NE Seminar: “Radiation Effects in Ceramic Nuclear Fuels”

Details

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.

Abstract

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.