Both reactors at a nuclear power plant in Scotland have been shut down after a lightning strike.

The lightning caused a power surge which activated safety systems at the Torness station in East Lothian.

A spokesman for British Energy said it was the first time such an incident had occurred at the plant and that it posed no risk to the public.

The reactors shut down after lightning struck pylons near the plant on 2 May, causing a power surge which tripped the station's safety system.

It shows everything is working as it should do. We don't have any safety concerns regarding this

NII spokesman

The spokesman said such events were "rare", although a similar incident had happened at Hunterston power station on the Clyde several years ago.

He said: "The reactor safety mechanism did what it was designed to do by closing down both the units and that is exactly what happened on May 2.

"There was a voltage pulse. It's like something happening in your house when your bulbs trip out.

Boiler pressures

"We quite often shut down the reactors for maintenance so it is not unusual for a reactor to shut down safely.

"We just want to get this into perspective. It is not a major incident and people should not be unduly concerned."

During the incident, boiler pressures were reduced and non-radioactive steam normally used to power the station's electricity-generating turbines was released.

The lightning hit a pylon

The spokesman said the incident was reported to the Nuclear Installations Inspectorate (NII) "right away".

He also confirmed that the number two reactor was shut down again on May 10 in a separate incident because of a mechanical fault with the cooling system.

An NII spokesman said: "Shut down after a lightning strike is a designed-for response.

"It shows everything is working as it should do. We don't have any safety concerns regarding this."

Dr Richard Dixon, head of research at Friends of the Earth Scotland, said: "I think it is probably really too early to tell how serious this was until we have seen some details from any NII investigation.

"But we suspect that because they had to shut the whole place for five days, it is probably a bit more serious."