Berlin - Swedish-owned electricity giant Vattenfall admitted Thursday that fuel rods may have been damaged when one of its German nuclear power stations suddenly shut down several days ago.

In Berlin, it promised a complete review of the management of the station which needed two years of repairs after a 2007 fire.

A repeat on Saturday of the electrical-transformer fire at Kruemmel power station has turned nuclear safety into an election issue in Germany and thrown a spotlight on Vattenfall, one of the companies running Germany's 12 nuclear power stations.

"All technical and organizational processes will be re-examined," said Tuomo Hatakka, chief executive of the Berlin-based subsidiary Vattenfall Europe. The company has appointed an executive, Stefan Dohler, to conduct the review.

Another executive said the rapid shutdown on Saturday had probably damaged some of the 80,000 uranium fuel rods.

Ernst Michael Zuefle, chief executive of Vattenfall Europe Nuclear Energy, said, "Some are probably defective."

He said both the 2007 and the Saturday short-circuits which set off electrical fires had had the same cause.

"At no point was there any danger to the public," Zuefle added.

Hatakka admitted the mishap had again reduced public trust in Vattenfall in Germany and indirectly apologized.

He said worries had arisen among the public and "we very much regret that."

"The incident was a setback in our efforts to raise trust."

He conceded that state nuclear regulators had not been promptly informed after the plant's sudden shutdown knocked out traffic lights and services in the nearby city of Hamburg.

The fire did not affect the reactor itself, but Vattenfall says it will remain offline for months while transformers are replaced.

Five German power stations have twin reactors, but there is only one installed at Kruemmel, near a river east of Hamburg. Other Vattenfall power stations generate power from coal and gas.

The company this week sacked the chief of the Kruemmel station, which has operated since 1984.

Polls show a majority of Germans are hostile to nuclear power, convinced it is unsafe. Under legislation from 2000, all German nuclear sites are to decommissioned by 2020. Germany has a general election on September 27.

This week, Swedish media reported that Sweden's nuclear-regulatory authority was considering stricter supervision of the company's operations in that country after 60 incidents at Vattenfall's Ringhals nuclear plant there. (dpa)