The techa river in Russia on one that runs along the eastern flank of the Ural Mountains. This 150 mile or 240 kilometer river starts at what was a secret nuclear processing town known as Ozyorsk, Chelyabinsk Oblast. The techa river while not the longest river out there it's basin covers 2,900 square miles or 7,500 square kilometers which is bad news when the water is radioactive. At first you might think this has something to do with Chernobyl but it doesn’t, it’s actually quite far away from it. After the end of the second world war Russia felt vulnerable that the United States were in possession nuclear weapons to which they created the Uranium Project. This project was a rushed effort to make catch up with the States in nuclear technology. They brought together the best scientific and technical specialists they could find. In a short period of time they had setup 2 experimental design facilities in Leningrad which is now St. Petersburg. Equipment was developed for uranium isotope enrichment by gaseous diffusion and a lab was built to develop heavy water reactors which were fuelled by natural uranium. The next step was to find a site to build these reactors well within the Russia border that were inaccessible by raiding aircraft. Lake Kyzyltash was the chosen location and only 2 years after the end of the war the first military reactor was ready to operate. The Mayak plutonium facility had 7 reactors were built in total 4 of which graphite moderated reactors with direct water cooling loops using water from lake Kyzyltash. Knowledge of the effects of radioactive waste on the environment was minimal back in those days, they knew they needed to contain and treat the highly radioactive waste but it didn’t go to plan. From 1949 - 1956 low contaminated waste was dumped directly into the techa river where high contaminated waste was directed over to a tank farm where large containers would be filled up with and constantly cooled to prevent self overheating. The system didn’t operate as intended which lead to small amounts of this high concentrated waste to leak into the river. In 1950 - 1951 leakage in the cooling system caused this a large amount of highly radioactive material to leak right into the techa river which was the source of water that was cooling the radioactive waste. Downstream there were 40 villages of which 24 directly relied on the techa river. A total population of 26,000 people were exposed to these high levels of radioactive material. By 1951 residents of the upper reaches of the techa river closest to the reactor were forbidden to drink the water, swim in it or use it for agriculture. A barbed wire fence was constructed along the river and a dam by built in 1956 to try to contain the water but there wasn’t much of a reduction of radiation downstream as radionuclides were mixed among bottom sediments in the river. This caused the government to build additional dam and canals to try to contain this mess. By the mid 1950s thousands of residents living near Mayak had been relocated to live somewhere else but the damage had already been done. Source: https://en.wikipedia.org/wiki/Techa_River http://users.physics.harvard.edu/~wilson/publications/pp747/techa_cor.htm Sofia Image: ... https://www.youtube.com/watch?v=yPYQoQ_H79o