Development of a method for studying 241Pu/241Am activity ratio in the soil of the main Semipalatinsk test site areas.

The methodology for determination of 241Pu in soils of the main test sites of the Semipalatinsk Test Site (STS) has been developed. The results of 241Am and 241Pu activity determination in soil samples sampled at the main testing sites of the STS are presented. 241Pu/241Am activity ratio is calculated. In most cases, on local sites, 241Pu/241Am activity ratio is in a rather narrow range, which makes it possible to estimate 241Pu activity based on the results of 241Am gamma-spectrometric analysis. The accuracy of 241Pu activity estimation using this method will be about 50%, which is quite enough in most cases.