Influence of decontamination process parameters on ultrasonic decontamination efficiency of pipeline

¹ Suzhou Nuclear Power Research Institute Co., Ltd., Suzhou, 215004, China
² Daya Bay Nuclear Power Operations and Management Co., Ltd, Shenzhen, 518124, China
³ Yangjiang Nuclear Power Co., Ltd, Yangjiang, 529500, China
⁴ Taishan Nuclear Power Joint Venture Co., Ltd; Taishan, 529228, China

^* Corresponding author’s e-mail: meguoxing@foxmail.com

Abstract

Many radioactive pollutants will be deposited inside the nuclear power plant pipelines after long-term service, which will form radioactive hot spots and increase the radiation dose rate level of operators. The ultrasonic decontamination efficiency was studied through the establishment of ultrasonic decontamination dynamic test bench, under different decontamination process parameters. It has also been applied in the engineering filed. The results show that: Ultrasonic decontamination efficiency increases with the increase of decontamination power, and the maximum decontamination efficiency of pollutants is up to 62.69%. The main reason is that the mechanical effect and cavitation effect of ultrasonic are significant with the increase of power, which is conducive to the removal of pollutants in the pipeline. When the decontamination time is 60min, the ultrasonic decontamination efficiency is more than 90%. Meanwhile, after ultrasonic decontamination of the pipeline hot spots, the contact dose rate at the pipeline hot spots is reduced by 75.20% at the highest, and the environmental dose rate is reduced by more than 90%, which reduces the collective dose level of operators working near the pipeline hot spot greatly, and ensures the health of the operators and environmental safety.