Reduction of contaminated concrete waste by recycling aggregate with the aid of pulsed power discharge

The Fukushima Dai-ichi Nuclear Power Plant accident has resulted in a large amount of radioactively contaminated concrete. The aim of this study is to investigate the possible application of the pulsed power discharge to reduce the amount of contaminated concrete as radioactive waste. An applicability of pulsed power discharge as a decontamination method by separating contaminated matrix from uncontaminated coarse aggregate was examined. In this study, a stable cesium (Cs) isotope was used to simulate radioactively contaminated concrete. As a result, while the volume of reclaimed aggregate from radioactive contaminated concrete reproduced by the electric pulsed discharge could reach 60%, nevertheless Cs detected in the reclaimed aggregate was only approximately 3% of quantity included in the concrete specimen. Thus most of the Cs was dissolved in water during the discharge process. It is expected that the decontamination method by the pulsed power could reduce the contaminated concrete waste by reusing aggregate. Further investigations are requested to test the applicability of this method under the realistic conditions close to the actual waste.