Workers needed to take samples of metal from holes drilled into the base of the Prototype Fast Reactor (PFR).
They opted for a simple solution – attaching some Blu-Tack to the end of a long flexible rod, and inserting it nearly 10 metres into the reactor core – saving the cost of developing a specialist tool for the job.
Samples of the metal stuck to the Blu-Tack and were collected for analysis.
Calder Bain, a member of the PFR design team told the Dounreay newsletter: “We are 60 years on from the decision to build the Prototype Fast Reactor and innovation has been the key to its success.
“There is a continual requirement for inventive methods to dismantle a complex nuclear reactor.”
WWF Scotland director Lang Banks said: “The ingenuity of those involved in cleaning up Dounreay’s radioactive legacy certainly has to be praised.
“However, not all the challenges faced in dealing with the thousands of tonnes of waste the nuclear industry has left in its wake right across the country will be so easy to solve.
“It’s just another reason why Scotland is right to be choosing an energy future based on renewables.”