¹³⁷Cs activity concentration in the ground-level air in the Ignalina NPP region

Abstract

Results of the137 Cs activity concentration measurements in the ground-level air in the Ignalina Nuclear Power Plant (Ignalina NPP) region in 1978-2006 are presented and discussed. The peculiarities of the trend of mean annual radiocaesium activity concentrations in the air during the studied period are explained and described empirically. The analysis of the radiocaesium concentration course after the Chernobyl accident shows that mean annual 137 Cs activity concentrations in the air are decreasing slower than it is expected due to its radioactive decay and aerosol, as the 137 Cs carrier, removal processes in the atmosphere. The Hybrid Single-Particle Lagrangian Integrated Trajectory model of the global dispersion and deposition of the admixture in the air is used to study episodic increases in the 137 Cs activity concentration in the ground-level air of more than 8 µBq m −3 . Modelling results show the transport of resuspended radiocaesium with air mass from the Chernobyl NPP accident polluted regions to be an important source of the radionuclide to the environment of the Ignalina NPP. It is shown that 137 Cs emissions from its generation sources (nuclear industry objects) and, probably, the depositional flux of the radiocaesium from the stratospheric reservoir, can contribute up to 10% to the mean annual 137 Cs activity concentration value. Mean arithmetic and mean geometric 137 Cs activity concentrations in the air during a year are calculated and compared.

Recent trends and explanation for airborne137Cs activity level increases in France

“…This mean level is not decreasing significantly anymore in France (excepted through the physical decay period of 137 Cs). This trend was also noticed in Lithuania [1]. Nevertheless, some variations with peak activities are registered regularly.…”

Accumulation and transfer of 137Cs and 90Sr in the plants of the forest ecosystem near the Ignalina Nuclear Power Plant

“…Aerosolborne radionuclides in the Ignalina NPP region have been continuously collected since 1978 using air filtration equipment installed 3.5 km south-east from the NPP. Emission of 137 Cs to the atmosphere from the Chernobyl NPP in 1986 resulted in an increase in mean annual activity concentration in the air of the Ignalina NPP region up to 1230 mBq m À3 whereas the annual geometric mean 137 Cs activity concentration in the air in the period 1978e1980 was 2.0 mBq m À3 (Jasiulionis and Ro zkov, 2007). Atmospheric activity concentrations of 137 Cs in the range 0.1e3 mBq m À3 were measured in the Ignalina NPP region in 2005, but sometimes the activity concentrations of 137 Cs were higher than global activity concentrations in the ground-level air.…”

14C AND OTHER RADIONUCLIDES IN THE ENVIRONMENT IN THE BORDER REGION OF LITHUANIA BEFORE THE START OF THE BELARUSIAN NUCLEAR POWER PLANT OPERATION

“…As it was previously shown in many studies (Mikhailov et al 1999;Mažeika 2002;Nedveckaitė et al 2007;Jasiulionis and Rozkov 2007;Gudelis et al 2010;Mazeika et al 2016;Jefanova et al 2018), Lithuanian terrestrial and aquatic ecosystems near the INPP contained traces of carbon-14 ( 14 C), tritium ( 3 H), cobalt-60 ( 60 Co), and caesium-137 ( 137 Cs) originating from the INPP. We assume that the same radionuclides, especially mobile ones, such as 14 C and 3 Н, may be present in the BelNPP environment in the future during its normal operation.…”