2023年11月27-30日に、原子力国際専攻岡本研究室　Ruicong XUさん （D３）が「第12回混相流計測技術国際シンポジウム（ISMTMF 2023）https://ismtmf2023.org/」において「Best Presentation Award」を受賞されました。

〈Name of award and short explanation about the award〉

Best Presentation Award

The 12th International Symposium on Measurement Techniques for Multiphase Flows (ISMTMF 2023) held in Tokyo, Japan on November 27-30, 2023, presented the “Best Presentation Award” to the researchers for their outstanding and attractive presentations in this symposium.

〈About awarded research〉

During the Fukushima Daiichi decommissioning, it is important to consider a retrieval of the resolidified debris for both air and underwater configurations. For the subsequent retrieval of debris from the reactor building, resolidified debris needs to be cleaned and cut into smaller pieces through various methodologies, such as laser cleaning and cutting. During these processes, radioactive aerosol particles on a submicron scale are expected to be generated. The containment spray system is required to be applied to remove these aerosols. The aerosol spray scavenging is a complex multi-phase flow process involving solid aerosol particles, liquid spray droplets and gas flows. While it was noted that the aerosols within the Greenfield gap are difficult to be removed effectively by traditional spray method. In this study, a series of experiments are conducted in our UTARTS facility with the aim to improve the aerosol removal efficiency by developing an electrostatic-charged spray system, which is also applicable to various engineering and industrial fields, including the gas filtration and environmental protection. In the experiments, a ring brass electrode connected with high voltage power supply is located near the outlet of the spray nozzle to charge the spray droplets with induction charging. The experimental results show that the aerosol removal can be accelerated through the electrically charged spray thanks to the additional aerosol collection by the electrical force. In addition, it is verified that the aerosol removal efficiency can be improved with the increase of supplied voltage. However, this improvement is found to become less significant when the voltage is larger due to the saturation of the specific charge of the droplets. The results obtained from the current study will be helpful for the optimization of spray system design for effective aerosol scavenging during the Fukushima Daiichi decommissioning.

〈Your impression & future plan〉

It is my pleasure and honor to win this award in strong competition with other outstanding researchers attended in this symposium. I would like to express my gratitude to my supervisors Prof. Miwa, Prof. Okamoto, and Prof. Suzuki for their very important guidance, support and encouragement during my research. I also appreciate Dr. Sharma and Dr. Ozdemir for their help in this study. I also thank all members of the Visualization Laboratory for their valuable suggestions during daily communications and meetings. I would like to appreciate the good organization of ISMTMF2023, which impressed me and gave me lots of unforgettable memories. In the future, I will continue my research on effective aerosol spray scavenging for Fukushima Daiichi decommissioning with great passion.