Studies on the kinetics of UO2 dissolution in carbonate-bicarbonate medium using sodium hypochlorite as oxidant

The dissolution of UO₂ in carbonate-bicarbonate solutions containing sodium hypochlorite as an oxidant has been investigated. The effect of temperature, sodium hypochlorite concentration and stirring speed was examined. In the temperature range of 303 to 318 K, the leaching reaction displayed linear kinetics. Apparent activation energy obtained from the differential approach was found to be 57 kJ mol^?1. This relatively high activation energy value indicates a chemically controlled behavior of UO₂ dissolution. The order of reaction with respect to sodium hypochlorite concentration was found to be unity.