General Corrosion and Passive Film Stability

Understanding long-term corrosion of Alloy 22 container in the potential Yucca Mountain repository for high-level nuclear waste disposal

“…Also, DOE's test results show exceptions, in conformance of chromium oxides, both in electrochemical tests of Alloy 22 in Na-K-Cl-NO 3 , up to 220°C (428°F) and in LTCTF long-term immersion tests, for 5 years, in simulated Yucca Mountain environments [8,6,7,14,45,44]. In the long-term immersion tests for over 5 years, some samples were analyzed, measuring general corrosion rates, and analyzing passive film chemistry, using X-ray Photoelectron Spectroscopy.…”

Review of the Modelling of Corrosion Processes and Lifetime Prediction for HLW/SF Containers—Part 2: Performance Assessment Models

“…Dusts were found to contain Cl − as well as NO − 3 salts and there then began a period when progressively higher temperature deliquescent brines involving ternary and, even, quaternary combinations of nitrate salts were proposed [116]. The resulting solutions, which could form by deliquescence at temperatures approaching 200 • C, had such high NO − 3 concentrations that uniform corrosion of Alloy 22, rather than localized corrosion, became a concern [117]. Although the DOE and EPRI questioned the feasibility of the formation of such concentrated brines and, if they did form, of their stability under repository conditions [115,116], these arguments were challenged by an active opposition from opponents of the project [118].…”