The report, by the Government's Health and Safety Executive, looks at why the electricity power supply to Dounreay's fuel cycle area - where some of the most potentially-deadly radioactive materials known to mankind are processed - was cut for 16 hours in May after an excavator driver's machine sliced through the main underground cable.
The month-long probe in June was by a total of 14 inspectors and senior officials from the agency's Nuclear Installations Inspectorate, plus one from the country's other atomic safety watchdog, the Scottish Environment Protection Agency.
The fine toothcomb exercise was ordered after a series of Dounreay scandals exposed in the late spring and early summer.
They included the Atomic Energy Authority being fined pounds 2,000 at Inverness Sheriff Court in January over an incident in which four men,breathed in radioactive dust.
Dounreay site managers are also likely to face prosecution over a mysterious incident where other workers were contaminated by plutonium.
Also came the publication of a damning report by senior inspector Tony Walker, of the HSE, into a probe which he undertook there from June to September last year.
This study, which had previously been officially classified as "secret'', was made public last June following demands by MPs investigating the decision to import atom bomb-grade uranium to Dounreay from Georgia.
In advance of tomorrow's expectedly hard hitting report the HSE has already clamped three so-called "Improvement Notices' on the Authority.Reuse content