A MAJOR staff shake-up has been announced at Dounreay following the embarrassing safety lapses which led to the plant being ordered effectively to close earlier this month.

The majority of changes involve drafting in more staff to key positions in a bid to restore confidence in the operation and strengthen the in-house management team.

The move follows a series of incidents which have called into serious question the safe operation of the nuclear facility over recent months.

The Caithness site is currently under detailed scrutiny by the Nuclear Installations Inspectorate after a double power cut earlier this month, when the mains power cable was sliced by an excavator operator and the back-up emergency power system failed to activate as it should have.

In January this year, the UK Atomic Energy Authority, Dounreay's operator, was fined #2000 at Inverness Sheriff Court for safety lapses which led to four workers breathing in plutonium dust while working on a waste dump at the complex.

Inspectors are still in discussions with the Crown Office in Edinburgh over a separate incident where three men in the reprocessing plants received very high doses of plutonium-based radiation in unexplained circumstances.

The Government's Health and Safety Executive will next month carry out the most exhaustive audit of Dounreay's safety and management ever done, with the report of the 10 inspectors involved being made public later this summer.

Some of the changes, which involve drafting in top experts into senior positions from other nuclear establishments and the hiring of another 20 skilled engineers in addition to the 20 recently recruited, clearly reflect the pressure from the NII. It has been taking a tough line on the UKAEA following the recent safety lapses.

Dounreay's director, Dr Roy Nelson, has made it clear that, in future, more senior staff will be directly employed by the authority rather than by outside private contractors, as the inspectorate has been demanding, so that a proper chain of command and responsibility is always clearly in place.

Yesterday he revealed that 20 staff are likely to be transferred soon to direct authority control from their present roles on site with private firms.

A new assistant director, who formerly managed two British nuclear power plants, will join Dounreay by the end of July, while the former station director of Hunterston power station, in Ayrshire, has already moved there ''to advise on the improvement of the site's safety systems''.

The head of radiation monitoring for all of Britain's UKAEA sites has now been relocated to Dounreay and the team has been strengthened by five additional radioactive protection advisers.

In a newsletter made available yesterday to all of the 1400 staff who work at Dounreay, Dr Nelson said: ''We must learn lessons from past mistakes and take remedial action promptly where we can see that it will help.

''Safe and responsible operations at Dounreay will only be achieved with the full commitment of everyone on site.''

Admitting that some of the recent criticism in the media had been ''deserved'', while some had been ''seriously misinformed'', he said that he recognised that some of the in-depth probes being conducted by official Government regulators into Dounreay's operations ''could be unsettling for many of you''.

The new assistant director is Mr Peter Welsh, who is on the board of Magnox Electric, the state-owned company which owns and operates the first generation of commercial atom power stations.

The former Hunterston official hired to improve safety systems is Mr Peter Robson.