| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
Accelerated Qualification of Nuclear Materials Integrating Experiments, Modeling, and Theories
|
| Presentation Title |
Atomistic-scale Simulations of Creep in Uranium Oxide Nuclear Fuel |
| Author(s) |
Conor Galvin, David Andersson, Ryan Sweet, Laurent Capolungo, Michael Cooper |
| On-Site Speaker (Planned) |
Conor Galvin |
| Abstract Scope |
In this work, we aim to address the steady-state diffusional creep regime in UO2. Diffusional creep in UO2 has two different contributions: i) bulk (Nabarro-Herring) and ii) grain boundary (Coble), which have different grain size dependencies. Therefore, it is important to identify the dominant mechanism if an accurate UO2 creep model is to be developed.
We use atomistic-scale simulations to predict and understand the creep contributions at grain boundaries in UO2 to explore their impact on Coble creep rates. In particular, we investigate the segregation of uranium vacancies and their diffusion coefficients at the grain boundary. These predictions are then used to directly compare to experimental results. In addition, the atomistic lower-length scale data is used to develop a mechanistic creep model for UO2. Using this model we identify the dominant mechanism, and predict creep rates as a function of stress, temperature, oxygen partial pressure and grain size. |
| Proceedings Inclusion? |
Planned: |