Ronneburg (Wismut uranium mining district)

Wismut, a Soviet and later Soviet-German company, mined 230,400 tonnes of uranium in Saxony and Thuringia between 1947 and 1990 for the USSR's nuclear programme. Ronneburg, active from 1950, was the most productive site. The Seelingstädt mill processed 108.8 million tonnes of ore.

Closure left an open pit, dumps of weakly radioactive waste rock and tailings ponds: 152 million m³ at the milling sites alone. The tailings still hold uranium (50–300 g/t) and radium.

Since 1991 the federally owned Wismut GmbH has moved most of the waste rock into the open pit. Within the mining area the University of Jena set up the "Gessenwiese" test field in 2004.