| Abstract [eng] |
Environmental science and enviroment protection is a rapidly developing science fields. It becomes even more important implying, what a global phenomenon will face a mankind in the future, and how it will to adapt to environmental changes. While the 14C isotope influence to the climate is not observed, the total cumulative atmospheric carbon after the beginning of the industrial revolution has significantly increased. In the begining of the 20 century the Suess effect was observed – atmospheric 14C/12C isotope ratio has been changed after increase of stable carbon isotope amount. The beginning of the nuclear weapons tests increased radiocarbon amount in the atmosphere to the levels much higher (around 2 times) than natural. Currently radiocarbon amounts almost reached the background level comparable to the level that was observed in 1950, but there are many studies that shows a local increase in the amount of radiocarbon around various purpose nuclear facilities. For plant biological radiocarbon uptake from the atmosphere during photosynthesis, tree ring analysis is an effective tool to observe operating conditions of nuclear facilities. Therefore, the main topic of this study was to determine the change in the concentration of 14C created in Ignalina nuclear power plant and compare it to the current background concentrations. 45 samples were collected from the trees in anthropogenicaly uncontaminated area and research areas near the Ignalina nuclear power plant. 8 of the best samples were physically and chemically treated in the laboratory, which leads to 285 tree rings samples. Each sample has been chemically treated by a method BABAB of isolation of cellulose. Collected data form 14C measurements provides an important information about radiocarbon pollution in the Ignalina nuclear power plant suroundings and allowes us to evaluate a local change in the concentration of 14C. The results show that a total 14C emmision from Ignalina NPP during the execution period, increased the local 14C consentration by 5%. 5% increment in the local 14C concentration, increases annual effective dose over the food chain for residents by 0,7 µSv. Also it was observed that 14C annual emissions into the environment does not correlate with the Ignalina NPP produced electricity over the year. |
