- Site: Heysham 1
- IR number: 21-051
- Date: July 2021
- LC numbers: 28
Executive summary
Purpose of Intervention
This was a planned Pressure Systems Safety Regulations (PSSR) 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 was carried out in accordance with the planned inspection programme contained in the Heysham 1 Integrated Intervention Strategy (IIS) for 2021.
Following the identification of PSSR 2000 shortfalls, ONR issued a Direction under Licence Condition (LC)15(4) requiring Heysham 1 to conduct a review and reassessment of safety addressing pressure systems in December 2020. Heysham 1 completed the requirements of the Direction, and the aim of this inspection was to ensure that adequate arrangements have been put in place to achieve sustained PSSR compliance at Heysham 1.
Interventions Carried Out by ONR
The inspection team reviewed progress against the PSSR recovery plan; evaluated the status of PSSR audit findings; examined arrangements for sustained PSSR compliance; and sampled the Licensee’s Asset Management System (AMS). The ONR inspection team was comprised of the nominated site inspector, a fault studies specialist inspector, and a structural integrity specialist inspector.
Based on the information collected, ONR’s site inspector conducted an unscheduled inspection of the camera cooling compressor. ONR’s fault studies inspector and the structural integrity inspector conducted walkdowns of the following systems:
- Liquid Nitrogen Storage and Vaporisation Plant
- Atmospheric Gland Steam Condenser
- Sub-Atmospheric Gland Steam Condenser
The inspection was rated against Licence Condition 28 (examination, inspection, maintenance and testing) and PSSR compliance.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
The inspection team sampled the sub atmospheric gland steam condenser for the turbine gland 1 steam system. At the time of the inspection, Licensee representatives were unable to identify the minimum allowable pressure (expected under PSSR Schedule 3 for sub atmospheric vessels). A regulatory issue has been raised to ensure that schedule 3 information is readily available to users, and this regulatory issue will be managed through normal regulatory interactions with the licensee.
The event recovery performed by the Licensee has resulted in the completion of a large number of inspections by the licensee organisation, with over 400 maintenance routines added to AMS as part of the PSSR event recovery. Future examinations are now well planned with improved governance arrangements. Accordingly, I consider a rating of green to be appropriate for LC 28 (examination, inspection, maintenance and testing) and PSSR compliance.
Conclusion of Intervention
NGL’s PSSR event recovery at Heysham 1 has achieved many safety improvements. Heysham 1 staff have conducted a reassessment of PSSR arrangements; completed many outstanding inspections; updated the Written Schemes of Examination (WSE); replaced components where necessary (for example, safety relief valves and bursting discs); established new maintenance routines in AMS; and improved process and oversight arrangements. From the sample of evidence inspected, I judge that NGL’s Heysham 1 staff have completed the five actions specified in the letter of direction to restore and sustain compliance with PSSR. I conclude that the improved PSSR arrangements are sufficient to allow ONR's regulation of PSSR at Heysham 1 to return to a routine level of oversight.