Office for Nuclear Regulation

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EDF Energy – Nuclear Generation Ltd – Hunterston B planned Intervention

Executive summary

Purpose of intervention

The purpose of this intervention was to undertake Licence Condition [LC] compliance inspections at EDF Energy Nuclear Generation Ltd’s [NGL’s] Hunterston B power station, in line with the planned inspection programme contained in the Hunterston B Integrated Intervention Strategy [IIS] for 2015/16.

Interventions Carried Out by ONR

I undertook a series of inspections associated with the statutory outage in Reactor 3, focussing on control and supervision; procedural use and adherence; working time directive and operating rule compliance. My inspections coincided with the Rapid Trend Review [RTR] programme coordinated by NGL’s Independent Nuclear Assurance [INA] team. The RTR programme examined a wider range of industrial safety, nuclear safety and quality assurance themes, the outcome from which I have taken into consideration.

This intervention included planned compliance inspections against the following specific Licence Condition:

I undertook a review of the station’s progress against regulatory issues relevant to Hunterston B.

Explanation of Judgement if Safety System Not Judged to be Adequate

No system based inspection was undertaken during this intervention.

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

I examined work order cards and work instructions across a number of work-faces during the inspection week; instructions were generally completed to an adequate standard. I observed some inconsistencies in the use of work instructions and rigour of check-sheet completion associated with equivalent Non Destructive Testing tasks undertaken by one of the station term contractors. The station has since undertaken a reactive quality assurance audit and implemented appropriate corrective measures. I have advised the station the need for these outage-related procedural inconsistencies to be considered as part of ongoing improvements to procedural use and adherence across the station.

I examined central control room [CCR] supervisor log data and limiting condition of operation [LCO] compliance check-sheets to verify that entry into Technical Specification action conditions is undertaken in accordance with station procedures. I observed that records of such entries are being managed generally well in light of the volume of planned and unplanned entries at the time but with some minor inconsistencies noted.

The Rapid Trend Review team summarised the three opportunities for improvement [OFI] from its inspections and surveillances. I have taken cognisance of two of these findings in this report due to the overlap in inspection activities during the week:

I examined the status of adherence of working patterns of staff and contractors to working time directive and the risk assessment process used to justify derogations for extended hour working. Improvements to the risk assessment process are evident through enhanced attention to fatigue and specific obligation on team leaders to reinforce mitigations to affected personnel.

The review of regulatory issues has now provided sufficient justification to close or recommend closure of a number of long-standing regulatory issues. The station has nonetheless accepted the need to improve its proactivity in issue management and timely resolution.

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

I have allocated an IIS rating of ‘3 – adequate’ for LC24 – Operating Instructions, in light of the generally satisfactory standard of procedural use and adherence sampled during the intervention.

There are no findings from this inspection that could significantly undermine nuclear safety.