| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Microstructural, Mechanical, and Chemical Behavior of Solid Nuclear Fuel and Fuel-Cladding Interface II
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| Presentation Title |
Faulted Loop Formation by Rapid 1D Migration of Interstitial Clusters in ThO2: Insights from Molecular Dynamics Simulations |
| Author(s) |
Lin-Chieh Yu, Yongfeng Zhang |
| On-Site Speaker (Planned) |
Lin-Chieh Yu |
| Abstract Scope |
Thorium dioxide (ThO2) is a promising nuclear fuel for next-generation reactors. However, irradiation-induced defects such as point defects, defect clusters, and dislocation loops can significantly reduce its thermomechanical performance. Understanding defect evolution is crucial for comprehending the microstructural evolution in ThO2. In this study, we employ molecular dynamics simulations to investigate the formation mechanism of faulted dislocation loops, a commonly observed type of defects that substantially degrades thermal conductivity. However, the loop formation mechanism remains unclear as the high migration barrier of Th interstitial makes loop formation by Th interstitial absorption unlikely. By monitoring the migration, growth, and interaction of interstitial-type of defects, we found that small clusters of Th and O interstitials exhibit higher diffusivities than individual Th defects, and they are responsible for dislocation formation. Notably, a unique cluster that performs 1D migration can cause rapid loop formation, suggesting a novel mechanism different than that in metals. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Nuclear Materials, Modeling and Simulation, |