ZURICH (Reuters) - Switzerland's Muehleberg nuclear power plant was shut down safely on Wednesday after maintenance work caused the feedwater system to stop, the operator said.
"The reactor is in a safe state. No radioactivity was released," operator BKW FMB Energie AG said in a statement.
The plant is expected to start running again in the evening, once authorities have deemed it safe to operate.
Following Japan's Fukushima nuclear disaster last year, Switzerland's nuclear plants have come under increasing public scrutiny. Last May around 20,000 people rallied against nuclear power - the largest demonstration of its kind since the 1980s.
Muehleberg, built in 1972, is one of the plants frequently cited by opponents of nuclear energy as ripe for mothballing.
The government decided to scrap plans to build new nuclear reactors after Fukushima shook public confidence in the industry. But it does not plan to shut existing power plants prematurely.
Switzerland derives about 40 percent of its power from nuclear plants.
(Reporting by Catherine Bosley, editing by Jane Baird)