Book Description

The current and future use of ion exchange (demineralization) as a method for treating liquid radioactive streams at nuclear power plants was investigated. Pertinent data were obtained by contacting utility companies, nuclear-steam-supply system vendors, selected AEC-operated facilities, as well as ion exchange resin and equipment manufacturers. Principal emphasis was on obtaining data concerning the decontamination of aqueous solutions characterized by levels of radioactivity that range from 10−7 to 1 mu Ci/ml. Ion exchange media commonly used in nuclear power plants are synthetic organic resins of polystyrene matrix. They are utilized primarily in the mixed-bed (deep-bed) ion exchange system. Powdered resin (mixed) systems (so-called filter- demineralizer'') are also used in several recent boiling-water-reactor plants. The term decontamination factor (DF), the ratio of the feed to effluent concentration, is widely used and is assumed by designers and operators of the plants to express the ion exchange system performance. In some cases, such DF values may not represent the true system performance. To achieve a desired DF, the feed and effiuent must be sampled for the nuclides of interest and the processing discontinued when the desired effluent concentration is exceeded. Average DF values that can be obtained for various ion-exchange systems and various groups of radionuclides if good engineering practice is used in the design and operation of these systems are listed. These values are based on ion- exchange fundamentals, literature data, laboratory experiments, and plant operating experience. They represent time-average values expected under normal operating conditions rather than maximum values attainable under optimum conditions. (auth).