Isolation and Recovery of Cs-137 from Reactor Actual Liquid Waste Samples for Various Purposes using Ion Exchangers of Different Kinds

Abstract

The sorption and recovery behaviors of Cs-137 from actual radioactive waste (ARW) solutions have been studied. Samples of these solutions have been analyzed radio-chemically to determine the absolute γ-activity with the aid of γ-standard point sources. Various kinds of ion-exchangers and sorbent materials have been used in the present study; these were: 1) Organic resins of different functional groups which were: a) the strongly acidic cation exchangers; Permuit X8 Na+ & H+ forms and Dowex-50 WX8 H+ form, b) the weak acid cation exchanger, Bio-Rex 70X8 Na+ form, c) the chelating resin Chelex-100 Na+ form. 2) Prepared inorganic sorbents such as a) ceric tungstate (CeW), b) zirconium phosphate (ZrP), c) zirconium titanium phosphate (ZrTiP) and zirconium molybdate (ZrMo), in addition to acidic alumina AG-4 and basic alumina AG-10. 3) A low cost natural sorbent material consisting in fine-ground particles of the outer bark of the Tree Casuarina Equisetifolia (TCE). X-ray and FT-IR analysis of the prepared ion-exchangers and the sorbent (TCE) have been carried out. The obtained data have been discussed. The study has been carried out under static and dynamic conditions. The influence of some parameters on the sorption processes has been investigated. The studied parameters, under static conditions were; contact time, resin weight, Cs+ and Sr2+ concentration, whereas under dynamic conditions the effect of flow rate, column dimensions and eluent type, has been investigated. The present study led to complete isolation and removal of Cs-137 from large volumes of the studied actual waste samples, under certain conditions and systems using some of the aforementioned ion exchangers. At the same time, concentrating of Cs-137 on very small columns has been achieved to be recovered and reused for various purposes. In addition, immobilization of Cs-137 in some chosen inorganic ion exchangers suitable for further treatment for final disposal has also been achieved.