Work is set to begin on the next phase to close historic trenches and vaults at Cumbria’s low level waste repository.
The repository, at Drigg, is managed by Nuclear Waste Services. It said civil engineering firm Graham Construction has been awarded a four-year contract to cap the vaults and trenches, which are now full and ready for permanent closure.
Work is now starting on the Southern Trench Cap Interim Membrane (STIM) which will involve placing a new protective layer over the legacy disposal trenches up to 10m thick. It will also include placing other construction materials to progress towards the final cap.
It will provide an engineered protective cover over the waste that has been disposed of in the trenches and vaults. Comprising of layers of material to permanently protect people and the environment, NWS said.
Work will start this month, with major work scheduled to begin in February.
Alongside this, NWS said it had also completed the design of the final cap, the extensive work and the rail transport arrangements that are necessary for procuring, importing and emplacing thousands of tonnes of materials, whilst complying with the conditions imposed by the planning authority.
Jonathan Evans, repository site programmes director, NWS, said: “Placing the engineered cap over the legacy radioactive waste disposal facilities at the UK’s Low Level Waste Repository is a first of its kind activity for the UK.
“The capping work is fully integrated with our ongoing disposal operations at the site. We are very pleased the initial work is progressing and we can move forward with this key phase.
“It is important that NWS caps the existing vaults and trenches to provide long-term protection of the environment for generations to come. This work is integral to our mission, to make the UK’s nuclear waste permanently safe, sooner.”
Alastair Lewis, Graham contracts director, said: “This is the largest nuclear project to date for the business and will continue on from previous works undertaken during the LLWR scheme.
We recognise the critical importance of this work in ensuring the long-term environmental protection provided by the Repository and are fully committed to delivering a high-quality solution in partnership with NWS.”
Martin Walkingshaw, chief operating officer at NWS, added: “NWS has been and will continue to engage with the local community with drop-in sessions and site tours to share more details about what residents will see and hear during this work.
“Plans are in place to mitigate and minimise any associated noise, dust, traffic, ecological and visual impacts in line with planning conditions. For example, through the installation of noise barriers and visual screening walls, regular noise monitoring of activities and a commitment to bring the majority of materials to the site via rail. NWS will continue its commitment to proactively engage the local community.”
Disposal of low level radioactive waste at the repository began in 1959 with waste being placed in lined trenches at the site, near the village of Drigg.
During the late 1980s and early 1990s concrete vaults were built for future disposals. Low level nuclear waste was disposed of in specially designed metal containers, which were placed in the engineered vaults at the repository.
