Ion Exchange

If the total solids content of the wastes is low (less than 1000 ppm), the volume of waste is small, or a final polishing of effluents is necessary, ion exchange is a suitable treatment method. At commercial power plants, ion exchange, filtration, and evaporation are the major processes used for liquid radioactive waste treatment. Both sulphonic and phenolic-carboxylic resins are used. Typical ion exchange units for waste treatment at boiling water reactor power plants include one 200 gpm mixed bed with no regeneration; one 75 gpm mixed bed, with no regeneration; and one 50 gpm mixed bed with no regeneration. Some boiling water reactors use very fine, 90% less than 325 mesh, ion exchangers as filters and ion exchange beds with no regeneration (Goldman 1968).

At pressurized water reactor power stations, typical ion exchange treatments include one 12 gpm mixed bed unit, no ion exchange in waste disposal system; 4 mixed bed units; and 45 ft.3 cation exchangers (Goldman 1968). All of the reactors use ion exchangers in coolant purification operations. On June 7, 1971, the Atomic Energy Commission published a schematic diagram of the general concept of radioactive waste handling systems for light water-cooled nuclear power reactors (Figure 8.7.1).

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