ENGINEERS at Oldbury atomic power station are still awaiting the go ahead to restart an allegedly clapped out nuclear reactor.

Station chiefs expressed confidence last month that regulators would give the green light for the station's number 2 reactor to be returned to normal service.

But the approval has so far failed to materialise, prompting further claims that the ageing power station is too worn out to make it even to its scheduled final shut down in December 2008.

Operators have to convince safety watchdogs that the reactor is sound despite serious degradation of its graphite core - vital for controlling nuclear reaction.

The situation at Oldbury was this week set to become even more critical as engineers prepared to shut down its only other functioning reactor as part of a statutory "outage" for inspection and maintenance.

It means the station will once again be totally out of action, generating not one single watt of power for the national grid.

Reactor two has now been down for more than a year while station operators British Nuclear Group prepares a safety case for its continued operation.

Anti nuclear campaigner Jim Duffy of the Shut Oldbury lobby group said it was clear that the Nuclear Installations Inspectorate (NII) had so far seen nothing to persuade them that the reactor was still safe.

Graphite corrosion in both reactors was now "extreme", he alleged "Oldbury suffers the worst weight loss of any reactor core in the UK," he said. "According to comments made last year by an independent nuclear engineer it could lead to a catastrophic nuclear-fuel fire and release of radiation."

The nuclear industry has ploughed £2 billion into research contracts since 2004 to investigate the safety of the material which makes up reactor cores in the UK's ageing fleet of power stations," said Mr Duffy.

"Despite sinking so much money into propping up these old reactors and the colossal time spent in outages it still cannot prove they are safe to operate. Oldbury's bosses should give up now for safety's sake and announce its permanent closure."

British Nuclear Group spokesman Tim Jones said graphite tests would now be carried out on Reactor 1 and confidence remained high that both reactors would get the all clear.

"We have carried out detailed visual inspections in the reactor core using state of the art remotely controlled camera technology. We have fully inspected more than 1,300 graphite channels in the heart of the reactor and found nothing of any significance," he said.

"Extensive tests have also been carried out on graphite samples taken from the core and we are currently assessing the results of those tests. Work on Reactor 2's safety case continues to go well and we look forward to being able to put a robust safety case to the Nuclear Installations Inspectorate for a restart in the near future.

"Safety remains the number one priority at our sites. We would only seek to re-start a reactor once we are entirely confident it was safe to do so and unless they considered it was completely safe, the NII would not allow us to.

"We continue to keep Oldbury's Site Stakeholder Group informed of the situation in relation to both reactors."