1950s disasters in the Soviet Union

thumb|Map of the Tobol basin. The Techa river (Теча) may be found to the left center, next to the regional ЧЕЛЯБИНСКАЯ ОБЛАСТЬ (Chelyabinsk Oblast) label. The Techa (, ) is an eastward river on the eastern flank of the southern Ural Mountains noted for its nuclear contamination. It is long, and its basin covers . It begins by the once-secret nuclear processing town of Ozyorsk about northwest of Chelyabinsk and flows east then northeast to the small town of Dalmatovo to flow into the mid-part of the Iset, a tributary of the Tobol. Its basin is close to and north of the Miass, longer than these

radioactive contamination of Lake Karachay