Development of decontamination technique before dismantling for decommissioning of commercial nuclear power plants

The decontamination technique before dismantling has been developed as one of the various techniques for decommissioning of commercial nuclear power plants. Chemical decontamination and fluidic abrasion for systems, such as piping, and gel spraying decontamination for large equipment or tanks were investigated in fundamental experiments to get optimized conditions for decontamination. Decontamination tests using cold simulated crude test specimens were carried out. Prospects for applying the decontamination technique to commercial nuclear power plant decommissioning seem good based on the results obtained. Investigations used a hot water loop which simulated the conditions of the primary cooling water in BWRs and PWRs.