Office for Nuclear Regulation

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Magnox Operating Unit (OU) compliance inspection of Licence Condition 22 (modifications)

Executive summary

Purpose of Intervention

The Office for Nuclear Regulation (ONR) undertakes all regulatory interaction with the Sellafield site licensee (Sellafield Limited, SL) against a strategy defined by the ONR Sellafield Sub Division. In accordance with that strategy, Licence Condition (LC) compliance inspections were carried out on the Magnox Operating Unit (OU), as planned, in October 2017.

The purpose of this inspection was for the ONR to determine the adequacy of implementation of the licensee's formal arrangements for compliance with LC 22 (modification or experiment on existing plant).

Interventions Carried Out by ONR

LC 22 requires that the licensee implements adequate arrangements to control any modification or experiment carried out on any part of the existing plant which may affect safety. On 26 October 2017, I carried out a planned, one-day, on-site LC 22 compliance inspection within Magnox East River (MER) plant. The inspection comprised discussions with SL staff and reviews of plant records and other documentation. In carrying out this inspection, the following ONR guidance was used:

Explanation of Judgement if Safety System Not Judged to be Adequate

This was not a system based inspection, and therefore no judgement has been made of the adequacy of implementation of any part of the safety case.

Key Findings, Inspector's Opinions and Reasons for Judgements Made

I examined evidence of the licensee's compliance with its arrangements for control of modification to existing plant and consider, on the basis of my sample, that the licensee is maintaining sufficient control of the engineered systems within its facilities, and is considering all modification to those facilities in a manner proportionate to the risks posed by such changes.

I examined evidence of control of temporary modifications on plant, and consider that the licensee has also demonstrated that, for the sample selected by my inspection, all such temporary modifications have been controlled adequately.

I noted that there were a number of plant modification proposals (PMP) outside the licensee's target for closure of 3 years. I found that this target was not always appropriate and that in some cases extended timescales were justified. ONR has a site-wide Regulatory Issue already open on management of overdue PMPs. My findings will be considered within this issue as necessary.

I consider that the licensee is compliant with its legal duties under LC 22, and that there are only limited opportunities for further ALARP improvements. Therefore, it is my opinion that an inspection rating of Green (no formal action) is merited.

I provided the licensee with some suggestions for improvements to their quality of PMP documentation and improved identification of hold-ups in closing PMPs.

From those areas sampled, I did not identify any significant shortfalls in the licensee's formal arrangements for compliance which would prompt a further inspection of those arrangements earlier than currently planned.

Conclusion of Intervention

From the evidence sampled during these inspections, I judge that there was sufficient evidence that the licensee's formal arrangements for compliance with Licence Condition 22 are being implemented adequately. No additional follow-up regulatory action is required above the actions identified in an extant ONR Regulatory Issue.