Decontamination device and method for radioactive metal waste

Cylindrical metal wastes such as pipelines are disposed in a cylindrical anode, and a rod-like cathode is inserted in the inside of the wastes, and DC voltage is applied from a DC power source connected between the anode and the cathode. Then, the inner surface of the cylindrical metal wastes is positively charged to dissolve the metal matrix on the inner surface thereof. Accordingly, since it is not necessary to connect an anode and metal wastes such as in a case of conventional contact-type electrolytic decontamination, operator's radiation exposure dose during the connecting operation can be reduced. In addition, since insulative annular plates each having an opening are disposed to the upper and lower portions of the cylindrical insulative shielding member electrolysis between the anode and the cathode is suppressed thereby capable of dissolving the metal matrix efficiently. Further, since radioactivity can be reduced with the reduced dissolving amount of the metal matrix, the amount of secondary wastes can be reduced. (T.M.)