Office for Nuclear Regulation

Framatome Saint-Marcel Works - Hinkley Point C intervention

Executive summary

Purpose of Intervention

This record describes an intervention performed at Framatome St Marcel works to assess the adequacy of the NNB Generation Company (HPC) Limited (hereafter referred to as NNB) arrangements for assuring the quality of the Hinkley Point C (HPC) nuclear steam supply system (NSSS).

The intervention supports ONR’s permissioning of NNB’s hold point 2.2.10, ‘Receipt of first NSSS at site’ and ONR’s regulatory strategy for HPC.

Interventions Carried Out by ONR

The intervention concentrated on assessing manufacturing activities undertaken by Framatome (NNB’s contractor for the NSSS) at St Marcel to judge whether NNB's arrangements were compliant against license condition 19.1 'Where the licensee proposes to construct or install any new plant which may affect safety the licensee shall make and implement adequate arrangements to control the construction or installation.'

Explanation of Judgement if Safety System Not Judged to be Adequate

This was not a system/structure based inspection.

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

The HPC manufacturing activity being undertaken at Framatome St Marcel has increased significantly in 2019 and an acceleration plan has been introduced to bring the delivery of the NSSS in line with the HPC integrated work schedule. In my opinion the measures included in the acceleration plan are incremental and do not reflect any radical changes to equipment or working methods. There has been a recent increase in quality events which do not appear to be a direct result of the acceleration plan, but rather a consequence of the scaling up of manufacturing activity.

In my opinion, the quality events indicate that the overall quality culture at the St Marcel works may not be sufficient to sustain an intense manufacturing programme. Framatome have responded to these events by introducing a quality action plan that is expected to deliver the necessary improvements. NNB have also responded to the scaling up of activities by having a dedicated quality lead and a resident project manager at St Marcel. Overall I consider the actions introduced by Framatome and NNB to meet the scale of the quality challenges are appropriate and will follow their progress through future interventions.

The manufacturing surveillance performed by the EDF SA industrial management group, Direction Industrielle (DI) acting on behalf of NNB is an essential aspect of NNB's oversight arrangements. The intervention demonstrated how the DI surveillance processes draw upon a large amount of experience gathered through the French nuclear programme. While, I expect NNB should make use of this experience, I also expect that NNB would have the dominant role in specifying the requirements for the DI surveillance; it was not clear from the information presented by NNB at the intervention that this was the case.

I investigated the arrangements in place at St Marcel for the inspection qualification activities performed by the Inspection Validation Centre (IVC). I found that the security arrangements in place to protect the details of the test piece were appropriate and that the IVC had been provided with adequate laboratory and office space to conduct the qualifications.

Framatome have made good preparations for the welding of the main coolant line by building a dedicated facility that pays attention to the layout of welding activities and cleanliness.

Conclusion of Intervention

The intervention provided an effective means of examining NNB's oversight arrangements for the manufacture of the NSSS and based on the overall evidence gathered, I have assessed these arrangements as green. My judgement is based upon the following:

While, in my opinion the current quality culture at St Marcel is not sufficient to sustain the scale and pace of the manufacturing activities for the HPC NSSS, I am satisfied that Framatome’s response to recent quality events, and in NNB’s engagement with the Framatome action plan, are expected to deliver the necessary improvements in quality. I have raised a regulatory issue that will enable ONR to track progress on the improvements.

The arrangements in place at St Marcel for the inspection qualification activities provide the IVC with the necessary facilities to conduct its activities effectively.

Appropriate preparations are in hand for the welding of the main coolant lines.

The DI surveillance processes appear to be based upon substantial experience gained at St Marcel and, in general, are likely to be effective. However, it is not clear that NNB are exercising a sufficiently demanding role in specifying the surveillance activities. This aspect is included in an existing regulatory issue and the evidence gained during the intervention will inform the progress of the issue.