Cesium removal from low-level liquid wastes with hexacyanoferrate(II) compounds

Experimental studies are being carried out to develop improved methods for decontamination of both currently generated and stored low-level liquid wastes (LLLW) at Oak Ridge National Laboratory (ORNL). These waste streams include the high-volume, but very low level, process waste and a variety of waste concentrates that consist of a smaller volume of higher activity and high salt content. Management and final disposal of these wastes would be much simpler if the major radioactivity could be removed and concentrated into a much smaller volume that could be dealt with separately. Inorganic ion-exchange processes are planned for future treatment of LLLW, and study is continuing to find superior processes. Recent work at ORNL confirms the reported selectivity of certain inorganic ion-exchange materials that have an extremely high affinity for particular elements. Several materials are known to be selective for cesium, and compounds containing transition metal hexacyanoferrate(II) are unusually efficient for removing cesium from a variety of neutral and alkaline waste solutions