The reactor at the Leibstadt nuclear power station in northern Switzerland shut down automatically because of a technical problem on Saturday, the Swiss Federal Nuclear Safety Inspectorate (ENSI) said.
The shutdown at Leibstadt, which was built in 1984 and is one of four nuclear power stations in the country, took place at 7:48 a.m. local time following a technical fault in the non-nuclear part of the plant, a statement by the operator said.
"The plant is in a safe condition. The automatic measuring network in the vicinity of the nuclear power plants has not shown any increase in radioactivity," ENSI said.
The shutdown at Leibstadt comes a week after the Mühleberg nuclear power plant outside Bern was permanently switched off. It was the first Swiss nuclear power reactor to be decommissioned. The reactor had been in service since 1972 and provided 5% of the electricity used in Switzerland. The decision to close the Mühleberg plant was made for business reasons.