Executive summary
Date(s) of inspection:
January 2025
Aim of inspection
To provide evidence to inform the ONR decision relating to the issue of a Licence Instrument for a Consent for return to service of Reactor 7 at Heysham B on completion of the work undertaken during the outage. The inspection examined the adequacy of conducting graphite inspections and the sentencing of collected graphite data.
Subject(s) of inspection
- LC28 - Examination, inspection, maintenance and testing - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
As part of the statutory outage of Heysham 2 Reactor 7, EDF Nuclear Generation Limited (NGL) perform graphite core inspections. I conducted a licence condition 28 Examination, inspection, maintenance and testing compliance inspection.
This intervention is one of a number of LC28 compliance inspections performed by ONR during the periodic shutdown of HYB Reactor 7. These inspections inform the ONR’s decision on whether to issue a licence instrument granting Consent for the return to service of HYB R7 following its 2024 periodic shutdown, as required by LC30.
This intervention specifically focused on arrangements for the graphite core examination, inspection and testing. I judged this intervention based on the findings of the intervention, the quality of the data I observed and the knowledge and experience of the licensee’s staff.
Conclusion
Following my intervention, I consider that the licensee’s arrangements with regards to collection of graphite core inspection data during this outage are suitable and adequate. In my opinion, the visual records and the data that I sampled were of adequate quality for NGL to form an accurate judgement and enable sentencing of the cracks.
At the time of my intervention, there was no reason to believe that the safety case requirements would not be met. A forthcoming assessment report will consider whether the results of the graphite core inspections are consistent with the graphite safety case, once the inspection schedule has been completed.
I have noted areas for improvement in NGLs arrangements and adherence to said arrangements for the graphite related activities. Whilst shortfalls have been identified, I consider them minor in nature and do not have a material effect on the generation of graphite inspection data, hence I have allocated an ONR IIS rating of ‘GREEN’ – no formal action.