EIS study on corrosion of overpack materials in bentonite

Ishikawa, Hiroki*; Tada, Eiji*; Nishikata, Atsushi*; Taniguchi, Naoki ; Tachikawa, Hirokazu*

In current concept of geological disposal of high-level radioactive waste, the vittrified wastes are stored in metallic container which is called overpack, and then disposed in deep underground. Similarly in direct disposal of spent nuclear fuel, the fuel assemblies are disposed in deep underground contained in metallic disposal container. In order to ensure the long term integrity and safety of overpack or disposal container, corrosion monitoring was performed using electrochemical impedance spectroscopy (EIS) technique.