title: Estimation of β-ray dose in air and soil from Fukushima Daiichi Power Plant accident.
abstract: Following the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident of 2011, which deposited radionuclides across Tohoku and northern Kanto, β-ray dose evaluation has been performed to estimate radiation exposure for small creatures like insects as well as human skin. Using the Monte Carlo radiation transport code MCNP-4C, we calculated the β-ray dose for (129m)Te, (129)Te, (131)I, (132)Te, (132)I, (134)Cs and (137)Cs in air as a function of altitude and in soil. These calculations of β-dose rate for each radionuclide were conducted for the conditions following the FDNPP accident, with (137)Cs deposition assumed to be 1000 kBq/m(2). Beta-ray dose rate was found to be ∼10-fold (resp. 5-fold) higher than the γ-ray dose rate in the soil (resp. on the ground surface) at ∼20 days after deposition, and ∼4-fold (resp. 1.7-fold) higher after 6 months or more. For convenience, the height dependence of the ratio for 0, 10, 30, 90, 180 and 365 days after deposition was obtained by a fitting function. The cumulative 70 µm β-ray dose at 30, 60 and 90 days after deposition was estimated to be 35, 45 and 53 mGy for the ground surface, and 61, 79 and 92 mGy in the soil, respectively. These results can be used to estimate the external β-ray exposure for small creatures as well as for human skin.
authors: Quantum Energy Applications, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527, Japan.
authors: Satoru
authors: S
authors: Endo
authors: Kenichi
authors: K
authors: Tanaka
authors: Tsuyoshi
authors: T
authors: Kajimoto
authors: Nguyen Tat
authors: NT
authors: Thanh
authors: Joji M
authors: JM
authors: Otaki
authors: Tetsuji
authors: T
authors: Imanaka
mesh_terms: D000818:Animals; D001610:Beta Particles; D004781:Environmental Exposure / Q000032:analysis / Q000706:statistics & numerical data*; D062406:Fukushima Nuclear Accident; D006801:Humans; D007313:Insecta / Q000502:physiology; D008954:Models, Biological; D015233:Models, Statistical; D011847:Radioactive Fallout / Q000032:analysis / Q000706:statistics & numerical data*; D012879:Skin Physiological Phenomena; D012990:Soil Pollutants, Radioactive / Q000032:analysis*
chemical_list: D011847:Radioactive Fallout; D012990:Soil Pollutants, Radioactive
keywords: Fukushima Daiichi Nuclear Power Plant accident; radiocesium; radioiodine; radiotellurium; β-ray dose