Office for Nuclear Regulation

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The Effluents and Encapsulation Plants Operating Unit (E&EP OU) at Sellafield

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, Decommissioning, Fuel and Waste (SDFW) Programme.  In accordance with that strategy, a Licence Condition (LC) compliance inspection at the Effluents and Encapsulation Plants Operating Unit (E&EP OU) was carried out, as planned, in December 2016.  

The purpose of this intervention was for ONR to determine the adequacy of implementation of the licensee's formal arrangements for compliance with LC 22 (modification or experiment on existing plant).  Additionally, to maximise regulatory efficiency, I also undertook follow-up enquiries against a recent event within the Waste Encapsulation Plant (WEP) whilst on 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 7 December 2016, I carried out a planned, one-day, on-site LC 22 compliance inspection within the E&EP OU.  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 these safety cases.

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 for some such modifications, there was merit in converting these to permanent design changes, but this observation did not, in my view, impact on the licensee's ability to manage its plant design.  

Additionally, I reviewed evidence of the licensee's completion of actions as part of an OU-wide improvement plan, created to deliver improvements within the oversight and governance of plant modification, following observed shortfalls and related events about a year ago.  Until now, I have tracked the licensee's delivery against this plan using ONR Regulatory Issue 4094; this compliance inspection provided evidence that was sufficient for me to have confidence in the improvements made by the licensee, and to therefore close the related Issue.

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.

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.  

I also undertook follow-up enquiries into a recent event within the Waste Encapsulation Plant relating to problems with an access door interlock system, to determine if the event merited formal investigation.  Following a walk-down of the relevant area of plant, and a number of meetings with the licensee, I consider that the licensee has responded adequately to the event, and that it does not meet the criteria for formal investigation by ONR.  I had already raised an ONR Regulatory Issue to track the licensee's internal investigation and associated corrective actions in respect of this event and I judge that this remains a proportionate regulatory response.  

Conclusion of Intervention

There are no matters to be taken forward arising from my LC 22 compliance inspection. I will continue to monitor SL's response to the event at the Waste Encapsulation Plant through my existing Regulatory Issue.