Calculation of pH, Conductivity, and Corrosion Potential of Stainless Steels in High Temperature Water Chemistry Conditions

A computer code that can calculate pH and conductivity in high-temperature water chemistry was developed. In the code, chemical species used in simulated reactor water conditions were considered. With given ionic concentrations, pH and conductivity of water could be computed at a given temperature. The corrosion potential of austenitic stainless steels (SSs) was also estimated based on the mixed-potential theory. With the given pH and dissolved gas (hydrogen, oxygen, and hydrogen peroxide), the corrosion potential could be estimated at a given temperature. The validation results showed that the code yielded reasonably accurate predictions compared to the experimental data. Therefore, predicted pH, conductivity, and corrosion potential can be used as input features for predicting stress corrosion cracking growth rates of SSs in nuclear power plant conditions.