MSE Colloquium: Rebecca Schaller, Sandia National Labs

Zoom link:

https://osu.zoom.us/j/97492349610?pwd=dWIwK0NSU0RwNzYvcHVER0RFL2ZsQT09

Meeting ID: 974 9234 9610

Evaluating Stress Corrosion Cracking of Spent Nuclear Fuel Interim Storage Canisters

In dry storage, spent nuclear fuel (SNF) is commonly stored in welded stainless steel canisters enclosed in passively-ventilated concrete overpacks. Over time, dust accumulates on the canister surfaces, and as the SNF cools, salts within that dust can deliquesce to form concentrated brines. If the salts contain aggressive species such as chloride, then the resulting brine can cause localized corrosion (pitting), and if sufficient tensile stresses are present in the metal, stress corrosion cracking (SCC) can occur. Over time, SCC cracks could penetrate the canister wall. The risk of corrosion and SCC is greatest in near-marine settings, where chloride-rich sea-salt aerosols are deposited on the canister surface. Developing an improved understanding of the occurrence and risk of SNF storage canister SCC is considered to be critical to demonstrating the safety of long-term dry storage of SNF. For this reason, the Department of Energy is funding a large effort to evaluate the occurrence and potential consequences of storage canister SCC as well as to develop prevention, mitigation, and repair technologies for this degradation mechanism, if it should occur. 

Bio

Rebecca Schaller is currently a staff scientist in the Materials Reliability Group at Sandia National Laboratories in Albuquerque, NM. She earned a B.S. degree in Spanish in 2005 from the University of Oregon and an M.S. degree in Physics from Portland State University in 2010. Rebecca received her Ph.D. in Materials Science and Engineering from the University of Virginia in 2016 under the direction of Professor John R. Scully. Her work focused on developing techniques to probe local-scale hydrogen concentrations and interactions in ultra-high-strength steels. During her graduate work, Rebecca received an Endeavour Research Fellowship, which was carried out in collaboration with Monash University and the Commonwealth Scientific and Industrial Research Organization in Clayton, Australia. Since completing her Ph.D., Rebecca has worked as a postdoctoral assistant at Sandia National Laboratories and an assistant professor at the University of British Columbia and has more recently returned to SNL as a staff scientist. Currently, her research focuses on chemical and morphological effects on corrosion at the local, microstructural level to better predict overall corrosion properties and rates.