Sensitivity of RPT Homogenization of Double-Heterogeneous Fuels to Reactor Characteristics Variation

The homogenization of double-heterogeneous TRISO (TRi-structural ISOtropic) fuels is valuable for efficient reactor simulations, but the impact of reactor design and operational parameter variations on the Reactivity-Equivalent Physical Transformation (RPT) method remains understudied. This paper investigates the sensitivity of RPT homogenization to changes in five key reactor char-acteristics: fuel form, fuel enrichment, fuel volume fraction, packing fraction, system temperature, and TRISO particle geometry. Using a base design similar to the AGR-1, we analyze the impact of these parameters on the RPT radius. Our findings indicate that while the RPT radius is largely invariant with changes in fuel form, fuel enrichment, and system temperature, significant changes in packing fraction or TRISO particle geometry necessitate recalculations. These results suggest that RPT homogenization can be consistently applied across varied operational conditions, reducing computational costs, except when packing fraction or TRISO particle geometry variations occur. This research enhances the understanding of RPT homogenization stability, informing more reliable and cost-effective reactor simulations.