About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Metallic Fuels - Design, Fabrication, and Characterization
|
| Presentation Title |
First-Principles Assessment of Thermal Conductivity, in UCO TRISO Fuel with Varying Carbon Stoichiometry |
| Author(s) |
Dhanish Sidhik, Barbara Szpunar, Jerzy Szpunar |
| On-Site Speaker (Planned) |
Dhanish Sidhik |
| Abstract Scope |
Understanding the thermal transport properties of irradiated TRISO fuel is critical for accurate performance prediction in high-temperature reactors. This study focuses on the uranium oxycarbide (UO₂₋ₓCₓ) phase that forms post-irradiation within TRISO fuel kernels. Using first-principles methods, we examine the influence of carbon incorporation on the thermal conductivity of this phase. Two compositions with varying carbon content are modeled in a rocksalt-type structure to reflect realistic irradiation-driven stoichiometries. Phonon thermal conductivity is computed using the finite displacement method within the Phonopy framework, based on force constants derived from density functional theory (DFT). Electronic thermal conductivity is estimated using BoltzTraP2, applying the Boltzmann transport equation under the constant relaxation time approximation. Results show that both phonon and electronic components of thermal conductivity are sensitive to carbon concentration, indicating that post-irradiation stoichiometry plays a critical role. These insights contribute to improved thermal modeling of TRISO fuels under in-reactor operating conditions. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Temperature Materials, Modeling and Simulation, Nuclear Materials |