Office for Nuclear Regulation

Heysham 1 – Inspection ID: 22-007

  • Site: Heysham 1
  • IR number: 22-007
  • Date: April 2022
  • LC numbers: 28

Executive summary

Purpose of Intervention

The purpose of this intervention was to carry out a licence condition compliance inspection at EDF Energy Nuclear Generation Limited’s Heysham 1 power station in line with the planned inspection programme contained in the Heysham 1 Integrated Intervention Strategy for 2021/22.  This intervention is in support of the ONR decision on plant restart of Reactor 2.

ONR Mechanical Engineering Inspectors carried out inspections against the requirements of Licence Condition 28: examination, inspection, maintenance and testing to inform the ONR decision relating to the issue of a licence instrument for consent for return to service of Heysham 1 Reactor 2 following its periodic shutdown (Licence Condition 30).  The activities examined were selected due to their nuclear safety significance.

The intervention included examination, inspection, maintenance and testing of:

  • gas circulators,
  • CO2 safety relief valves,
  • control rod drop times and control rod actuator maintenance,
  • secondary shutdown system nitrogen injection valves.

Explanation of Judgement if Safety System Not Judged to be Adequate

This intervention was not a System/Structure Based Inspection and so no judgement of the safety system was made.

Key Findings, Inspector’s Opinions and Reasons for Judgements Made

Based on my sampling, I am satisfied from a mechanical engineering perspective that during the Heysham 1 Reactor 2 2022 (026) periodic shutdown:

  • Examination, inspection, maintenance and testing associated with gas circulators, CO2 safety relief valves, control rod drop times, control rod actuator maintenance and secondary shutdown system nitrogen injection valves is being adequately controlled, in line with the requirements of the safety case.
  • Sufficient records are being kept and monitored to identify problems both reactively and proactively.

Conclusion of Intervention

Based on my sampling undertaken as part of this intervention, I am satisfied that the Licence Condition 28 arrangements in place are adequate and have been adequately implemented with no significant shortfalls. I have therefore given this intervention an Integrated Intervention Strategy rating of GREEN.

From a Mechanical Engineering perspective, I would therefore support a request under Licence Condition 30 to return Heysham 1 Reactor 2 to operation following its 2022 (026) periodic shutdown.