Evaporation losses as limiting factor for the erection of thermal power plants near medium-sized rivers

It is shown that with recirculation cooling, the loss of water in the river due to evaporation rather than heating-up of the river may become the limiting factor for the installation of further power plants although heating-up cannot always be neglected when nuclear power stations are situated near small rivers. In cases of local and regional water shortage, the conclusion so far has always been a change from wet recirculation cooling to dry cooling. The authors' considerations, however, lead to a different result which is put up for discussion. Water management policies such as water storage or water supply from areas richer in water may postpone the transition from wet to dry cooling for some decades. A cost factor estimation shows that it is more economical to use wet recirculation cooling as long as possible. (orig./TK)