A Comprehensive Electrochemical Impedance Spectroscopic Study of Passive Carbon Steel in Concrete Pore Water

The prediction of corrosion damage to times that are experimentally inaccessible by a large factor (e. g., to over 1000 to 1,000,000 years) is vitally important in assessing various concepts for the disposal of High Level Nuclear Waste (HLNW). Such prediction can only be made using deterministic models, whose outputs are constrained to being "physically real" by the time-and space-invariant natural laws [conservation of mass, energy, charge and mass-charge equivalence (Faraday's Law)]. In this paper, we explore the long-term passivity behavior of carbon steel in contact with concrete pore water solution at 80 degrees C [sat. Ca(OH)(2) + sufficient NaOH to yield pH(25C) = 13.5] by modeling the electrochemical impedance spectroscopic behavior using the Point Defect Model. As a result, we developed a single set of kinetic parameters that might be used, in order to predict the accumulation of general corrosion damage to the supercontainer in Belgium's HLNW clay repository. The re