About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Metallic Fuels - Design, Fabrication, and Characterization
|
| Presentation Title |
First-Principles Evaluation of Heat Capacity in Disordered Uranium Oxycarbide Phases for TRISO Fuel Application |
| Author(s) |
Asmabi Thottathil, Jerzy Szpunar, Barbara Szpunar |
| On-Site Speaker (Planned) |
Asmabi Thottathil |
| Abstract Scope |
Accurate prediction of thermal behaviour in TRISO fuel is essential for ensuring the safety and performance of next-generation high-temperature reactors. A key challenge lies in understanding the thermophysical properties of uranium oxycarbide (UCO) fuel, which undergoes significant compositional and structural evolution under irradiation. Among the irradiation-induced phases, rocksalt (UC₁₋ₓOₓ) and fluorite (UCₓO₂₋ₓ) structures emerge within the fuel kernel. This study employs first-principles methods to evaluate the isochoric (Cᵥ) and isobaric (Cₚ) specific heat capacities of these disordered UCO phases. By integrating the quasi-harmonic approximation (QHA) with finite-temperature ab initio molecular dynamics (AIMD), we account for both vibrational and anharmonic contributions to heat capacity in microstructures representative of irradiation-driven disorder. The findings will enhance understanding of how carbon–oxygen distribution influences the thermal storage behaviour of UCO fuel. The resulting data serve as input for fuel performance codes such as BISON, improving thermal transport predictions of the TRISO under irradiation conditions. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Modeling and Simulation, High-Temperature Materials, Nuclear Materials |