About this Abstract |
| Meeting |
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Symposium
|
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Presentation Title |
Beyond Empirical Models: Mechanistic Irradiation-Enhanced Densification in UO2 Pellets |
| Author(s) |
Michael R. Tonks, Brandon Battas |
| On-Site Speaker (Planned) |
Michael R. Tonks |
| Abstract Scope |
Residual porosity in sintered UO₂ fuel pellets significantly influences early-stage performance in reactor environments. Although irradiation-enhanced densification is a key factor governing in-reactor microstructural evolution, it is currently represented by empirical models in fuel performance codes such as BISON. These empirical relationships often lack generality across varying operating conditions and fuel types. To address this limitation, we present a mechanistic model of irradiation-enhanced densification developed through a multiscale approach. At the mesoscale, we simulate the effects of grain topology, and grain boundary and bulk diffusion, on the densification process. Insights from these mesoscale simulations are used to calibrate two critical parameters in the mechanistic model. Model predictions are subsequently compared with available experimental data, demonstrating improved fidelity relative to empirical approaches and supporting broader applicability for next-generation fuel performance simulations. |
| Proceedings Inclusion? |
Undecided |