The mineralization of radioactive contaminated organic wastes by mediated electrochemical oxidation process has some attractive features as alternative to incineration process: The process operates safely at low temperatures and ambient pressures. JAERI has been investigated the process since 1996 and confirmed complete mineralization of this organic solvent. In order to greatly improve current efficiency for the oxidation reaction, further experiments were performed under condition of strong mixing of organic solvent and anolyte with an aide of ultrasonic wave. The current efficiencies for the oxidation reaction by ultrasonic agitation between organic solvent and anolyte were twice to that by mechanical agitation. On the basis of these results, two processes, one for destruction of a small amount of TBP/dodecane and the other for destruction of intermediate compounds following alkaline hydrolysis of a large amount of TBP/dodecane, were proposed.