Іnfluence of terrain on the dose load formation on Сryptomeria japonica, formed as a result of the Fukusima-1 accident
Keywords:Fukushima NPP, radioecology, radionuclide contamination, dosimetry
The presented paper considers the spatial distribution of the dose load on phytocenoses contaminated with radionuclides as a result of the accident at the Fukushima NPP area. The influence of the terrain features on the redistribution of radionuclide contamination in mountainous areas has been studied. The aim of the work was to construct a map of the absorbed dose distribution not only around the sampling points, but also to describe the surrounding area in more detail, which may allow predicting the main patterns of migration and redistribution of radionuclides in the studied ecosystem. To achieve the goal of this work, we used dosimetry and gamma-spectrometry methodologies. Maps and materials were obtained using GoogleEarth and ArcGis software packages. To determine the dynamics of dose loads on the elements of the phytocenosis of mountainous areas of Japan and compare it with doses that cause radiobiological effects for endemic subalpine mountain belt of Japan Cryptomeria japonica. Using Erica Tool, absorbed doses for Japanese cedar plants were calculated from the content of radionuclides, ranged from 2.65 to 121.4 μGy/h. As a result of this work, it was determined that the features of the terrain have a decisive influence on the distribution of radionuclide contamination in the resettlement zone formed after the accident at the Fukushima-1 nuclear power plant. Surface flux and horizontal transfer significantly affect the redistribution of contamination, so to obtain valid results in long-term radioecological studies is absolutely necessary to determine the dynamics and predict the migration routes of radionuclides. It can also be argued that even with a significant effect of relief on the redistribution of radionuclides in the study area Namie will not form a dose that will have a significant impact on the growth and development of the determining factor for the formation of the Japanese cedar Cryptomeria japonica.
2. Prokhorov, V.M Migration of radioactive contamination in soils. Physicochemical mechanisms and modeling: (Migratsiya radioaktivnykh zagryazneniy v pochvakh. Fiziko-khimicheskiye mekhanizmy i modelirovaniye) / ed. R. M. Aleksakhin. Moscow: Energoizdat, 1981, 98p.
3. Andoh, M., Nakahara, Y., Tsuda, S., et al. Measurement of air dose rates over a wide area around the Fukushima Dai-ichi Nuclear Power Plant through a series of car-borne surveys. Journal of environmental radioactivity. 2015, 139, p. 266-280.
4. Evrard, O., Laceby, J. P., Lepage, H., et al. Radiocesium transfer from hillslopes to the Pacific Ocean after the Fukushima Nuclear Power Plant accident: A review. Journal of environmental radioactivity. 2015, 148, p. 92–110.
5. Cresswell, A. J., Sanderson, D. C. W., Harrold, M., et al. Demonstration of lightweight gamma spectrometry systems in urban environments. Journal of environmental radioactivity. 2013, 124, p. 22–28.
6. Brown, J. E., Alfonso, B., Avila, R., et al. A new version of the ERICA tool to facilitate impact assessments of radioactivity on wild plants and animals. Journal of environmental radioactivity. 2016, 153. p. 141–148.
7. Watanabe, Y. Influence of the FNPP Accident on Coniferous Trees: A Review: Low-Dose Radiation Effects on Animals and Ecosystems. Springer Singapore, 2020, 320 p.
8. Brown, J. E.; Alfonso, B.; Avila, R.; et al. The ERICA Tool. Journal of Environmental Radioactivity. 2008, 99 (9), pp 1371–1383.