[3H05-10] Technologies for Dismantling, Decontamination and Evaluation

[3H07] Fundamental Study on Mechanism of Blasting Decontamination Device for Small Diameter Pipe (Part5)

*Seigo Kai¹, Hideharu Takahashi¹, Hayato Taniguchi², Akihiko Kawashima², Hiroshi Takahashi³, Keisuke Jinza⁴, Hiroshige Kikura¹ (1. Tokyo Institute of Technology, 2. Shintokogio, Ltd., 3. Fuji Furukawa Engineering & Construction Co.Ltd., 4. Fuji Electric Co., Ltd.)

Keywords:Decommissioning, Decontamination, Blasting, Barrel, Small-diameter pipe

In the decommissioning of nuclear power plants, a large amount of contaminated pipe is generated due to the adhesion of radioactive corrosion products, called CRUD (Chalk River Unidentified Deposit), to the pipe in the plants. The decontamination of these pipe is an important process to reduce the amount of radioactive waste and to reduce the radiation exposure during the decommissioning. In this study, the decontamination mechanism of small-diameter pipe in decommissioning of nuclear reactors was investigated using a dry decontamination system with separate mechanisms for blast and barrel polishing. The characteristics of blast and barrel polishing were investigated. Based on the experimental results, a decontamination model for decontaminating small-diameter pipe was examined, in which the decontamination effect is achieved by the impact of the blast mechanism's jetted particles on the contaminated area and the effect of the barrel mechanism's rotational motion on expanding the decontamination area.