GNF and X-energy team up to produce TRISO fuel

07 November 2019

Global Nuclear Fuel (GNF) and X-energy are to collaborate to produce high-assay low-enriched uranium (HALEU) tristructural isotropic (TRISO) particle nuclear fuel, which they expect to be able to produce at lower costs than other potential manufacturers.

TRISO particles (Image: Idaho National Laboratory)

The two companies yesterday announced the signing of a teaming agreement to develop the fuel for its potential supply to the US Department of Defense for micro-reactors and to NASA for its nuclear thermal propulsion requirements. Using X-energy's operating commercial-scale TRISO production equipment and GNF's licensed nuclear fuel fabrication facility in Wilmington, North Carolina, the arrangement is expected to produce TRISO fuel of "significantly higher quality and at costs that are substantially lower than other potential manufacturers", they said.

X-energy CEO Clay Sell said TRISO was a robust fuel form well-suited to military and space applications, but its economic viability in the market place had in the past been limited by the "extremely high and unnecessary cost" of working with HALEU in a Category I facility - the highest strategic significance classification used by the US Nuclear Regulatory Commission for special nuclear materials and the facilities that possess them. Physical security requirements differ by category, with Category I facilities subject to the most stringent requirements.

"Utilising X-energy's already operational state-of-the-art equipment in GNF's licensed facility changes the dynamic for TRISO-fuelled reactor deployment," Sell said.

GE Hitachi Nuclear Energy President and CEO Jay Wileman said combining X-energy's technical knowledge and experience as the only current producer of TRISO fuel and GNF's licensed operating facility and half century of commercial fuel experience and leadership "make this a formidable team".

TRISO-coated fuels, which are used in high-temperature reactors (HTR), have a uranium kernel coated with three layers of pyrolytic carbon and one layer of silicon carbide. These coatings encapsulate all fission products, effectively giving each TRISO particle its own containment. X-energy is manufacturing TRISO particles at a pilot fuel facility at Oak Ridge National Laboratory, and is continuing to build on the TRISO fuel technology developed under the US Department of Energy (DOE) Advanced Gas Reactor Fuel Qualification Program through two active cooperative agreements with the DOE. The company is also developing the Xe-100 200 MWt (75 MWe) reactor, which will use 'pebbles' of fuel containing TRISO fuel particles, and has previously requested a DOE loan guarantee for commercialisation of the TRISO-based fuel supply chain.

According to World Nuclear Association, the world's main HTR fuel fabrication plant is at Baotou in China, which makes 300,000 fuel pebbles per year for the the HTR-PM reactor under construction at Shidaowan. Japan's Nuclear Fuel Industries Ltd (NFI) also has 400 kgU/yr HTR fuel production capacity at Tokai. X-energy earlier this year signed a memorandum of understanding with that company to create a partnership for the supply of TRISO nuclear fuel fabrication equipment, planning for the transfer of commercial-scale equipment from NFI’s Tokai Works facility to X-energy’s Oak Ridge TRISO fuel fabrication facility. It has also previously agreed to work with Centrus Energy Corp on the preliminary design of a TRISO fuel fabrication facility.

BWX Technologies in October announced the restart and plans for the expansion of its existing TRISO fuel production line at its facility in Lynchburg, Virginia.

Researched and written by World Nuclear News