The world’s deepest nuclear clean-up job has won another top award for engineering excellence.
Judges in this year’s Scottish Saltire Awards named the shaft isolation project at Dounreay as one of the country’s best examples of civil engineering.
It was second only to the construction of a new road bridge across the River Forth at Kincardine.
And it takes to four the number of top awards won by the team behind the £290 million project.
Some of the most hazardous radioactive waste from Britain’s abandoned fast reactor experiment has lain submerged in water for 50 years in the 65-metre deep vertical shaft beneath Dounreay.
The first phase of the clean-out involved isolating the shaft from the surrounding groundwater by building a “grout curtain” in the rock up to 80 metres beneath the surface.
The three-year project costing £27 million involved drilling more than 300 boreholes and injecting a very fine grout into fissures to seal up a 10-metre band of rock on all side of the shaft.
Judges in the annual Saltire Awards paid tribute to an “exceptionally high level of initiative, teamwork and skill shown in the successful developing and execution of this strategic, complex, project in a hostile and challenging environment”.
The project greatly reduced the amount of groundwater entering the shaft, saving taxpayers an estimated £200 million on the cost of emptying when the first robots descend in 2017 to begin scooping out the waste.
“There is still a long way go to and lot more engineering excellence needed to complete the job but everyone involved in this phase of work can take great pride in the success it has achieved so far,” said Warren Jones, a geologist with Dounreay Site Restoration Ltd and project manager for shaft isolation.
The main contractor for shaft isolation was BAM Ritchies. Halcrow Group Ltd was consulting engineer.
Previous awards have come from the British Construction Industry Awards 2009, the Construction News Specialist Awards 2009 and the 2009 Ground Engineering Awards.