Date(s) - 12/01/2022
1:55 pm - 2:55 pm
Rhines Hall 125
Lingfeng He, Ph.D.
Associate Professor, Nuclear Engineering
North Carolina State University
Dr. Lingfeng He is an Associate Professor of Nuclear Engineering at NC State University. He was a distinguished staff scientist and High-Resolution Materials Characterization group lead at INL prior to joining NCSU in 2022. He studies materials behavior in extreme environments, with a focus on environmental degradation of materials in nuclear power systems. Dr. He serves as the PI/Co-PI for 17 R&D projects and 47 Nuclear Science User Facility (NSUF) Rapid Turnaround Experiments besides supporting multiple DOE programs at INL. He is the top collaborator at NSUF. He has published 127 peer-reviewed journal articles and held 5 patents. He is the recipient of the INL Laboratory Director’s 2020 Exceptional Scientific Achievement Award.
Ceramic nuclear fuels have been widely used in light water reactors (LWRs) or proposed as accident-tolerant fuels for LWRs or candidates for advanced reactors. In reactor environments, radiation-induced microstructural changes in ceramic nuclear fuels can affect their mechanical/thermal properties and structural integrity/durability. Investigating early-stage microstructural changes is of significance in understanding the performance degradation of ceramic nuclear fuels in reactor environments.
In this work, we study the microstructural evolution as a function of temperature and irradiation dose in both oxide and nitride nuclear fuels using a combination of in situ/ex situ ion irradiation, advanced characterization, and modeling. The irradiation-induced dislocation loops and phase changes are characterized using electron microscopy techniques. Loop density and diameter are analyzed using a kinetic rate theory that considers stoichiometric loop evolution. The energetics of dislocation loop types and phase relationships are studied using multiscale modeling.