Executive summary
Date(s) of inspection:
March 2025
Aim of inspection
The aim of the inspection was to inspect NNB Generation Company (HPC) Ltd's (NNB GenCo) readiness for the upcoming Unit 1 HR Dome concrete pour works. In addition, the inspection aimed to inspect arrangements for compliance with Licence Condition (LC) 19, construction or installation of new plant, in relation to civil engineering construction assurance. LC19 requires that where the licensee proposes to construct or install any new plant, which may affect safety, the licensee makes and implements adequate arrangements to control the construction or installation.
The objective of the inspection was to obtain evidence in relation to the adequacy of NNB GenCo’s arrangements for the control of the concreting works for the Unit 1 HR Dome. The particular focus of the inspection was on the implementation of arrangements to ensure conformant and safe construction of the dome, in accordance with the design intent, and the avoidance of latent defects that may impact upon safety case claims. The inspection also considered the adequacy of arrangements to control the safety of construction activities, with the aim of assessing compliance with the CDM 2015 Regulations.
Subject(s) of inspection
- CDM 15 - Rating: GREEN
- LC 19 - Construction or installation of new plant - Rating: GREEN
Key findings, inspector's opinions and reasons for judgement made
The evidence sampled provided confidence that adequate arrangements are in place in readiness for pouring the concrete of the Unit 1 HR dome and that activities being undertaken under these arrangements are being adequately controlled. Furthermore, where sampled, the evidence demonstrated that concreting of the dome aligned with the design intent and the safety case.
I also judge that the civil engineering contractor and sub-contractor's arrangements in relation to construction of the nuclear safety significant HR dome were being implemented and were aligned with relevant good practice.
This inspection highlighted no significant regulatory issues.
A small number of minor observations were made.
On the basis of the evidence sampled, and in recognition of progress to date, I was satisfied that the arrangements in place comply with LC19 and CDM 2015.
Conclusion
On the basis of the evidence sampled, I judge that NNB GenCo has implemented corporate arrangements in compliance with LC19 (construction or installation of new plant). In relation to the specific areas sampled, I judge that NNB GenCo’s implementation of arrangements for the concreting of the Unit 1 HR dome to adequately controlled.
Overall, I was satisfied with the adequacy of NNB GenCo's ongoing arrangements for the concreting of the Unit 1 HR dome. On the basis of the evidence sampled, and in recognition of progress to date, I was satisfied that the arrangements in place comply with LC19. Upon consideration of the ONR guidance in relation to inspection ratings, I judge that a rating of Green (no formal action) is appropriate.