The stress-corrosion-crack initiation and growth-rate response was evaluated on as-received, coldworked, and aged Alloy 22 (UNS N06022) and titanium Grade 7 in 105 °C to 110 °C, aerated, concentrated, high-pH groundwater environments. Time-to-failure experiments on actively loaded tensile specimens evaluated the effects of applied stress, welding, surface finish, shot peening, cold work, crevicing, and aging treatments in Alloy 22. Titanium Grade 7 and stainless steels were also included in the matrix. Long-term crack-growth-rate data showed stable crack growth in titanium Grade 7. Alloy 22 exhibited stable growth rates under "gentle" cyclic loading, but was prone to crack arrest at fully static loading. No effect of Pb additions was observed.

This paper provides an update on research addressing the effects of material condition and applied stress on stress corrosion cracking (SCC) in waste package and drip shield materials for the Yucca Mountain Project. Time-to-failure experiments are being performed on smooth bar tensile specimens in a hot, concentrated, mixed-salt solution chosen to simulate concentrated Yucca Mountain water. The effects of applied stress, welding, surface finish, shot peening, cold work, crevjcing, and aging treatment are being investigated for Alloy 22 (UNS N06022). Aging treatments were designed to produce topologically close-packed phases (TCP) and long-range ordering (LRO) and are under investigation as worse-case scenarios for possible microstructures in Alloy 22 (UNS N06022). Titanium Grade 7 and 3 16NG stainless steel are included in the matrix, as they are identified for drip shield and waste package components, respectively. Sensitized 304SS specimens are included in the test matrix to provide benchmark data. This research complements high-resolution crack-growth-rate experiments currently being performed in a parallel research project.