Executive summary
Date(s) of inspection:
- October 2025
Aim of inspection
The aim of this inspection was to confirm that the safety function(s) claimed by the extant safety case(s) are being adequately fulfilled in accordance with Licence Condition 23 and that the equipment is in suitable condition, suitably configured and maintained in accordance with Licence Condition 28. An additional aspect of this inspection was to provide evidence on station’s compliance against the specific topic area of electrical safety and the requirements of the Electricity at Work Regulations 1989(E@WR).This was a planned intervention and part of the 2025/2026 ONR integrated intervention strategy for operating reactors.
Subject(s) of inspection
- LC23 - Operating rules - Rating: Green
- LC28 - Examination, inspection, maintenance and testing - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
The inspection activities undertaken at Dungeness B (DNB) as part of this electrical themed intervention focused on an assessment of the condition of safety related essential electrical engineering plant and equipment, including relevant supporting systems such as lighting and small power supplies, switchrooms/houses, buildings, enclosures and the civil structural and architectural elements. In addition, it confirmed that the safety function(s) claimed by the extant safety case(s) are being adequately fulfilled and that the equipment is in suitable condition, suitably configured and maintained in compliance with licence conditions 23 and 28.
The reactors at DNB ceased operational service in 2023 and are currently de-fueling. At this point reactor decay heat has reduced, relative to that of an operating reactor station, to such an extent that the time that operators have to respond to cooling issues has increased. This has enabled changes within the arrangements and has reduced the burden presented to operators by the previous operating reactor arrangements.
From the sample inspected:
- EDF NGL adequately demonstrated that the necessary maintenance was carried out in accordance with the maintenance instructions and that these records were stored appropriately, readily available and completed to the level of detail required by them in accordance with licence condition 28.
- EDF NGL adequately demonstrated how the operating instructions and technical specifications encompassed the availability of the plant and equipment, what they would be revised to, and a demonstration of a complete and clear auditable trail through to the safety case from the technical specifications, which appeared clear to the operators with an appropriate awareness brief given to them as a result of the changes made. EDF NGL advised on an equipment unavailability review and its control for the backup cooling vessel pumps, and this was demonstrated in the control room, in line with licence condition 23.
Conclusion
On the basis of the evidence sampled at the time of the inspection, I judge that EDF NGL were able to adequately demonstrate the implementation of arrangements in compliance with licence condition 28 at DNB. Noting ONR guidance on inspection ratings, it is my opinion that an inspection rating of GREEN - no formal action is merited here.
On the basis of the evidence sampled at the time of the inspection, I judge that EDF NGL were able to adequately demonstrate the relevant station operating instructions and technical specifications and what they had been revised to, with a clear and auditable trail through to the safety case from the technical specifications in compliance with licence condition 23 at DNB. Noting ONR guidance on inspection ratings, it is my opinion that an inspection rating of GREEN - no formal action is merited here.