Method of decontaminating equipment in nuclear power plant

Physical decontamination is impossible for equipments of complicated shapes such as pipeways, large equipments or those equipments being in use. In view of the above, equipments to be decontaminated are immersed in a decontaminant to which a foaming agent forming fine bubbles are added. In the liquid decontaminant, bubbles are formed and bursted repeatedly and ultrasonic waves are generated upon bursting of bubbles. When the liquid decontaminant is caused to flow recyclically, the bubbles are bursted in the boundary layer and the radioactive corrosion products are defoliated by the vibrations of supersonic waves generated thereby. Thus, deposited radioactive corrosion products can be defoliated and discharged without imparing the durability or the strength of the equipments. (T.M.)