Microstructure and Chemical Property Studies in the Materials of Sodium-cooled Fast Reactor

with  Dr. Yi Xie, Purdue University
Friday, August 5th, 10:15am – 11:15am
117A Randolph Hall

 The U-10Zr (wt.%) fuel is the leading fuel candidate for sodium-cooled fast reactor (SFR) and is anticipated to be fabricated in rod geometry by extrusion technology. Understanding the microstructure and phase evolutions as a result of irradiation and thermal cycling at elevated temperatures is of paramount importance for the development and ultimately licensing of this fuel form. The compositions with higher Zr contents are also important as during reactor operation the Zr redistributes and results in a Zr-rich fuel center region. Thermal cycling neutron diffraction experiments were carried out to study the evolutions of microstructure and phase from the time-of-flight neutron diffraction data, with a focus on lattice parameter, atom ordering, unit cell volume, texture, and weight fractions. Lanthanide-induced fuel-cladding chemical interaction (FCCI) is the key concern of the fuel. To investigate the effects of composition and microstructure of cladding on FCCI, out-of-pile diffusion couple tests were carried out with a focus of chemical interaction zones formed by between lanthanides and different types of stainless steels, including HT-9, Fe-Cr oxide dispersion-strengthened (ODS), Fe-Cr-Ni ODS, wrought SS316L, and additively manufactured SS316L. Radionuclide release in the primary sodium coolant due to fuel and cladding failures is one of the many issues associated with the development and deployment of SFR. Tellurium (Te) is one of the main radionuclides released from the fuel fragmentations. It has been commonly detected in the primary sodium coolant under normal and abnormal operating conditions. Immersion corrosion experiments were carried out to study the Te-induced corrosion effects on SS304L and its alloy elements.

Yi Xie is an Assistant Professor in the School of Nuclear Engineering at Purdue University. Her research areas are focused on advanced manufacturing and materials degradation. She developed the fast heating system which achieves exceptional heating rate and energy saving for materials fabrication; she also investigated the corrosion problems of materials in extreme environments, and developed advanced nuclear fuels with higher-fission rate characteristics. She is the PI of the Materials Innovation for Nuclear Energy laboratory and advises four PhD students and one Master student. She is the Virtual Labs Faculty Fellow and Paul Zmola Scholar at Purdue University. She has more than 50 peer-reviewed journal articles and conference papers. She serves the Program Committee of ANS's Materials Science & Tech Division and User Org Committee of DOE Nuclear Science User Facilities, and serves the TMS 2023 Annual Conference as the organizer of the symposium Microstructural, Mechanical and Chemical Behavior of Solid Nuclear Fuel and Fuel-cladding Interface, and co-organizer of the symposium Additive Manufacturing for Energy Applications V. She obtained the Bachelor degree from University of Science and Technology of China and the PhD degree from The Ohio State University. She was a postdoc at Virginia Tech and the inaugural Glenn T. Seaborg Distinguished Post-Doctoral Fellow and Research Staff at Idaho National Laboratory.