Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Takeuchi, Erina; Atarashi-Andoh, Mariko; Nishimura, Shusaku; Nakanishi, Takahiro; Tsuzuki, Katsunori; Koarashi, Jun; Matsunaga, Takeshi
no journal, ,
no abstracts in English
Fujimaki, Shu; Kawachi, Naoki; Suzui, Nobuo; Yin, Y.-G.; Ishii, Satomi
no journal, ,
no abstracts in English
Cs in lichens after the Fukushima Nuclear AccidentDohi, Terumi; Omura, Yoshihito*; Fujiwara, Kenso; Iijima, Kazuki
no journal, ,
Large quantity of radionuclides, including 
Cs and Cs, were released into the atmosphere caused by the Fukushima Dai-chi Nuclear Power Plant (FDNPP) accident on March 11, 2011. As lichens are known to be effective tools to monitor environmental radioelements in both time and space, lichen samples are expected to be used to examine and monitor radiocaesium fallout from FDNPP in Japan. The purpose of this study is to discuss the estimation of radiocaesium fallout in the ecosystem based on the following examinations using lichens. Fifty-eight samples including foliose and fruticose lichens were collected from northern to central Japan especially focusing on Fukushima Prefecture during 2012 and 2013. After correction for radioactive decay (on each sampling date), the detected radiocaesium concentrations ranged from 16.1 Bq kg
(d.w.) to 510,000 Bq kg for Cs and from 33.8 to 880,000 Bq kg for Cs in lichens. Cs concentration in the lichen samples generally increased with increase in the amount of fallout estimated by the Cs deposition in soil. The positive correlation was supported between Cs in lichens collected from Fukushima Prefecture and Cs inventories on soil calculated by Inverse Distance Weighted with Spearman's rank correlation coefficient (0.90, p 
0.01). The activity ratios of Cs and Cs for the lichen samples (
= 44) collected within Fukushima Prefecture (decay corrected to March 11, 2011) were between 0.95
0.04 and 1.080.41. The ratios are consistent with those for radiocaesium derived from the FDNPP accident (reported as 0.89 to 1.2). The ratios obtained from lichen samples collected in outside of Fukushima Prefecture were 0.750.23 to 1.480.48. They were consistent with those from Fukushima. But one sample showing significantly small value, 0.480.16, might be influenced by different origin from Fukushima.
I in soil samples collected around the Tokai Reprocessing PlantYokoyama, Hiroya; Fujita, Hiroki; Koarashi, Jun
no journal, ,
Iodine-129 (I) is a radioisotope of iodine with long half-life (1.57
10
years). In nature, I is mainly produced in the atmosphere via nuclear reactions of cosmic rays with xenon. I concentrations in soil around the Tokai Reprocessing Plant (TRP) have been monitored since its commencement of operation. In this study, we conducted speciation analysis of I for soil samples collected around the TRP. Results showed that more than 80% of I was bound to Fe/Mn oxides ( 70%) and organic matter (6
15%) in all soils except for one collected at the 8 km sampling point. Only 810% of the total I was associated with the water soluble, exchangeable, and carbonate fractions, which are considered as a readily leachable or bioavailable fraction of I in the soils. The results suggest that vertical migration of I in the soils by precipitation or pore water is limited.
Iijima, Kazuki; Funaki, Hironori; Hagiwara, Hiroki; Nakanishi, Takahiro; Tsuruta, Tadahiko
no journal, ,
JAEA has carried out the project on the Long-term Assessment of Transport of Radioactive Contaminant in the Environment of Fukushima (F-TRACE project) since the end of 2012. Radiocaesium has been distributed by the fallout from the Fukushima Dai-ichi Nuclear Power Plant accident mainly to the coastal area of Fukushima Prefecture. In this project, the transport behavior of radiocaesium through water systems located in coastal areas of Fukushima was investigated to establish predictive modeling tools for distribution of radiocaesium and to estimate future effective dose of the residents. One of the study rivers in the coastal area was Ukedo River which was selected due to the high contamination of radiocaesium in the catchment especially upstream in contrast with less contamination downstream. This paper provides an overview of the results of field observations on the distribution and evolution of radiocaesium activity concentration in the Ukedo River water system carried out in 2013 and 2014. It can be concluded that the dam has a significant ability to constrain transport of radiocaesium from upstream to downstream.