INVASIONS of nuclear sites by "determined" protestors cannot be prevented, the Government's director of civil nuclear security has admitted.Michael Buckland-Smith also discloses in a report placed in the House of Commons library that there have been delays in the vetting of staff at nuclear installations in line with new procedures introduced following the terrorist attacks on New York and Washington.

By David Green

INVASIONS of nuclear sites by "determined" protestors cannot be prevented, the Government's director of civil nuclear security has admitted.

Michael Buckland-Smith also discloses in a report placed in the House of Commons library that there have been delays in the vetting of staff at nuclear installations in line with new procedures introduced following the terrorist attacks on New York and Washington.

About 100 activists with the Greenpeace environment group climbed over the outer perimeter fence at Sizewell B earlier this year and occupied the roof of the pumphouse.

A few protestors managed to get inside buildings but British Energy claimed that none of them had penetrated sensitive areas of the plant.

The company admitted shortly after the invasion that, because the Sizewell B perimeter fence was nearly one mile long, it could not prevent invasions by protestors.

However, it claimed to have known of the whereabouts of the protestors immediately - as a result of closed circuit television monitors and other security devices.

The report from Mr Buckland-Smith is mainly concerned with security at the Sellafield and Dounreay nuclear reprocessing plants in Cumbria and Caithness.

These are regarded by the Government as high priority terrorist targets because they store plutonium and other extremely hazardous materials.

However, the new report suggests that staff with the highest security classifications at the plants were at one time subject to a ten-month delay in vetting. This has now been reduced to five months.

Some new recruits have had to be accompanied by staff already vetted.

The report admits that terrorist groups may try to exploit disaffected members of staff at nuclear installations, including those in debt or suffering from alcoholism or drug abuse.

However, it reveals that no action has so far been taken to reduce the risk of such members of staff becoming security risks.

John McNamara, British Energy spokesman, said a vetting procedure had already been in place prior to the September 11 terrorist attacks but this had been upgraded in the light of the events.

"There are no delays in our vetting arrangements. Contractors coming on to site are also vetted and this is done well in advance," he said.

Charles Barnett, chairman of the Shut Down Sizewell Campaign, said he was alarmed by the Buckland-Smith report.

"If Sellafield and Dounreay are high security risks then Sizewell B should also be in this category. If Greenpeace can get into the plant then it would be easy for determined terrorists," he said.