Evaluation of disposal stability of cement waste forms mixed with concentrated liquid waste for efficient treatment of AUC process waste

The uranium reconversion process is performed to convert concentrated UF6 into UO2. Ca(OH)2 is used to neutralize liquid waste generated during the uranium reconversion process, and all waste generated during this process is then collectively named lime waste. The present study aimed to improve cost-effectiveness and efficiency in lime waste treatment by replacing water, required in the cementation process, with concentrated liquid waste. The concentrate/cement ratio in the cementation process was set to range from 1.90 to 2.30, and the content of waste (lime + salt) ranged from 73.4 to 73.5 wt%. The optimum concentrate/cement ratio was determined to be 1.91, considering cost-effectiveness and safety. The structural stability of cement waste forms generated under the optimum operating conditions was evaluated according to the waste acceptance criteria (WAC). The feasibility of waste disposal was demonstrated by the evaluation of the leaching index of Cs, Sr, and Co.