Crevice corrosion of nickel-based alloys considered as engineering barriers of geological repositories

Nickel-based alloys are considered among other candidate materials as engineering barriers of geological repositories due to their excellent corrosion resistance. This review provides a comprehensive overview of crevice corrosion in nickel-based alloys, specifically Alloy-22, which has been extensively studied for its potential application in high-level nuclear waste repositories such as Yucca Mountain, USA. The objective is to assess the effect of environmental and metallurgical variables on the susceptibility of these alloys to crevice corrosion, a degradation process that could limit waste container lifetimes. The methodology includes a critical analysis of the existing literature, highlighting recent works and criticisms regarding current criteria for assessing crevice corrosion in repository conditions. The findings indicate that while the established criterion effectively rules out crevice corrosion in saturated repositories, there is a pressing need for developing a less conservative criterion to ensure the safe use of these alloys in unsaturated repositories. This review underscores the importance of understanding the underlying factors influencing crevice corrosion to enhance the long-term safety of nuclear waste management strategies.