US companies collaborate on TRISO fuel facility
30 November 2018
Centrus Energy Corp and X-energy are to proceed with the preliminary design of a facility to fabricate advanced nuclear fuels based on X-energy's uranium oxycarbide tristructural isotropic (TRISO) fuel forms.
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Individual TRISO particles are typically about 0.85 millimetres in diameter (Image: Idaho National Laboratory)
A new services contract builds on a prior contract signed in March to complete a conceptual design of the facility, which itself followed a 2017 memorandum of understanding on the development of a fabrication facility to provide TRISO fuel for X-energy's Xe-100 high temperature gas-cooled modular reactor and other advanced reactors.
Under the agreement, Centrus will provide X-energy with technical expertise and resources to support preliminary facility design, including detailed nuclear criticality safety analysis, infrastructure design, and balance of plant support systems, as well as initial work on a licence application for the facility. Centrus is also providing facility space to X-energy at Centrus' Technology and Manufacturing Center in Oak Ridge, Tennessee, where X-energy and Centrus employees are working together on the project.
"We see great promise in this market and believe the advanced TRISO fuel to be produced in this facility will offer an attractive and competitive solution to power advanced reactors around the world," Centrus President and CEO Daniel Poneman said.
Pete Pappano, X-energy's principal investigator and vice president of fuels production, said the collaboration had already succeeded in producing a conceptual layout of the TRISO-X Fuel Fabrication Facility.
"With this new agreement, X-energy and Centrus will complete the preliminary and final designs of the TRISO-X Facility, positioning the companies to be first to market in the sector of high assay low enriched uranium (HALEU) TRISO-based fuel for advanced reactors and, potentially, accident tolerant fuel for the existing light water reactor fleet," he said.
The Xe-100 is a 200 MWt (75 MWe) reactor, which X-energy envisages being built as a standard "four-pack" plant generating about 300 MWe. The plant will use 'pebbles' of fuel containing TRISO fuel particles. Each TRISO particle has a kernel of enriched uranium oxycarbide, encased in carbon and ceramic layers which prevent the release of radioactivity. The layers provide each particle with its own independent containment system, while the graphite surrounding the particles moderates the nuclear reaction. Such fuel cannot melt down.
X-energy has already successfully fabricated its first fuel pebbles using natural uranium at a pilot scale fuel facility at the Oak Ridge National Laboratory. The company earlier this year received an award of USD4.5 million from the US Department of Energy for a total cost-shared value of USD8.9 million to design a commercial scale fuel fabrication facility and submit a licence application to the US Nuclear Regulatory Commission by mid-2021.
X-energy President Harlan Bowers said in March that the fabrication facility is scheduled to be producing fuel by 2025, to support first-of-a-kind reactor deployment by the mid- to late-2020s.
Researched and written by World Nuclear News