TERRESTRIAL DISTRIBUTION OF C-14 IN THE VICINITY OF QINSHAN NUCLEAR POWER PLANT, CHINA

We used accelerator mass spectrometry (AMS) to study radiocarbon-specific activity levels in agricultural and botanical samples (moss and pine needles) distributed within a 6.5-km radius of the Qinshan Nuclear Power Plant (NPP). The C-14-specific activity in moss samples (ranging from 265.6 to 223.0 Bq/kg C) decreased with increased distance from the stacks of Plant III (heavy water reactor) and reached the background level (223.8 Bq/kg C) at 6.5 km distance. Compared to the pine needles, the moss was a better indicator for investigating the C-14 distribution near Qinshan NPP. The C-14-specific activity distribution in moss samples showed that the diffusion of C-14 discharged from the Qinshan NPP was affected by both geographical and meteorological factors. Excess C-14-specific activity in the food samples ranged from 8.5 to 13.0 Bq/kg C (except for rice samples), resulting in a minimal radiation dose of 0.5 mu Sv per year to the public.Geochemistry & GeophysicsSCI(E)3ARTICLE159-665