Long-term corrosion performance of the waste package is among the key engineered barrier system attributes of a potential high-level waste repository at Yucca Mountain, Nevada. Waste package degradation processes are evaluated on the basis of independent investigations conducted at the Center for Nuclear Waste Regulatory Analyses. This paper summarizes the results of laboratory measurements and model analyses focused on uniform, localized, and microbially influenced corrosion, and stress corrosion cracking of Alloy 22 (UNS N06022).