CAMPAIGNERS say the emergency shutdown of a Severnside reactor ought to be a signal to dump nuclear power for good.

Residents on both sides of the river were alarmed by a massive plume of steam and deafening roaring noise as Oldbury's second reactor went into automatic shutdown following an electrical fault.

Power station operator Magnox said there was no cause for alarm, as the fault was in the turbine hall, a non-nuclear part of the site. As staff were preparing to carry out routine maintenance and an inspection of the graphite core, a relay mechanism overheated and caused an automatic shutdown.

Magnox spokeswoman Zoe Young said: "We can understand people are concerned about nuclear because of what has happened in Japan, but we can assure people there is no cause for concern whatsoever here. The shutdown was standard procedure and there was nothing at all radioactive about the steam. It was in the non-nuclear side of the site."

She said Reactor 2 will now be out of operation for at least five weeks. Reactor 1 will continue to operate. Both reactors were due to begin a gradual shutdown process in June but Magnox is applying for an extension for the first reactor, until December 2012.

Directly across the road from Magnox's Oldbury site, energy firm Horizon wants to build two or three nuclear reactors by 2018. A public consultation recently closed on a national new-generation nuclear power programme.

Barbara French, from Brockweir, founded SCAR (the Severnside Campaign Against Radiation) in the 1980s, and is now involved with pressure group STAND (Severnside Together Against Nuclear Development).

She said: "They should shut both reactors down now, as they are well past their sell-by date. The nuclear plants in Japan were built in 1979, but Oldbury's reactors were running in 1967. They should have stopped running 20 years ago but they have been granted extension after extension. I hope after what has happened in Japan, we will see the end of nuclear power, as it's unaffordable and dangerous."