ANTI-nuclear campaigners were predicting the beginning of the end for Dounreay's nuclear activities last night following the news that the Government's two main watchdogs are about to launch a major safety audit of the Caithness plant.

The Scottish Environment Protection Agency and the Nuclear Installations Inspectorate division of the Health and Safety Executive will next month begin work. A team of 10 inspectors will be led by NII's deputy chief inspector Jim Furness, who visited the plant earlier this week.

HSE's director general Jenny Bacon said yesterday: ''We will produce a report of the audit and hope to be able to publish it later this summer.''

Scottish Secretary Donald Dewar, meanwhile, stressed the independence of the regulators and added: ''Given the nature of the work carried out at the site, and understandable public disquiet about the recent spate of incidents at Dounreay, a thorough inquiry is essential.

''I am responsible for nuclear safety in Scotland, and the NII reports to me on safety matters affecting nuclear licensed sites in Scotland. There will be absolutely no question of any kind of reprocessing taking place until NII is satisfied that this can be done safely. My paramount concern is to ensure public safety.''

Dounreay's leading critic Mrs Lorraine Mann paid tribute to Mr Dewar for putting safety ahead of political sensitivities.

She said: ''I think this could well bring the curtain down on reprocessing and processing work at Dounreay, which obviously I would welcome. But I think it also opens up Dounreay's future which is decommissioning. Dounreay could genuinely become recognised internationally as environmental good guys. Could they handle that? Could I handle that?''