Distribution of 137Cs in different soil particle sizes in the vicinity of the Qianshan nuclear power plant

We investigated the size distribution of Cs-137 in soils in the vicinity of the Qinshan nuclear power plant. The soil samples were separated into five fractions, namely coarse sand (2000-250 mu m), fine sand (250-53 mu m), silt (53-20 mu m and 20-2 mu m), and clay (< 2 mu m). The results show that Cs-137 was concentrated in the clay and silt fractions. X-ray diffraction analysis of size-fractionated samples showed that micaceous minerals such as chlorite and muscovite are critical in the fixation of Cs-137 in the soil. No significant relationship was observed between Cs-137 concentrations and organic carbon content in the soil.