Office for Nuclear Regulation

HLWP - Progress Follow up on Improvement Notice and Preliminary Enquiries on INF1 2019/645

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 within the Spent Fuel Management (SFM) value stream, as planned, in October 2019. 

Interventions Carried Out by ONR

On 10 October 2019, I, the site inspector for the operational waste facilities, accompanied by a human factors specialist inspector, carried out a review of progress against an Improvement Notice issued on the Waste Vitrification Plant following an event which occurred on the 07 February 2019.  In addition I conducted preliminary enquiries on an event which also occurred in the same facility on the 25 September 2019 and was reported under INF1 2019/645.

On the 16 October 2019 I carried out a planned licence condition compliance inspection within the Highly Active Liquor Evaporation and Storage (HALES) facility accompanied by an ONR control and instrumentation specialist inspector.  The purpose of this inspection was for the ONR to determine the adequacy of implementation of the licensee’s formal arrangements for compliance with L28 (examination, inspection, maintenance and testing).  This compliance inspection was also observed by an inspector from the Integrated Regulatory Review Service (IRRS) as part of their mission to the UK.

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 reviewed progress against the improvement plan previously provided by SL to address the shortfalls identified in the Improvement Notice.  In particular I noted that a significant number of safety briefs have already been completed with staff and a significant number of changes have been made to the training programme description documents. 

  In addition the existing operating instructions have been subjected to a number of procedural workshops attended by operators, managers and human factor specialists to ensure their adequacy.

Overall I judge that the facility has made significant progress into addressing the Improvement Notice and should be in a position to close it in line with the 31 January 2020 due date.

As a result of my preliminary enquiries on the event reported under INF1 2019/645, I am satisfied that SL are taking the appropriate actions to address any learning and that the event does not meet the ONR formal investigation criteria.

 The LC28 inspection targeted instrumentation found to be outside its specified tolerance band during routine maintenance and attributed to “calibration drift”.  The shortfalls previously identified by ONR are currently being tracked via a Regulatory Issue and the purpose of this LC28 compliance inspection was to review progress in this area. 

From the evidence provided during this inspection I am satisfied that SL is actively addressing the shortfalls previously identified.  Due to the multiple safety measures in place and the limited impact on safety, I judge that the shortfalls identified are not significant and therefore an inspection rating of Green (No Formal Action) is merited for this aspect of LC28.  Notwithstanding this, rectification of the shortfalls will continue to be monitored via the Regulatory Issue.

The intervention was performed in line with ONR's guidance requirements (as described in our technical inspection guides) in the areas inspected.

Conclusion of Intervention

From the evidence gathered during this intervention, I do not consider there to be any matters that have the potential to impact significantly on nuclear safety.    

At present, no additional regulatory action is needed over and above the planned interventions within Spent Fuel Management value stream at the Sellafield Nuclear Site as set out in the Integrated Intervention Strategy, which will continue as planned.