Effect of Dissolved Oxygen on the Corrosion Behavior at the Crevice Surface in High Temperature Water under Gamma-ray Irradiation

Abstract

In order to evaluate the effects of dissolved oxygen concentration on the radiolytic water quality within the cracks of stress corrosion cracking （SCC） under irradiation and the spatial distribution of water quality along the depth axis during irradiation, we conducted immersion tests of stainless steel with a crevice gap and computational simulations of water radiolysis. It has been confirmed that Fe₂O₃ is formed throughout the entire crevice region, irrespective of the dissolved oxygen concentration. Furthermore, it has been estimated that oxidant species generated by radiolysis within the crack are consumed by the growth of oxides under irradiation, and that the reduction in pH at the crack tip occurs by hydrolysis of dissolved metallic elements and enrichment of anions.