Origin and Components of Radioactive Aerosols on the Cover Site at the Chernobyl Nuclear Power Plant

It is shown that essentially three sources determine the ¹³⁷Cs concentration in aerosols at the site of the object Cover at the Chernobyl nuclear power plant: a natural source (global transport of air masses and local wind uplift of dust) and two technogenic sources (work performed at the industrial site and operation of the object). Continual aerosol sampling for two weeks at the site in 2000 using FPP-15-1,5 filters shows that the ¹³⁷Cs/²⁴¹Am ratio remained in the range 50–70. This shows that during that period the artificial radioactive aerosols resulted from work performed at the site and wind uplift. The effect of work performed inside the object Cover on the aerosol conditions around the object is studied for the fire which occurred on January 14, 1993 in room 805/3.