Dounreay Site Restoration's 2010 offshore radioactive particle recovery programme recovered 279 fragments of nuclear fuel, 40 of them categorized as "significant risk", by the end of September.
The expanded programme this year covers 12.5ha around the disused sea outfall 600m from the shore and uses a remotely operated vehicle with a Groundhog detection system up to 30m below the surface.
A team of 22 people from Land and Marine, supported by Nuvia, is working around the clock on a barge moored offshore.
Some 23 days this year have been lost to bad weather and the project is continuing into October.
The programme has cost £1.5m so far this year.
