Executive summary
Date(s) of inspection
- November 2025
Aim of inspection
This was a planned follow-up inspection of EDF Nuclear Generation Limited's (NGL's) implementation of operational arrangements for Seasonal, Severe Weather and Marine Impact Preparations ("Seasonal Readiness") at Hartlepool Nuclear Power Station (HAR) to ensure the facility is being adequately prepared to withstand predictable seasonal hazards. A previous ONR inspection (IR-53356) identified potential enhancements to EDF NGL's seasonal readiness arrangements, and raised the regulatory issue RI-12063.
The aim of this activity was to:
- Ensure that risks associated with seasonal hazards are being adequately managed by EDF NGL.
- Gather evidence to support closure of RI-12063.
- Gain assurance that safety improvements resulting from EDF NGL's updates of relevant external hazards safety cases are being appropriately implemented.
Subject(s) of inspection
- LC 24 - Operating instructions - Rating: AMBER
- LC 28 - Examination, inspection, maintenance and testing - Rating: AMBER
- Overall Inspection Rating - Rating: AMBER
Key findings, inspector's opinions and reasons for judgement made
To deliver the aims of this inspection, we considered EDF NGL's delivery of seasonal readiness for compliance with relevant licence conditions. Evidence was sampled from:
- Seasonal readiness quality plans and associated activities.
- Examination, inspection, maintenance and testing of relevant nuclear safety significant assets that could be affected by seasonal hazards.
- Operating instructions relating to seasonal readiness and for relevant seasonal hazards.
LC24 Operating Instructions – Amber rating (seek improvement) – I judge this rating appropriate based on my sample of EDF NGL’s compliance with their seasonal readiness arrangements and operating instructions for relevant seasonal hazards. Seasonal readiness was not completed by the required deadline, and EDF NGL could not provide adequate evidence of complying with all required activities in their seasonal readiness arrangements. Operating instructions sampled were, in places, unclear and ambiguous regarding actions or references to plant. Additional clarity could be provided.
LC28 Examination, Inspection, Maintenance and Testing (EIMT) – Amber rating (seek improvement) – I judge this rating appropriate based on my sample and that repairs have been undertaken by EDF NGL following the inspection to address the most serious nuclear safety risks. We identified latent defects on nuclear safety significant systems that could potentially challenge the delivery of required safety functions during the winter season. Routine seasonal readiness activities were marked as completed for these safety systems. The dutyholder’s EIMT arrangements were not sufficient, in terms of frequency and depth, to identify the defects despite significant evidence showing repeated failure of components since 2022. Other gaps related to defects and their management were also identified indicating a lack of rigour with which seasonal readiness activities were delivered and unclear decision making.
ONR has reduced confidence in the dutyholder’s seasonal readiness implementation and whether the plant has been adequately prepared to withstand predictable seasonal hazards. I issued a provisional Red rating for LC28 shortfalls and demanded improvement. EDF NGL has responded to the most significant concerns raised during the inspection, demonstrating an intent to return to compliance. This includes addressing the most serious risks and accelerating the delivery of outstanding work related to seasonal readiness.
I have undertaken enforcement action in accordance with ONR guidance given the significance of the identified shortfalls. I have issued an enforcement letter to EDF NGL outlining my concerns and raising conditions that must be met before return-to-service of the power station. Delivery of these matters will be tracked via a regulatory issue. An additional regulatory issue has been raised to ensure EDF NGL enhances its arrangements for compliance with LC24 and LC28, which will supersede existing RI-12063. Follow-up regulatory activities will be undertaken.
Conclusion
The inspection has been awarded an overall inspection rating of Amber (Seek improvement) based on our sample. The reasons for this are:
- LC28 Examination, inspection, maintenance and testing arrangements were not adequate and EDF NGL is not proactively managing defects. Latent defects were identified on ‘bottom-line’ safety systems that made them susceptible to winter hazards and could challenge delivery of nuclear safety functions. EDF NGL has addressed the most serious risks following the inspection activity.
- EDF NGL is not complying with its seasonal readiness arrangements relevant to LC24. Some operating instructions relevant to seasonal readiness are, in places, unclear and ambiguous, with inconsistencies.
I have taken appropriate enforcement action in relation to these gaps including raising regulatory issues to ensure EDF NGL improves its compliance.