[2G05-07] Radiolysis and Electrochemistry

[2G07] Electrochemical Corrosion Potential Calculation Model for Hydrogen Peroxide Environment with Electrochemical Parameters Determined by Polarization Measurements

*YOICHI WADA¹, Kazushige Ishida¹, Masahiko Tachibana¹, Mayu Sasaki², Makoto Nagase², Ryosuke Shimizu² (1. Hitachi, Ltd., 2. Hitachi-GE Nuclear Energy, Ltd.)

Keywords:ECP, stainless steels, hydrogen peroxide, stress corrosion cracking, elctrochemistry

High temperature electrochemical reaction parameters for 316L stainless steel (SUS316L) have been determined based on data measured in pure water at high temperatures to realize an electrochemical corrosion potential (ECP) model for SUS316L in a hydrogen peroxide (H₂O₂) environment. Calculated ECPs of SUS316L agreed with measured values in the cases that it was acceptable for the model to have an error range of ±0.1 V in a range from the deaerated condition to 1000 ppb H₂O₂ concentration. The ECP model was also applicable to 304 stainless steel. It is expected that the dedicated ECP model will have greater validity for, and better interpretability of, the ECPs of stainless steels determined in a BWR environment than previous models.