Effects of environmental factors on copper corrosion in an aerobic deep geological repository

The corrosion behavior of copper in an aerobic deep geological repository (DGR) environment was investigated with respect to pH, chloride, and temperature using electrochemical tests, surface analyses, response surface methodology (RSM), and corrosion simulation. A regression model was developed using RSM to predict corrosion rates based on environmental factors. The corrosion rate increased with temperature and chloride concentration, while pH had a minimal effect. Among all factors, temperature had the most significant effect. The corrosion simulation results in the early stage of immersion were consistent with the RSM results, indicating that the RSM-based model can effectively predict copper corrosion at the initial stage. However, over time, the simulation showed that only temperature remained significant due to the depletion of reactive species caused by their slow diffusion in the DGR environment. These findings provide insight into predicting copper corrosion rates based on environmental factors in the aerobic DGR environment.