Examination of Pb-Bi cleaning technology

Abstract

The accelerator driven system (ADS) is proposed to transmute minor actinides (MA) in high level waste from nuclear power generation, Liquid Pb-Bi alloy is a candidate material for spallation target and coolant of ADS. Pb-Bi cleaning technology is required to reduce radiation exposure during maintenance service and to decontaminate replaced components. In this study, two cleaning methods, silicon oil at 180℃ and mixture of acetic acid, hydrogen peroxide and ethanol (1 : 1 : 1) cleaning, were tested. Specimens were prepared by immersion in melted Pb-Bi. After silicon oil tests, almost of Pb-Bi remained on the surface of the specimens. It was found that some blushing were needed to remove Pb-Bi effectively. On the other hands, Pb-Bi was easily dissolved in the mixed acid and almost perfectly removed. From the results of corrosion tests, the mixed acid did not effect on base metals.