Dynamics of radionuclide activity concentrations in weed leaves, crops and of air dose rate after the Fukushima Daiichi Nuclear Power Plant accident. (October 2020)

• Record Type: Journal Article
• Authors: Fesenko, Sergey; Shinano, Takuro; Onda, Yuichi; Dercon, Gerd
• Is Part Of: Journal of environmental radioactivity. Volume 222(2020)
• Publication Date: 2020-10
• Subjects: FDNPP accident -- Radioiodine -- Radiocaesium -- Weed -- Buckwheat -- Rice -- Soy bean; Radioactivity -- Periodicals; Radiation, Background -- Periodicals; Radioecology -- Periodicals; Radioactive pollution -- Periodicals; Environmental Pollutants -- Periodicals; Radioactive Pollutants -- Periodicals; Radioactivity -- Periodicals; Radioécologie -- Périodiques; Pollution radioactive -- Périodiques; Fond de rayonnement -- Périodiques; 539.752
• DOI: 10.1016/j.jenvrad.2020.106347
• Languages: English
• ISSNs: 0265-931X

Abstract

Abstract: Data on reduction of radioactivity in plants are highly important for making decision on emergency response and remediation of contaminated areas. Dynamics of the 131 I and 137 Cs concentrations in the weed leaves sampled in the areas affected by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in Japan was assessed for the period March–December 2011. The effective half-lives for 131 I and 137 Cs of 3.8–4.2 days and 7.1–13.3 days in the weed leaves were calculated for the first two months after the deposition. The approach for assessment of the aggregated transfer factors based on the ambient dose equivalent rate was suggested and validated. The geometric means of the soil to the weed leaves aggregated transfer factors were estimated for June–December 2011. Soil to crop 137 Cs- concentration ratios (buckwheat, brown rice and soybean) were estimated for 2011–2016. Soil to crop concentration ratios were found to decrease in the order of soybean > buckwheat > brown rice. The effective half-lives for 137 Cs in these crops were estimated to be between 1 and 2.5 years for the period 2011 2016, and longer than 5–7 years after 2016. It was found that these data comply with the Chernobyl related data obtained for similar conditions and complement of international documents on radionuclide transfer in agricultural environment such as the IAEA TRS 472. Highlights: Effective half-lives for 131 I in the weed ranged 3.8–4.2 days for the first two months after the major deposition events. Effective half-lives for 137 Cs in the weed leaves ranged 7.1–13.3 days for the first two months after the deposition. Tag to the weed observed during first year after the FDNPP accident are similar to those measures after Chernobyl accident. First half-lives for 137 Cs soil to plant C r in 2012–2016 ranged 1.0 and 2.5 years and second half-lives - 6.3–7.3 years. Half-lives values for 137 Cs Cr in 2011-2016 comply with the similar data derived after the Chernobyl accident.