GROUT INJECTION trials for the secondary waste storage shaft isolation project at the Dounreay nuclear plant in north east Scotland began last month.
The work, being carried out by Ritchies, follows several months of borehole drilling and hydrotesting (GE June 05).
The trials will allow the project team to finalise the selection of grouts to be used for full-scale shaft isolation, establish grouting pressures and volumes and ensure optimum filling of fractures in the rock.
Project geologist Colin Munro said: 'Trials will allow us to directly observe and measure the effects that grouting has on the cracks and fissures in the Caithness flagstones which underlie the Dounreay site.
'The target permeability for the rock mass around the shaft after grouting is extremely low. Trials will allow us to experiment with a variety of grout mixes and techniques to ensure we achieve this criteria.' The trials are expected to take until mid-December.