Transport and deposition of radioactive aerosols released into the atmosphere by the accident of the Fukushima Daiichi Nuclear Power Plant

Massive radioactive substances were released into the atmosphere after the accident of the Fukushima Daiichi Nuclear Power Plant (FD1NPP) caused by the Tohoku Earthquake and Tsunami on 11 March 2011, and were transported and deposited on the land surfaces in a regional scale. This report will focus on the several dataset already opened of the atmospheric radioactivity measured at seven stations in Kanto area just after the accident, because it is essential to estimate initial radiation exposure and to evaluate atmospheric transport models. The ratio of particulate I-131 to the total I-131, and I-131/Cs-137 will be discussed. Furthermore, by analyzing a large amount of dataset such as radiation dose, fallout, and meteorological data at the routine monitoring sites near the FD1NPP, possible mechanism of regional transport and deposition of radioactive substances will be discussed, comparing with the result of numerical simulation by the model.