Executive summary
Date(s) of inspection
- September 2023
Aim of inspection
The aim of the inspection was to gather sufficient evidence of the implementation of the licensee’s arrangements for managing safety case commitments (SCCs) and safety case open points (SCOPs), to form a judgement as to whether these are being appropriately sentenced, managed and closed out in line with NNB Generation Company (HPC) Ltd’s (NNB GenCo) processes in support of its safety case production.
In addition, the inspection gathered evidence in support of ONR’s assessment of the Hinkley Point C Summary Safety Case Document #2 (SSCD#2), examining ongoing safety case development.
The inspection targeted, on a sampling basis, the arrangements associated with identification and sentencing of safety case commitments and safety case open points and their implementation to form a judgement on their adequacy.
Subject(s) of inspection
- LC14 – Safety documentation – Rating: Green
Key findings, inspector’s opinions and reasons for judgement made
During this inspection, I sampled NNB GenCo’s arrangements for SCCs, SCOPs and future activities and their implementation. I sampled a selection of SCCs and SCOPs, focused on governance and evidence of challenge from Independent Technical Assessment (ITA) and the Design Authority (DA), and the traceability from the originating gap/shortfall to the associated SCC/SCOP.
I am satisfied that NNB GenCo’s arrangements for SCCs, SCOPs and future activities are appropriate, although the working level arrangements for closure of SCCs, SCOPs and future activities have not yet been finalised. Based on my sample, I am satisfied that adequate challenge is being provided by ITA and SCC/SCOP committee members. I identified areas for further improvement in how this is being documented, which is being tracked by regulatory issue RI-11723.
I consider that there are areas for further improvement in the traceability from the originating gap/shortfall to the associated SCC/SCOP, which is being tracked by regulatory issue RI-11724.
Responses to questioning during the inspection provided confidence that NNB GenCo is making progress on addressing SCCs which are associated with the early commissioning hold point. I observed that the closure of the SCCs in support of the early commissioning hold point will be dependent on adequate resources within the DA and commissioning.
Conclusion
I judge that an inspection rating of green (no formal action) is appropriate for LC14 (safety documentation). I consider that the licensee has implemented its arrangements to enable the production of an adequate safety case but I have highlighted two shortfalls in records associated with SCCs and SCOPs and the traceability of the HPC safety case.
To record and track resolution of the two shortfalls I have raised two level 4 regulatory issues (RI-11723 and RI-11724).
I will consider a follow-up inspection on the closure of the SCCs and SCOPs, given their role in addressing gaps/shortfalls in the safety case ahead of the early commissioning hold point. The purpose of this inspection would be to gain confidence in the implementation of the licensee’s arrangements for management and closure of SCCs and SCOPs. It has been provisionally agreed, subject to endorsement, that this inspection will be held in January 2024.