- IR number: 22-034
- Date: June 2022
- LC numbers: 28
Purpose of Intervention
This report records the findings of an intervention at Torness 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 in-service inspection programme being undertaken during the periodic shutdown, including Pressure System Safety Regulations (PSSR) 2000 inspections, weld inspections, reactor internal inspections and other safety-related systems external to the reactor pressure vessel. I also sought an update on progress being made at Torness in line with the licensee’s fleetwide corrosion management programme.
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 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. At the time of my inspection, the licensee was investigating a leak identified in the decay heat boiler feed pipework on R2, Quadrant D. The extent of condition and remediation of this defect before return to power is still under consideration by the licensee. I will consider the outcome of this emergent work as part of my structural integrity periodic shutdown assessment report.
I sampled the in-service weld and component inspection results, which were found to be acceptable. From a sample of training records made during my inspection, I am content that the personnel who carried out these inspections are suitably qualified and experienced personnel (SQEP). The component and weld inspections were ongoing at the time of my inspection, therefore I will confirm that these have been satisfactorily completed before return to power as part of my structural integrity periodic shutdown assessment report.
At the time of my inspection, the licensee was experiencing technical difficulties with key inspection equipment during the reactor internal inspection programme. Resolution of these issues is ongoing, as is confirmation that the scope of necessary inspections in accordance with the maintenance schedule have been completed. I will consider this further within my structural integrity periodic shutdown assessment report.
From the information that I have sampled, I am satisfied that the licensee is following its guidance for the survey of pipe supports and hangers on steam and feed pipework systems and reactor pressure boundary pipework supports. Assessment of survey results and the completion of remedial action was ongoing at the time of my inspection, so I will confirm satisfactory completion of all surveys and required remedial action as part of my structural integrity periodic shutdown assessment.
During my inspection, I undertook a plant walkdown, where I visited the seawater cooling system, steam and feed systems (turbine hall and reactor building), and the carbon dioxide (CO2) and nitrogen (N2) storage plants. I observed a good standard of housekeeping in the areas I visited. Whilst I did not witness or observe any specific EIM&T activities in detail, those that were in progress during my walkdown appeared to be well managed and controlled. I have recorded no significant findings related to personal safety as a result of my walkdown.
I observed outage assessment panel (OAP) meeting 9. 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 teleconference. The meeting was conducted in a business-like manner, following a standard agenda. I was satisfied that the meeting was well attended and that all participants had the opportunity to contribute to the sentencing of inspection results.
At the time of my inspection, the Flow Accelerated Corrosion (FAC) inspection programme was progressing well, with no significant structural integrity issues. I identified a minor shortfall with respect to the completion of mandatory FAC Coordinator training, which has been acknowledged by the licensee with action taken to address the shortfall. In my opinion, this shortfall does not affect the adequacy of the site FAC inspection programme or the completion of FAC related maintenance necessary to support the return to power of Torness Reactor 2.
In response to the licensee’s extant regulatory issue on fleetwide management of external pipe and vessel corrosion, I discussed the progress that had been made at Torness with the site corrosion coordinator. It was evident that work is still ongoing to address issues identified previously, although notable progress has been made in improving the understanding of plant material condition, compared to previous ONR inspections. At the time of my site inspection, I found no issues related to external pipework corrosion that are likely to impact the return to power of Torness Reactor 2. I will brief the relevant ONR inspector in charge of the regulatory issue on corrosion management of my findings.
Conclusion of Intervention
I judge that, at the time of my inspection at Torness nuclear power station, personnel were conducting their inspections in line with the Reactor 2 pre-outage intentions documentation and associated inspection specifications.
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 Torness Reactor 2 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.