Office for Nuclear Regulation

Sizewell B - Early Outage Review

Executive summary

Purpose of Intervention

The purpose of this intervention was to carry out licence compliance inspections at EDF Energy Nuclear Generation Limited’s Sizewell B power station to inform ONR’s decision whether to consent, in accordance with LC 30(3), to restart of the reactor following completion of refuelling outage 16.

Interventions Carried Out by ONR

During this intervention, we reviewed activities undertaken in support of the Sizewell B statutory shutdown and measured compliance against the following Licence Condition:

The following key activities were undertaken:

Explanation of Judgement if Safety System Not Judged to be Adequate

No system inspection was undertaken during this intervention.

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

This intervention reviewed a number of NGL’s activities conducted during the Sizewell B periodic shutdown. During the shutdown, maintenance activities are conducted (in accordance with the plant maintenance schedule) and refuelling operations performed.

During the intervention we observed the conduct of the EOR and participated in a safety walk-down with the EOR team, both in containment and the wider site. On conclusion of the EOR, the licensee’s internal regulator identified three areas for Improvement (AFI) and one opportunity for improvement (OFI). We are satisfied that actions to address these findings will be tracked to resolution by the licensee’s Corrective Action Process. Overall, we concluded that the EOR provided an effective review of the outage activities and safety management arrangements.

To sample the management of the outage we undertook an inspection of the processes and procedures in place to ensure appropriate control and oversight of operations during the outage. We also observed the operation and conduct of the Outage Control Centre (OCC) and attended three of the routine OCC briefings, sampling both the morning and evening briefings. From the above sampling, we considered that NGL had control of the outage activities, ensured that risks were appropriately managed and adequate safety was maintained.

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

Conclusion of Intervention

I consider that the implementation of licensee’s arrangements for the management of periodic shutdowns is adequate and meets relevant guidance

I consider that based on the evidence acquired during this intervention, that an inspection rating of Green is appropriate for LC 30 (Periodic Shutdown). This means that no significant issues were found.

There were no findings from this inspection that significantly undermine nuclear safety or which would result in changes to the planned interventions and inspections of Sizewell Power Station.