Vertical construction at Oak Ridge is nearly finished. The hard part starts now.
TRISO-X, a wholly owned subsidiary of X-energy, announced on August 24 that its TX-1 advanced nuclear fuel fabrication facility has entered its next construction phase, with Clark Construction Group staying on as general contractor. The new phase covers auxiliary buildings, interior build-out and equipment installation.
What changes when a nuclear job goes inside
Clark’s remaining scope is the interior of a 214,000-square-foot process equipment and administration building, installation of the fuel fabrication equipment itself, and construction of an adjacent graphite matrix powder building. On paper that reads like fit-out. In practice it is a different job than the one Clark just finished.
Structural work on a licensed nuclear materials facility is demanding but familiar. Process-equipment installation inside one is not. The trade mix shifts to pipefitters, instrumentation technicians, cleanroom trades and radiological controls, working under a Nuclear Regulatory Commission license rather than a building code alone. Every weld, every penetration and every commissioning step carries a documentation burden that most commercial GCs never encounter.
The license is real and independently verifiable: the NRC granted TRISO-X a 40-year Special Nuclear Material License, which the company describes as the first Category 2 nuclear fuel facility license issued to process High Assay Low Enriched Uranium. The “first ever” framing is X-energy’s.
The demand behind it, and the caveats
TRISO-X projects 700,000 TRISO pebbles a year at full output, equal to five metric tons of uranium, or enough fuel for up to 11 Xe-100 reactors. Those are company projections in a forward-looking-statements release. So is the claim that this will be the first new commercial-scale U.S. nuclear fuel fabrication facility in over half a century, though that one is hard to argue with.
Joel Duling, TRISO-X’s president, called the phase change “an important transition point as we move toward installing the systems and equipment that will make the facility operational.” Downstream, the fuel is meant for X-energy’s four-unit plant at Dow’s UCC Seadrift operations on the Texas Gulf Coast and the Cascade Advanced Energy Facility with Energy Northwest and Amazon.
The company has also bought another 70 acres at Horizon Center, extended its research agreement with Oak Ridge National Laboratory and won a Tennessee economic development grant. Whether the reactors that eat this fuel get built on the announced schedule is a separate question. The fuel plant is going up regardless, and it is teaching a large commercial contractor a set of skills the industry will need repeatedly.
Related on Exchange: TVA’s gas plant replacement at Kingston.
Sources: X-energy / TRISO-X, August 24, 2026; X-energy Q2 2026 results.