The UK's Sellafield nuclear reprocessing plant is being operated with reduced staffing after monitoring found higher-than-normal levels of radiation.

Sellafield said in a statement Friday it had found "elevated levels of radioactivity at one of the on-site radiation monitors at the north end of the site."

It said only essential workers are being asked to report for shifts Friday.

The company said the station in northwestern England is continuing to operate normally.

"Levels of radioactivity detected are above naturally occurring radiation but well below that which would call for any actions to be taken by the workforce on or off the site," the company said.

It gave no further information.