A mechanistic study of the uniform corrosion of copper in compacted Na-montmorillonite/s and mixtures

• Published in: Corrosion science 1992, Vol.33 (12), p.1979-1995
• Main Authors: King, F., Litke, C.D., Ryan, S.R.
• Format: Article
• Language: English
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/0010-938X(92)90196-A

The uniform corrosion behaviour of copper has been studied in environments similar to those expected in a Canadian nuclear fuel waste disposal vault. Under the experimental conditions used, the rate of corrosion is limited by the diffusion of copper through the compacted clay-sand buffer material that will surround the nuclear waste containers. The extent of the copper diffusion process was determined at the end of each test by measuring the copper concentration profile in the buffer material. In the presence of γ-radiation, the copper diffused further than in the unirradiated tests, but the corrosion rate was lower. Rate control by copper diffusion can account for both of these effects, with the effect of γ-radiation being to reduce the extent of sorption of copper by the clay. The results are consistent with a mass transport controlled corrosion reaction dominated by pore-water diffusion in the presence of γ-radiation and surface-water diffusion in the absence of radiation.