Threshold stress intensity factor of delayed hydride cracking in irradiated and unirradiated zircaloy-4 cladding

The delayed hydride cracking (DHC) is becoming important because of its extended long-term dry storage and lower dry storage temperature than expected. However, it remains difficult to predict the DHC behavior of PWR spent fuel cladding due to the limited data of K-IH (i.e., threshold stress intensity factor), especially for irradiated claddings. In this regard, the K IH for unirradiated and irradiated (49.641 GWd/tU) Zircaloy-4 claddings were experimentally measured using a pin-loaded-tension (PLT) technique and described by investigating the affected parameters. In addition, the results were compared with estimations from our previous studies. From the analysis, DHC is not expected to be a major concern during the predicted conditions of dry storage. (C) 2020 Elsevier B.V. All rights reserved.