Executive summary
Date(s) of inspection: February 2024
Aim of inspection
This is a planned inspection of EDF Energy Nuclear Generation Ltd’s Heysham 2 Power Station (HYB) 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 is 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: Not rated
- 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
We carried out a themed inspection incorporating a multi-disciplinary team of inspectors and 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 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 operating rules and instructions in place to respond appropriately and safely to a potential fuel snag/ledge faults due to SRGW debris.
We noted minor shortfalls against a systematic approach to training and subsequently advised the station to carry out a training needs analysis on the new alternative load monitoring (ALM) system which would be used if the ultimate pull limits were to be utilised. Theses minor shortfalls will be followed up with EDF as part of regular human factors Level 4 engagements by the human factors specialist inspector. 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.
Overall, as no significant issues were found or raised, we judged that an overall rating of Green was appropriate for this inspection.
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.