Executive summary
Date(s) of inspection: September 2024
Aim of inspection
The aim of this inspection was for ONR to gain confidence in the ongoing development and implementation of the licensee’s arrangements for cable pulling operations, the arrangements for controlling contractors on-site and the training of operatives.
Subject(s) of inspection
- LC19 - Construction or installation of new plant - Rating: Amber
Key findings, inspector's opinions and reasons for judgement made
Our recent inspection revealed notable progress since SF-45, particularly in certain areas of cable management at NNB GenCo. However, significant gaps remain in the overall arrangements for cable installation.
Our sample revealed the following:
Currently, NNB GenCo does not have a fully developed cable strategy or process for the installation and subsequent management of cables. This gap poses a risk, as the actual value of unterminated cables and those coiled on containment is not fully realised. This is due to the figure quoted not appropriately accounting for cables that have been moved or removed.
After initial cable pulling, there was no clear process or engineering consideration for the alteration or removal of containment. This lack of support and storage for cables could lead to potential damage to cables and pose a risk to personnel.
Temporary cables were not installed according to British Standards, and we observed similar issues of inadequate control over cable installation in the turbine hall, indicating that the problem is not isolated to the HF building. We clarified that the responsibility for implementing a suitable and sufficient strategy is NNB GenCo responsibility. NNB GenCo accepted that the extant philosophy does not reflect the issues faced at site now.
Given the number of shortfalls identified and the absence of a robust cable strategy, we have rated the inspection amber. Our preliminary findings were shared with and accepted by NNB GenCo (HPC) management at the conclusion of the inspection. A regulatory issue will be raised to monitor progress against the gaps identified.
Conclusion
There has been a significant increase in the volume of cable routing, laying, terminating and testing since ONR ast inspected the arrangements in March 2024
Through this inspection, areas for improvement were identified in the clarity, consistency, and application of the management system arrangements for cable routing, laying, terminating and testing. Consequently, an AMBER rating was assigned to the inspection, and a Level 3 Regulatory Issue has been raised to seek improvements in the areas identified.