Stockholm - A reactor at the Swedish nuclear plant Ringhals has been offline for a month after problems with auxiliary coolant pumps were detected during annual maintenance work, the plant said Friday. Two of the three auxiliary pumps had "insufficient capacity," Ringhals spokesman Gosta Larsen told local media.
The maintenance work began early May and the problems were detected during the overhaul.
The reactor was to remain offline pending further analysis, Larsen said, adding that Westinghouse that designed the plant was also to assess the matter.
The Swedish Nuclear Power Inspectorate (SKI) has been notified and a spokesman said the agency was waiting for a report from Ringhals.
The Ringhals plant, 60 kilometres south of the west coast city Gothenburg, operates four reactors and provides about a fifth of Sweden's electricity.
State-controlled energy group Vattenfall owns some 70 per cent of Ringhals, while energy company E.ON owns the rest.
Sweden has operated 12 nuclear reactors at most. Two at the Barseback plant in southern Sweden have been decommissioned, the most recent in May 2005.