TRISO-X, which is a wholly-owned subsidiary of X-Energy, says the first such project in the US can move on to “interior buildout, installation of fuel fabrication equipment and continued construction of supporting facilities”.
The plan is for the completed TX-1 to produce about 700,000 TRISO-X fuel pebbles each year – equivalent to five tonnes of uranium, with capacity to fuel up to 11 Xe-100 reactors. Initially, it is expected 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.
The US Nuclear Regulatory Commission granted TRISO-X a 40-year Special Nuclear Material License for the facility earlier this year, enabling it to commercially manufacture 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, said: “We are moving from constructing the core and shell of the facility to building out the interior utilities, installing manufacturing equipment, and constructing key support capabilities. Every milestone brings us closer to establishing a new domestic source of advanced nuclear fuel and supporting the deployment of the next generation of American nuclear reactors.”
In July TRISO-X received a grant from the State of Tennessee of USD11 million to support the continued development of its fuel fabrication campus in Oak Ridge, including a potential second commercial fuel facility and a dedicated research and development centre.
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How the completed TRISO-X fuel fabrication campus could look (Image: X-energy)
Together, the three facilities are designed to establish domestic, commercial-scale manufacturing and research capabilities for TRISO-X fuel, the company’s proprietary tristructural isotropic – or TRISO – fuel for advanced nuclear reactors. In addition to TX-1, a second, larger fuel fabrication facility, TX-2, is anticipated to significantly expand capacity, with enhanced automation and production efficiency based on TX-1 operational experience. A dedicated fuel fabrication laboratory facility, TX-L, will focus on fuel innovation, testing, and continuous improvement of TRISO manufacturing processes.
X-energy said TX-1, TX-2, and TX-L are 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 Oak Ridge National Laboratory 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 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 fuel is composed of small spheres of enriched uranium that are coated with multiple layers of carbon and ceramic materials, forming a robust shell that can withstand high temperatures. HALEU contains between 5% and 20% of fissile uranium-235 – a higher enrichment than that found in typical uranium fuel used in today’s operating commercial reactors, which contains between 3.5% and 5% U-235.
