Office for Nuclear Regulation

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Heysham 1 Power Station - Reactor 2 Statutory Outage 2015 - LC28 Compliance Inspection   

Executive summary

Purpose of intervention

This report records the findings of an intervention visit to Heysham 1 Nuclear Power Station during the 2015 Reactor 2 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. The information provided in my intervention record will also be used to inform my assessment report on the structural integrity aspects of the return to service of Heysham 1 Reactor 2.

Interventions Carried Out by ONR

I undertook on-site meetings and plant inspections with the licensee and their contractors to determine the adequacy of the work being undertaken on Reactor 2 in complying with the requirements of Licence Condition 28. I concentrated my intervention on items I judged important to nuclear safety. I sampled aspects of the inspection programme undertaken during the periodic shutdown on the steam and feed systems and other safety related systems external to the reactor pressure vessel. I also sampled aspects of the inspection programme undertaken on the metallic components internal to the reactor pressure vessel.

Key Findings, Inspector's Opinions and Reasons for Judgements Made

I visited site approximately half way through the periodic shutdown. The status of the inspections highlighted good progress on the reactor external inspection programme, with 391 out of the 661 programmed inspections completed. Most of the reactor internal inspections were also complete at the time of my visit.

I sampled the inspection work that had been undertaken as part of the reactor external inspection programme, looking at both the inspection work itself and the categorising of the results, and was satisfied with what I found. No potentially significant issues had been found from this inspection programme at the time of my visit.

I observed the licensee’s weekly Outage Assessment Panel (OAP) meeting during my visit. The OAP meets to review the inspection work undertaken during the periodic shutdown and sentences the inspection findings. I am satisfied that the OAP was following due process and found evidence of the panel taking a conservative approach on the findings

I undertook a plant walk down during my visit, escorted by the OAP chair. Where questioned, the OAP chair was able to provide explanations of the operation and the inspection/maintenance of the systems planned, in progress or completed during the periodic shutdown. I observed a lower level of housekeeping than expected in some of the areas I visited, however I did not consider this be of detriment to personal or nuclear safety.

I reviewed the progress of the reactor internal inspection programme. Good progress was reported with no major issues identified at the time of my visit. I sampled video footage showing the wall cover plates in the hot box dome as well as under core footage and found due process for the scope of inspection and off-line audit was being followed satisfactorily. A non-conformance was being investigated at the time of my visit. I will monitor the sentencing of this non-conformance during a further site visit and through review of the approved OAP minutes.

I discussed progress on examination, inspection, maintenance and testing activities associated with the seawater cooling systems. The work programme was progressing well, and I observed some of the maintenance work on the drum screen system and within the reactor seawater pump house during a system walk-down with the system engineer.

I discussed progress on examinations and inspections undertaken by the Pressure Systems Safety Regulations (PSSR) surveyor during the periodic shutdown. The work was progressing to programme and no significant issues had been found at the time of my visit. I noted that some repair work was planned for the de-aerator system. The system engineer for this system was unavailable at the time of my visit; therefore I have arranged to return to site when the system engineer is available to gather additional information which will be used to inform my assessment report on the structural integrity aspects of the return to service of Heysham 1 Reactor 2.

I sampled the scope of work being undertaken on the steam and feed pipework hangers. The pre-outage hot hanger survey was complete, and the report had been made available before my site visit. The cold survey was complete and in the reporting stage for which the results will be reported to and sentenced through the OAP. The system engineer responsible for the hanger inspection and maintenance provided evidence of the work that was being undertaken in response to the survey report. I am content that this work is being completed as specified and that the licensee is following due process.

Most of the inspections for Flow Accelerated Corrosion (FAC) were complete and the results were being reported through the OAP. I sampled several inspections and the licensee demonstrated that the programme was being managed in accordance with their own internal arrangements.

Conclusion of Intervention

From the information that I have sampled, I judge that Heysham 1 nuclear power station personnel were conducting their inspections of Reactor 2 in line with the pre-periodic shutdown intentions documentation and associated inspection specifications. The inspections conducted so far have not identified any issues that are likely to affect nuclear safety and I am content that any issues identified are being adequately managed.

I will monitor the minutes from the remaining OAPs for any emerging issues from the inspections that have yet to be completed. I will return to site to gather additional information on the de-aerator repairs and the sentencing of non-conformances through the reactor internal inspection audit. My findings will be reported in my structural integrity assessment report on the return to service of Heysham 1 Reactor 2 following its 2015 periodic shutdown.

Based on my intervention, I conclude that the licensee has performed the work to an adequate standard. I consider an IIS rating of 3 (adequate) against license condition 28 is appropriate.