The Properties of Zeolite A in Molten LiCl Waste

An advanced spent fuel management process based on the Li reduction of oxide spent fuel to a metallic form, under development at Korea Atomic Energy Research Institute (KAERI), will generate a LiCl waste. To develop an immobilization process of the LiCl waste salt using zeolite A, the behavior of zeolite A in molten LiCl salt with CsCl and SrCl₂ has been investigated at 923 K. All the types of zeolite A’s have been transformed into zeolite Li-A after contact with molten LiCl salt. The sodalite phase has also been formed for the high LiCl/zeolite ratio, and this sodalite formation has been enhanced by an addition of CsCl or SrCl₂. These results seem to be caused by the high temperature and Li concentration during the occlusion step. Ion-exchange properties of Cs and Sr at 923 K were very similar to those of the LiCl-KCl eutectic salt at 725 K: an uptake of Cs reached an equilibrium state very rapidly and kept constant, while that of Sr reached a maximum and decreased slightly.