[M-AG38_2AM1] 福島原発事故により放出された放射性核種の環境動態

[MAG38-07] 福島第一原子力発電所事故により放出されたヨウ素131の大気中動態に関する数値シミュレーション

*滝川 雅之¹、鶴田 治雄² (1.独立行政法人海洋研究開発機構、2.東京大学大気海洋研究所)

キーワード：数値モデル, 大気環境

A large amount of radioactive materials was released into the atmosphere after the accident of the Fukushima Daiichi Nuclear Power Plant (FD1NPP). Inhalation of iodine 131 is important for internal exposure, but the observation of iodine is quite limited especialy in the early phase of the accident. We have conducted the simulation of radionuclides using a regional chemical transport model for March 2011. Calculated accumulated deposition of iodine 131 and caesium 137 was compared with the estimation using aircraft monitoring by MEXT and DOE (Torii et al., 2013). The model well captured the meridional gradient in the ratio of iodine 131 to caesium 137 around FD1NPP. The ratio of iodine 131 to caesium 137 is larger than 15 in the south of FD1NPP, and relatively small (around 0.7) in the northwest. This result implies that the regional model and the source term estimated by JAEA can generally reproduce eventual releases which cause large depositon ofer the land in March 2011.