Carbon-14 in Tree Rings in the Vicinity of Ignalina Nuclear Power Plant, Lithuania

The results of ¹⁴C measurements in the annual tree rings from the Ignalina Nuclear Power Plant (INPP) vicinity, Lithuania, for the period of its operation from 1984 to 2002 are presented. The terrestrial samples, mainly moss and related topsoil, are studied in places as well. The tree rings have shown the slightly enhanced ¹⁴C activity due to operation of the nuclear power plant. The maximal calculated normalized ¹⁴C release of 11 TBq/GW_e/year and the maximal effective dose of 2.0x10^-3 mSv/year resulting from the ¹⁴C were estimated for 1999. The excess of ¹⁴C specific activity measured in the moss and soil samples from moss-covered sites near the nuclear power plant (up to 0.5 km) showed highly elevated ¹⁴C contents (up to 813 pMC), probably indicating releases of the particulate material.