- Site: Heysham 2
- IR number: 21-047
- Date: June 2021
- LC numbers: 24, 26
Executive summary
Purpose of Intervention
This report describes an inspection of EDF Energy Nuclear Generation Limited (NGL’s) Heysham 2 Power Station licensed site, undertaken to assess the actions that have been taken to address the requirements of improvement notice ONR-IN-20-003. The inspection was focused on the improvements to the procedures and supervision of work associated with safety mechanisms on station.
Interventions Carried Out by ONR
The intervention included inspections against the following Licence Conditions:
- LC24 – Operating Instructions
- LC26 – Control and Supervision
The intervention scope was confined to the maintenance, inspection and testing of safety mechanisms at Heysham 2 and the requirements of improvement notice ONR-IN-20-003. Safety mechanisms are defined as:-
- Reactor Safety Systems
- Quadrant Protection Systems
- Control Rods
Explanation of Judgement if Safety System Not Judged to be Adequate
No system based inspection was undertaken hence, this is not applicable for this intervention.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
Station have carried out lots of improvements as a result of the the log/lin flux detector event (INF1 2020/256), which occurred on 16 April 2020 and the subsequent improvement notice ONR-IN-20-003, issued by ONR on 14 August 2020.
Over 250 procedures have been updated with the requirements of the improvement notice, including adding additional hold points in the procedures to minimise the risk of safety mechanisms not functioning as intended.
The role of the nominated test engineers (NTEs) has been clarified to minimise the risk of the NTEs being drawn into the work thus preventing them from carrying out independent checks.
Station, with help from the human factors team at the centre, are reviewing and updating all the safety mechanism procedures, check sheets and pre-job briefs to minimise human performance error traps. This improvement is over and above the requirements of the improvement notice and should be complete by the end of the year
Conclusion of Intervention
Based on my inspection, the licensee has made significant improvements in all procedures and check-sheets associated with safety mechanisms to meet the requirements of improvement notice ONR-IN-20-003. In addition, the role of the NTE has been better defined and the training emphasises the responsibilities of the NTE.
Therefore, in my judgement the station has met the requirements of improvement notice ONR-IN-20-003. I informed the station lead team of this during the close-out meeting and will formally write to confirm this.
On the basis of the improvements made I have rated LC24, Operating Procedures and LC26, Control and Supervision as Green as no further regulatory action is required. There are still human factors improvements to the procedures that are required but these are subject to an existing regulatory issue due to be closed by the end of the year. These improvements are also being tracked by the internal regulator, INA.