Executive summary
Date(s) of inspection:
July 2025
Aim of inspection
In accordance with the Office for Nuclear Regulation’s (ONR’s) Sellafield Strategy, each year ONR performs a series of planned inspections to seek assurance of compliance against selected licence conditions, targeted at those facilities with significant importance to nuclear safety. One such inspection was undertaken at Special Nuclear Materials (SNM) facilities North and South within the Sellafield site in West Cumbria to sample evidence of implementation of Sellafield Limited's arrangements for compliance with Licence Condition (LC) 35 in order to inform a regulatory judgement regarding the licensee’s compliance with its legal duties under the nuclear site licence.
Subject(s) of inspection
- LC 35 - Decommissioning - Rating: GREEN
Key findings, inspector's opinions and reasons for judgement made
The inspection was undertaken on 9 July 2025 by the SNM site inspector and a nuclear liabilities specialist inspector. The inspection was also attended, partially, by the ONR head of regulation for Sellafield Operations.
The inspection targeted compliance against Licence Condition (LC) 35 (Decommissioning). The inspection focused on the requirements for transition into and delivery of the Post Operational Clean Out (POCO) phase of decommissioning for a number of facilities within the Special Nuclear Materials Value Stream (SNM) North and South on the Sellafield site.
The inspection involved a planning phase and a one day site visit, which included discussions with relevant Sellafield Limited personnel, review of records, sampling of information contained within electronic databases and other documentation and a plant walkdown.
From a mixture of sampling records and discussions with Sellafield Limited personnel, I concluded the following:
No significant matters were identified that required immediate regulatory attention.
I saw evidence of implementation of the LC 35 corporate arrangements for transition into and delivery of POCO. I also saw evidence of progress made with POCO delivery at SNM South (FL6 and SMP) and at SNM North (FL5 and Store 17). This included collaboration with other value streams.
Various documents have been produced in support of POCO and initial decommissioning work for FL5, FL6 and SMP and further work is being planned to prioritise the POCO work.
Resources remaining challenging for SNM and this is being escalated internally within SNM value stream.
Two new L4 Regulatory Issue were raised:
- Sellafield Limited to review the End of State POCO Summary documents and either finalise or confirm that they are not needed and superseded by other documents.
- Sellafield Limited to review, update and align all relevant POCO trackers and schedules with the 10-year POCO plan and Site Master Schedule.
Regulatory advice was also provided.
Conclusion
On the basis of the evidence sampled at the time of the inspection, I found that SNM (North and South) is compliant with the licensee’s corporate arrangements for LC 35.
Taking all of the above into account, and noting the ONR guidance on inspection ratings, it is my opinion that, on balance, an inspection rating of Green (i.e. no formal action) for Licence Condition 35 is merited here.