INL begins irradiation testing of Lightbridge fuel samples

The irradiation testing campaign is designed to collect key material performance data for the Lightbridge fuel design, Lightbridge said. The start of irradiation follows the successful fabrication and loading of enriched uranium-zirconium coupon samples into an experiment assembly earlier this year.

Irradiation testing involves exposing materials to intense irradiation conditions, to study the effects of those conditions on reactor materials and fuels. The Advanced Test Reactor (ATR) at Idaho National Laboratory is a one-of-a-kind pressurised water test reactor which operates at very low pressures and temperatures compared to a large commercial nuclear power plant, and produces neutrons - rather than heat - as its main output. It is the only US research reactor capable of providing large-volume, high-flux thermal neutron irradiation in a prototype environment.

The irradiation testing campaign is expected to provide essential data on the fuel alloy's microstructural evolution, thermal conductivity properties, and other data as a function of burnup that are critical to the qualification and licensing of Lightbridge Fuel for future commercial use.

Some irradiated samples will be removed at various burnup levels during the testing campaign, to undergo post-irradiation examination at INL to assess the fuel alloy's performance. This will support further design qualification for licensing report submissions.

Jess Gehin, Associate Laboratory Director for Nuclear Science & Technology at INL, said the start of irradiation testing of the samples represents a major achievement for both INL and Lightbridge. "The ATR provides a world-class platform for evaluating advanced nuclear materials under realistic conditions, and we look forward to analysing the results of this important experiment," Gehin said.

"The start of capsule irradiation testing marks a pivotal step in demonstrating the performance of Lightbridge Fuel," Lightbridge Vice President of Engineering Scott Holcombe said. "The data generated in this phase will help us validate some key thermo-mechanical properties of our fuel alloy and how these properties vary with irradiation, moving us closer toward commercial deployment of Lightbridge Fuel in existing and new water-cooled reactors."

Lightbridge Fuel is described by the company as a proprietary next-generation nuclear fuel technology for existing light-water reactors and pressurised heavy-water reactors which it says significantly enhances reactor safety, economics, and proliferation resistance. It is also developing Lightbridge Fuel for new small modular reactors.