Switzerland's Beznau Nuclear Power Plant could be temporarily shut down as early as Friday because of the heatwave gripping the country, operator Axpo said.
The move would be triggered by rising temperatures in the Aare river, which supplies cooling water to the plant's two reactors.
If the river remains warmer than 25 degrees Celsius for three consecutive days after the return of cooling water used by the reactors, the plant must be powered down to protect local wildlife and vegetation, Axpo said.
The utility had already reduced the output of the roughly 55-year-old reactors by half on Tuesday.
Water drawn from the Aare is used to cool the reactors and warms by several degrees in the process before being discharged back into the river, contributing to higher water temperatures.
Axpo said exceptions to a potential shutdown could be made if continued operation is necessary to maintain electricity supplies, ensure grid stability or meet nuclear safety requirements.
