Office for Nuclear Regulation

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Sizewell B - Outage Management and Rapid Trending Review

Executive summary

Purpose of Intervention

The purpose of this intervention was to undertake Licence Condition (LC) compliance inspections at EDF Energy Nuclear Generation Ltd's (NGL's) Sizewell B power station, in line with the planned inspection programme of the Operating Facilities Operating Reactors sub-programme intervention plan for 2017/18.

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 inspection we observed the conduct of the RTR and participated in a contractor management walk-down and a safety walk-down with the RTR team. On conclusion of the RTR, the licensee's internal regulator identified two Opportunities for Improvement. We are satisfied that actions to address these opportunities will be tracked to resolution by the licensee's Corrective Action Process. Overall, we concluded that the RTR provided an effective review of the outage activities and safety management arrangements.

To sample the management of the outage we observed the operation of the Outage Control Centre (OCC) and attended two of the routine outage meetings. We considered that the OCC and the meetings demonstrated that NGL had control of the outage activities, ensured that risks were appropriately managed and adequate safety was maintained.

Whilst it was early in the outage and limited intrusive work had started, during a walk-down inside the reactor containment we observed a good standard of housekeeping and a robust safety culture.

We engaged with NGL on their plans for resolution of an emergent issue with steam generator D. NGL are developing a technical work package to address this issue which will be subsequently assessed by ONR's specialist inspectors. The management of this issue by the station was considered appropriate.

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)