〈Name of award and short explanation about the award〉

Innovation Award

The 20th Conference of Japan Society of Maintenology held in Tokyo, Japan on August 5-8, 2024, presented the “Innovation Award” to the researches for the originality and innovation of their works presented in the student session.

〈About awarded research〉

Key challenges in Fukushima Daiichi (1F) decommissioning include remotely cleaning radiation hotspots and cutting fuel debris within the damaged primary containment vessel. Though high-power laser is an applicable technique, submicron radioactive Aerosol Particles (APs) can be generated, thus necessitating effective aerosol control and removal to reduce radiation exposure risks. Conventional water spray is difficult to scavenge these small APs. The use of pre-injection of charged mist can be the available options to improve the aerosol scavenging efficiency. This study performs a series experiments in our UTRATS facility. We use fiber laser to irradiate different material sample surface for the generation of APs. By using our developed charging system, the water mist is charged and injected into the vessel to agglomerate with APs to enlarge their size and hydrophilicity prior to water spray activation. The effectiveness of mist charging on improving aerosol scavenging efficiency is confirmed. Various laser & mist parametric effects are also investigated. Data from our experiments is expected to be useful for further model developments and validations regarding the aerosol scavenging in 1F decommissioning as well as other environmental applications.

〈Your impression & future plan〉

I am deeply honored to receive this award at the conference, especially given the strong competition from so many exceptional students. I want to sincerely thank my supervisors, Prof. Miwa, Prof. Okamoto, and Prof. Suzuki, for their crucial guidance, support, and encouragement throughout my research. My gratitude also goes to Dr. Sharma and Dr. Laffolley for their significant contributions and efforts in this study. I am equally grateful to the members of the Visualization Laboratory for their insightful suggestions during our daily interactions and meetings. Additionally, I commend the organizers of JSM for their excellent arrangements, which left me with countless unforgettable memories. Moving forward, I will continue my research on effective aerosol spray scavenging for the Fukushima Daiichi decommissioning with unwavering passion.