Sources of anthropogenic radionuclides in the southern Urals

Abstract About two-thirds of the 137 Cs deposition 10 to 25 km west of Kamensk Uralskyi in the southern Urals comes from unreported releases to the environment. In this area, the contamination from the Kyshtym accident in 1957 was measured at 10 to 60 kBq 90 Sr m −2 , while the deposition of 137 Cs from this accident was less than 1 kBq m −2 . Nevertheless, a total deposition of 12 kBq m −2 was measured. Of this, about 4 kBq were from global fallout from nuclear weapons testing and debris from the Chernobyl accident, but 8 kBq 137 Cs m −2 were not accounted for. Hence, the southern Urals have significant sources of radioactive contamination other than those officially reported. This fact may have an impact on the global inventories of 90 Sr and 137 Cs.