Method of decontamination for radioactive metal waste

Since the surface of a metal matrix after electrolytic decontamination of removing oxide layers is activated, rusts (oxide layers) are tend to be formed in a corrosion accelerating atmosphere. Further, in an alternating electrolytic decontamination method, an oxide layer removing rate is remarkably greater as compared with that of the metal matrix. By utilizing the two tends contaminated oxide layers are at first eliminated by alternating current electrolysis from radioactive metal wastes in which contaminates are present in the oxide layers and the meal matrix. Subsequently the metal wastes in which the metal matrix is exposed are stored for a predetermined period of time in a corrosion accelerating circumstance to form oxide layers and then the resultant oxide layers are removed again by the alternating current electrolysis. This can remarkably shorten the total decontamination time required for the electrolytic decontamination without increasing secondary wastes. (T.M.)