Executive summary
Date(s) of inspection: September 2024
Aim of inspection
System based inspections (SBIs) are an essential element of ONR’s overall intervention on a nuclear site and consist of a series of inspections which seek to ascertain the adequacy of the implementation of the Licensees arrangements as part of Licence Condition compliance.
An SBI of the Emergency Diesel Generation was carried out at Torness. The diesel generator systems are provided to supply the necessary on-site power to maintain essential electrical services following a loss of grid event.
The aim of this SBI was to determine the adequacy of the safety systems, structures and components associated with the provision of Emergency Generation (diesel generators and associated support systems).
Subject(s) of inspection
- LC10 - Training - Rating: Green
- LC23 - Operating rules - Rating: Green
- LC24 - Operating instructions - Rating: Green
- LC27 - Safety mechanisms, devices and circuits - Rating: Green
- LC28 - Examination, inspection, maintenance and testing - Rating: Green
- Overall Inspection Rating - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
This SBI of the Emergency Diesel Generators at Torness was carried out by a multidisciplinary team of ONR specialist inspectors, including the Torness nominated site inspector.
During this SBI of the Emergency Diesel Generators at Torness, We sampled the following to inform my judgement:
- Licence Condition 10 - Personnel training records and training material relating to Emergency Diesel Generators
- Licence Condition 23 - Limits and Conditions of Operation relating to Emergency Diesel Generators and diesel stocks
- Licence Condition 24 – Maintenance Instructions and Station Operating Instructions for normal operation of unit at power associated with the Emergency Diesel Generators
- Licence Condition 27 - the plant walkdown, in combination with discussions with system engineers and completion of maintenance activities responsible for Emergency Diesel Generators
- Licence Condition 28 - Work Order Cards, Plant Item Operating Instructions, and Company Technical Standards relating to diesel generator test runs and diesel generator air supply valves
I provided a small number of observations for EDF NGL Torness to consider, which will be followed up through normal regulatory activities.
Conclusion
LC 10, Training: I judged that the Licensee has adequate arrangements in place for training, and the individuals we sampled were appropriately trained for the tasks undertaken. I therefore consider an inspection rating of Green (No Formal Action) to be appropriate.
LC23, Operating rules: I judged that from our sample, that the Licensee has an adequate process in place for identifying the operating rules to demonstrate the safety of an operation and maintain configuration control. I therefore considered an inspection rating of Green (No Formal Action) to be appropriate.
LC24, Operating instructions: I judged that although a small number of observations were made, the Licensee had an adequate process in place for the production and implementation of Operating Instructions, and the management of Safety Mechanisms, Devices and Circuits. I therefore considered an inspection rating of Green (No Formal Action) to be appropriate.
LC27, Safety mechanisms, devices and circuits: This inspection combined LC 24 and 27, thus the judgements made above (LC 24) are repeated here.
LC28, Examination, inspection, maintenance ant testing:
I judged that the Licensee had adequate arrangements for the regular and systematic examination, inspection, maintenance and testing of all plant which may affect safety. I therefore considered an inspection rating of Green (No Formal Action) to be appropriate