Office for Nuclear Regulation

NNB GenCo Hinkley Point C - LC17; Management systems compliance arrangements

Executive summary

Purpose of Intervention

In accordance with the Office for Nuclear Regulation’s (ONR’s) Hinkley Point C Construction inspection plan, ONR performs a series of planned compliance inspections of identified licence conditions, to ensure that NNB Generation Company (HPC) Ltd (NNB GenCo), is proportionately and adequately developing and implementing its licence condition (LC) compliance arrangements commensurate to the current stage of the project.

Interventions Carried Out by ONR

This intervention was part of a multi-part intervention to examine the adequacy of NNB GenCo’s implementation of its LC17 compliance arrangements. The intervention was undertaken in order to gain confidence that the transformers associated with the low voltage (LV) switchgear have been subject to an appropriate test regime and review of test results, such that it is able to fulfil the safety case requirements associated with the equipment.

LC17 requires the licensee to make and implement adequate quality management arrangements in respect of all matters which may affect safety and the following guidance was utilised:

Explanation of Judgement if Safety System Not Judged to be Adequate

N/A as this was not a safety systems inspection.

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

NNB GenCo and its counterparts in Direction Industrielle (DI) provided a clear demonstration of how they manage oversight of the testing of transformers associated with LV switchgear to ensure that the equipment complies with the test specification and is capable of performing its safety related duty.

NNB GenCo provided evidence to show that it has appropriate understanding of test requirements and the role that DI play in ensuring the transformers are subjected to appropriate tests and the results are acceptable.

ONR observed that NNB GenCo and Edvance demonstrated a questioning attitude when discussing test results with ABB.

Three non-conformance reports (NCR) were noted for the transformer types under test and, at the time of writing this report, it was unclear whether the NCR process was being followed.  I note that the issue of application of the NCR process by NNB GenCo is being looked at across a number of disciplines within ONR and I will ensure my concerns are captured by the relevant ONR Inspectors.  I do not consider that the lack of clarity regarding the application of the NCR procedure raises concerns over NNB GenCo’s demonstration of its management of the transformer testing process.

Conclusion of Intervention

I judge that overall an inspection rating of GREEN (no formal action) is appropriate for licence condition 17, management systems.  This is because I found NNB GenCo to be compliant with its legal duties with only minor areas for improvement.