Work to decommission the waste shaft at Dounreay has been highly commended in a showcase of Britain’s leading ground engineering projects.
The shaft isolation project picked up the award during the finals of the GE Awards 09 in London at the weekend.
The £27 million project involved drilling more than 300 boreholes around the 65-metre deep shaft and injecting very fine grout that spread through the fissures to form a barrier around the waste.
It has greatly reduced the amount of groundwater entering the shaft, saving taxpayers an estimated £200 million in water treatment costs when the shaft is emptied.
The judges described the four-year scheme as "an extremely challenging project which involved many successful trials prior to coming up with the solution".
The work was carried out by BAM Ritchies, part of the BAM Nuttall group, for Dounreay Site Restoration Ltd.
Work is now underway to prepare for the construction of the retrieval plant in 2012, with the first waste due to be recovered in 2017.