in the 1970s the opposition to the construction of new plants increased in importance. despite the accident at the lucens nuclear power plant, the debate mostly regarded technical aspects such as the construction of facilities in densely populated areas or the cooling system. numerous were the concerns about an overexploitation of the aar and rhine waters, already used for the cooling of the beznau and mühleberg stations and in numerous hydroelectric plants. in march 1971 the federal council forbade the use of river water for direct cooling of new plants. since the kkg should also have been cooled by the aar, the project had to be adapted by adding the cooling tower.