Geoecological investigations of artificial radionuclides in the aquatic system of the Ob River and Kara Sea

Numerous studies have considered whether run-off from large Siberian rivers, in particular the Ob River, has the potential to transport radioactive contaminants from the nuclear sites – SPA “Mayak” and Siberian Chemical Combine (SCC), located in the vicinity of these rivers, to distant locations including the Kara Sea. The plutonium-producing radiochemical plant of SPA ''Mayak'' stored a lot of radioactive wastes in Lake Karachai. Radioelements are carried to the rivers with flood and ground waters [1]. As contamination is transported, radioactivity is removed through Techa-Iset’-Tobol-Ob river system but has the potential to reach the Kara Sea and further to other seas within the Arctic basin via ocean currents. The Siberian Chemical Combine, is located in Seversk city on the bank of Tom River, that drains into the Ob network. SCC liquid wastes were detected in the Tom River, which flows into the Ob River [2]. In this paper the data of our investigations during last years on studying the radioecological situation in two parts of the Ob river-Kara Sea aquatic system Ob-Irtysh river’s system and Ob Bay and adjacent part of the Kara Sea, with a main focus on the behavior and migration pathways of man-made radionuclides are presented.