Preparatory work has begun on a major engineering phase at the UK’s low-level radioactive waste repository as Nuclear Waste Services (NWS) replaces a protective membrane over legacy disposal trenches ...
Preparatory work has begun on a major engineering phase at the UK’s low-level radioactive waste repository as Nuclear Waste Services (NWS) replaces a protective membrane over legacy disposal trenches in the southern part of the site.The Southern Trench Interim Membrane (Stim) project involves laying a new liner over historic trenches and vaults prior to installation of a permanent cap at the low-level waste repository in Cumbria. The liner is intended to remain in place for up to 100 years while the final engineered cap is completed. NWS says the southern liner must be in place before capping of the northern trenches can proceed.
The operation requires large quantities of aggregate, which NWS plans to bring to the repository by rail using the site’s existing sidings. Between 27 January and September this year, the company is preparing for roughly 200 freight train arrivals to deliver more than 175,000 tonnes of aggregate for use in Stim and in the construction of the final cap. Over the four-year contract the total volume to be delivered will be about 280,000 tonnes.
Project partners include construction contractor Graham, specialist transport provider Nuclear Transport Solutions (NTS) and SLR (formerly Wardell Armstrong), acting as construction quality assurance contractor. NWS has emphasised that using rail freight is a deliberate choice to reduce road traffic: to date the deliveries have used 161 trains rather than lorry movements, a change NWS says has avoided about 7,000 lorry journeys and nearly 1.5M road kilometres, and will continue as the current round of deliveries continues.
Rail deliveries are also presented by the company as offering environmental advantages. NTS’s rail division established a new service for the programme, which NWS describes as “pivotal” to the logistics and emissions reduction for the project.
The repository, which handles the disposal of the UK’s low-level radioactive waste, has carried out capping and containment works over several phases in recent years as part of long-term management of legacy waste from earlier decades. Replacing membranes and installing engineered caps are intended to prevent water ingress and reduce the risk of environmental contamination over the long term.
Work on the Stim project marks the next phase of the repository’s longer-term plans to complete final capping across the site. The replacement membrane in the southern trenches is described by NWS as a temporary measure to support those final works and to maintain safe containment of the existing disposals for decades to come.
Christine Bradley, NWS interim head of repository site project delivery, said: “The restart of the rail deliveries marks the next phase of the Stim project and builds on the strong safety and delivery performance and successes achieved during previous rail campaigns.
“This is an example of a shared commitment to coordinated delivery and close collaboration between our delivery partners NWS, NTS, Graham, SLR and Breedon’s Quarry.
“I’m really looking forward to another great year of making safe progress, hitting delivery milestones and quality standards, and getting that bit closer to successfully capping the Repository.”
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