Executive summary
Date(s) of inspection:
June 2023
Aim of inspection
The aim of the intervention is to inspect compliance with site Licence Conditions 27 and 28 at EDF Energy Nuclear Generation Ltd’s Torness power station.
The inspection is in accordance with ONR’s integrated intervention strategy for the site. ONR technical inspection guide NS-INSP-GD-027 (Safety Mechanisms, Devices and Circuits) and NS-INSP-GD028 (Examination, Inspections Maintenance and Testing) will be used as the basis for the inspection.
Subject(s) of inspection
- LC 27 - Safety mechanisms, devices and circuits - Rating: GREEN
- LC 28 - Examination, inspection, maintenance and testing - Rating: GREEN
Key findings, inspector's opinions and reasons for judgement made
Background
The inspection activities undertaken at Torness (TOR) focused on the arrangements that have been established to ensure the reliable operation of the gas circulators (GCs) and their speed control using variable frequency convertors (VFCs) following the implementation of off-load depressurised refuelling (ODR). The aim was to provide ONR with regulatory confidence in the implementation the arrangements established for the GCs and VFCs in compliance with licence condition 27 and licence condition 28.
Findings
From the sample inspected, EDF Energy NGL adequately demonstrated the implementation of the arrangements established to ensure the reliable operation of the for the GCs and VFCs following the implementation of ODR, including a sample inspection and observation of the actual condition of the GCs and VFCs, a summary of the GC and VFC safety cases, a summary of the VFC lifetime management strategy, a demonstration of GC and VFC related performance, a demonstration of completed GC and VFC maintenance schedule routines and an inspection of completed GC and VFC maintenance records.
Conclusion
On the basis of the evidence sampled at the time of the inspection:
ONR were provided with regulatory confidence in the implementation the arrangements established for the GCs and VFCs in compliance with licence condition 27 and licence condition 28. We judge that EDF Energy NGL were able to adequately demonstrate the implementation of the arrangements in compliance with licence condition 27 and licence condition 28 at TOR. Noting ONR guidance on inspection ratings, it is our opinion that an inspection rating of GREEN - no formal action is merited here for both licence conditions.