Abstract
The effects of HCO3- Cl- and SO42- on corrosion behavior of copper as a candidatematerial for overpacking for geological disposal of high level radioactive wastes arestudied at 303K in dissolved oxygen (DO)-controlled, ground water-simulating aqueoussolutions by using a cyclic polarization curve method. Two types of polarization curvewere determined Type A in which free corrosion proceeds in the active dissolutionmode, and Type P in which passivation takes place in a potential domain characterizedby a potential that corresponds to Eb, the potential at which the passivated film isbroken. Polarization dependence on DO was also determined when only HCO3-ispresent, a type P curve results for DO‹0.5ppm; when DO›15ppm, however, a Type P results for HCO3-10ppm; when either Cl- or SO42- coexists with HCO3-, HCO3-promotes passivation while Cl- and SO42- promote active dissolution. The constantpotential test shows that the passivated film of copper is easily broken if Cl- is present.
