Executive summary
Date(s) of inspection:
March 2023
Aim of inspection
The aim of this inspection was to gain suitable and sufficient assurance that NNB Generation Company (HPC) Ltd (NNB GenCo) and its contractors have control of the fabrication being carried out on site and relevant inspection processes and procedures are being applied. This was achieved by sampling evidence of the specification of procedures and their transposition down to working level instructions. Evidence was also sought that such working level instructions were being properly followed.
Licence condition (LC) compliance inspections are an essential element of ONR's inspection strategy on any nuclear site and consist of a series of inspections, each of which is intended to establish whether a licensee has adequate arrangements in place for compliance with a specific LC.
The aim of this inspection was to gain assurance that structures, systems and components (SSCs) installed at Hinkley Point C (HPC) will deliver the intended claimed safety function, and to assess compliance with LC19. LC19 requires that: "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."
Subject(s) of inspection
- LC19 - Construction or installation of new plant - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
The inspection targeted welding and non-destructive testing of a range of SSCs that had been installed within the plant, such as of containment heat removal system (EVU) pipework and the reactor cavity pool. It also targeted the arrangements in place for welding and NDT of future activities, such as installation of the spent fuel pool and the use of synergic Metal Active Gas (MAG) welding for stainless steel liners.
During my inspection, I sampled welding procedures, control of welding consumables, inspection and test plans (ITP), weld records, surveillance frequencies, NDT requirements and percentages, and radiographs, and observed a demonstration of synergic MAG welding. No issues were raised as a part of this inspection. I am content that, for the activities sampled, NNB GenCo and its contractors showed adequate control over the fabrication, and surveillance processes and procedures applied on site.
Conclusion
At the time of my inspection, and from the information I sampled, I am content that the licensee has implemented adequate LC19 arrangements to control welding and NDT of class 3 pipework and spent fuel pool/stainless steel liners at the HPC site.
I consider that, in accordance with ONR guidance on the application of inspection ratings, a GREEN rating is appropriate for this inspection, with no formal action as a result of my inspection.