| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Microstructural, Mechanical, and Chemical Behavior of Solid Nuclear Fuel and Fuel-Cladding Interface II
|
| Presentation Title |
Effects of Charge State on Chromium Substitution and Oxygen Vacancy Segregation Energies at Grain Boundaries in Uranium Dioxide |
| Author(s) |
Mack Wesley Cleveland, Ericmoore Jossou |
| On-Site Speaker (Planned) |
Mack Wesley Cleveland |
| Abstract Scope |
Uranium dioxide is the main fuel used in light water reactors. Promoting large grains during fuel sintering slows down fission gas diffusion to grain boundaries that degrades thermal conductivity and creates thermal stresses. Transition metal oxide dopants such as chromia help tune grain growth. Chromium solubility depends on its charge state, but recent spectroscopic studies of chromia doped uranium dioxide challenge previous simulation work that points to a +2-charge state in the bulk by suggesting that the chromium ion exists in a +3-charge state in the bulk, while a +2-charge state can be found in grain boundaries. This work uses density functional theory calculations to study how charge state interacts with the local atomic environment at the grain boundaries. Grain boundary structures were generated, and chromium substitution energies were calculated while varying the charge state and defect position to analyze charge state’s effect on grain boundary segregation energy. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Modeling and Simulation, Nuclear Materials, Ceramics |