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

This intervention included compliance inspections against the following Licence Conditions:

I undertook further regulatory interactions with the station safety representatives; independent nuclear assurance evaluators and the Western Link principal contractors.

Explanation of Judgement if Safety System Not Judged to be Adequate

No system inspection was undertaken during this intervention

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

The LC23 compliance inspection sampled a subset of limits and conditions in order to:

From this inspection we noted that for the majority of station fuel limits, compliance is demonstrated largely with calculational tools from measured surrogate parameters. Accordingly, we performed a more detailed inspection of the calculational process, and judged that NGL provided a satisfactory demonstration of the process by which these calculations are performed. From this inspection we derived sufficient confidence that the station employs appropriate processes to ensure accurate translate of surrogate parameters into meaningful and measurable limits, according to approved company procedures.

I undertook a routine visit to the Western Link construction site, a follow-up to an interaction with the Principal Contractors, Siemens and Iberdrola in October 2014. Progress on construction of the Convertor station is significant since my last visit. I requested that the station should begin to develop a strategic plan by which to engage with ONR on LC22 modifications required to permit commissioning activities that have a direct interface with Hunterston B power station. Further dialogue with ONR specialists is scheduled to take place in the Autumn of 2015.

From an LC15 perspective, I observed that the station has now recovered from programme difficulties encountered late 2014. The station has invested well in internal and contract resource to complete the various safety factor reports, and a clear focus on ensuring that effective and early prioritisation of shortfalls identified from the third review cycle.

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

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