The pressure group Celtic League claims it has official evidence that a recent accident at a power station was more serious than originally reported.

Celtic League General Secretary Bernard Moffatt says his correspondence with the Department of the Environment, Transport and the Regions, has indicated that the system failures at the Wylfa nuclear power station on Anglesey were "worrying".

The incident on 16 January began when a grab left behind a fuel element in a channel during a refuelling operation.

The staff closed down reactor one as a precaution, but due to switching problems, reactor two later shut itself down automatically.

The DETR says no operating rules were breached and normal cooling was established.

'More serious'

However, Mr Moffatt says that it was "more serious than first reported, and focuses attention on the wisdom of using old reactors."

The plant's operators, BNFL, said the incident was rated as zero on the international safety scale from 0 to 7.

Station manager Stuart Price apologised for the subsequent noise created when the reactor's steam was released.

Mr Price admitted that the steam discharge was "rather alarming" but there was no risk to anyone living in the area or people working at the plant.