Data quality, issues, and guidelines for electrochemical corrosion potential measurement in high-temperature water

The electrochemical corrosion potential (ECP) of a metal is influenced by a large number of variables, such as oxygen, hydrogen, and hydrogen peroxide (H2O2) concentrations, the surface chemistry, impurities, hydrodynamic flow conditions, type of reference electrode, etc. The state of reference electrode development and qualification, water chemistry conditioning procedures, surface history, etc. is such that achieving total agreement from all international investigators is difficult. However, identification of key factors, preferred techniques, and sensible ranges in potentials for several standard conditions is possible. The purpose of this paper is to identify factors that influence ECP measurements in high-temperature water, propose recommended techniques, and characterize the expected range of corrosion potentials for specific materials, dissolved gas chemistries, water chemistry/pH, and temperature associated with boiling water reactor (BWR), pressurized water reactor (PWR), and related high-temperature water environments.