Executive summary
Date(s) of inspection
- September 2026
Aim of inspection
The aim of the inspection is to gain confidence in NNB’s arrangements during commissioning of the KCM system (I&C for the conventional island & electrical distribution) to support the release of the auxiliary transformer energisation (TAE) hold point 1.3.1.
Subject(s) of inspection
- LC12 - Duly authorised and other suitably qualified and experienced persons - Rating: Green
- LC20 - Modification to design of plant under construction - Rating: Green
- LC21 - Commissioning - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
This was a planned compliance inspection delivering intervention H26-46 (previously known as H25-17 part 2), sampling the implementation of commissioning arrangements for the first batch (Batch 1) of Instrumentation and Control (I&C) cabinets associated with the KCM system to support Auxiliary Transformer Energisation (TAE). The KCM Batch 1 cabinets are the first I&C cabinets to be installed and commissioned on site. This inspection therefore presented an opportunity to gain confidence in the practical implementation of I&C commissioning arrangements.
The inspection focused on Licence Condition (LC) 21 and the arrangements supporting commissioning activities undertaken using a phased approach, whereby some testing activities were deferred until supporting equipment became available. The inspection sampled Commissioning Procedures (CPs), Commissioning Instructions (CIs), associated Commissioning Open Points (CmOPs), Temporary Means and Devices (TMDs) used in support of the specific commissioning activity, commissioning records and competence management arrangements.
Particular attention was given to CP 033, relating to redundancy testing of KCM cabinets, as this procedure required the use of TMDs and included activities deferred as part of the phased approach. Additional sampling included CP 030, covering energisation of the cabinets and CP 016P, associated with hardwired input and output verification between KCM and SPPA-T2000.
Sampling demonstrated that suitable arrangements were in place to identify, manage and track deferred commissioning activities arising from the phased commissioning approach, including through the use of CmOPs. Review of the sampled records and discussions with commissioning personnel provided confidence that these arrangements were understood and being effectively implemented, such that deferred commissioning activities remained under appropriate control.
No significant shortfalls were identified from the samples examined. I therefore judge an inspection rating of GREEN (no formal action) is appropriate for LC21, LC20 and LC12.
Conclusion
I judge that a GREEN (no formal action) rating is appropriate for LC21. The inspection provided confidence that KCM commissioning activities are being managed within a structured governance framework and that deferred testing requirements are appropriately identified and controlled through established commissioning arrangements. Evidence sampled provided confidence that safety requirements, validated via commissioning, remain visible and traceable through to completion.
I judge that a GREEN (no formal action) rating is appropriate for LC20. The evidence sampled demonstrated arrangements capable of controlling commissioning modifications and temporary commissioning configurations.
I judge that a GREEN (no formal action) rating is appropriate for LC12. The evidence sampled provided confidence that personnel undertaking commissioning activities were appropriately qualified, experienced and authorised.