A C-Mn steel, ASTM A516 Grade 55, is the primary candidate material for the outer metallic barrier in the current advanced conceptual design for the waste package in the proposed high-level radioactive waste repository at Yucca Mountain. The expected performance of thii steel and that of the alternate material, A387 Grade 22 (2 1/4Cr-1Mo) steel, as affected by thermal embrittlement, dry or humid air oxidation, uniform and
localized aqueous corrosion, microbially influenced corrosion, and stress corrosion cracking, is discussed on the basis of experimental studies and a review of information and data available in the literature.
Keywords: carbon steel, low-alloy steel, thermal embrittlement, air oxidation, humid air corrosion, pitting corrosion, microbially influenced corrosion, stress corrosion cracking, containers, nuclear waste