About this Abstract |
| Meeting |
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Symposium
|
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Presentation Title |
Assessment of a Mechanistically Informed Engineering Scale Fuel Performance Model to Predict Microstructure and Thermal Conductivity Evolution in Oxide Fuel |
| Author(s) |
Joshua Ferrigno, PC Simon, Tsvetoslav Pavlov, Marat Khafizov |
| On-Site Speaker (Planned) |
Marat Khafizov |
| Abstract Scope |
Mechanistic models of fuel behavior are important to development of fuel performance codes with predictive capabilities. Accurate determination of temperature is a critical step as the rate of various mechanisms impacting microstructure evolution are functions of temperature. Large temperature gradient inside a fuel pin leads to a radially dependent fuel restructuring including grain size, porosity, and chemical state of fission products. The evolution of microstructure impacts thermal conductivity, which results in a coupled multiphysics behavior. We demonstrate an integrated analysis of fuel post-irradiation evaluation (PIE) and modeling to assess the accuracy of physical models implemented in BISON fuel performance code to model behavior of mixed oxide fuels under fast reactor conditions.
Electron microscopy characterization and thermal conductivity measurements were performed to analyze changes in central void, grain morphology, porosity and selected fission products as a function of radial position for 3 radial segments with distinct burnups. Fuel behavior was modeled using selected multiphysics processes including heat diffusion, central void evolution, grain growth, mechanistic fission gas release and Lucuta correlation for thermal conductivity. Model adequately captures central void evolution and grain growth. It provides reasonable estimate for fission gas atoms dissolved and trapped in nanoscale bubblesand thermal conductivity. Agreement between measured thermal conductivity and Lucuta correlation predictions can be improved if the conductivity is evaluated using input from experimental characterization. This suggests that further improvements to microstructure evolution modules can be made. Specifically, oxygen stoichiometry and porosity evolution, which are not considered in the multiphysics model. |
| Proceedings Inclusion? |
Undecided |