Executive summary
Date(s) of inspection: November 2024
Aim of inspection
The aim of this inspection was to seek assurance that SL’s arrangements for compliance with LC35 (Decommissioning) are being adequately implemented for the decommissioning of B204 on Sellafield Ltd.’s nuclear licensed site at Sellafield, Cumbria. The inspection also covered how the decommissioning of the medium active north (MAN) cell is being progressed as a Remediation Accelerated Decommissioning (RAD) pilot project.
Subject(s) of inspection
- LC35 - Decommissioning - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
The inspection focused on key topics including decommissioning progress and planning, safety cases, asset management, characterisation and radioactive waste management.
- The main decommissioning activity within B204 is the Remediation Accelerated Decommissioning (RAD) trial in the Medium Active North (MAN) Cell with the remainder of B204 in care and maintenance. There is no decommissioning plan in place for B204 as required by SL’s arrangements and LC35(2). However, as most of the facility is in care and maintenance, we judged that this shortfall is of little safety significance.
- There is currently a Care and Maintenance Safety Case in place for B204 and there is a plan to move to a Decommissioning Risk Case (DRC), which is a new safety case architecture, based on a modular, task-based approach that recognises the well-developed and repeatable nature of the decommissioning activities. It is an approach being developed for the Remediation Accelerated Decommissioning (RAD) trials.
- There are asset management challenges in B204, in particular the condition of the roof which is known to allow rainwater ingress. A Facility Health Report has been produced that details current asset condition, identifies knowledge gaps, and provides forward actions to improve asset condition. One of the forward actions is the repair of the roof, which was due to be completed in 2024, but the work is now due to begin early 2025.
- There is an extant radioactive waste inventory, which will be updated once further characterisation work has taken place pending the publication of the DRC.
Conclusion
Based on the sampling undertaken during this inspection, we judged that the licensee is adequately implementing its LC35 arrangements and this inspection is rated GREEN, but two observations were made. Firstly, there is no decommissioning plan in place for B204 as required by SL’s arrangements and LC35(2). However, as most of the facility is in care and maintenance, we judged that this shortfall is of little safety significance. Secondly, the B204 roof is leaking and a plan to replace the roof by 31/03/2024 has been delayed. However, the roof repair is now due to begin in 2025 and preparations have begun to facilitate roof access and scaffolding to carry out the repair.