The current content of artificial radionuclides in the water of the Tobol–Irtysh river system (from the mouth of the Iset River to the confluence with the Ob River)

Data on content of 90Sr, 137Cs, 239,240Pu and 3H in water of the Tobol–Irtysh part of the Techa–Iset–Tobol–Irtysh–Ob river system (through which the “Mayak” PA radioactive wastes are transported) are presented and discussed. The data were received in 2004–2005 under the ISTC project on radioecological monitoring of the Tobol and Irtysh rivers. Monthly observations of 137Cs, 90Sr and 3H content in water in the area of the Tobol and Irtysh confluence have been conducted starting from May 2004. To obtain information on the investigated river system as a whole, the radioecological survey of the Tobol and Irtysh rivers at the section from the mouth of the Iset River to the confluence with the Ob River was carried out in 2004. It is shown that the impact of “Mayak” PA waste transport by 90Sr is distinctly traced as far as the area of the Irtysh and Ob confluence.