X-energy announced that Joel Duling, president of its nuclear fuels subsidiary TRISO-X, will retire effective Nov. 20, 2026, after more than four decades in nuclear operations, manufacturing and program management.
Duling will transition to a part-time senior advisor position focused on strategic fuel partnerships and fuel supply chain development, reporting to X-energy CEO J. Clay Sell. The company said it is evaluating both internal and external candidates for a permanent successor.
Jason Hatfield, TRISO-X vice president and chief of staff, will assume interim leadership of the subsidiary. Dragan Popovic, X-energy's global chief operating officer, will continue overseeing construction of the TX-1 fuel fabrication facility in Oak Ridge, Tennessee.
During Duling's tenure, TRISO-X advanced construction on what X-energy described as the first purpose-built commercial TRISO fuel fabrication facility in the United States. The subsidiary secured the first U.S. Nuclear Regulatory Commission license to commercially manufacture high-assay low-enriched uranium-based TRISO fuel and submitted advanced nuclear fuel for irradiation testing at Idaho National Laboratory's Advanced Test Reactor.
Construction of the 214,000-square-foot TX-1 facility has progressed to interior buildout and installation of fuel fabrication equipment, with continued work on supporting facilities as part of the Advanced Reactor Demonstration Program.
"It has been a true honor and a privilege to lead TRISO-X and work alongside such an exceptional team," Duling said in a statement.
