Assessment of chlorination technique for decontamination of radioactive concrete waste using simulated concrete waste

A chlorination technique was investigated as an option for the decontamination of radioactive concrete waste, which is one of the most common types of wastes generated during the decommissioning of nuclear power plants. Simulated concrete waste that includes target nuclides of Co, Sr, and Cs was utilized to evaluate the removal efficiency of each nuclide after the chlorination process. The effects of the reaction temperature, the Cl2 flow rate, and the reaction time were explored in this study. Among these parameters, the reaction temperature was identified as the key parameter that most strongly affects the removal efficiency. The removal efficiency of Cs surpassed 90% when the temperature exceeded 800 °C, while that of Co was over 95% at 1000 °C. The removal efficiency of Sr was relatively lower at 70–80% at temperatures of 700 and 800 °C. It was estimated that the chlorination technique can reduce the radioactivity of Cs and Co in low-level concrete waste to meet the clearance level. In consideration of its simple process, the chlorination technique can be a promising option for the decontamination of radioactive concrete waste. •A chlorination technique was evaluated as a decontamination method for radioactive concrete waste.•Target nuclides of Cs, Co, and Sr were selectively removed by chlorination and water washing.•The chlorination temperature was identified as the key parameter determining the removal of target nuclides.•The removal efficiency of the target nuclides ranged from 50 to 95% according to reaction conditions.