Along with gold,deep level mining in South Africa(SA)for over century also brought large amounts of geologically associated uranium(U)to surface.Much of the radioactive heavy metal is now contained in approximately 7 bn t of tailings produced since 1886 which cover about 400 km2 often located in densely populated metropolitan areas such as Johannesburg.At concentrations that exceed U-levels in tailings of dedicated uranium mines,e.g.in Namibia or Germany,gold mining tailings in the Witwatersrand contain an estimated 700,000 t U.