Executive summary
Date(s) of inspection:
March 2026
Aim of inspection
Following on from the Level 3 regulatory issue (RI-12148), to gain confidence in NNB GenCo Ltd's continued intelligent customer role with regard to impacts on primary circuit source terms, and specifically the operation of the radio protection guide (RPG) Exemption Committee.
Subject(s) of inspection
- LC19 - Construction or installation of new plant - Rating: GREEN
Key findings, inspector's opinions and reasons for judgement made
The intervention provided suitable time to discuss the current arrangements for assessing the impact on the primary circuit source term due to material exemptions.
The focus was to gain confidence in NNB GenCo Ltd's continued intelligent customer role with regard to impacts on primary circuit source terms, and specifically the operation of the radio protection guide (RPG) Exemption Committee.
A review of documentation and observation of the March 2026 RPG Exemptions Committee was undertaken.
Overall I was content that at the time of the intervention NNB GenCo Ltd demonstrated a robust process for assessing, recording and understanding RPG exemptions and that the impact on the primary circuit source term were appropriately recorded and tracked.
Conclusion
I judged that, on the basis of evidence sampled at the time of this intervention, NNB GenCo Ltd demonstrated that exemptions which could impact on the primary circuit source term undergo suitable internal assessment and challenge. This gave reassurance of NNB GenCo Ltd being an intelligent customer with regard to the proposed material changes, and an intervention rating of Green (no formal action) is appropriate.