Dr. Marat Khafizov,
Associate Professor
Nuclear Engineering Program
Mechanical and Aerospace Engineering
The Ohio State University

Abstract

Understanding the impact of radiation environment on physical properties of nuclear fuel is important for design, operation, and safety analysis of nuclear reactors. Fuel performance codes are used to analyze behavior of fuels under various operating conditions. Predictive capability of traditionally engineering scale fuel performance codes depends on a development of mechanistic models for microstructure evolution and structure-property relationship based on atomic level understanding of materials behavior. Validation of lower scale models for microstructure evolution under irradiation has been hindered by availability of table-top experimental methods suitable for defect characterization at the atomic level. This presentation will discuss extensive characterization of defects in ion irradiated fluorite oxides including urania, thoria, and ceria. Ion beam radiations over a range of temperatures to a few displacements per atom dose provide optimal conditions for producing both point and extended defects. Electron microscopy is used to characterize extended defects, while optical and Raman spectroscopies are used to characterize point defects. Quantitative analysis of dislocation loops evolution using rate theory model provides means for measuring mobility of defects and predicting point defect concentration. Raman and optical spectroscopies probe vibrational and electronic properties of defects all tightly coupled to atomic structure of the defects and can serve an important role in validating atomistic level models. Thermal conductivity is used as a model physical property for testing structure-property relationship models. Finally, the implications of findings from the atomic level calculations on fission gas behavior will be discussed.

Biography  

Prof. Marat Khafizov is an associate professor in the Department of Mechanical and Aerospace Engineering at The Ohio State University where he directs Thermal properties of Materials for Extreme environments (TME) laboratory. His research interests are in investigating the impact of radiation damage on properties of materials and development of experimental methods for measuring material’s physical properties in extreme environments. Dr. Khafizov serves as the Deputy Director for the Center for Thermal Energy Transport under Irradiation, an Energy Frontiers Research Center funded by the U.S. Department of Energy, Office of Basic Energy Sciences. In this capacity, he coordinates center’s experimental and modeling research aimed at understanding microstructure evolution and its impact on thermal transport in oxide and nitride fuels.  Prior to joining OSU, he was a research scientist at Idaho National Laboratory (INL) where he was a member of the Center for Materials Science of Nuclear Fuel (CMSNF) aimed understanding of the impact of radiation damage on thermal transport in materials for nuclear fuel. While at INL, he was involved with the development of thermal conductivity microscope (TCM). Prof. Khafizov obtained his Ph.D. degree in Physics from University of Rochester in 2008.

Thursday, September 19. 2024
4:10 pm seminar

zoom link upon request