Executive summary
- Date(s) of inspection: June 2024
Aim of inspection
This was a System Based Inspection (SBI) of EDF Energy Nuclear Generation Ltd.’s (NGL’s) Heysham 1 Power Station, undertaken as part of the planned intervention strategy for the Operating Facilities Division (OFD) of the Office for Nuclear Regulation (ONR). The work was carried out in accordance with the planned inspection programme contained in the Heysham 1 Integrated Intervention Strategy (IIS) for 2023/24. The Secondary and Tertiary Shutdown Systems were inspected due to there importance to nuclear safety.
Inspection scope
The inspection sampled the following Shutdown System areas:
- Secondary Shutdown System
- Tertiary Shutdown Systems
Thematic focus
- Spares management and obsolescence.
- Industrial health and safety – including Pressure Systems Safety Regulations (PSSR), confined spaces (asphyxiation) and local area risk assessments and mitigation quality.
- Awareness of manufacturer / supplier advice, information and recommendations – and how these have been implemented.
- Adequacy of operational records including drawings –
- fit for purpose, up to date and design intent understood.
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
- LC34 - Leakage and escape of radioactive material and radioactive waste - Rating: Not rated
- Overall Inspection Rating - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
- We sampled a selection of training arrangements and discussed activities important to nuclear safety for the Secondary Shutdown (SSD) and Tertiary Shutdown (TSD) systems with individuals responsible for implementation. This included sampling the task to training matrix and the on the job training process for the Operate Technician role. Through our sample examination and discussions, we judge that EDF Nuclear Generation Limited (EDF NGL) has implemented adequate arrangements for suitable training for those who have responsibility for operating and maintaining the SSD and TSD systems.
- We sampled operating rules as defined through Technical Specifications (Tech Specs) for the Secondary and Tertiary Shutdown Systems, which we consider had been clearly derived from the safety case. We confirmed that appropriate compliance was demonstrated through surveillance schedules identified in the Tech Specs. We confirmed, for the SSD, surveillance was carried out every shift. This involved a combination of plant configuration checks and Central Control Room (CCR) indication checks. For the Tertiary Shutdown System, we confirmed that surveillance of operating rules was carried out through appropriate maintenance and testing arrangements, which were clearly defined.
- We sampled operating instructions for initiation of the SSD system located in the Central Control Room (CCR). We confirmed these instructions were readily accessible and adequately produced. We also sampled operations and maintenance instructions for topping up the nitrogen storage facility and for carrying out maintenance for important components of the TSD system. From our sample, we are content that EDF NGL is adequately operating the SSD and TSD systems in accordance with written instructions.
- We noted that each of the maintenance Work Order Cards examined for the SSD and TSD systems was adequately annotated, signed and completed within the inspection period specified within the plant maintenance schedule. This included functional testing of nitrogen injection control valves for the SSD and the exercising and testing of essential valves and flow controllers for the TSD. We therefore judge that the examination, maintenance, inspection, and testing activities on the secondary and tertiary shutdown system are being adequately completed in accordance with schemes laid down in writing.
- During the plant walkdown, we observed:
- Appropriate housekeeping;
- Appropriate plant labelling, with minor defects or replacement tags required;
- Structures systems and components important to nuclear safety for the SSD and TSD systems in adequate condition; and
- Minor corrosion defects.
Conclusion
Site Licence Condition 10 –Training
ONR Inspection Rating Green (No Formal Action):
We are content that the arrangements for Licence Condition 10 are adequate and implemented appropriately in line with the licensee’s arrangements. Based on the evidence sampled during this inspection, we consider that an inspection rating of Green (no formal action) is appropriate for Licence Condition 10.
Site Licence Condition 23 – Operating Rules
ONR Inspection Rating Green (No Formal Action):
From the evidence sampled, it is my opinion that a clear line of sign is evident from living safety case documents to Tech Specs, and that the site surveillance requirements are being appropriately observed. Therefore, we consider an inspection rating of Green (no formal action) is appropriate for Licence Condition 23.
Site Licence Condition 24 – Operating Instructions
ONR Inspection Rating Green (No Formal Action):
From the information sampled, we are content that the licensee is operating in accordance with adequate written instructions. We consider compliance with Licence Condition 24 to be adequate, and judge that a rating of Green (No formal action) is appropriate.
Site Licence Condition 27 – Safety Mechanism Devices and Circuits
ONR Inspection Rating Green (No Formal Action):
From the areas sampled, the arrangements where adequately implemented and mechanisms, devices, and circuits important to nuclear safety were connected and in good working order. We therefore judge a green rating (no formal action) is appropriate for Licence Condition 27.
Site Licence Condition 28 – Examination, Inspection, Maintenance and Testing
ONR Inspection Rating Green (No Formal Action):
From the evidence sampled, maintenance activates on the Secondary and Tertiary Shutdown System are bring adequately completed in accordance with schemes laid down in writing. Therefore, we judge a rating of Green (no formal action) to be appropriate for Licence Condition 28.
Site Licence Condition 34 – Leakage and Escape of Radioactive Material and Radioactive Waste
ONR Inspection Rating Not Rated (No Formal Action):
We judged that we did not gain sufficient evidence to underpin a rating for this LC.
Consequently, we judged an overall rating of GREEN was appropriate for this System Based Inspection of Shutdown Systems