Sizewell B - Cross-Cutting Lightening Hazard Inspection
- Site: Sizewell B
- IR number: 17-143
- Date: October 2017
- LC numbers: 10, 23, 24, 27, 28
Purpose of Intervention
The work was carried out in-line with the planned ONR Project Task Sheet TS065.
This was a reactive unplanned inspection of EDF Energy Nuclear Generation Ltd.'s (NGL's) Sizewell B Power Station, undertaken for the Operating Facilities Division (OFD) of the Office for Nuclear Regulation (ONR).
Interventions Carried Out by ONR
During this intervention, an inspection of the Lightning Protection System was undertaken, during which compliance against the following licence conditions (LC) was examined.
- LC 10 - Training
- LC 23 - Operating Rules
- LC 24 - Operating Records
- LC 27 - Safety Mechanisms Devices & Circuits
- LC 28 - Examination, Inspection Maintenance and Testing
Explanation of Judgement if Safety System Not Judged to be Adequate
No system based inspection was undertaken during this intervention.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
From the inspection on the Lightning Protection System ONR concluded that:
- LC 10 (Training) - ONR examined the training records of a number of personnel involved in the management, maintenance and inspection activities associated with the Lightning Protection System. ONR judged that the personnel undertaking the activities were suitably qualified and experienced. No significant shortfalls were identified. ONR therefore assigned a rating of Green (no formal action) for LC 10 compliance.
- LC 23 (Operating Rules) - There are no operating rules for the Lightning Protection System as it is passive. From the sample inspected, ONR identified that there were no significant shortfalls identified in the delivery of the required safety functions. ONR therefore assigned a rating of Green (no formal action) for LC 23.
- LC 24 (Operating Instructions) - ONR examined a limited sample of maintenance instructions (MIs) and consider them to be adequate for undertaking EIMT and that there were no significant shortfalls identified in the delivery of the required safety functions. ONR therefore assigned a rating of Green (no formal action) for LC 24.
- LC 27 (Safety Mechanisms, Devices and Circuits) - The Lightning Protection System is present, properly connected and in good working order. There were no significant shortfalls identified in the delivery of the required safety functions. ONR judged that a rating of Green (no formal action) was appropriate for LC 27.
- LC 28 (Examination, Inspection, Maintenance and Testing) - ONR examined a limited sample of maintenance instructions and work order cards. ONR confirmed that the maintenance activities were conducted annually as appropriate and that the maintenance instructions appropriately completed. ONR judged that the lightning Protection System was being adequately maintained. ONR therefore assigned an IIS rating of Green (no formal action) for LC 28.
- LC 34 (Leakage and Escape of Radioactive Material and Radioactive Waste) - The Lightning Protection System does not contain radioactive material; therefore this licence condition was deemed not applicable in this instance.
The intervention was performed in line with ONR’s guidance requirements (as described in our technical inspection guides) in the areas inspected.
Conclusion of Intervention
From the evidence sampled during this inspection against LCs 10, 23, 24, 27, 28 and 34, ONR consider that the Lightning Protection System met the requirements of the safety case.
There are no findings from this inspection that could significantly undermine nuclear safety. At present, no additional regulatory action is needed over and above the planned interventions at Sizewell B Power Station as set out in the Integrated Intervention Strategy, which will continue as planned.