Scientists have begun tests on the use of spent grain from distilleries and also seaweed, crab shells and coffee grounds in absorbing Strontium-90.
The radioactive isotope is present in liquid waste inside Dounreay's Shaft.
Sunk in the 1950s close to the shores of the Pentland Firth, The Shaft plunges 65.4m (214.5ft) below ground.
Radioactive waste was disposed there from 1959 to 1977, when an explosion ended the practice.
It has been the subject of local legend, including the claim that one worker dropped his mother-in-law's ashes inside.
Thurso's Environmental Research Institute, which is part of the University of the Highlands and Islands' North Highland College, has started the investigation into the potential of spent grain, seaweed, shells and coffee grounds.
Known as biosorption, non-living biological materials are used as an alternative to artificially-made materials.
Biosorption is already used to extract tiny pieces of gold and silver from sewage.
Mike Gearhart, who leads the Dounreay Shaft and Silo project team, said: "We are pleased to be working with ERI to identify a sustainable solution that can be sourced locally.
"We still have a number of issues to address but results to date have been very promising."
The Silo - which has been described as being like a swimming pool with a concrete roof - was also used for dumping radioactive material from experiments at Dounreay.
Grain after it has been used for making whisky could be put to a new purpose in the clean up of radioactivity at the Dounreay nuclear site near Thurso.