Ecological Chronology of Nuclear Fuel Cycle Sites

We compared 14C levels in annual growth rings of pine trees around the Tomsk nuclear fuel reprocessing plant (NFRP) and the Chernobyl nuclear power plant (NPP). At the Chernobyl site, samples were taken from the control area (within a 30-km radius zone around the site) to a distance of 80 km. In Tomsk, we collected samples between 8–10 km and 10–15 km from the site, taking into account prevailing wind directions. Background samples were collected 200 km from the plant. Samples were converted to benzene and counted in an ultra-low-level LSC Quantulus 1220™. Because of the Chernobyl accident, a signal can be detected in the background of routine plant operation. Comparison with the Tomsk data suggests that the routine discharges from Tomsk are more significant than the discharge from the Chernobyl accident. We estimated Tomsk NFRP annual discharge level at up to 30–45 TBq 14C from 1985 to 1988.