Office for Nuclear Regulation

Sellafield – Inspection ID: 52120

Executive summary

Date(s) of inspection:

  • September 2023

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

  • LC35 – Decommissioning – Rating: Green

Key findings, inspector’s opinions and reasons for judgement made

The inspection was undertaken on 14 September 2023 by the SNM site inspector and a nuclear liabilities specialist inspector. 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, including plant walkdowns, discussions with relevant Sellafield Limited personnel, review of records, and sampling of information contained within electronic databases and other documentation.

From the evidence sampled, I   saw evidence that SNM were implementing  the  corporate arrangements for transition into and delivery of  POCO.

Resources remain a challenge for SNM in terms of delivery of POCO and the licensee assured  me that the work is being prioritised involving all stakeholders from all value streams, and that the safety of  operational activities was not compromised.

Some minor deviations from the Sellafield Limited   corporate  arrangements identified,   relevant  to documentation, and I gave regulatory advice in these areas, as  appropriate.

Overall, I did not identify any significant shortfalls in the implementation of the Sellafield Limited  corporate  arrangements and I am satisfied that the licensee is   largely  complying with its legal duties for LC35.


On the basis of the evidence sampled at the time of the inspection,  I  found that SNM (North and South) is largely compliant with the licensee’s corporate arrangements for  Licence Condition 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 appropriate.