Corrosion Behavior of Waste Package and Drip Shield Materials

The susceptibility to various forms of corrosion that could be experienced by the alloys considered by the U.S. Department of Energy for the waste package and drip shield, the principal components of the engineered barrier system for the proposed repository at Yucca Mountain, is evaluated on the basis of experimental studies conducted at the Center for Nuclear Waste Regulatory Analyses. Environmental, metallurgical, and mechanical conditions for the occurrence of uniform corrosion, localized corrosion, and environmentally assisted cracking of Alloy 22 (58Ni-22Cr-13Mo-3W-4Fe), the preferred material for the outer container, and Titanium-Grade 7 (Ti-0.15 Pd), the alloy proposed for the drip shield, are reported.