Air concentration estimation of radionuclides discharged from Fukushima Daiichi Nuclear Power Station using NaI(Tl) detector pulse height distribution measured in Ibaraki Prefecture |
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| Authors: | Yuta Terasaka Hiromi Yamazawa Jun Hirouchi Shigekazu Hirao Hiroki Sugiura Jun Moriizumi |
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| Affiliation: | 1. Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Nagoya, Japan;2. Nuclear Safety Research Center, Japan Atomic Energy Agency, Ibaraki Prefecture, Japan;3. Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima Prefecture, Japan |
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| Abstract: | Air concentrations of 133Xe, 131I, 132I, 133I, 132Te, 134Cs, 136Cs, and 137Cs in the early stage of the Fukushima Daiichi Nuclear Power Station (FNPS1) accident were estimated for six locations in Ibaraki Prefecture from pulse height distributions measured with NaI(Tl) scintillation detectors continuously operated as a part of monitoring station systems. Air concentration of 133Xe in Ibaraki was estimated for the first time, which showed the maximum value of 150 kBq m?3 in the plume arrived at the southern part of Ibaraki around noon of 15 March 2011. The plume was found to consist mainly of noble gases without other nuclides at significant level and to correspond to the hydrogen explosion at Unit 3. Spatiotemporal distributions of 131I and other nuclides were discussed for the plumes detected during the periods of 15–16 and 20–21 March. Variations in radionuclide composition among the plumes and within each plume were also discussed. |
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| Keywords: | Fukushima Daiichi Nuclear Power Station accident NaI(Tl) detector pulse height distribution air concentration xenon-133 iodine-131 atmospheric transport |
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