Radionuclide contamination peculiarities on the P-2 test settlement (Semipalatinsk Test Site, Opytnoe Pole)

In the paper the results of radionuclide contamination investigation on the P-2 test settlement situated on the Opytnoe Pole of the Semipalatinsk Test Site are presented. On this settlement four ground explosions were carried out. In the result on this territory 215 Ci plutonium were discharged. Estimation of sum activity for radionuclide discharge from all explosions to 2001 beginning makes up - Pu - 630 Ci, 137Cs - 890 Ci and 90Sr - 360 Ci. The main factor of P-2 settlement radioactive contamination in the result of considered test is the essential value of plutonium and 241Am. The examination of the settlement was carried out with step 200 m, and in the most contaminated places with step 50 m with sampling of soil specimens for laboratory analysis. For determination of coordinates of points for radiometric measurements and specimens sampling the 'Garmin GPS-12XL' personal navigator was applied. In the examined settlements close to the P-2 settlement the 275 soil specimens were sampled. Concentration determination for 241Am, 239Pu, 137Cs, 152Eu and others have carried out by the instrumental γ-spectrometric method with applying of the planar (GL101) and coaxial (GX1520) 'Canberra' germanium detectors. Measured concentrations of these radionuclides make up: 137Cs - 10-28000 Bq/kg; 152Eu - 5-6600 Bq/kg; 239Pu - 50-140000 Bq/kg; and 241Am - 5-12600 Bq/kg. Consideration of concentration and ratio for these radionuclides is allowing to determine the tests conducting places and contribution of separate explosions on the P-2 settlement in the radionuclide distributions