Executive summary
Date(s) of inspection: March 2024
Aim of inspection
Licence Condition (LC) compliance inspections are an essential element of ONR's intervention strategy on any nuclear site and consist of a series of inspections, each of which is intended to establish whether the licensee, NNB Generation Company (HPC) Ltd (NNB GenCo), has adequate arrangements in place for compliance with a specific LC.
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.'
The aim of this inspection was to gain assurance that NNB GenCo has adequate arrangements in place for compliance with LC19, in relation to high integrity component (HIC) welding and associated non-destructive testing (NDT) for the installation of the main coolant line (MCL) to be carried out by Framatome at the Hinkley Point C (HPC) site. The inspection was undertaken as part of a series of planned interventions in accordance with the HPC Intervention Strategy for 2023/2024.
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.'
The aim of this inspection was to gain assurance that NNB GenCo has adequate arrangements in place for compliance with LC19, in relation to high integrity component (HIC) welding and associated non-destructive testing (NDT) for the installation of the main coolant line (MCL) to be carried out by Framatome at the Hinkley Point C (HPC) site. The inspection was undertaken as part of a series of planned interventions in accordance with the HPC Intervention Strategy for 2023/2024.
Subject(s) of inspection
- LC19 - Construction or installation of new plant - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
During the inspection, I sampled the licensee’s review and acceptance process for relevant documentation prior to start of HIC welding and NDT onsite, alongside welder training and qualification arrangements, and the process for repair welding if required. I sampled the licensee’s approach to ensuring welding engineers' competency and structural integrity interaction with site facing teams in relation to HIC welding and NDT onsite. I also sampled the arrangements for completing the Inspection and Test Plan (ITP) for HIC welding and NDT onsite, surveillance frequencies and NDT requirements/percentages for HIC welding onsite. In addition, I sampled the hold point (HP) management and release process in relation to first HIC welding onsite (HP.2.2.16) and the process for categorisation of non-conformances. I also conducted a site walkdown of the reactor building, the Framatome storage facility and welding consumable area.
At the time of my inspection, and from the information I have sampled, I am content that the licensee has adequate LC19 arrangements in place for HIC welding and NDT of the MCL at the HPC site and that the licensee is sufficiently prepared at this stage of the project from a structural integrity perspective. I identified a shortfall in the arrangements for asset care and maintenance of primary circuit components when in storage and therefore I have raised a level 4 regulatory issue. I will monitor progress of the issue via regular engagement with the licensee.
Conclusion
The inspection gathered evidence over a range of areas and the overall conclusion was that the LC19 arrangements for high integrity component welding and non-destructive testing of the main coolant line at HPC site are adequate. Whilst I identified a shortfall in the care and maintenance of primary circuit components, I judge the shortfall to be relatively minor. Therefore, I consider that, in accordance with ONR guidance on the application of inspection ratings, a green rating is appropriate for this inspection.