Aggregated Transfer Factors of 90Sr in Woody Plants in the Area Influenced by a Nuclear Facility

The data on the variability of aggregated transfer factors (Tag) of 90Sr in different species of woody plants growing in the area influenced by the Mayak Production Association are summarized. The radioecological situation in this territory is primarily determined by two events: the discharge of radioactive waste into the Techa River (1949−1951) and the Kyshtym accident (1957). The main causes of Tag variability are analyzed, including species-specific characteristics of plants, different soil moisture regimes, and the level of 90Sr contamination. The dependence of this radionuclide’s Tag in trees on soil contamination density is described by a power function. In buffer zones and background areas the 90Sr Tag corresponds to the variability ranges established by the IAEA, while in more contaminated impact areas, the accumulation capacity in trees tends to decrease.