Research into the current radiological state of air and monitoring observations on STS and the adjacent territory.

The article presents the assessment of levels and the pattern of STS air radioactive contamination. Levels of air radioactive contamination with artificial radionuclides at different distances from ground zeros of nuclear tests (0.08-10 km) were determined. The maximum concentration of 239+240Pu in the air did not exceed 6.5·10-3 Bq/m3 at the crater ridge of the "Atomic Lake", the one at the P3 technical site, the "Experimental Field", reached 1.6·10-2 Bq/m3. Based upon monitoring observation data (2016-2021) on the STS territory, 239+240Pu concentration in the air of the "Balapan" and "Degelen" sites varied between 3.0·10-9 and 1.1·10-6 Bq/m3. In settlements adjacent to the STS territory, 239+240Pu concentrations in the air is: Kurchatov t. - 3.0·10-9 to 6.0·10-7 Bq/m3, the Dolon small village - 4.5·10-9 to 5.8·10-6 Bq/m3, the Sarzhal small village - 4.4·10-7 to 1.3·10-6 Bq/m3. Values derived for concentrations of artificial radionuclides at STS observation posts and the adjacent territory are at the level of background values for this region.

Studying of tritium content in snowpack of Degelen mountain range.

The paper presents the results of investigation of tritium content in the layers of snow located in the streambeds of the "Degelen" massif contaminated with tritium. The objects of investigation were selected watercourses Karabulak, Uzynbulak, Aktybai located beyond the "Degelen" site. We studied the spatial distribution of tritium relative to the streambed of watercourses and defined the borders of the snow cover contamination. In the centre of the creek watercourses the snow contamination in the surface layer is as high as 40 000 Bq/L. The values of the background levels of tritium in areas not related to the streambed, which range from 40 to 50 Bq/L. The results of snow cover measurements in different seasonal periods were compared. The main mechanisms causing tritium transfer in snow were examined and identified. The most important mechanism of tritium transfer in the streams is tritium emanation from ice or soil surface.