ASSESSMENT OF THE CONTAMINATION BY 14C AIRBORNE RELEASES IN THE VICINITY OF THE IGNALINA NUCLEAR POWER PLANT

A radiocarbon (C-14) activity analysis in the tree rings around Ignalina nuclear power plant (INPP) has been carried out with the aim to test the hypothesis to use C-14 tree-ring analysis data as a tool for the reconstruction of gaseous releases from NPP to the environment. The INPP has been in decommissioning state since the end of 2009. Tree-ring samples for C-14 analysis were collected 7 yr after final power unit shutdown from the INPP vicinity. The samples from 5 sampling locations were collected, prepared and measured using the Single Stage Accelerator Mass Spectrometer (SSAMS). Data analysis represents observable Ignalina NPP influence by C-14 increase up to 15 pMC (percent modern carbon) in tree rings. Good correlations of the C-14 concentrations and wind direction were obtained. The main purpose of this article was to match C-14 measurement data along with the atmospheric dispersion modeling of emissions in order to retrospectively characterize the emission source.