Office for Nuclear Regulation

Sizewell B - Planned compliance inspection

Executive summary

Purpose of Intervention

The purpose of this intervention was to undertake a regulatory inspection at EDF Energy Nuclear Generation Limited’s Sizewell B Power Station, in accordance with ONR’s Integrated Intervention Strategy (IIS) 2019-20 for the Operating Reactors Sub-Division.   

Interventions Carried Out by ONR

The site inspector, supported by two other ONR inspectors, carried out an inspection of Licence Condition (LC) 28 (examination, inspection, maintenance and testing).

Because Sizewell B has just finished a refuelling outage, where a significant amount of inspectorial effort was spent examining specific maintenance activities, the purpose of this inspection was not to inspect the conduct of maintenance but rather the planning and monitoring of maintenance and the management of defects. To this end we held discussions with the engineering groups responsible for defining and reviewing maintenance strategy and for monitoring the health of the plant; we also held discussions with the maintenance group responsible for planning and monitoring maintenance activities. We sampled corporate procedures; maintenance and system health-related reports; and the inputs to, and outputs from, a number of review meetings.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable. This was not a system/structure based inspection.

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

Overall, we considered that the licensee has put robust arrangements in place to manage the planning and monitoring of maintenance, and that these meet the expectations as set out in ONR’s guidance for LC 28. We saw evidence that these arrangements were being adhered to in practice. Where review or monitoring processes indicated issues with either the delivery of maintenance or the health of systems, we were satisfied that action was being taken to address these issues.

We considered that the close working between the Pressurise Systems Safety Regulations (PSSR) and Lifting Operations and Lifting Equipment Regulations (LOLER) competent person and the licensee is an example of best practice, and ensures consistency between potentially disparate inspection regimes. It also allows each party to have access to the best information available.

Conclusion of Intervention

Based on the sample of evidence inspected, we concluded that the licensee was complying with its legal duties and the expectations of our guidance and an inspection rating of “Green – no formal action” was applied.

There are no findings from this intervention that could significantly undermine nuclear safety.  At present, no additional regulatory action is required over and above the planned interventions at Sizewell B.