Some important issues in electrochemistry of carbon steel in simulated concrete pore water Part 2 – Experimental

The prediction of corrosion damage to times that are experimentally inaccessible by a large factor (e.g. to over 1000 years) is vitally important in assessing various concepts for the disposal of high level nuclear waste. Such prediction can only be made using deterministic models, whose predictions are constrained to being ‘physically real’ by the natural laws [conservation of mass, energy, charge and mass charge equivalence (Faraday’s law)]. In this paper, the authors describe the measurement of experimental data that will allow the deterministic prediction of damage to the carbon steel overpack of the super container in Belgium’s proposed Boom Clay repository using the point defect model to extrapolate damage to future times. In this paper, the authors describe an experimental programme that is designed to generate values for various model parameters that will be required in making the damage predictions. The impact of chloride, sulphide and thiosulphate anions and mixtures of these species, on the electrochemical behaviour of carbon steel in contact with simulated concrete pore water, is examined.