Abstract:

Magnitude 9.0 earthquake occurred in Coastal waters of northern Japan on March 11, 2011, triggered a succession of disasters and led to nuclear leakage in Fukushima Nuclear Power Station. The level of this　nuclear accident raised from 5 to 7 (the highest level of nuclear accidents). The spread and migration of radioactive materials after the nuclear leakage is the focus and a hot spot in nuclear accidents. HYSPLIT model is used to simulate radioactive materials’ trajectories after the nuclear leakage. The results show that atmospheric particulates with radioactive materials mainly move to the east and northeast over the Pacific, and even enter the United States. Sometimes they represent southward and turn to southwest trajectories or movement tendencies making them to move into China. Radioactive materials’ trajectories in the next four months, May to August, are speculated by historical meteorological information, and air dispersion from Fukushima is mainly northward, northeast and west directions. Due to factors such as  atmospheric turbulence, wind direction, rainfall, ocean current and so on, radioactive materials will still have influence in China. Atmospheric particulates with radioactive material into China mostly come from high altitude.

Key words: nuclear leakage, radioactive materials, trajectory, HYSPLIT model