Office for Nuclear Regulation

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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 2016/17

Interventions Carried Out by ONR

This intervention included compliance inspections against the following Licence Conditions:

Licence Condition 25 – Operational Records

I met with the station independent nuclear assurance (INA) station evaluators to review the station’s safety performance and internal regulatory surveillances undertaken during the previous month.

I also attended a debrief meeting for Level 2 exercise Kestrel, chaired by the Ayrshire Civil Contingencies Team.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable as no system inspection was undertaken during this intervention.

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

I undertook a planned intervention against LC 25, during which I:

Examined operational records pertinent to the most recent shutdown and restart of Reactor 3. A sample of records associated with two recent forced shutdowns indicated records are comprehensive, but with some minor inconsistencies in rigour noted.

Reviewed various control room records, including Technical Specification daily surveillances, reports from conservative decision making (CDM) meetings and major plant status.

Sampled operational records pertinent to return of plant to service following planned maintenance. I noted some inconsistencies in the rigour with which various elements of handover during and after maintenance are recorded and raised a level 4 regulatory issue as a means for monitoring improvement in this process.

Examined records of and justifications for plant maintenance schedule suspensions and deferrals. All records sampled appeared to be appropriate in relation to justifications for deferral and suspension.

Undertook task observations relating to plant configuration and associated procedural use and adherence. Procedural adherence appeared to be appropriate but I identified to the station some areas for improvement in relation to procedural quality for Technical Specification-related plant configurations.

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

In relation to LC 25, I considered that an inspection rating of ‘Green’ is warranted on the basis that the station records I observed are broadly aligned with company arrangements. There are discrepancies and some deviations which require further review by the licensee to ensure consistency in rigour with which operational records are made.

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