- Site: Heysham 1
- IR number: 22-002
- Date: April 2022
- LC numbers: 28
Purpose of intervention
This report records the findings of an intervention visit to Heysham 1 Nuclear Power Station during the 2022 Reactor 2 (R2) periodic shutdown. The intervention was undertaken to confirm the adequacy of the work conducted by the licensee, EDF Energy Nuclear Generation Limited (NGL), to comply with the requirements of Licence Condition 28: Examination, Inspection, Maintenance and Testing (EIM&T).
Interventions carried out by ONR
I undertook on-site meetings and plant inspections with relevant staff from the licensee to determine the adequacy of the work being undertaken to comply with the requirements of Licence Condition 28. I concentrated my intervention on items I judged important to nuclear safety, from a structural integrity perspective.
I sampled aspects of the corrosion programme and the inspection programme undertaken during the periodic shutdown, including Pressure System Safety Regulation (PSSR) 2000 inspections, weld inspections, reactor internal inspections and other safety related systems external to the reactor pressure vessel.
Explanation of judgement if safety system not judged to be adequate
N/A as this was not a safety systems inspection.
Key Findings, inspector’s opinions and reasons for judgements made
Based on my observations and discussions with station staff, I am content that adequate EIM&T has been undertaken for seawater and main cooling systems at the time of my inspection.
I am satisfied that the Pressure System Safety Regulation (PSSR) Competent Person (CP) is providing appropriate support and oversight to the licensee, in accordance with the PSSR statutory maintenance schedule and associated Written Scheme of Examinations (WSE). From my discussion with the PSSR CP, there appears to be appropriate engagement between the two parties to facilitate inspection, sentencing and remediation in accordance with the requirements of the PSSR.
I sampled weld inspection results which were found to be acceptable. I am also content that the personnel who carried out these inspections are suitably qualified and experienced personnel (SQEP). Some material and weld inspections I chose to sample were not completed at the time of my inspection. I will follow up the results of these in my assessment report.
Discussions on the link between safety case requirements and the remote visual inspection of pressure vessel insulation retaining strips, and the licensee’s understanding of the components they are inspecting in this area is ongoing. There does not appear to be a significant shortfall. This will be followed up in my assessment report.
From the information that I have sampled, I am satisfied that the licensee is following their guidance for the survey of pipe supports and hangers on steam and feed pipework systems, and reactor pressure boundary pipework supports.
As part of my inspection, I carried out a plant walkdown. I visited the Start-Up vessel and the Pile Cap and Boiler Closure Units. The areas I visited were well controlled; I observed a good standard of housekeeping and have recorded no significant adverse findings as a result of my walkdown.
As part of my inspection, I also observed outage assessment panel (OAP) meeting 206. The meeting was attended by representatives for the majority of the inspection areas being conducted during the periodic shutdown and included SQEP and independent nuclear assurance support from the licensee’s headquarters at Barnwood via Skype. The meeting was conducted in a business-like manner, following a standard agenda. I was satisfied that the meeting participants all had the opportunity to contribute to the sentencing of inspection results.
A discussion took place with the main boiler system engineer and the inspection lead, via Skype. At the time of my inspection, the boiler closure unit stud bolt integrity checks were in progress with 4 out of 6 pods being completed. In total, 3 stud bolts have generated ultrasonic indications. All studs are scheduled to be exchanged during the current periodic shutdown. Based on the inspection results I sampled, I am content with the quality of inspection records. I am satisfied that appropriate actions are being undertaken to address root causes of stud bolt degradation.
The Flow Accelerated Corrosion (FAC) inspection programme was progressing well, with no significant structural integrity issues at the time of my inspection. Some FAC inspections had been removed from the programme. I am satisfied that this has been appropriately considered.
From my discussion with the Corrosion Management Engineer, I am content that the licensee is adequately managing corrosion for Heysham 1 R2.
Conclusion of intervention
I judge that, at the time of my visit to Heysham 1 nuclear power station, personnel were conducting their inspections in line with the R2 pre-outage intentions documentation and associated inspection specifications.
At the time of my sample inspections and from the information that I have reviewed so far, I am satisfied that the licensee’s programme for managing examination, inspection, maintenance and testing is adequate and aligns with the requirements of LC28.
I will use the minutes from the remaining OAP meetings to monitor for any emerging issues from the inspections that have yet to be completed and give it due consideration as part of my structural integrity assessment report on the return to service of Heysham 1 R2 following its 2022 periodic shutdown.
In my opinion, the licensee has performed the examination, inspection, maintenance and testing work to an adequate standard against the requirements of LC28. I consider that, in accordance with ONR guidance on the application of inspection ratings, a GREEN rating is appropriate for this inspection, warranting no formal action as a result of my inspection.