They found deficiencies in many aspects of the plant and noted an "us and them" attitude prevailing between contractors and management.
The report, written last year by a member of the Nuclear Installations Inspectorate (NII), also points to a number of failed management strategies put in place during the doomed plant's past decade - including the privatisation of various skills in handling radioactive waste, which then simply had to be bought back in from the privatised company. Other contractors brought on to the site were found to lack expertise in the high safety standards demanded by the nuclear industry.
The NII found that in many parts of the "fuel cycle area", where reactor elements are reprocessed and useful products separated from irradiated and useless waste, there were faults in "containment, ventilation, shielding and instrumentation. There were instances where known problems had not been dealt with". Some parts of the areas were "awash" with various sorts of waste, while the whole fuel reprocessing system had been stopped by a single instrument failure. That meant that radioactive waste built up elsewhere, compounding the plant's problems.
The report is just the latest in a long litany of problems for the site. Since it began operating in 1959 it has suffered fires in reactors and, most significantly, an explosion in an underground shaft which held radioactive waste.
Though the NII wrote the report last summer, the timing of its publication last night was the choice of the UK Atomic Energy Authority (UKAEA), which operates Dounreay. That coincided with public hearings last night in Thurso, the town nearest the plant, which heard evidence from witnesses as part of an investigation into security and quality control.
David Eves, deputy director-general of the Health and Safety Executive (HSE), which runs the NII, said yesterday: "At present the issues are being actively considered by the UKAEA. It is HSE's opinion that currently the site is not unsafe."Reuse content