US-based X-energy announced on 9 August that it will expand its fuel division as a wholly owned subsidiary called TRISO-X to commercially develop its proprietary tristructural isotropic (TRISO) fuel for the burgeoning advanced nuclear energy sector. Dr Pete Pappano, X-energy’s Vice President of fuel production, will lead the new company as its President. Since joining X-energy in 2015, Dr Pappano has been instrumental in supporting the company’s ability to produce advanced nuclear fuel at a commercial scale. As the leader of X-energy’s ARC15 project, a five-year programme funded by the Department of Energy, he established a commercial-scale fuel line at Oak Ridge National Laboratory, which has demonstrated the company’s patented TRISO fabrication process leading to higher yields and higher quality fuel.

“After years of seeing the incredible results from our partnership with Oak Ridge, I’m thrilled to embark on this next chapter in the development of X-energy’s advanced fuel program,” said Dr Pappano. “We’re ready to commercialise our TRISO fuel so the entire advanced nuclear industry can benefit from its unparalleled safety and performance.”

The new company takes its name from the TRISO nuclear fuel developed by X-energy for its flagship Xe-100 reactor, but the fuel is compatible with a variety of other advanced reactor designs under development. “We’re ready to commercialise our TRISO fuel so the entire advanced nuclear industry can benefit from its unparalleled safety and performance,” Dr Pappano added.

X-energy CEO J. Clay Sell said: “The nuclear energy industry is on the cusp of a paradigm shift that will be driven by advanced reactors like the Xe-100. Many of the next generation reactor designs are powered by TRISO fuel and meeting this demand will require new supply chains and fabrication processes. It’s a once-in-a-lifetime business opportunity that we’ve been preparing for and no one is better suited to lead this effort than Dr Pete Pappano.”

X-energy is ready to begin commercial production after years of refining its TRISO fabrication processes. TRISO-X is poised to break ground on a commercial facility in order to meet the Xe-100 deployment schedule that sees at least four Xe-100 modules coming online in Washington state by 2027. TRISO-X is also advancing plans for a second fuel fabrication facility in Canada to serve the Canadian market.

The Xe-100 design is under consideration by Ontario Power Generation for the Darlington New Nuclear Project, and X-energy is currently advancing design and engineering work with the utility. At the same time, X-energy is well-advanced in the Canadian Nuclear Safety Commission’s optional Pre-Licensing Vendor Design Review.

“Canada is at the forefront of SMR deployment, and the Xe-100 presents a true opportunity to deploy inherently safe Generation IV advanced reactors in the near term,” said Katherine Moshonas Cole, President of X-energy Canada. “The formation of our TRISO-X subsidiary provides assurances for high-quality fuel supply. I’m excited TRISO-X is looking at Canada for building capacity. This is a big opportunity to grow the uranium value chain here in Canada, creating sustainable jobs for Canadians.” 

X-energy’s TRISO-X fuel consists of kernels of high-assay low-enriched uranium the size of a poppy seed wrapped in three alternating layers of pyrolytic carbon and silicon carbide. More than 18,000 of TRISO-X particles are embedded in a graphite fuel pebble, making the fuel “meltdown proof.” These fuel pebbles are loaded into Xe-100 reactor modules and together are capable of producing 320 MWe in the standard four-pack Xe-100 plant configuration.

“TRISO-X is key to the safety of advanced nuclear reactors,” said Dr Brandon Blamer, Pebble Lead & Process Engineering Manager. “Each TRISO-X particle carries its own containment vessel and is made from materials that will never melt. This fuel is unlike anything used in American reactors today and is going to revolutionize the nuclear industry.” “TRISO-X fuel is small, but mighty,” said Dr Dan Brown, TRISO Fuel Fabrication Manager. “We’ve built on decades of research to create a safe, clean, and efficient fuel that is ready to power the next generation of nuclear reactors.”