Office for Nuclear Regulation

Compliance inspection of Licence Condition 22

Executive summary

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).

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).

In addition, on the 5th December I followed up on an incident at MRF on red cell vent system, had initial discussions on a proposed modification to the SIXEP MASWEP B tank and had an update meeting on three regulatory issues with the Magnox OU. 

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 4 December 2019, I carried out a planned, one-day, on-site LC 22 compliance inspection within Magnox Reprocessing Facility (MRF). The inspection comprised discussions with SL staff and reviews of plant records and other documentation, plus a plant visit.  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, whether the licensee is maintaining sufficient control of the engineered systems within their facilities, and is considering all modifications to those facilities in a manner proportionate to the risks posed by such changes. 

I noted that there were a small number of permanent Plant Modification Proposals (PMPs) outside the licensee’s target for closure of 3 years, though there were no temporary modifications outside the target of 1 year. There is a recurring theme related to the overdue PMPs where the process was slowed by the updating of the drawings. This is a minor issue and I have passed this to the ONR Corporate Inspectors for their information. Overall, I judged that the licensee is managing the completion of PMPs in a satisfactory manner.

I examined evidence of control of temporary plant interventions on plant, and consider that the licensee has demonstrated that it is controlling these adequately. 

I consider that the licensee is compliant with its legal duties under LC 22.  Therefore, I judge 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 with LC 22 which would prompt a further inspection of those arrangements earlier than currently planned.

I carried out a follow up on an incident where an operator had accepted an alarm associated with the Red Cell Vent system but had not carried out the appropriate follow up action. On the basis of our discussions I judge that this incident does not meet the ONR investigation criteria as there was no compromise of the ventilation safety system intent and no challenge to nuclear safety.

I had a meeting to discuss the proposed PMP for the introduction of the use of MASWEP B tank on the SIXEP plant. From our discussions, I was content that the PMP was a category C and would not require ONR permission to proceed.

I carried out an update meeting with the Magnox OU on three Level 4 Regulatory Issues. On the basis of our discussions and evidence provided, I was satisfied that the intent of the regulatory issues for two had been met and will proceed with closure.  I was content with the progress being made in addressing the third issue. 

Conclusion of Intervention

From the evidence sampled during this inspection, I judge that the licensee’s formal arrangements for compliance with Licence Condition 22 are being implemented adequately and an inspection rating of Green (no formal action) is merited.