Researchers at the Department of Energy's (DOE) Oak Ridge National Laboratory (ORNL) have successfully completed mechanical property measurements on irradiated HALEU TRISO fuel particles, marking another step in ORNL's leadership in developing and qualifying next-generation nuclear fuel.
The achievement follows ORNL's recent neutron scattering measurements on HALEU-containing TRISO particles earlier this year.
Tristructural isotopic (TRISO) fuel's multiple layers of protective coating make it among the most robust nuclear fuel in the world. Understanding how these layers change after irradiation is critical for predicting fuel performance in advanced reactor designs.
Using ORNL's instrumented indentation system for irradiated materials and nuclear fuels, researchers measured the mechanical properties of the individual inner and outer pyrolytic carbon and silicon carbide layers of TRISO particles from the Advanced Gas Reactor Fuel Development and Qualification Program. Tests in ORNL's nanomechanics laboratory showed changes in hardness and stiffness, including reduced modulus and hardness in the silicon carbide layer and changes in the pyrolytic carbon layers.
"These measurements can help compare a particle's original manufactured condition with how it behaves after irradiation at different temperatures and burnups," said ORNL's Katherine Montoya, a R&D associate staff member in the Particle Fuel Forms group. "These data improve nuclear fuel performance models and support the broader adoption of gas reactors."
