Department of Chemistry Seminar – Dr. Lingfeng He, North Carolina State University
About the event
Speaker: Lingfeng He, Ph.D.
Associate Professor of Nuclear Engineering
North Carolina State University
Title: Advanced Characterization of Irradiated Nuclear Fuels
Abstract: Nuclear fuel experiences substantial alterations in both its microstructure and chemical composition during its time in a reactor. While some fission products remain integrated within the uranium dioxide (UO2) matrix, other inert gases like xenon (Xe) and krypton (Kr), as well as certain 4d group metals (molybdenum, technetium, ruthenium, rhodium, and palladium), form nanoprecipitates within the UO2 matrix. In certain areas of the UO2 fuel, these Kr/Xe precipitates and metallic precipitates can also come together to create paired structures at the rim regions. Furthermore, as the burn-up levels increase, grain subdivision within the UO2 occurs, giving rise to a high burn-up structure (HBS) characterized by the presence of nanograins. Advanced electron microscopy and synchrotron characterization techniques have been employed to investigate the microstructure of an irradiated UO2 fuel from Belgium Reactor 3 (BR3). To emulate the microstructural changes of nuclear fuels in reactor environments, in-situ ion irradiation has been used to visualize the dynamic evolution of fission products and HBS in the BR3 fuel.
Bio: Lingfeng He is an Associate Professor of Nuclear Engineering at North Carolina State University (NCSU) and holds a join faculty appointment with Idaho National Laboratory (INL). Prior to joining NCSU in 2022, he served as a distinguished staff scientist and led the High-Resolution Materials Characterization group at INL. Dr. He leads the Materials In eXtremes (MIX) lab at NCSU and his research primarily centers on investigating materials’ responses to radiation, corrosion, stress, and ultrahigh temperature extremes. Dr. He serves as the PI/Co-PI for 17 R&D projects and 48 Nuclear Science User Facility (NSUF) Rapid Turnaround Experiments besides supporting multiple DOE programs. He is the top collaborator at NSUF. He has published 140 peer-reviewed journal articles and held 5 patents. He is the recipient of the INL Laboratory Director’s 2020 Exceptional Scientific Achievement Award.