Use of mathematical statistics at calculation of background radiation of contaminated territory

Mathematical apparatus used at statistical data processing, received as a result of the Semipalatinsk Test Site (STS) investigation conducted by the Institute of Radiation Safety and Ecology of the National Nuclear Center of the Republic of Kazakhstan, was carried out. Calculations of the background radiation of the investigated STS territory are represented. Gradation of the radiation contaminated territory is represented. Great data array of 137Cs contents in soil of the STS is worked up, background importance of 137Cs contents is estimated. Rank of 137Cs radionuclide contamination is carried out and a map of its distribution on the STS territory is made. (author)