Executive summary
Date(s) of inspection: April 2024
Aim of inspection
The aim of the inspection was to gather sufficient evidence of the implementation of the licensee’s arrangements for the Safety Case Commitment (SCC) and Safety Case Open Point (SCOP) process, to form a judgement as to whether these are being appropriately managed and closed out in line with NNB Generation Company (HPC) Ltd’s (NNB GenCo) processes. This is the second of two inspections on this topic, following an earlier inspection in September 2023 on the identification and sentencing of SCCs and SCOPs. This inspection focused on adequate closure of SCCs (as well as SCOPs and future activities, where appropriate).
In addition, the inspection gathered evidence in support of ONR permissioning of future hold points.
The inspection targeted, on a sampling basis, the arrangements associated with management and closure of SCCs, SCOPs and future activities and their implementation to form a judgement on their adequacy.
In addition, the inspection gathered evidence in support of ONR permissioning of future hold points.
The inspection targeted, on a sampling basis, the arrangements associated with management and closure of SCCs, SCOPs and future activities 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 management and closure of SCCs, SCOPs and future activities, targeting primarily on SCCs. I sampled a selection of documentation updated to close out SCCs, and observed a SCC/SCOP committee meeting focused on how the updates to documentation have addressed each of the gaps identified by the SCCs.
I am satisfied that NNB GenCo’s arrangements for management and closure of SCCs are appropriate, noting that further work is anticipated on the management and closure of SCOPs and future activities later in the year. Based on my sample, I am satisfied that adequate challenge is being provided by the internal regulator and SCC/SCOP committee members.
I observed demonstrable progress in response to regulatory issue RI-11723, which was raised during my previous inspection on SCCs, SCOPs and future activities in September 2023. NNB GenCo will provide further information after the inspection to address this regulatory issue, with closure of the regulatory issue expected before the 400V AC uninterruptable power supply (UPS) distribution system (LVL) commissioning control point.
Responses to questioning during the inspection provided confidence that NNB GenCo is making progress on addressing SCCs. The closure of the SCCs supports the safety case underpinning the commissioning control point for the LVL.
Conclusion
I judge that an inspection rating of green (no formal action) is appropriate for licence condition (LC) 14 (safety documentation). I consider that the licensee has implemented its arrangements to enable the production of an adequate safety case. I observed improvements since my previous inspection in the processes for SCCs, in regard to clarity of requirements for closure, records and traceability of evidence.