b'Initial calculation results 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.test configurations. There are twoC-3A, C-3B, C-5. However, based on models with similar input files andhistorical experiments peak clad-meshes for the solid and annularding temperatures of 1078C have fuel. The models focus specificallya high likelihood of failure due to on the fuel, cladding, and heat sink,eutectic penetration regardless of while the surrounding componentscladding creep damage. THOR-C-2, are excluded. Components notC-3B, C-4, and C-5 all cross this included in the analysis are thethreshold. Comparison of annular THOR capsule, outer containment,and solid fuel results indicate insulation, and outer can, which willincreased fuel-cladding interaction have little impact on the thermalthough further analysis is required mechanical results of the fuel andto draw clearer prediction of failure cladding during the duration of theprobabilities. None of the modeling transient experiments. to date includes the calculation and effects of fuel-cladding eutectic Accomplishments: interaction, which will likely play a The THOR-C experiments have beensignificant role in cladding mechan-analyzed using the ABAQUS codeical behaviors and accelerate ulti-and the BISON fuel performancemate failure. A comparison between code. Initial calculation resultsannular and solid fuel is shown in provide valuable insight to theFigure 1. The two experiments have performance of the experiments,different cladding materials, and the the BISON approach to modelingannular fuel has approximately 7% THOR experiments, and a start tohigher input power. The annular assessment of code capabilities forfuel produces the largest fuel transient metallic fuel analysis.growth and cladding hoop strain. The results show some good agree- The cladding hoop stress increased ment between the two codes forsignificantly as compared to the predicting specimen temperatures,solid fuel after 5 seconds into the however, some notable discrepan- transient. The cladding creep strain cies exist especially during the highis more than a magnitude higher for temperature phase of the transientthe annular fuel.that will be further investigated. Cumulative damage fraction calculations show failure of several experiments including THOR-C-2, 188 2023|AFC ACCOMPLISHMENTS'