The Idaho National Laboratory (INL) has begun irradiation testing of fuel samples made from a uranium-zirconium alloy developed by Lightbridge Corporation. This operation is part of a Cooperative Research and Development Agreement between the company and the federal laboratory, aimed at qualifying the technology for future commercial use in nuclear reactors.
A facility dedicated to testing in a representative environment
The samples were loaded into an experimental capsule designed for the Advanced Test Reactor (ATR) at INL. This pressurised water research reactor, unique in the United States, allows high-flux thermal neutron irradiation under conditions representative of those in commercial reactors, while operating at lower pressure and temperature. Unlike power reactors, its primary output is neutrons for material research purposes.
Critical data for fuel validation
The testing campaign aims to collect data on the microstructural evolution, thermal conductivity, and other properties of the alloy as a function of burnup. These results are essential for future regulatory submissions. Some samples will be removed at various irradiation stages for post-irradiation examination within the laboratory, supporting the technical qualification of the fuel.
A milestone for Lightbridge’s industrial strategy
Lightbridge Corporation is developing its metallic fuel for use in light-water and pressurised heavy-water reactors, as well as in next-generation small modular reactors. The stated goal is to enable the commercial adoption of a fuel with increased energy density and technical characteristics compatible with existing systems.
Lightbridge’s Vice President of Engineering, Scott Holcombe, stated that the tests will help “validate some key thermo-mechanical properties” of the fuel, with a view to integration in water-cooled reactors.
