Behavior of radiocesium in irrigation water in Hama-dori district, Fukushima Prefecture, Japan
Moono Shin1, Tomijiro Kubota2, Susumu Miyazu2, Sangyoon Lee3 and Takuro Shinano4
Abstract
The 2011 Great East Japan earthquake and tsunami led to dispersal of radionuclides into the surrounding area from the Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Plant(FDNPP), evacuation instructions of residents were issued in some areas. Before agricultural activities can safely resume after this accident, it is nessessary to evaluate the dynamics of radiocesium in irrigation water in the area.
In the present study, we monitored the concentrations of the different forms of radiocesium in irrigation water and analyzed its change over time and change between location of the concentration within 10–20-km zone from FDNPP at the Hama-dori district, Fukushima prefecture, Japan.
Our study yielded several key findings. First, at the investigated site, the concentration of total and dissolved radiocesium in the irrigation water tended to decline with the increasing distance toward the downstream. Second, concentration of radiocesium in the irrigation water during rain was tend to higher, found mainly in suspended particulate form and its concentration tended to decline over time. However, concentration of dissolved radiocesium was relatively unchanged.
It may be possible for farming to recommence in regions where decontamination of agricultural land has been completed, but continuous monitoring will be required.
Keywords: irrigation water, radiocesium, radionuclide, nuclear
1 Preparatory Office for Faculty of Agriculture / Fukushima University / 1 Kanayagawa, Fukushima, Fukushima 960-1296 Japan.
2 Division of Regional Resources Engineering / Institute for Rural Engineering / NARO / 2-1-6 Kannondai, Tsukuba, Ibaraki 305-8609 Japan
3 Division of Hillside Horticulture Research / Western Region Agricultural Research Center / NARO / 2575 Zentsuji-machi, Zentsuji, Kagawa 765-0053 Japan
4 Agricultural Radiation Research Center / Tohoku Agricultural Research Center / NARO / 50 Harajuku-minami, Arai, Fukushima, Fukushima 960-2156 Japan