C-14 LEVELS IN TREE RINGS LOCATED NEAR QINSHAN NUCLEAR POWER PLANT, CHINA

Specific activities of radiocarbon in annual tree rings corresponding to 1980-2009 are reported for a pine tree located 2 km from the Qinshan Nuclear Power Plant (Qinshan NPP), China. While a negligible enhanced C-14 activity due to operation of the Qinshan NPP Plant I is evident, a relative increase (1.8-62.6 Bq/kg C) was observed in the specific activity after operation of the Qinshan NPP Plant II in 2002 and Plant III in 2003. The enhanced values were primarily affected by the C-14 discharged from Plant III (CANDU-type reactor), and a good correlation was found between the C-14 discharged from Plant III in the growing season and the C-14 excess value. The excess C-14 activities peaked in 2005 (at 302.0 Bq/kg C, which is 62.6 Bq/kg C above the "clean air" C-14 level), and then declined due to the improvement in C-14 discharge management of Plant III. In 2009, the C-14-specific activity was near the background level.Geochemistry & GeophysicsSCI(E)46ARTICLE2195-2025