Executive summary
Date(s) of inspection
- June 2026
Aim of inspection
ONR Licence Condition 28 (LC28) requires the licensee to make and implement adequate arrangements for the regular and systematic examination, inspection, maintenance and testing of all plant which may affect safety. For any plant or process that is shut down for the purpose of enabling these activities, LC30 requires ONR to provide consent before said plant or process is started up again.
The aims of this inspection are:
- To provide regulatory confidence in the implementation of the Sizewell B Refueling Outage 20 (RO20) Outage Intentions Document in relation to structural integrity.
- To provide evidence to inform the ONR decision relating to the issue of a Licence Instrument for a Consent for return to service of Sizewell B on completion of the work undertaken during RO20.
Subject(s) of inspection
- LC28 - Examination, inspection, maintenance and testing - Rating: Green
- PSSR - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
I visited site approximately 2.5 weeks into the planned periodic shutdown. The aim of which was to witness key activities and obtain evidence to inform a judgement on the adequacy of the implementation of LC 28 arrangements. At the time of my inspection about half of the inspections had been completed.
I sampled examinations and inspections undertaken by the Pressure Systems Safety Regulations (PSSR) Competent Person (CP) during the periodic shutdown. I judge that, during my visit, the PSSR examinations were being managed effectively by the Licensee and the CP and no significant issues had been found.
I was satisfied, from a structural integrity perspective, with the experience demonstrated, processes referenced and judgments made by station in relation to LC 28. I judge that the station were compliant with their arrangements to meet LC 28 during the time of the inspection.
I undertook a plant walk down during my visit, escorted by station staff. They were able to provide satisfactory explanations of both the operation of the systems and the planned or already performed inspection/maintenance of the systems during the periodic shutdown.
I have noted some areas to follow up on which include an arc strike on the Steam Generator A shell and a loose parts alarm in Steam Generator C as they have implications for the validity of the overall Return to Service recommendation. I will form a judgement on the adequacy of the Licensee's position within my assessment report (AR-01933).
Conclusion
I judge that, at the time of my visit to the Sizewell B nuclear power station, personnel were conducting their inspections in line with the pre-outage intentions documentation and associated inspection specifications. I judge that the Licensee was adequately managing any defects or anomalies identified.
ONR will maintain an oversight for any emerging issues, from the inspections that have yet to be completed and report on any outstanding issues, where deemed necessary, in the structural integrity assessment report (AR-01933).
Based on the activities sample during my inspection to date, I judged, from a structural integrity perspective, that the site has demonstrated compliance with their LC28 arrangements, I have therefore rated the inspection green.