[2K05-08] 1F Accident 1

[2K07] Research on Radioactive Aerosol Control and Decontamination at Fukushima Daiichi Nuclear Power Station Decommissioning

(3) Development of the electro-scavenging technique using multi-scale charged spray droplets

*Ruicong Xu¹, Avadhesh Kumar Sharma¹, Shuichiro Miwa¹, Shunichi Suzuki¹ (1. UTokyo)

Keywords:Aerosol removal, Spray scavenging, Droplet charging, Fukushima Daiichi decommissioning

During the Fukushima Daiichi decommissioning, addressing the retrieval of resolidified debris in both air and underwater scenarios is crucial. This involves cleaning and segmenting the debris using methods like laser cutting. In these processes, submicron radioactive aerosols are likely produced, necessitating a containment spray system for their removal. The aerosol spray scavenging, a complex multi-phase flow process, faces challenges in effectively removing aerosols in the 0.1-1 μm range. This study, conducted in the UTARTS facility, explores enhancing aerosol removal efficiency through an electrostatically-charged spray system. Experiments ae performed with several ring brass electrodes near the spray nozzle, charging the droplets and accelerating aerosol removal via electrical force. Results indicate that increased voltage improves removal efficiency, though benefits diminish at higher voltages due to droplet charge saturation. These findings aid in optimizing spray system design for effective aerosol scavenging in the Fukushima Daiichi decommissioning.