Office for Nuclear Regulation

Safety Case Engineering Change Themed compliance inspection

Executive summary

Purpose of Intervention

This was a planned themed 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 accord with the planned inspection programme contained in the Heysham 1 Integrated Intervention Strategy (IIS) for 2020/21.

Interventions Carried Out by ONR. 

The inspection theme was designed to sample the adequacy of production and implementation of safety cases. The inspection sampled the training of individuals involved in safety case production and the implementation of the modified safety case, operating rules and operating instructions

As part of this intervention I, the nominated site inspector, with assistance from a fault studies specialist inspector carried out a combined remote and onsite inspection sampling compliance against:

The purpose of LC10 is to ensure that the licensee make and implement adequate arrangements for suitable training for all those on site who have responsibility for any operations which may affect safety.

The purpose of LC14 is to ensure that the licensee make and implement adequate arrangements for the production and assessment of safety cases.

The purpose of LC23 is to ensure that the licensee, in respect of any operation that may affect safety, produce an adequate safety case to demonstrate the safety of that operation and to identify the conditions and limits necessary in the interests of safety.  Such conditions and limits are referred to as operating rules.

The purpose of LC24 is to ensure that the licensee, for all operations which may affect safety, are carried out in accordance with written operating instructions.

In addition to the themed inspection, I conducted a plant tour of the reactor pile cap and held meetings to gather operational intelligence.

The intervention was performed in line with ONR's guidance requirements (as described in our technical inspection guides) in the areas inspected.

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

The inspection sampled five safety case engineering changes (ECs) which had been completed within the last two years.  I selected the five ECs based on the safety significance of the proposed changes.

For all five sampled ECs, no regulatory issues were identified.  In summary:

The roles involved in a typical safety case modification are the Responsible Engineer, Author, Verifier, Categoriser and Case Officer.  Training records for all roles involved in the production of the sampled safety cases were current and accurate.  It was noted, and deemed good practice, that NGL’s asset management process places firm hold points on the various roles involved in the safety case modification process to ensure the individual carrying out that role has received the necessary training.

The five sampled ECs provided robust examples to demonstrate adequate safety case production and assessment had been conducted and where appropriate, operating rules and operating instructions had been adequately amended and implemented.

I found that the sampled arrangements and their implementation adequately satisfied the requirements necessary to demonstrate compliance with LC10, LC14, LC23 and LC24.  I therefore rated this inspection as Green, no formal action, for all four licence conditions.

In addition, from the sample of physical arrangements inspected when gaining access to site and during the plant tour, I was content that NGL were adequately implementing measures to reduce the risks associated with COVID-19 transmission.  The site continue to utilise thermal imaging at site entrances; hand sanitiser stations; personnel testing, isolation and track and trace measures; disinfectant and cleaning materials in all offices; signage and briefing material used to reinforce the 2 metre social distancing rule and hand wash policy and the wearing of facemasks when in doors.

Conclusion of Intervention

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.