URANIUM IN THE SUMMER AND WINTER ATMOSPHERE OVER YAKUTSK

The distribution of uranium (U) in the surface atmosphere over Yakutsk in summer and winter is examined. During 2019-2020, some studies of the chemical composition of particulate matter in summer precipitation, as well as in the solid and soluble phases of the snow cover in winter were carried out in the city. It was found that in summer, U is concentrated mainly in the dust fraction, in combination with a group of siderophile elements. In winter, particulate matter is more dispersed. Specific minerals in atmospheric dust that correlate with U are carbonates. In the soil-dust-snow system, a uniform decrease in U is observed. However, in the water phase of snow, the concentration of U becomes an order of magnitude higher. Most of the uranium (about 90%) falls out of the atmosphere in summer. The total volume of atmospheric uranium entering the city is about 16.4 mg/(m2 year). In the areas of contrasting anomalies, the value increases up to 48 mg/(m2 year).