On variations of volumetric activity of 90Sr and 137Cs in the Baltic Sea coastal waters near the shore of Lithuania in 2005–2009

Monitoring of the volumetric activity of a radionuclide 137Cs in the coastal waters of the Baltic Sea was carried out near the settlement of Juodkrante in the summer – autumn of 2004. Three measurement stages of the VA of this radionuclide were carried out and hydrometeorological situations were considered simultaneously. 137Cs VA change cyclicity was found out near the seacoast. Extreme data for the whole period of observation were 48 and 94 Bq/m3. Maximal values exceeded minimal data approximately two times, which practically coincided with the radioactive “background”. The method of mathematical modeling was used to find out possible reasons of 137Cs VA change near the sea‐coast. Because of lack of information about the location and power of a possible “source” of radioactive pollution, repeated calculations were carried out, assuming its various places of formation and various power, i e search of optimum coincidence of calculation and measurement data was selected. Optimum coincidence of theoretic and measurement results was found at the location of a radioactive “source” in the southern part of the Lithuanian sea area at a distance of 25–35 km from Juodkrante. The VA of the radioactive “source” was 5000 Bq/m3 in the summertime and 15000 Bq/m3 in October of 2004. Agreement of measurement and calculation results was satisfactory for all the observation stages.

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COMPARISON AND ANALYSIS OF INVESTIGATION RESULTS ON VOLUMETRIC ACTIVITY OF 137CS AT THE BALTIC SEA COAST IN 2003–2005

Journal of Environmental Engineering and Landscape Management ◽

10.3846/16486897.2007.9636909 ◽

2007 ◽

Vol 15 (2) ◽

pp. 55-60 ◽

Cited By ~ 3

Author(s):

Dmitrijus Styrо ◽

Rasa Morkūnienė ◽

Nijolė Astrauskienė ◽

Asta Daunaravičienė

Keyword(s):

Baltic Sea ◽

Radioactive Contamination ◽

Coastal Waters ◽

The Baltic Sea ◽

Volumetric Activity ◽

Autumn Period ◽

Analogous Data ◽

Comparison And Analysis ◽

The Baltic ◽

Sea Coast

Measurements of 137Cs volumetric activity (VA) in coastal waters of the Baltic Sea (near Juodkrante) were carried out in 2005. The highest values occurred in springtime; later they decreased, and in the summer‐autumn period approximate homogeneous values of 137Cs varied in the range of 41–57 Bq/m3, and the lowest values were observed in autumn. Comparison of these values with analogous data obtained in 2003 and 2004 was carried out. The highest average annual value of 63 Bq/m3 is proved to be in 2004. Furthermore, that year the greatest 137Cs volumetric activity variations in the range of 49–91 Bq/m3 were observed. These variations are related to possible appearance of additional sources of radioactive contamination in the sea. Evidently, such sources did not exist in 2005, when a satisfactory coincidence of measured and calculated results was obtained.

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