Office for Nuclear Regulation

Sizewell B - Inspection of LC26 and LC28

Executive summary

Purpose of Intervention

The purpose of this intervention was to undertake regulatory inspections at Sizewell B Power Station, operated by EDF Energy Nuclear Generation Limited (EDF NGL) in accordance with ONR’s Intervention Plan for the site. 

Interventions Carried Out by ONR

During this intervention, a team of ONR inspectors including the Site Inspector and a number of specialist Inspectors carried out compliance inspections against the following Licence Conditions (LC), which are applicable provisions of the Energy Act 2013:

 The LC26 inspection formed part of a series of inspections to be conducted across NGL’s fleet of nuclear power stations to evaluate the effectiveness of the company’s arrangements for controlling the work contractors involved in projects, operations and maintenance. The inspection involved interviews with personnel from NGL and contractor organisations, observations at point of work, and review of documentation.

During our LC28 inspection, we sampled implementation of NGL’s arrangements to monitor delivery of maintenance of plant which may affect safety and NGL’s process to plan and prioritise defect resolution. The inspection involved discussion with personnel responsible for overseeing this work and examination of the company’s electronic maintenance database.

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 safety system inspection was undertaken. Hence this is not applicable.

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

LC26 - Control and supervision

The inspection team held discussions with a number of managers on the arrangements for the selection, capability and competence of contractors and sub-contractors involved in work on site. The management team were consistent in their response and the arrangements were deemed to be adequate. 

We also had discussions on the control and supervision arrangements of contractors and sub-contractors on site, including EDF oversight and the authorisation of individual supervisors, clarifying roles and responsibilities. The management team were consistent in their response and the arrangements were deemed to be adequate.

A number of planned work activities were sampled and we judged that in most cases the appropriate level of control and supervision was implemented commensurate with their safety significance, and therefore, no formal enforcement action is required.
A number of minor shortfalls in work activity controls, and a number of areas for improvement were identified and communicated to the licensee. Progress against these areas will be tracked through routine regulatory interventions.

LC28 - Maintenance

We are satisfied that the tiered approach adopted for categorisation of maintenance at Sizewell B (based on safety significance of the work) is consistent with that described in guidance issued by ONR  and IAEA. We reviewed the station’s arrangements to ensure that maintenance activities are conducted in accordance with frequencies identified within the maintenance catalogue and are content that these arrangements are consistent with relevant good practice. Finally, we sampled NGL’s maintenance records and concluded that this data demonstrated that NGL had made decisions regarding prioritisation of outage defects on a risk informed basis.

Conclusion of Intervention

After considering the evidence from the inspection, ONR concluded that the licensee met legal requirements for LC26 and LC28. We awarded Green inspection ratings (no formal action) for both license conditions. From the evidence gathered during this intervention, it was judged that there were no matters that have the potential to impact significantly on nuclear safety.

A number of minor areas for improvement were identified during the intervention; these areas were communicated and accepted by the Licensee during the closing meeting.  Progress against these areas will be tracked through routine regulatory interventions.