Office for Nuclear Regulation

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Level 4 External Hazards meeting

Executive summary

Purpose of intervention

The purpose of this Level 4 meeting was to discuss progress on external hazards with EDF NNB Generation Company Ltd (NNB GenCo) for its new build site at Hinkley Point C (HPC).

Interventions Carried Out by ONR

This intervention at this Level 4 meeting covered the following matters:

Explanation of Judgement if Safety System Not Judged to be Adequate


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

The meeting covered external hazards for HPC. I consider the following issues are of regulatory importance:

Seismic Hazard: Significant concerns were raised by ONR in 2012 on the adequacy of NNB GenCos initial seismic hazard analysis for the HPC site; this was communicated by letter and raised as Issue 1794. A programme of work to revise the analysis was presented that appeared to be consistent with relevant good practice in this technical area. However, the proposed timescale to complete this significant package of work is very challenging if both the Licensee and ONR are to meet their obligations in respect of permissioning for First Nuclear Safety Concrete. I consider it important that the project programme is made visible to ONR by end of June. I have elevated this matter as an issue for the next Level 3 meeting, to advise senior management that delivery of this work by NNB GenCo on time will be critical to allowing me to support the permissioning License Instrument for First Nuclear Safety Concrete.

ONR assessment of PCSR 2012: The first stage of this assessment was presented to NNB GenCo; further detailed assessment work is planned and will be complete by end December 2014. This is a challenging timescale for ONR and a challenge to NNB GenCo to complete the outstanding items of work still needed to support permissioning of First Nuclear Safety Concrete. For these reasons, the RAG status on both sides remains at Amber.

Conclusion of Intervention

The subject topics of this meeting provide significant challenges to ONR and NNB GenCo. The importance of NNB GenCo completing their seismic hazard work as planned so that ONR will have time to assess and then support permissioning for First Nuclear Safety Concrete will be raised at the next Level 3 meeting.

No new issues were raised by this intervention. No existing issues were closed.