received a 40-year Special Nuclear Material License under 10 CFR Part 70 from the U.S. Nuclear Regulatory Commission, enabling TRISO-X to commercially manufacture fuel using high-assay low-enriched uranium (HALEU) covering both TX-1 and TX-2 under a single license.
TRISO-X’s fuel fabrication campus is the product of nearly a decade of fuel development and qualification by X-energy and TRISO-X, beginning in 2016 with a pilot facility at ORNL to optimise established TRISO manufacturing processes for commercial scale production. 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 (INL’s) Advanced Test Reactor, with testing ongoing to qualify TRISO-X fuel for use in the Xe-100 and expand the performance envelope for TRISO fuels.
TRISO-X also has a pilot facility located inside the ORNL campus, which has been operational since 2016 and serves as the primary testing ground for the company’s proprietary fuel fabrication process. It operates through a public-private partnership Unlike the future commercial plant that will produce tonnes of fuel, the ORNL pilot line produces kilogram quantities of HALEU. TRISO-X uses this site to adapt and refine established TRISO production methods for commercial-scale use. Fuel produced there is used for critical testing. The pilot facility allows engineers to validate the “spherical fuel pebble” design intended for X-Energy’s Xe-100 reactor.
TRISO-X additionally has a R&D centre located within the Centrus Technology Manufacturing Center (TMC) in the industrial area of Oak Ridge town. Centrus provides the facility space, technical expertise, and engineering resources for TRISO-X’s development activities. Employees from both companies work together at this site on the design and licensing of fuel fabrication technology.
The R&D centre at the TMC is specifically used to train operators who will eventually work at the commercial facility being built at the Horizon Center. While the pilot facility at ORNL handles the nuclear chemistry and fabrication R&D, the Centrus Technology Manufacturing Center focuses on the mechanical engineering and operator training aspects of the project.
