- Site: Heysham 2
- IR number: 19-138
- Date: December 2019
- LC numbers: N/A
Executive summary
Purpose of Intervention
This inspection forms one of three planned site-based inspections that aim to enable ONR to have confidence that:
- EDF Energy Nuclear Generation Limited’s hazard & risk identification, assessment and control processes for conventional plant are adequate,
- The inspection & maintenance (including defect categorisation and prioritisation) processes for conventional plant are adequate,
- The operational methods in place for conventional plant are adequate,
And as a result,
- The asset condition and operation of conventional plant is adequate and risks (to people and nuclear & non-nuclear plant) are therefore reduced as low as reasonably practicable.
Interventions Carried Out by ONR
A team of four inspectors (two site inspectors, an Internal Hazards specialist inspector and a Conventional Health & Safety specialist inspector) examined Heysham 2’s arrangements for asset care and operation of high hazard conventional plant. The inspection comprised a number of office-based sessions, reviewing the evidence provided and discussing relevant topics with NGL personnel. A substantial plant tour was also organised, allowing time to examine a number of high hazard, conventional/process risk areas; oxygen, methane & hydrogen compounds and diesel, carbon dioxide & other chemicals storage.
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
We judged that, overall, the plant condition in the areas inspected met regulatory expectations. Some minor areas for improvement have been identified and were fed back to station personnel. However, for one item (a corroded line on the outlet of a methane relief valve), it is considered appropriate to raise a level 4 regulatory issue to ensure work is not deferred.
We consider that, with a few exceptions, defects are generally prioritised appropriately, however, we did identify some examples where the auditable trail of decisions made concerning defect prioritisation was not robust and so not able to be demonstrably justified. This included a long-standing nuclear safety-related common plant alarm which lacks apparent justification for its state, for which a level 4 regulatory issue will be raised.
We identified that some PIOIs have not been regularly updated and in one case the PIOI was not being followed as written. We instructed the TSSM to ensure that the station follows this up to ensure staff and contractors are not exposed to increased risk when undertaking these activities. A level 4 regulatory issue will be raised to enable this to be tracked to a satisfactory conclusion.
Conclusion of Intervention
Based on the sample inspected, I rate the inspection as GREEN – no formal action. This is in line with the established ONR guidance (2016/118606):
- “Relevant good practice generally met, or minor shortfalls identified, when compared with appropriate benchmarks”,
- “No significant shortfalls identified in the delivery of safety or security functions.”
- “Relatively minor, if any, deficiencies in compliance arrangements.”
Three level 4 regulatory issues will be raised to track progress made against the more significant shortfalls identified during the inspection.
The output of this inspection, together with those on the same theme at other stations, will be collated and assessed later in 2020 to give a fleet-wide appraisal.
I believe that no additional regulatory interventions are needed over and above those already planned at Heysham 2 Power Station.