Fri. May 31, 2024 4:45 PM - 5:00 PM 201A (International Conference Hall, Makuhari Messe)

The social debate on the extent of the area of deposition of radioactive fallout from the 1945 atomic bombings of Hiroshima and Nagasaki, the so-called "Black Rain" area, has been continuing. In this session, we will present an overview of the research study that has been conducted since January 2021 toward more accurate estimation of the area, as well as the results obtained. This research has been conducted in two main parts: (1) construction and calculation of simulation models, and (2) measurement of radioactive and trace materials, which is mainly soil survey to obtain the validation data.