Part of Kent's nuclear power station has been shut down.

EDF energy say the Dungeness B 21 reactor was taken offline yesterday afternoon following a fault with a steam valve.

It is third unplanned shutdown in four months.

The second reactor at the site - which provides power for 1.5 million homes - is still running normally.

Reactors in this situation tend to be back in action in a week.

Managers stressed this was not to do with the current series of storms.

An EDF Energy spokesman said: “We took the decision to take Dungeness B Unit 21 offline following a fault on a conventional steam valve.

“Safety systems operated as they should and we took the conservative decision to bring the unit offline. We will give an update when the unit has been returned to service.”

Both the nuclear plant’s reactors, 21 and 22, shut down automatically because of Storm St Jude last October when flying debris caused a switch-off of power.

Both were synchronised back to the National Grid by November 16.

Reactor 21 was closed again last December after a fault was found in its accompanying turbine.

There was another closure in January but, unlike the others, that was a planned one for refuelling.

During these shutdowns properties continue to be powered through the National Grid.

The two Dungeness reactors are numbered as part of a nationwide list of reactors at EDF Energy nuclear power stations, also including Hartlepool and Sizewell B in Suffolk.