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.