| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Elucidating Microstructural Evolution Under Extreme Environments
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| Presentation Title |
Examining Fission Gas Diffusion at Grain Boundaries in Advanced Nuclear Fuels |
| Author(s) |
Sarah C. Finkeldei, John M Proctor, Oran Lori, Shen Dillon, Joshua T White, Yongqiang Wang, Michael Cooper, David Andersson |
| On-Site Speaker (Planned) |
Sarah C. Finkeldei |
| Abstract Scope |
This study investigates atomic transport phenomena of non‐equilibrium defects at grain boundaries (GBs) under extreme environments to elucidate interactions between point defects, solutes, and line defects at GBs. Fission gas implantation and generation of FG surrogates (He) were enabled by ion implantation at the IBML, LANL and irradiations at UCI’s TRIGA reactor in doped UO2. Electrochemical impedance spectroscopy will unravel defect mobilities upon irradiation at GBs. Moreover, a nucleation rate limited creep model was developed via bicrystal experiments, enabling a more accurate description of stress range, grain size and temperature dependence. Additionally, our new cluster dynamics model predicts steady-state concentrations of defects at UO2 GBs by tracking rate of point defect production, and depletion, under irradiation. Under irradiation the concentration of U interstitials are predicted to be significantly enhanced at UO2 GBs and their fast mobility results in GB U self-diffusion being orders of magnitude greater than bulk U self-diffusion. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Nuclear Materials, Ceramics, High-Temperature Materials |