Detailed deposition density maps constructed by large-scale soil sampling for gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant accident.
Soil deposition density maps of gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant (NPP) accident were constructed on the basis of results from large-scale soil sampling. In total 10,915 soil samples were collected at 2168 locations. Gamma rays emitted from the samples were measured by Ge detectors and analyzed using a reliable unified method. The determined radioactivity was corrected to that of June 14, 2011 by considering the intrinsic decay constant of each nuclide. Finally the deposition maps were created for (134)Cs, (137)Cs, (131)I, (129m)Te and (110m)Ag. The radioactivity ratio of (134)Cs-(137)Cs was almost constant at 0.91 regardless of the locations of soil sampling. The radioactivity ratios of (131)I and (129m)Te-(137)Cs were relatively high in the regions south of the Fukushima NPP site. Effective doses for 50 y after the accident were evaluated for external and inhalation exposures due to the observed radioactive nuclides. The radiation doses from radioactive cesium were found to be much higher than those from the other radioactive nuclides.
Japan Atomic Energy Agency, 2-2-2 Uchisaiwai-cho, Chiyoda-ku, Tokyo 100-8577, Japan. Electronic address: saito.kimiaki@jaea.go.jp.
Kimiaki
K
Saito
Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
Isao
I
Tanihata
Japan Atomic Energy Agency, 2-2-2 Uchisaiwai-cho, Chiyoda-ku, Tokyo 100-8577, Japan.
Mamoru
M
Fujiwara
Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
Takashi
T
Saito
University of Tokyo, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Susumu
S
Shimoura
University of Tokyo, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Takaharu
T
Otsuka
University of Tsukuba, 1-1-1 A-405 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
Yuichi
Y
Onda
Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan.
Masaharu
M
Hoshi
Japan Chemical Analysis Center, 295-3 Sannocho, Inage-ku, Chiba-shi 263-0002, Japan.
Yoshihiro
Y
Ikeuchi
Japan Atomic Energy Agency, 2-2-2 Uchisaiwai-cho, Chiyoda-ku, Tokyo 100-8577, Japan.
Fumiaki
F
Takahashi
Japan Atomic Energy Agency, 2-2-2 Uchisaiwai-cho, Chiyoda-ku, Tokyo 100-8577, Japan.
Nobuyuki
N
Kinouchi
Japan Atomic Energy Agency, 2-2-2 Uchisaiwai-cho, Chiyoda-ku, Tokyo 100-8577, Japan.
Jun
J
Saegusa
Japan Atomic Energy Agency, 2-2-2 Uchisaiwai-cho, Chiyoda-ku, Tokyo 100-8577, Japan.
Akiyuki
A
Seki
Japan Atomic Energy Agency, 2-2-2 Uchisaiwai-cho, Chiyoda-ku, Tokyo 100-8577, Japan.
Hiroshi
H
Takemiya
Japan Radioisotope Association, 2-28-45 Honkomagome, Bunkyo, Tokyo 113-8941, Japan.
Tokushi
T
Shibata
D062406:Fukushima Nuclear Accident; D062305:Geographic Mapping; D007564:Japan; D055848:Nuclear Power Plants; D011834:Radiation Monitoring; D011847:Radioactive Fallout / Q000032:analysis*; D011868:Radioisotopes / Q000032:analysis*; D012990:Soil Pollutants, Radioactive / Q000032:analysis*
D011847:Radioactive Fallout; D011868:Radioisotopes; D012990:Soil Pollutants, Radioactive
Deposition density maps; Fukushima Dai-ichi NPP accident; Gamma-ray emitting radioactive nuclides; Gamma-ray spectrometry; Soil sampling