Executive summary
Date(s) of inspection:
- February 2023
Aim of inspection
The System Based Inspection (SBI) considered the adequacy of the licensees’ carbon dioxide system safety case implementation.
This intervention assessed the licensee’s safety case application for its carbon dioxide storage, distribution and blowdown systems. It was conducted by Office for Nuclear Regulation (ONR) Mechanical Engineering and Structural Integrity inspectors. They were supported by the Heysham 1 ONR nominated site inspector. Throughout this intervention record, “I” refers to all ONR inspectors.
The inspection involved:
- discussions with licensee staff;
- a review of licensee safety case documents; and
- a walkdown of licensee facilities.
Subject(s) of inspection
- LC 10 - Training - rating: Green
- LC 23 - Operating rules - rating: Green
- LC 24 - Operating instructions - rating: Green
- LC 27 - Safety mechanisms, devices and circuits - rating: Green
- LC 28 - Examination, inspection, maintenance and testing - rating: Green
- LC 34 - Leakage and escape of radioactive material and radioactive waste - rating: Green
Key findings, inspector's opinions and reasons for judgement made
From my inspection sample, I judge that the licensee has adequately demonstrated implementation of its carbon dioxide storage, distribution and blowdown systems safety case. The Licence Condition ratings are summarised below:
- Licence Condition 10 (Training) – I sampled training records for individuals involved in carbon dioxide system operation, examination, inspection, maintenance and testing. I judge that the licensee adequately demonstrated training identification and implementation. Hence, I assigned a Green (No formal action) rating for Licence Condition 10 compliance.
- Licence Condition 23 (Operating rules) – I sampled carbon dioxide system safety case limits and conditions. I judge the operating rules were clearly identified, adequately linked to the safety case and were understood by operators. I also sampled records showing adequate compliance with these rules. Hence, I assigned a rating of Green (No formal action) for Licence Condition 23 compliance.
- Licence Condition 24 (Operating instructions) – I sampled carbon dioxide system operating instructions. I judge the operating instructions were included in the licensees’ document management system and that they identify the necessary checks and actions required in the interests of safety. I found that these were adequately linked to the operating rules and that records showed compliance. Hence, I assigned a Green (No formal action) rating for Licence Condition 24 compliance.
- Licence Condition 27 (Safety devices, mechanisms and circuits) – I sampled carbon dioxide system safety mechanisms, devices and circuits. I judge that the licensee has adequate safety devices, mechanisms and circuit arrangements:
- to identify them within its safety case; and
- to ensure that the plant is not operated, inspected, maintained or tested unless they are properly connected and in good working order. Hence, I assigned a Green (No formal action) rating for Licence Condition 27 compliance.
- Licence Condition 28 (Examination, inspection, maintenance and testing) – I sampled the carbon dioxide system examination, inspection, maintenance and testing. I judge the licensee adequately demonstrated that its associated activities are in accordance with written schemes and completed within identified timescales. For LC28 I judge that the licensee adequately demonstrated compliance with its arrangements. Hence, I assigned a Green (No formal action) rating for Licence Condition 28 compliance.
- Licence Condition 34 (Leakage and escape of radioactive material and radioactive waste) – I sampled the licensee’s arrangements for detecting and preventing an escape of radioactive material in, or from its Carbon Dioxide system. I judge that the licensee adequately demonstrated compliance with these arrangements. Hence, I assigned a Green (No formal action) rating for Licence Condition 34 compliance.
Conclusion
Based on the information sampled during my inspection, I conclude that the licensee has adequately demonstrated carbon dioxide system safety case understanding and implementation.