Numerical investigation of the modeling of transporta¬tion and deposition of the radioactive pollution in the Caucasian Region in case of the hypothetical accident on the Armenian Nuclear Power Plant

Abstract

By means of regional model of development of atmospheric processes in the Caucasian Region and the equation of a substance transfer the spatial distributions of the radioactive pollution (¹³¹I) and zones of radioactive deposition are investigated. In the model the radioactive decay and aerosols deposition processes are taken into account. The distribution of radioactive pollution is simulated in cases of the South, South West and South East background winds. The distribution of only one radionuclide aerosol ¹³¹I with diameter 10is considered.

It is shown, that the relief of the Caucasus significantly influences on the trajectory of the pollution distribution.  The North West orientation of the Main Caucasian Range resists air motion to the north, constrains the radioactive pollution in the boundary layer to flow around the Main Caucasian Range from the west or east sides. It is obtained that the 48 hours are necessary for the radioactive cloud to overflow the South Caucasus and distribute over the territory of the North Caucasus. The radioactive pollution is falling out mainly in the central, southeast and northwest parts of the South Caucasus. The zone of the radioactive deposition is extended along the background wind and deformed by the influence of the relief. The maximum length of the zone of significant deposition of radioactive substance equals approximately 750 km in case of the background South East wind and 350 km in other cases. The maximum width of the zone approximately equals 150 km. It is obtained that the surface density of the deposited radioactive nuclide in the zone of significant radioactivity decreases from 360 a.u./m² down to 1 a.u./m² when the concentration of 10  aerosol ¹³¹I in emission plume during 6 hours are equal to 100 a.u./m³.