Analysis of 14C level around Qinshan NPP base

By using the method of alkaline solution absorption, the activity concentrations of Carbon-14 as well as its variation tendency in air and biological samples were analyzed. The air samples and biological samples were collected around the Qinshan nuclear power plant base (Qinshan NPP Base) in 2002 to 2009 and 2007 to 2009 respectively. The results showed that, since 2002, the annual average activity concentrations of Carbon-14 in air samples were in the range of 38.3 mBq/m3 to 55.4 mBq/m3. Although the monitoring results of Xiajiawan village and Yanliucun village were comparatively higher than the reference site in Hangzhou City, the results were still at the same level. Meanwhile, monitoring results of Xiajiawan village and Yangliucun village in the summer of 2004 and 2005 are relatively high, with the peak value of 55.4 mBq/m3 appeared in Xiajiawan village during the summer of 2005. Correspondingly the annual airborne Carbon-14 of 2004 and 2005 discharged from the Qinshan NPP 3rd Phase were higher than normal as well, it can therefore be concluded that the activity concentration of Carbon-14 around the Qinshan NPP Base are related to the discharged source term. The activity concentration of Carbon-14 in rice and leaf vegetable samples from Xiajiawan village and Yangliucun village were slightly higher, but within the same level, than that of Hangzhou. The activity concentration of Carbon-14 in the mullet samples collected from the sea area around Qinshan NPP Base are approximately the same with the sea area of Zhoushan. (authors)