Stress corrosion cracking (SCC) is a possible failure mode for Cu containers in an underground nuclear waste disposal vault. It is difficult to guarantee that SCC will never initiate on Cu containers based only on the results of relatively short-term experiments. Therefore, the extent of SCC is being predicted based on the argument that the rate of crack propagation will be limited. Several environmental factors will limit the rate of cracking, including: the general absence of aggressive SCC
agents in the vault, the limited time of rapid strain of the container shell and the limited supply rate of oxidants (principally dissolved O2) to the container surface through the compacted clay-based material in which the containers will be placed. In the first part of this study, the effect of oxidant flux on the crack velocity is being determined. The SCC behaviour of two high-copper alloys has been determined in nitrite-containing
environments over a range of oxidant fluxes...I
Keywords: copper, nuclear waste containers, stress corrosion cracking, nitrite, modeling, lifetime prediction