- Site: Heysham 2
- IR number: 21-012
- Date: April 2021
- LC numbers: 24, 28
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 was included planned compliance inspections against the following Licence Conditions:
- LC24 – Operating Instructions
- LC28 – Examination, inspection, maintenance and testing
The intervention scope was confined to the maintenance, inspection and testing of safety mechanisms at Heysham 2. 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 120 procedures have been updated with the requirements of the improvement notice, including adding additional independent hold points in the procedures to minimise the risk of safety mechanisms not functioning as intended.
The training of the nominated test engineers (NTEs) and supervisors for safety mechanisms has been reviewed and improved 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 is approximately 50% complete.
During the inspection I found a couple of procedures that were not originally considered to be in improvement work scope but should have been. Station have carried out a review and there are other procedures that either need to be withdrawn from use or included in the improvement work scope.
Conclusion of Intervention
Based on my inspection, the licensee has made significant improvements in many 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 role of responsibilities of the NTE.
However, there are other procedures and check-sheets that either need to be withdrawn from use or included in the improvement work scope. Station have therefore requested an extension to the improvement notice. As regulatory action is required I have rated the inspection against LC24 and LC28 as Amber.