US-based Mirion Technologies has been awarded a strategic design contract with X-Energy Reactor Company to provide detailed design support for the Burn Up Measurement System (BUMS) for the fuel cycle of the Xe-100 high-temperature gas-cooled reactor (HTGR). BUMS is a key element of the online reactor’s fuel handling system. BUMS, composed of high-purity Germanium (HPGe) detectors to ensure accuracy, is designed to maximise nuclear fuel utilisation. Mirion said this will make the system more productive while minimising waste.
In 2021, X-energy was awarded $1.2bn billion in federal cost-shared funding from the US Department of Energy’s Advanced Reactor Demonstration Program (ADRP) to develop, license, build and demonstrate an operational advanced reactor and fuel fabrication facility by the end of the decade.
The Xe-100 is a high-temperature gas reactor with a thermal output of 200 MWt or an electrical output of 80 MWe. It was one of two designs selected by DOE in 2020 to receive $80m each of initial cost-shared funding to build an advanced reactor demonstration plant that can be operational within seven years. The Xe-100 evolved from both the UK’s Dragon reactor at Winfrith in Dorset and the Pebble Bed Modular Reactor project in South Africa. It will use TRIstructural ISOtropic (TRISO) fuel comprising three layers of carbon and ceramic materials that surround kernels or balls of high-assay low-enriched uranium (HALEU) fuel.
BUMS measures key gamma indicators to determine the level of burn-up, the initial enrichment of the fuel, and the plutonium/uranium (Pu/U) content in each fuel pebble being circulated through the reactor. X-energy President Harlan Bowers says BUMS is “a critical subsystem of our reactors that both ensures we meet our fuel efficiency projections while at the same time safely and reliably operating”. He added that tests of the BUMS prototype are expected to begin in 2024 and construction of the first operational units will start in 2025.
Image: The Xe-100 reactor design (courtesy of X-energy)
