Leaching performance of uranium from the cement solidified matrices containing spent radioactive organic solvent

The spent radioactive organic solvent (TBP/OK) was solidified by sulfoaluminate cement (SAC) with addition of zeolite, Ca(OH)2 and T-80 type emulsifier (Tween 80). Leaching characteristics of uranium immobilized in the solidified matrices was investigated through the semi-dynamic leaching test. The leaching behavior was evaluated by several leaching parameters and predicted by one-dimensional radionuclide decay model based on the Fick's second law. The results showed that the leaching rate and the cumulative leaching fractions (CLF) of uranium in 42 d were 5.70 × 10−7 cm/d and 4.80 × 10−5 cm, respectively. The solidification material used in present work was acceptable for solidification of uranium. The predictive values of CLF of uranium from the solidified matrices by the mathematical model were consistent with the experimental data in leaching period.