US-based Centrus Energy and X-energy are to proceed with the preliminary design of a facility to fabricate advanced uranium oxycarbide tristructural isotropic (Triso) fuel forms for X-energy's high temperature gas-cooled reactor (X-100), and other advanced designs.
A new services agreement builds on a previous contract signed in March to complete a conceptual design of the facility. Both come under a 2017 memorandum of understanding on the development of a fabrication facility to provide Triso fuel.
Under the latest agreement, Centrus will provide X-energy with "technical expertise and resources" to support the preliminary design of the facility, including nuclear criticality safety analysis, infrastructure design, and balance of plant support systems. It will also support initial licensing work.
X-energy will also be provided with space at Centrus' facility in Oak Ridge, Tennessee, where X-energy and Centrus employees are working jointly on the project.
The team had already produced a conceptual layout of the Triso-X Fuel Fabrication Facility, according to Pete Pappano, principal investigator and vice president of fuels productio at X-energy.
"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 Triso-based fuel for advanced reactors and, potentially, accident tolerant fuel for the existing light water reactor fleet," Pappano said.
The Xe-100 is a 200MWt (75MWe) reactor, which X-energy envisages being built as a standard "four-pack" plant generating about 300MWe. The plant will use 'pebbles' of fuel containing Triso fuel particles.
X-energy has already fabricated its first fuel pebbles using natural uranium at Oak Ridge National Laboratory. The company has also received an award of $4.5 million from the US Department of Energy (DOE) for a total cost-shared value of $8.9 million to design a commercial scale fuel fabrication facility and submit a licence application to the US Nuclear Regulatory Commission by mid-2021.
