Nuclear watchdog orders improvements of reactor backup systems

Sep 14, 2006, 15:22 GMT

Stockholm - Further improvements of backup and safety systems are required before two nuclear reactors north of the Swedish capital can go online, a Swedish nuclear watchdog said Thursday.

The Swedish Nuclear Power Inspectorate (SKI) announced its decision after reviewing a report from the Forsmark nuclear power plant where a reactor was shut down late July, and two of four emergency generators failed to start.

Four of Sweden's 10 reactors have been taken offline due to assessments they had similar flaws as the Forsmark reactor, north of Stockholm.

The operators of Forsmark were ordered to make the battery-powered net 'more durable to high-voltage transients' and to secure the power generation from the diesel-fuelled generators, SKI said.

The agency said the incident had not caused any damage to the reactor and staff operated in accordance with their guidelines.

However, the incident was regarded as 'serious' since security systems that were needed, partly malfunctioned.

SKI has earlier listed the incident as a 2 on the seven-point international nuclear event scale (INES).

Environment Minister Lena Sommestad announced plans to host an international conference with SKI on nuclear safety, citing that the 'incident at Forsmark reminded us that nuclear power is a complex and vulnerable energy source' and there was need to share experience.

Regarding the two Oskarhamn reactors in south-eastern Sweden, SKI said one of the reactors could restart pending 'necessary measures' but noted that the operator had only applied to restart one of them.

Sweden operated 12 nuclear rectors at most. Two at the Barseback plant in southern Sweden have been decommissioned, most recently in May 2005.