Office for Nuclear Regulation

Heysham 1 – Inspection ID: 51354

Executive summary

Date(s) of inspection:

  • December 2022

Aim of inspection

This is a planned inspection 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 will be carried out in accord with the planned inspection programme contained in the Heysham 1 Integrated Intervention Strategy (IIS) for 2022/23.

Subject(s) of inspection

  • LC7 – Incidents on the site – Rating: GREEN

Key findings, inspector’s opinions and reasons for judgement made

The inspection was conducted over one day and sampled the adequacy of arrangements associated with the reporting, sentencing, investigation and remedial actions as a result of incidents where ‘configuration control’ shortfalls had been judged to be contributory to the incident.

Prior to the inspection a comprehensive list of the previous four years of incidents where configuration control was a contributory or root cause was provided. A sample of incidents were selected from this list.  For all incidents sampled I was satisfied with the arrangements followed by the dutyholder which included:

  • assigning the correct configuration control incident coding (used for trending and shared with a dedicated configuration control task team)
  • appropriate actions were placed and tracked to closure
  • for a selection of incidents where improved plant identification/signage was judged necessary, these improvements were visibly inspected in situ on the plant
  • for a selection of incidents where improved procedures were judged necessary, these procedures were inspected

The following topics were also discussed and examined during the inspection:

  • How configuration management is controlled at site through implementation of company standards and local conduct of operations procedures.
  • How controlled ‘Orange’ locks are used to ensure Technical Specification related plant is positioned and locked in the correct configuration.
  • How fuel route also utilise ‘Purple’ locks on plant that could present an operational (not nuclear safety) risk.
  • How ‘Yellow’ locks are used on non- nuclear safety related plant to prevent inadvertent operation.
  • The application of a Human Performance Evaluation Tool (HUET) following incidents

I also took the opportunity to inspect the performance of the weekly screening meeting where incidents are initially presented and sentenced.  During this meeting I noted good representation and challenge from key engineering, operational and safety department staff.

Overall I judged that the licensee adequately demonstrated compliance with the requirements of LC7 and therefore rated this inspection as Green, no formal action.


No regulatory issues were generated and there were no findings from this inspection that could significantly undermine nuclear safety.  At present, no additional regulatory action is needed over and above the planned interventions at Heysham 1 Power Station as set out in the Integrated Intervention Strategy, which will continue as planned.