[H-CG22] Monitoring the Comprehensive Nuclear-Test-Ban Treaty: Status, operations, and scientific application

[HCG22-P02] Characteristics and sources of Cs-137 detected at IMS radionuclide monitoring stations in East Asia

*Akiko FURUNO¹, Ryuta Ohmori², Hisanori Tateoka², Yuya Minakawa², Toshiyuki Kurihara¹, Yoichi Yamamoto¹, Yutaka Tomita¹ (1.Japan Atomic Energy Agency, 2.ALTEN Japan Co. Ltd.)

Keywords:CTBT, radionuclide monitoring station, Atmospheric dispersion

Our team manages the Okinawa and Takasaki stations, which are part of the International Monitoring Stations (IMS) network for airborne radionuclides operated by CTBTO. The Okinawa station occasionally detects Cs-137. Since there are no nuclear facilities on the main island of Okinawa, where the Okinawa station is located, it is highly likely that it has arrived from a distant source. Cs-137 is mainly detected in Okinawa from winter to spring, so in this study, we hypothesize that the Cs-137 detected in Okinawa is related to the Asian dust, and we will check the Cs-137 detection status at IMS observation stations in East Asian countries and conduct preliminary verification using the atmospheric dispersion model FLEXPART.