Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Microstructural Evolution of U-Zr Nuclear Fuel Throughout Fabrication and Irradiation" By Walter J. Williams Purdue MSE Preliminary Exam Advisor: Professor Maria A. Okuniewski ABSTRACT Advanced modeling and modern material science techniques are being coupled to help explain and predict how the microstructure, and thus the overall behavior, of U-Zr alloys will evolve during irradiation. Historically, the complexity of the operating environment and convolved phenomena have hindered fuel engineers from providing quantitative, mechanistic explanations and computational models desired for fuel design optimization decisions. Deployment of material science instruments and microstructural/performance modeling platforms capable of handling nuclear material has provided a pathway for a more detailed exploration into the fundamental phenomena that impacts bulk fuel behavior. Two microstructural phenomena, fuel swelling and thermally driven constituent redistribution, were identified as areas warranting further investigation. The scoping analysis suggested that the following parameters should be explored as driving forces for the phenomena of interest: temperature, composition, crystallographic texture, temperature gradient, fission density, and fission rate. Separate effects testing was chosen to deconvolve these driving forces and phenomena in order to further the fundamental understanding of fuel performance. In order to isolate these variables while remaining relevant to the regimes observed in pin type fast reactor fuels, a novel fabrication technique was utilized to create thin foils of various U-Zr alloys. The microstructure throughout fabrication was investigated through scanning electron microscopy, electron dispersive spectroscopy, and neutron diffraction in order to create an out-of-pile baseline for microstructural evolution. Date: Friday, May 3, 2019 Time: 9:00 A.M. Place: ARMS 1028