Executive summary
Date(s) of inspection: May 2024
Aim of inspection
This was a planned inspection of EDF Energy Nuclear Generation Ltd’s Torness Power Station (TOR) following ONR's assessments of the seal ring groove wall debris (SRGW) safety case NP/SC 7819 and the ultimate pull safety case NP/SC 7825.
This planned inspection was undertaken to assess the adequacy of the implementation of risk reduction measures and potential recovery operations for fuel snags due to SRGW debris and ensure the safety case claims of NP/SC 7819 and NP/SC 7825 are appropriately met.
Subject(s) of inspection
- LC10 - Training - Rating: Green
- LC23 - Operating rules - Rating: Green
- LC24 - Operating instructions - Rating: Green
- LC26 - Control and supervision of operations - Rating: Green
- LC28 - Examination, inspection, maintenance and testing - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
ONR carried out a themed inspection covering multiple licence conditions to gain confidence in the station's implementation of risk reduction measures and recovery operations due to potential fuel snag/ledge faults due to seal ring groove wall (SRGW) debris and to ensure the safety case claims of NP/SC 7819 and NP/SC 7825 are appropriately met.
The inspection included technical discussions with station leads for graphite, fuel route and fuelling machine engineers, review of station guidance, operating rules and instructions and a plant walkdown to observe the plant and discuss changes with the operators.
Based on our sample, we were satisfied that the station has appropriate control and oversight and that operating rules and instructions in place to respond appropriately and safely to a potential fuel snag/ledge faults due to SRGW debris.
We noted two minor shortfalls and subsequently advised the station to carry out a training needs analysis for the Fuel Handling Assessment Panel (FHAP) and to provide clarity in the guidance with regards to control and process for the "formal decision making" needed for the highest "overload limit 3" allowed under the Ultimate Pull safety case (NP/SC 7825). As part of the walkdown, we noted some gaps in the netting/guards of the handrails on the fuelling machine platforms. As a result, we raised a regulatory issue (Level 4) for the station to review the fuelling machine edge protection (risk from dropped objects). This did not affect our confidence in the ability of the station to respond appropriately to a potential fuel snag/ledge due to SRGW debris.
Conclusion
Based on the sample we covered during the inspection, we gained confidence in the station ability to respond appropriately and safely to fuel snag/ledge faults due to SRGW debris and we were content that the station has implemented the safety case requirements appropriately.
As no significant issues were found or raised, a Green rating was given for this inspection.