German minister angry after reactor restart glitch

FRANKFURT, July 6 (Reuters) - Germany's environment minister on Monday demanded a tighter nuclear exit programme after the northern Kruemmel reactor failed to complete a restart over the weekend and instead stopped working, causing power cuts.

The 1,346 megawatts unit on Monday remained shut, with environment minister Sigmar Gabriel vowing only federal supervisors will allow its reopening, as operator Vattenfall Europe [VATN.UL] had tried to bypass a local authority.

Gabriel also said that after the election on Sept. 27, his party, the Social Democrats, would ensure that the country's nuclear exit programme will be tightened rather than relaxed, as his coalition partners, the Conservatives (CDU) wish.

"I demand that Chancellor Angela Merkel and Economy Minister Karl-Theodor zu Guttenberg (of the CDU) change their course, in the interest of citizens' safety," Gabriel said.

He said the eight oldest reactors should shut immediately while newer ones should be allowed to operate longer.

The Kruemmel power station went off the grid at midday on Saturday when a transformer short-circuited after running at half load ahead of the botched full reopening.

This came after another transformer malfunction on Wednesday already caused the go-slow, soon after the plant had restarted on June 28 in the wake of a two-year outage necessitated by a safety-related incident in the summer of 2007.

Kruemmel was built in 1984 and is meant to close in 2018 under a nuclear exit deal agreed in 2001, which envisages that all 17 German reactors, which generate a total 21,497 MW, close by 2021 at the latest.

The Conservatives want to allow longer running times, while stopping short of any new construction of nuclear plants, which are finding favour elsewhere in the world because they are free of harmful carbon dioxide missions.

Vattenfall Europe on Sunday apologised for the problems, which also entailed disruptions to the cooling of water cleaning systems and a defective fuel element.

Some 1,500 traffic lights in Hamburg stopped working and industrial power consumers in the aluminium and steel industries were also affected by load drops.

"We will draw conclusions from the...incident. Such a thing must not happen again," said Vattenfall's head of German nuclear operations, Ernst Michael Zuefle.

Vattenfall had initially informed the police, not nuclear supervisors in the state of Schleswig Holstein where Kruemmel is situated, which caused Gabriel to seize control.

The wholesale power market can live without the capacity for now as demand is low in the summer holiday period, traders said.

(Reporting by Vera Eckert; Editing by Keiron Henderson)