Dounreay operates facilities for the disposal of low-level radioactive waste adjacent to the nuclear licensed site. The shallow engineered concrete vaults constructed below the ground surface are the final resting place for much of the radioactive waste that was produced during the operational life of the site and will be produced by the site’s decommissioning and remediation programme.
Contractor CAN Geotechnical and geotechnical designer Golder Associates (UK) Ltd (a member of WSP) have been working with Dounreay to carry out the rock face stabilisation work. The work consists of scaling loose rock, repairing existing rock netting systems, and installing additional rock bolts, netting and catch fences to protect against falling rock from the faces. This will ensure the excavations are safe before an initial phase of backfilling around the low level waste vault begins. The backfilling is an integral part of the disposal process and will be undertaken in tandem with the grouting around the waste containers in the vault.
Backfilling is scheduled to begin in January 2022 and the first stage of grouting around the waste packages is planned for April 2022. This backfill and grouting process represents a significant milestone in the Dounreay waste disposal process towards the ultimate closure of the facilities. Further campaigns are planned as more waste packages are placed in the vaults.
Colin Smith, the CAN site manager, said:
It’s really great to be supporting DSRL by providing safe conditions for the ongoing disposal operations. The safety of our abseiling team is also paramount when carrying out the work, and our techniques are all accredited by the Industrial Rope Access Trade Association (IRATA).
It’s important we have safe methods to recover from any incident, particularly at height, and we regularly undertake rescue training. We’ve been undertaking some rescue exercises while working at Dounreay, to practice recovery of injured personnel from up on the rock faces. This has allowed us to keep our training fresh but also to test how we would interact with the Dounreay team if an emergency arose.