Radionuclides from the Fukushima accident in Europe - Modelling the air mass transport

Measurements of airborne radioactive aerosol concentrations of ¹³¹I, ¹³⁷Cs and ¹³⁴Cs were carried out in daily samples after the Fukushima disaster during the period of March - April, 2011. Rather diluted activities were detected in Vilnius on 23 March, 2011. The two maxima of activity concentrations were found which most probably are related to the complicated air masses transport. Activity concentrations of ¹³¹I and ¹³⁷Cs ranged from 12 mBq/m³ and 1.4 mBq/m³ to 3700 mBq/m³ and 1040 mBq/m³, respectively. Small variations in the activity ratio of ¹³⁴Cs/^137Cs (around 0.9) in measured samples were found. Results were compared with the data obtained during the Chernobyl accident. Modeling of long range air masses transport indicated a rather complicated pathway of radioactive cloud transfer across the Pacific and the North America to the Europe.