Distributions of tritium with different chemical form in the soil around Qinshan Nuclear Power Plant

摘要

Tritium with different chemical forms have different effects on the human body. In tritium migration and conversion, soil plays a significant role. In this study, our samples are from the surrounding environment of the Qinshan Nuclear Power Plant, in addition, Qinshan Phase III Nuclear Power Plant is the only heavy water reactor nuclear power plant (CANDU type, 700 MWe) in China. Both tritiated water (HTO) and non-exchangeable organically bound tritium (NE-OBT) were measured at the surface soil (0-2 cm) at 8 sampling sites and their depth profiles in the subsurface 30 cm of soil in two sampling sites around Qinshan Nuclear Power Plant in 2015, 2016 and 2018. The distribution analysis showed the further away from the nuclear power plant, the lower activity concentration of HTO at the surface soil. Also, in the depth profile, the HTO activity concentration decreased as the depth increase. Through soil analysis at different depths of sampling points A and D, it is concluded that the activity concentration of NE-OBT is the largest in the surface soil of the selected sampling points, which is similar to the HTO of most sampling points.