US nuclear fuel technology company Lightbridge Corporation announced a significant milestone in its nuclear fuel development efforts. It performed a co-extrusion demonstration of a coupon sample consisting of an alloy of depleted uranium and zirconium with an outer cladding made of nuclear-grade zirconium alloy material. The co- demonstration was conducted at the Idaho National Laboratory (INL). It entailed pressing the metallic alloy billet encased in zirconium alloy cladding through a die to produce a cylindrical rod approximately eight feet long.
Lightbridge said the demonstration coupon sample represents a key fabrication milestone under its Strategic Partnership Project Agreement with Battelle Energy Alliance (BEA), which is Department of Energy’s (DOE) operating contractor for INL.
The uranium-zirconium alloy used in the demonstration rodlet is the same composition that Lightbridge plans to use for its future commercial Lightbridge Fuel product. INL and Lightbridge will now analyse the co-extruded coupon sample to confirm the extrusion process parameters.
This paves the way for future production of coupon samples using enriched uranium, which will undergo capsule irradiation testing in INL’s Advanced Test Reactor (ATR) under an existing Cooperative R&D Agreement between Lightbridge and BEA. This planned irradiation testing programme, coupled with post irradiation examination activities, aims to generate critical irradiation performance data for Lightbridge’s fuel and support regulatory licensing efforts for its commercial deployment.
“The co-extrusion of this coupon sample leverages the capabilities of INL’s Materials and Fuels Complex and underscores our commitment to advancing nuclear energy innovation,” said INL Associate Laboratory Director Ron Crone. According to Dr Scott Holcombe, Vice President of Engineering at Lightbridge Corporation, the co-extrusion demonstration “is a testament to the continuous progress we have made over the past year on demonstration of our fuel fabrication process in our collaborative efforts with INL”. In May 2024, INL and Lightbridge demonstrated the production of a partial-length rod sample using an alloy of depleted uranium and zirconium.
Lightbridge Fuel is a proprietary next-generation nuclear fuel technology for existing light water reactors and pressurised heavy water reactors, intended to significantly enhance reactor safety, economics, and proliferation resistance. The Company is also developing Lightbridge Fuel for new small modular reactors. Lightbridge has two long-term framework agreements BEA. DOE’s Gateway for Accelerated Innovation in Nuclear (GAIN) programme has twice supported Lightbridge fuel development. Lightbridge is participating in two university-led studies through the DOE Nuclear Energy University Programme at Massachusetts Institute of Technology and Texas A&M University.
