Neutronic comparison of proposed claddings for accident tolerant fuel with Zirconium based cladding in PWRs

Accident tolerant fuels are expected to maintain safety for longer periods of time with respect to standard PWR fuels in the case of design bases and beyond design bases accidents while maintaining good operational characteristics during normal operations. There are several new concepts to consider such as improving oxidation resistance and/or strength of current Zirconium alloy, replacing Zirconium with higher strength and/or oxidation resistance material, and introducing alternative fuel forms. In the meantime, fuel burnup, fuel pin lifetime, maximum operating temperature, clad failure mechanisms, and corrosion rates must be considered in the more detailed analysis. In this study, 304 stainless-steel, FeCrAl, and SiC are selected as new clad materials and their neutronic performances are compared with performance of standard Zirconium alloy clad. Non-linear reactivity model and MONTEBURNS code are used for calculations. Results show that SiC results in longer fuel cycle length among other cladding materials without changing any operational and fuel characteristics. On the other hand, the other materials considered in this study need reevaluation of enrichment and/or geometrical design parameters.