The Nuclear Fuel Materials Group advances safe and efficient nuclear power by applying materials science to design, develop, optimize, and test prototypical advanced nuclear fuels and structural materials that will accelerate the deployment of higher performance nuclear energy systems. Material systems of emphasis include a range of fuel, cladding, and structural systems that support both existing commercial light water nuclear reactors as well as advanced concepts for a range of applications. The group maintains international leadership in the science of coated particle fuel development (e.g. TRISO), use of advanced and additive manufacturing technologies to provide innovative performance solutions to traditional fuel and cladding materials, development of methods for advanced materials characterization and modeling , and execution of irradiations and post irradiation examination (PIE) focused on the performance of nuclear fuel materials. Leveraging ORNL’s nuclear infrastructure, including hot cells and low-activation laboratories, the group has established PIE capabilities on a wide range of materials from full-length commercial rods to individual microspheres including techniques for mechanical properties measurements, high-resolution gamma-ray spectroscopy, high temperature fuel safety testing, 3D x-ray computed tomography and microstructural characterization.