Radiocarbon Impact on a Nearby Tree of a Light-Water VVER-Type Nuclear Power Plant, Paks, Hungary

Abstract

Tree-ring series were collected for radiocarbon analyses from the vicinity of Paks nuclear power plant (NPP) and a background area (Dunaföldvár) for a 10-yr period (2000–2009). Samples of holocellulose were prepared from the wood and converted to graphite for accelerator mass spectrometry (AMS) 14 C measurement using the MICADAS at ETH Zürich. The 14 C concentration data from these tree rings was compared to the background tree rings for each year. The global decreasing trend of atmospheric 14 C activity concentration was observed in the annual tree rings both in the background area and in the area of the NPP. As an average of the past 10 yr, the excess 14 C emitted by the pressurized-water reactor (PWR) NPP to the atmosphere shows only a slight systematic excess (∼6′) 14 C in the annual rings. The highest 14 C excess was 13′ (in 2006); however, years with the same 14 C level as the background were quite frequent in the tree-ring series.