LITHOSPHERE, 2003, No. 19, p. 130

Though Belarus has no it’s own power generation industry three nuclear power plants (NPP): the Chernobyl, Ignalina and Smolensk ones are located at its frontiers. Since 1994 the program of radiocarbon environmental monitoring of the territory adjacent to operating nuclear power plants had started at the Institute of Geological Sciences. The determination of the radiocarbon concentrations in natural objects from the areas adjacent to the Ignalina, Chernobyl NPP and the ¹⁴C «background» concentration in the sites distant from nuclear power plants was carried out.

It was found that in areas distant from an operating NPP the ^I4C concentration is characterized by values of 105–108 % pMC, which are close to the present day natural background level (Levin et al., 1985). In the area of the Ignalina plant rather high ¹⁴C contents of vegetation (up to 150–190 % pMC) and water of the lake Drisvyaty (127–154 % pMC) connected by canals with the Ignalina NPP were noted. Biocarbonates are also enriched in radiocarbon. Shells of lake mollusks Anadonta cygnaea and Dreissena contain 120–150 % pMC. Shells of eggs of poultry fed with crops grown up in areas around the lake show 152 %. The ¹⁴C concentration in rings of pine trees of 1978, 1982 and other years appears to be in a close correspondence (Banis, 1988) with concentrations of this isotope in the Drisviaty lake water (from 115 to 150 %).

The radiocarbon behaviour was found to be ambivalent in plants from the Chernobyl zone. On the one hand, concentrations of ^I4C in plants sampled in 1994–1996 are similar to those from the Ignalina NPP region and show increased values (up to 130–140 %), probably reflecting the impact of the Chernobyl NPP in operating conditions. On the other hand, an emission of the radiocarbon resulted from the Chernobyl NPP accident was recorded in the biosphere and its concentrations increased toward the plant. So, ¹⁴C values were about 200 % pMC near Minsk (May – June, 1986) and reached 600–700 % pMC near Gomel. These data permit a realistic estimate of concentrations of the radiocarbon emission at an instant of the accident. The radioisotope is well preserved and its redistribution occurs mainly due to biochemical processes. This is well shown by the radiocarbon distributions in a profile of the soil boggy medium. Concentrations of ¹⁴ C in the upper part of the profile were as high as 825 % and regularly decreased with depth to 145 %.

The investigations described prove the necessity of the radiocarbon monitoring all over the country territory.

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