Method of mixing radioactive wastes

Purpose: To automatically determining the mixing ratio between ion exchange resins and electrolyte solution. Constitution: Spent ion exchange resins stored in a tank A and an aqueous solution of sodium sulfate at a known concentration resulted from the regeneration of the resins stored in a tank B are mixed in a predetermined ratio within a mixing tank, then sent to a centrifugal thin film drier and powderized therein. A flow meter, an electroconduction meter and a thermometer are disposed to a pipeway for transferring sodium sulfate in the tank B to the mixing tank and outputs from these meters are inputted to a microcomputer to determine the amount of sodium sulfate. While on the other hand, values measured from an electroconduction meter and a thermometer disposed to the inside of the mixing tank are transmitted to the microcomputer to determine the amount of the resins based on the change of the electroconductivity with time in the mixing tank, and the aqueous solution of sodium sulfate is transferred so as to obtain a predetermined mixing ratio. (Seki, T.)