About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Advanced Characterization of Materials for Nuclear, Radiation, and Extreme Environments VI
|
| Presentation Title |
Influence of Point Defect Evolution on Thermal Conductivity Degradation and Fission Gas Behavior in UO₂ Under Accelerated Irradiation |
| Author(s) |
Mutaz Alshannaq, Marat Khafizov |
| On-Site Speaker (Planned) |
Mutaz Alshannaq |
| Abstract Scope |
The evaluation of thermal properties is essential for understanding nuclear fuel performance. During reactor operation, the buildup of fission products and irradiation-induced lattice defects lead to a degradation in thermal conductivity, hence impacting fuel temperature, and fission gas release (FGR). Despite its importance, the reduction in thermal conductivity caused by point defects (PDs) is not mechanistically modeled in current fuel performance codes (FPCs). In this work, we investigate the effect of PD accumulation described through a rate theory (RT) model on the lattice thermal conductivity of UO₂ and fission gas release (FGR) by modifying the Lucuta thermal conductivity correlation (LC) and investigate their behavior under accelerated conditions. We demonstrate that point defect accumulation, driven by the fission rate, notably reduces thermal conductivity in the cooler rim region. This leads to increased thermal resistance and elevated local temperatures compared to predictions from the standard Lucuta correlation, especially at low burnup. |