Effects of hydride precipitation on the mechanical property degradation of Zircaloy 4 and Zirlo

Mechanical integrity of zirconium alloy cladding is important to achieve the performance goal not only in high burn up and extended fuel cycle operation and but also in long term dry storage of spent fuel. Especially, it is well-known that hydride precipitation critically promotes the degradation of the mechanical integrity. Thus, many studies on the hydride-induced degradation and embrittlement of zirconium alloys have been reported. However, few studies on the quantitative and mechanistic analysis for the degradation have been carried out. In this study, mechanical properties degradation of two popular zirconium alloys, Zircaloy 4 and Zirlo, with increasing hydrogen concentration was experimentally investigated and the degradation mechanism was discussed