[16p-P9-1~66] 2 Ionizing Radiation（Poster）

[16p-P9-66] Successive Radiation Measurements in FMU Building Since the Great East Japan Earthquake Occurred

〇Ryo Ozawa¹, Tsuneo Kobayashi² (1.Fukushima Medical Univ., 2.Fukushima Medical Univ. Professor Emeritus)

Keywords:Great East Japan Earthquake

The gross rate of radiation at 4th Floor, Building No.4, FMU has been measured since the Great East Japan Earthquake occurred. The maximum gross rate after the nuclear power plant accident was 9.3 times the average. An effective half-life is 724 days. A present gross rate is 13.2% of maximum, and 1.09 times the average. The effective half-life is less than that of Cs or I, because the radioactive materials were decontaminated by natural phenomena like the wind and rain.