What is Kyshtym disaster?
The '''Kyshtym disaster''' was a [[radiation]] contamination disaster on 29 September 1957, in [[Mayak]], a [[nuclear plant]] in [[Russia]] (then a part of the [[Soviet Union]]). It measured as a Level 6 disaster on the [[International Nuclear Event Scale]] (the [[Chernobyl disaster]] and the [[Fukushima I nuclear accidents|Fukushima]] disaster are the only accidents listed as more serious than this one). [[File:Satellite image map of Mayak.jpg|thumb|250px|[[Satellite (artificial)|Satellite]] image of the Mayak site area]] '''Mayak''' is the name for a number of nuclear facilities, which are about {{convert|150|km|mi}} from [[Ekaterinburg]], in [[Russia]]. The facilities were also known as ''Chelyabinsk-65'', or ''Chelyabinsk-40''. Mayak was built between 1945 and 1948. It was the first plant that could produce [[nuclear energy|nuclear]] material in the [[Soviet Union]]. At times, up to 25.000 people worked at Mayak. They produced the [[plutonium]] [[fuel]] that was used for the first Soviet [[atomic bomb]], amongst other things. Between 1948 and 1987, a total of ten nuclear reactors were built. Until 1991, all but two were closed. The two remaining produce [[radioactive decay|radioactive]] [[isotope]]s for [[health care]] and for [[research]] purposes. During different accidents, a large amount of radioactivity was [[wikt:released|released]] into the [[environment]]. The biggest of these accidents happened in 1957, and is known as ''Kyshtym Disaster'' today. It happened in a plant near Kishtim (Кыштым). There were many accidents in this secret plant.<ref>{{cite journal | last = Larin | first = Vladislav | title = Mayak's walking wounded |journal = Bulletin of the Atomic Scientists| volume = 55 | issue = 5 | pages = 20–27 | date = September–October 1999 | url = http://thebulletin.metapress.com/content/q27k0g110k554870/?p=1e082b5efa3e4feeba52c0e5b0bcceb1&pi=7 | doi = 10.2968/055005008}}</ref> The most serious of them happened on September 29, 1957. The cooling system of the plant failed to work. A (non-nucl