I have seen considerable progress at Dounreay over the past three years and this is a credit to everyone concerned, particularly the staff

Laurence Williams, HM Inspector of Nuclear Installations

But he said the ability to fully decommission the site would critically depend on Dounreay's ability to recruit sufficient numbers of qualified staff.

The audit was ordered after a number of safety lapses at the nuclear plant, culminating in a contractor's digger cutting through the main power supply in 1998.

Nuclear safety inspectors made 143 recommendations in a damning report on the Dounreay plant following this incident.

The HSE report said the site had fulfilled 89 of those - while the remaining 54 were either medium or long-term matters.

Mr Williams said: "I have seen considerable progress at Dounreay over the past three years and this is a credit to everyone concerned, particularly the staff.

"The consents we have granted over the last few months to allow the restart of a number of plants are an indication of our growing confidence that safety at Dounreay is improving."

The plant has begun decommissioning

The report was welcomed by Dounreay plant director Peter Welsh, who agreed that a lot had been achieved in the last three years.

"We have worked very hard to eliminate the weaknesses identified by the regulators," he said.

"We've spent the last three years addressing all those concerns that the regulators have and I think the fact that they have decided to close out, or issue the final report on that audit, is an achievement.

"The publication of the final report on the safety audit is a tribute to the way staff responded to the 1998 recommendations."

Dounreay spokesman Colin Punler said that staff still had to face some of the greatest challenges.

There's still a lot of work to be done. There's certainly no room for complacency

Dounreay spokesman Colin Punler

He said the report was "a milestone in the history of the site".

But he added: "There's still a lot of work to be done. There's certainly no room for complacency."

In July last year, the UK Government ruled out the plant's future role as a nuclear reprocessing site.

Three options had been considered for dealing with 24 tonnes of radioactive fuel from Dounreay's Prototype Fast Reactor (PFR).

The government decided to store the fuel on-site, rather than reprocess it at Dounreay or Sellafield.

Since 1998, the United Kingdom Atomic Energy Authority (UKAEA) workforce at Dounreay has risen from 817 to 1,158.