The long-term integrity of Alloy 22 containers for the disposal of high-level nuclear waste, in the absence of conditions leading to stress corrosion cracking, may be determined by the long term passive dissolution rate and localized corrosion susceptibility. Investigations were conducted to determine the localized corrosion susceptibility, as well as the uniform corrosion rate, and the extent of preferential dissolution of alloying elements under passive conditions. Localized corrosion susceptibility was determined as a function of temperature, Cl- concentration, and Cl- to NO3- concentration ratio. Corrosion rate measurements under passive and transpassive conditions were performed as a function of
temperature, solution pH, and Cl- concentration. Preferential dissolution was assessed by analyses of test solutions using inductively coupled plasma mass spectrometry. Results of these investigations indicate that the passive dissolution rate is low with some evidence of preferential dissolution of Ni and Mo from the oxide film under passive conditions. The localized corrosion susceptibility of Alloy 22 was found to be strongly dependent on material condition and environment composition.