Office for Nuclear Regulation

Hinkley Point C – Inspection ID: 51713

Executive summary

Date(s) of inspection:

  • February 2023

Aim of inspection

The purpose of this inspection was to assess the capability and effectiveness of NNB Generation Company (HPC) Ltd’s (NNB GenCo) internal regulator function.

This inspection was undertaken as part of the Office for Nuclear Regulation (ONR) inspection plan.

Subject(s) of inspection

  • LC 17 – Management systems – rating: Green

Key findings, inspector’s opinions and reasons for judgement made

NNB GenCo carries out its internal challenge capability through an internal regulator, known as Internal Nuclear Regulation (INR). INR reports independently of the delivery functions.

We found that INR is well established within NNB GenCo. There is an underpinning suite of adequate documents in place, such as INR mandate, strategy or relevant procedures.

INR delivers its work in line with its annual assessment plan. Some INR assessments are delivered jointly with ONR. In addition to monthly reporting to the project, INR issues its quarterly reports which highlight areas of positive INR influence. We found evidence of INR advice being issued to drive improvements within the project. INR recently improved its data management including trending. INR also seeks improvement through its self-assessment process.

Overall, INR retains its capability despite significant churn of its key personnel.

From our sample of key stakeholders, we found that INR is seen as an important part of NNB GenCo’s assurance model. In general, INR’s work is valued and respected across the project.

Although we found the areas of interest broadly adequate, we provided to NNB GenCo several recommendations on how its INR function can be further improved, in areas such as preventing INR working in silos, conducting a soft skills support training programme to increase INR’s effectiveness and effective delivery of INR messages across the organisation.


Overall, based upon the evidence obtained during the inspection, we concluded that NNB GenCo has a capable and efficient independent nuclear regulator function. On this basis we judged that an overall inspection rating of GREEN is appropriate.