The Temperature Heatsink Overpower Response Commissioning (THOR-C) and THOR-Metal (THOR-M) experiments will be performed as part of an ongoing project for testing sodium fast reactor fuels with the Japan Atomic Energy Agency (JAEA). The THOR-C experiments consist of fresh metallic fuel pins and have been analyzed using the ABAQUS, Ansys codes and the BISON fuel performance code. THOR-M-Loss of Flow-1 (THOR-M-LOF-1) is designed to test an EBR-II irradiated fuel pin under LOF conditions. Simulation of the THOR-MLOF-1 experiment required first simulating the base irradiation of the fuel pin in EBR-II. These calculations provide valuable insight to the performance of the experiments, the BISON approach to modeling THOR experiments, and a start to assessment of code capabilities for transient metallic fuel analysis. The results show some good agreement between the two codes for predicting specimen temperatures, however, some notable discrepancies exist especially during the high temperature phase of the transient that will be further investigated. CDF calculations show failure of several experiments including THOR-C-2, C-3A, C-3B, C-5. However, based on historical experiments peak cladding temperatures of > 1078?C have a high likelihood of failure due to eutectic penetration regardless of cladding creep damage. THOR-C-2, C-3B, C-4, and C-5 all cross this threshold. Comparison of annular and solid fuel results indicate increased fuel-cladding interaction though further analysis is required to draw clearer prediction of failure probabilities. None of the modeling to date includes the calculation and effects of fuel-cladding eutectic interaction, which will likely play a significant role in cladding mechanical behaviors and accelerate ultimate failure.
