b'Figure 1. (Left) Simulated FAST Test Geometry (width x10 magnification). Note that each simulation was performed with individual rodlets and not in the double configuration. This was done to simplify computational time as there was negligible neutronic and thermal communication between rodlets. (Right) The BISON material model intercoupling flow chart for the fuelFigure 2. A comparison plot between expected cladding strain in the FAST-008 test with the as-run ATR flux (predicted curves) and the scaled flux to match the equivalent EBR-II test (scaled curves). The temperature curves for both conditions are shown to demonstrate equivalent thermal conditions and the lack of impact that cladding deformation has on the thermal behaviors of the experimentand underpredicted in the plenumbehavior in prototypic fast reactor region. The plenum pressure istests on HT9 to that of the FAST also consistently underpredictedtests. This helps provide a basis when compared to the PIE results.for using FAST experiments to These comparisons highlightdesign and test advanced nuclear gaps within the models and thefuels for use in advanced reactors.discrepancy between irradiation 192 2023|AFC ACCOMPLISHMENTS'