Office for Nuclear Regulation

LC17; Manufacturing and Testing Activities - Ultimate Diesel Generator Engine (MSC 28)

Executive summary

Purpose of Intervention

In accordance with the Office for Nuclear Regulation’s (ONR’s) Hinkley Point C (HPC) 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 one day intervention was undertaken 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 Ultimate Diesel Generator (UDG) engine has been subject to an appropriate manufacturing and test regime, 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:

Due to the ongoing Covid-19 pandemic, this intervention was carried out remotely via Skype.  NNB GenCo and Responsible Designer (RD) staff, along with ONR Inspectors, attended remotely, with only Direction Industrielle (DI) attending the Motoren und Turbinen-Union Friedrichshafen (MTU) works in person, on behalf of NNB GenCo.  DI undertake surveillance of the HPC manufacturing supply chain on behalf of NNB GenCo.

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 provided an adequate demonstration of how it remotely manages oversight of the testing of UDG engines to ensure that the equipment complies with the specification and can perform its safety related duty.  ONR also observed that MTU gave an adequate demonstration of how it carries out testing and interacted positively with both NNB GenCo and DI.

NNB GenCo demonstrated that it has appropriate understanding of the UDG engine test requirements such that the UDG engines are subjected to appropriate tests and the results are assessed against the requirements set out in the specification.

A number of minor concerns were noted with regard to:

I do not consider that the minor concerns noted here raises concerns over NNB GenCo’s demonstration of its management of the UDG engine testing process; I expect NNB GenCo to take note of the concerns and consider how best to take account of them. 

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.