ASSESSMENT OF REGULARITIES OF GROUND-LEVEL AIR RADIONUCLIDE CONTAMINATION AT THE RUSSIAN COAST OF THE BALTIC SEA IN THE COURSE OF THE LONG-TERM LENINGRAD NUCLEAR POWER PLANT (1983-1999) OPERATION

Lidia D. Blinova1, Lidia V. Goloubeva1, Victor N. Dushin2, Tatiana G. Michurina1

1Regional Environmental Monitoring Laboratory, V.G. Khlopin Radium Institute, Ministry of Russian Federation on Atomic Energy, Box 170/5, Sosnovy Bor, Leningrad region, 188 540 Russia,
2Regional Environmental Monitoring Laboratory, V.G. Khlopin Radium Institute, Ministry of Russian Federation on Atomic Energy, 2-nd Murinsky pr. 28, St.-Petersburg, 194 021 Russia

Long-term results of ground-level air radionuclide contamination at the Russian coast of the Baltic Sea (nuclear facilities in the vicinity of the town of Sosnovy Bor) are under consideration. As compared with 1992-1997, the Leningrad Nuclear Power Plant (NPP) equipment hermetic sealing (in 1998-1999) caused both the reduction of detection frequency of 131I aerosol and the maximum concentrations of 137Cs in the ground-level air at the NPP site. Long-term weekly nuclides’ concentration time series were examined by the correlation analysis. Results of the analysis are presented. The seasonal fluctuations of 7Be concentrations in the ground-level air were examined by the harmonic (Fourier) analysis. The seasonal fluctuations of its concentrations with the maximum in spring-summer period are shown.