A Review of Root Causes of SCC Phenomena in BWR/RBMK: An Overview of Radiation-Induced Long Cell Action Relevant to SCC

In a review of recent occurrences of Stress Corrosion Cracking (SCC) in Japanese Boiling Water Reactors (BWRs) and Russian High Power Channel-type Reactors (RBMKs), the author proposes a hypothetical mechanism which states; ‘radiation-induced ‘long cell action’ causing electrolytic corrosion.’ This article provides the currently available technical bases for the proposed mechanism which was introduced in a companion paper also presented at this conference [1]. There is some experimental evidence indicating that long cell action may not be negligible in nuclear reactor environments, when induced by the radiolysis of water. There are also some surprising similarities between SCC in the reactor systems and the basic mechanism of underground corrosion by long cell action. In this mechanism, the ‘long cell action’ is induced by a difference in availability of oxygen inside the soil. Conduction of electrons through an electric conductor over a long distance plays a significant role as they are released by dissolution of metallic ions and sucked up from the metal surface.