The Dounreay nuclear reprocessing plant has received a health and safety award.
The plant received a gold award
The plant, which has had safety problems in the past, received a gold National Safety Award from the British Safety Council and the Royal Society for the Prevention of Accidents for "outstanding achievement".
Dounreay was recognised for high health and safety standards.
David Ballard, director general of the British Safety Council, said: "The National Safety Awards highlight organisations that reach top levels of health and safety.
"They are a mark of proven and significant achievement in safety standards."
Dounreay site director Peter Welsh said: "I am delighted that our safety record means once again we are considered to be one of the safest places to work in Britain."
The award comes despite safety problems at the Caithness site over the years.
Concerns have been raised about the discovery of radioactive particles on a nearby beach.
The plant has also dealt with a number of safety incidents and was fined more than £100,000 in 2000 after three workers were contaminated with radiation and a power cable was cut.
The plant was given a clean bill of health by inspectors in 2002 following a safety review.
Work has begun on decommissioning the site, which is expected to take between 50 and 60 years at a cost of £4bn.