The more than 50-year-old Swiss nuclear power plant Beznau, located near the German border, has shut down its second reactor due to the high temperatures.
The shutdown has nothing to do with the safety of the reactors but is related to environmental regulations, the operator said on Thursday.
The operator, Axpo, must adhere to limits on the water temperatures in the river Aare. The plant draws water from the river to cool the reactors and later returns it warmer than before.
If the Aare is already very warm due to the outside temperatures, additional warm water cannot be discharged. This is intended to protect the flora and fauna of the Aare, Axpo stated.
South of the nuclear power plant, the water temperature was 24.6 degrees Celsius on Wednesday evening, according to the Federal Office for the Environment.
The first of the two reactors at the Beznau nuclear power plant was shut down on Tuesday, and the second was taken offline on Wednesday evening.
Axpo assured that sufficient electricity for industry and households would continue to be produced in Switzerland.
The two reactors in Beznau went into operation in 1969 and 1971, making them among the oldest nuclear power plants still in operation worldwide. They are located less than 10 kilometres from the German border.
Switzerland has decided to phase out nuclear power, but existing plants are allowed to operate as long as they are safe. Axpo plans to take Beznau two reactors offline in 2032 and 2033.
