* Safety issues at Muehleberg, Beznau, Leibstadt, Goesgen
* No Swiss nuclear plants need to be shut down-ENSI
* Utility groups BKW, Axpo say will meet stricter rules
* Socialists, ecologists ask nuclear plants be shut down
ZURICH, May 5 (Reuters) - The Swiss nuclear safety body ENSI said on Thursday it had detected problems at the country’s nuclear power plants, but there was no need for a shutdown.
A safety check of the country’s five reactors after the disaster at Japan’s Fukushima site had shown weak points regarding the storage of fuel assemblies, Federal Nuclear Safety Inspectorate ENSI said in a statement.
“There is no immediate danger for the population, which means that none of the Swiss nuclear plants needs to be shut down,” ENSI said.
It gave plant operators until Aug. 31 to show how they would resolve the safety issues. Plant operators BKW BKWN.S and Axpo said they would meet the stricter requirements issued by ENSI.
But the Socialist and Ecologist parties called for an immediate shutdown of the nuclear plants. The ecologists said they would take steps to improve nuclear safety supervision.
The cooling systems of the Muehleberg plant, operated by BKW, and of Axpo’s Beznau plant, which has two reactors, were not sufficiently protected in the event of an earthquake or flood and problems were also found at Goesgen and Leibstadt, ENSI said.
Switzerland got about 10 percent of its energy from nuclear power in 2009, according to the Swiss Federal Office for Energy.
It suspended the approvals process for three new nuclear power stations in March so safety standards could be reviewed after an earthquake and tsunami crippled Japan’s Fukushima plant.
Many countries are starting to look at how they can become less dependent on nuclear power after the Japanese crisis. Germany shut down all seven of its nuclear power plants that began operating before 1980. (Reporting by Silke Koltrowitz)