Distribution of 129 I in the environment released from the FDNPP accident and estimation of 131 I/ 129 I ratio

Outdoor decontamination efforts have been ongoing since the Fukushima Daiichi nuclear power plant (FDNPP) accident; however, little is known about indoor contamination. Therefore, house dust was sampled based on particle size in 21 wooden buildings (19 residential houses and 2 community centers) within the evacuation area close to the FDNPP, Fukushima Prefecture, Japan. Activities of radiocesium (137Cs) per gram of house dust increased with decreasing particle size (mean: 6.1 × 103, 2.6 × 103, 1.6 × 103, 7.5 × 102, 5.0 × 102, and 4.6 × 102 Bq/g for <4–20, 20–63, 63–180, 180–500, 500–1000, and 1000–2000 μm, respectively). The 137Cs concentrations in house dust were inversely related to the square of distance from the FDNPP for <4–1000 μm particles. From the results of the multiple linear regression analysis, distance from the FDNPP and direction from the FDNPP (northwest) were significantly related to the radioactivity of house dust. It was found that 19%, 33%, and 48% of 137Cs in house dust were extracted in water, 1 M HCl, and not extracted, respectively. Considering the bioaccessibility and assuming a 20 mg/day daily intake of house dust, the daily doses would be 7.2 Bq/day (mean) and 18 Bq/day (95th percent quantile). These results provide valuable insight into indoor radioactive Cs contamination in the area around the FDNPP and possible oral exposure to indoor radioactive Cs after returning home.

Fukushima Nuclear Accident

Human decontamination

10.1016/j.envint.2018.02.015

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Widespread distribution of radiocesium-bearing microparticles over the greater Kanto Region resulting from the Fukushima nuclear accident

Progress in Earth and Planetary Science (2021)

Yoshinari Abe Seika Onozaki Izumi Nakai Kouji Adachi Yasuhito Igarashi

Abstract The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in March 2011 emitted a considerable amount of radioactive materials. This study isolated radiocesium-bearing microparticles (CsMPs), a form of radioactive materials emitted from the FDNPP at the early stage of the accident, from aerosols collected hourly on filter tapes at seven monitoring stations at the greater Kanto Region, including the Tokyo metropolitan area, on 15 March 2011. The aerosols had a spherical shape ~ 1 μm in diameter with activity of less than 1 Bq of 137 Cs per particle. Their physical and chemical characteristics, including radioactivity ratio 134 Cs/ 137 Cs as well as chemical composition and state, are essentially the same as previously reported CsMPs. This study demonstrated that air parcels containing CsMPs emitted from the FDNPP were widespread over the greater Kanto Region, more than 250 km away from the FDNPP, during the daytime of 15 March. Trajectory analysis indicated that these particles were emitted from the reactor No. 2 of FDNPP between 14 March evening and 15 March early morning. The information obtained on the widespread distribution of CsMPs can be useful for assessing the actual impacts of radioactive contamination from the FDNPP accident on the environment and human health.

Fukushima Nuclear Accident

10.1186/s40645-020-00403-6

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Reconstruction of uranium and plutonium isotopic signatures in sediment accumulated in the Mano Dam reservoir, Japan, before and after the Fukushima nuclear accident

Chemosphere (2019)

Hugo Jaegler Fabien Pointurier Silvia Diez-Fernández Alkiviadis Gourgiotis Hélène Isnard

Isotopic signature

Fukushima Nuclear Accident

10.1016/j.chemosphere.2019.03.064

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Anthropogenic radionuclides in the atmosphere observed at Tsukuba: characteristics of the radionuclides derived from Fukushima

Journal of Environmental Radioactivity (2013)

Taeko Doi K. Masumoto Akihiro Toyoda Atsushi Tanaka Yasuyuki Shibata

Fukushima Nuclear Accident

Aerodynamic diameter

10.1016/j.jenvrad.2013.02.001

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Pre- and post-accident 129 I and 137 Cs levels, and 129 I/ 137 Cs ratios in soil near the Fukushima Dai-ichi Nuclear Power Plant, Japan

Journal of Environmental Radioactivity (2015)

Tetsuya Matsunaka Kimikazu Sasa Keisuke Sueki Tsutomu Takahashi Yukihiko Satou

Fukushima Nuclear Accident

Deposition

Soil horizon

10.1016/j.jenvrad.2015.10.010

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Pre- and Post-Accident ¹⁴C Activities in tree rings near the Fukushima Dai-Ichi Nuclear Power Plant

Radiocarbon (2019)

Tetsuya Matsunaka Kimikazu Sasa Tsutomu Takahashi Masumi Matsumura Yukihiko Satou

ABSTRACT Areas affected by routine radiocarbon ( 14 C) discharges from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) and accidental releases in March 2011 were investigated by analysis of cores from Japanese cypress and cedar trees growing at sites 9 and 24 km northwest of the plant. 14 C concentrations in tree rings from 2008–2014 (before and after the accident) were determined by accelerator mass spectrometry, with 14 C activities in the range 231–256 Bq kg −1 C. Activities during the period 2012–2014, after FDNPP shutdown, represent background levels, while the significantly higher levels recorded during 2008–2010, before the accident, indicate uptake of 14 C from routine FDNPP operations. The mean excess 14 C activity for the pre-accident period at the sites 9 and 24 km northwest of the plant were 21 and 12 Bq kg −1 C, respectively, indicating that the area of influence during routine FDNPP operations extended at least 24 km northwest. The mean excess tree-ring 14 C activities in 2011 were 10 and 5.8 Bq kg −1 C at 9 and 24 km northwest, respectively, documenting possible impact of the FDNPP accident on 14 C levels in trees.

Fukushima Nuclear Accident

Accelerator mass spectrometry

10.1017/rdc.2019.147

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Citations (2)