Damage evaluation of cladding integrity for spent fuel in interim storage

In this study we propose a rupture criterion for the creep crack growth in Zircaloy cladding on spent fuel in interim storage. Based on the creep fracture mechanics parameter, C∗, and the strain energy density criteria, the relationship between the creep crack growth rate and the fracture mechanics parameter, C∗, is established theoretically. The effects of hydride orientations, initial crack lengths and storage temperature profiles on cladding failure are discussed in detail. The results show that the initial crack length and the storage temperature profile play an important role in cladding failure during interim dry storage. We found that a higher storage temperature will cause a larger creep growth rate, leading to unstable crack conditions in the cladding. The results presented in this study provide a reliable evaluation of cladding integrity for spent fuel in interim dry storage.