It was confirmed today that a fire broke out in the Sellafield nuclear fuel processing plant on Christmas Eve.
Mr Nigel Monckton, spokesman for British Nuclear Fuels Limited (BNFL) said the fire occurred in a maintenance cell in the site's Vitrification plant at lunchtime Christmas Eve.
He said the fire was brought under control within one hour by the plant's fire brigade and no personnel sustained injuries.
"There was no release of activity from the plant" which was not operating at the time, he added.
The Nuclear Installation Inspectorate was informed of the incident, he said, and the plant's management is currently undertaking an investigation into the matter.
Initial investigations suggest the fire was started by sparks from nearby production operations.