Development of Separation Technique of Sodium Nitrate From Low-Level Radioactive Liquid Waste Using Electrodialysis With Selective Ion-Exchange Membranes

An advanced method, in which electrodialysis separation of sodium nitrate and decomposition of nitrate ion are combined, has been developed to remove nitrate ion from low-level radioactive liquid wastes including nitrate salts of high concentration. An engineering scale apparatus with two electrodialytic devices, in which the sodium and nitrate ions were separately removed by each device, was produced on the basis of the results of fundamental investigation previously reported, and the performance of the apparatus was tested. Both the ions were successfully removed at the same time, though these ions were separately transferred using two electrodialytic devices. And also effect of several experimental parameters such as current and temperature on current efficiency of both the ions of each device was investigated.