An experimental study on liquid radioactive waste treatment process using inorganic ion exchanger

Using commercial inorganic, organic sorbents and activated carbons, the tre atment of low level liquid radwaste in nuclear power plant was studied. The batch, column and pilot tests were performed using simulants and actual li quid radwaste. The tests were focused on the removal capacity of the sorben ts under sodium ion concentration since the liquid radwaste commonly contai ns a large amount of sodium ion which may affect the removal capacity of io n exchangers. The target ions to remove with sorbents were radionuclides su ch as Co-58, Co-60, Cs-134, and Cs-137 which are the major species in the l iquid radwaste. The fundamental experiments showed that the inorganic sorbe nts and activated carbons have a better efficiency under sodium ion concent ration for a cesium removal than a cobalt removal, whereas the organic resi n is better for the cobalt removal. A new process for liquid radioactive wa ste treatment was proposed here based upon the experimental results. That i s composed of a filter, activated carbon, inorganic ion exchanger, organic cation exchanger and organic anion exchanger in series. The process showed that the activated carbon was not effective for the cobalt removal, but had the ability to reduce the COD of liquid waste. The organic anion exchanger was used to control pH and to remove radioactive iodine if present. This c ombined process of using the inorganic ion exchanger was 4 similar to 8 tim es more effective than that of the conventional organic ion exchanger.