Journal of Nuclear Fuel Cycle and Waste Technology

This paper shows our experiment is performed to understand the exposure tendency of 137Cs according to the height of area and also, to supplement it by considering chemical characters of 137Cs exposed to the soil. The samples we use for this experiment are from the general flat area of Yeonggwang county where it has NPPs, the high places of Keumjung & Bulgap mountains, and Naejan mountain where it is quite far from the NPPs. The data from this experiment show that the exposure of 137Cs is not harmful since its range is around 252 Bq/kg-dry in most of sampled soils such as from the general flat area, the high place of Keumjung mountain where is 2 km away from the NPPs, the other high place of Bulgap mountain where is about 20 km away from the NPPs, and Naejan mountain where it is far from the NPPs. Not like the general flat area, however, the data show that the higher the area is the more 137Cs is exposed. That is, at the top of mountains, the more 137Cs is exposed compared to at the bottom area. It is almost 2 6 times more than the general flat area of Yeonggwang county where it has NPPs. The data also show that the spread of 137Cs is deeply related to the geographical(the height of area, rainfall, etc..) factors and chemical factors of soils. As the geographical factors, there are far more chances to be exposed of 137Cs at the high area of mountains through the air compared to at lower area and therefore, we can get more high-leveled readings of 137Cs at the high area while it is low-leveled ones at the general flat area even if both of them have the same soil conditions. Regarding the chemical factors of soil, it is clarified that the CEC is the key factor. The CEC means the capability of sticking 137Cs accumulated into the soil. Hence, the more CEC it has the more high-leveled readings of 137Cs we get under the same geographical condition.

Keywords

137Cs,soil,CEC,Activity,geographical factors