The LLW Repository was established in 1959 and is now managed by Nuclear Waste Service (NWS).  It is the UK’s principal disposal site for low-level radioactive waste (LLW) which is currently disposed in engineered concrete vaults. Historic disposals have included tumble tip trenches. A programme of interim capping of the southern trenches known as the southern trench interim membrane (STIM) project, and preparations for final capping of the original disposal vault and the northern trenches, is currently underway.

The visit took place one year ahead of the LLW Repository’s 2026 Environmental Safety Case (ESC) submission. The purpose of the visit was to offer the combined NWS-contactor ESC team an important opportunity to deepen its understanding of the site, its unique characteristics, and the current progress on closure works. A site tour provided valuable context around local constraints, community considerations, and environmental sensitivities. The agenda also included a visit to neighbouring Drigg beach and a collection of presentations to provide an overview of the ESC. These covered topics included the site description and history, site ecology, ESC approach, engineering design, near field, site evolution, assessments, and forward look. Quintessa employees also supported the preparation and delivery of a subset of the presentations.

Highlights included seeing the diverse ecology on the site and the progress on STIM, for which Quintessa staff have contributed to design and optimisation work. It was also a first visit to the LLW Repository site for some employees and provided a networking opportunity with NWS and other contractors. Quintessa would like to thank NWS for providing this enjoyable and productive opportunity.