Neutronic analysis of different sandwich cladding material options for (Th-²³³U-²³⁵U)O₂ annular fuel in advanced PWR assembly

This study investigates the performance and safety characteristics of (Th-²³³U-²³⁵U)O₂ fuel in various cladding materials, including SiC and a sandwich cladding system combining SiC with SS-310, in comparison to traditional UO₂ fuel with Zirlo™ cladding. Utilizing a dual-cooled annular assembly design, the (Th-²³³U-²³⁵U)O₂ fuel demonstrates significant enhancements in cycle length, outperforming conventional UO₂ assemblies. The radial power distribution analysis reveals that (Th-²³³U-²³⁵U)O₂ fuel reduces maximum radial power, contributing to uniform power distribution and enhanced reactor safety. Reactivity feedback coefficients, including Fuel Temperature Coefficients (FTCs) and Moderator Temperature Coefficients (MTCs), are consistently negative for (Th-233U-²³⁵U)O₂ fuel with advanced claddings, indicating improved inherent safety.