THE MECHANISM OF LOCALIZED IN-PILE CORROSION OF ZIRCONIUM ALLOYS

The role of beta-particles for the localized in-pile corrosion of comp onents made of zirconium alloys, such as fuel channels closely facing stainless steel component. has been discussed and the distribution BE beta-particles near fuel channels has been evaluated using a multi-lay er calculation method. It is shown that electric charges which come fr om beta-particles produced mainly by the Compton effect! but not by be ta-emitting radionuclides, make electric fields in and on the zirconiu m oxide surfaces in the reactor by a model analogous to an electric ci rcuit, and that these electric Gelds induced by beta-particles could b e essential for the understanding of localized in-pile corrosion of zi rconium alloys. The mechanism of the localized is-pile corrosion of zi rconium alloys adjacent to other welded alloys is also discussed as an enhanced corrosion by electric potentials using the proposed electric circuit model in detail.