Follow Us We are first in your inbox with the most important news in the industry―keeping you smarter and one-step ahead in this ever-changing and competitive market.Start your free subscription The Allure of TRISO Nuclear Fuel Explained Tristructural isotropic (TRISO) particle fuel has long been used in high-temperature gas-cooled nuclear reactors, but it is seeing a resurgence as a result of other applications. Modern TRISO fuel designs are under consideration for an assortment of advanced reactors, including high-temperature reactors and microreactors, and even as accident-tolerant fuel for light water reactors. In October 2020, when the U.S. Department of Energy (DOE) announced it chose TerraPower and X-energy to each receive $80 million in initial federal funding under the agency’s Advanced Reactor Demonstration Program (ARDP) to build their two distinct advanced nuclear reactors and begin operating them within seven years, the advanced reactor community was abuzz about the agency’s larger scope for X-energy. Under the award, Rockville, Maryland–based X-energy will deliver a commercial four-unit power plant (likely in Washington state) based on its Xe-100 reactor design—an 80-MWe/200-MWth pebble-bed high-temperature gas-cooled reactor (HTGR). But X-energy will also leverage the award to deliver a commercial-scale fuel fabrication facility for its proprietary TRISO-X TRi-structural ISOtropic (TRISO) particle fuel, technology it developed under the 2015 DOE Advanced Gas Reactor (AGR) Fuel Qualification Program. As some industry observers noted, the award re-establishes a longstanding commitment by the DOE to render the U.S. into a technology purveyor of the specialized nuclear fuel form that is expected to quickly gain traction around the world as new advanced reactor designs emerge on the global power scene.