Office for Nuclear Regulation

Sizewell B Power Station Planned Compliance Inspections

Executive summary

Purpose of intervention

The main purpose of this intervention was to undertake a system based inspection (SBI07) on the circulating water (DA) and auxiliary circulating water (EA) systems at EDF Energy Nuclear Generation Limited’s (NGL’s) Sizewell B power station in line with the planned inspection programme contained in the Sizewell B integrated intervention strategy (IIS) for 2015/16.  During this visit a number of other information gathering exchanges were undertaken.

Interventions Carried Out by ONR

A system based inspection of the DA and EA systems was undertaken by an ONR inspector and a supporting mechanical handling technical specialist. The aim of the inspection was to confirm the adequacy of the implementation of the safety case with respect to the identified systems against the following LC’s:

The inspection was based on sampling the implementation of the arrangements in place against each licence condition. Meetings were held with key site personnel and the main findings of the discussions were communicated.

I conducted an inspection of the Sizewell B on-site emergency preparedness and response (EP&R) capability with the ONR principal civil nuclear security inspector and an ONR EP&R inspector.

I attended a meeting with the ONR project inspector and the station outage manger and project lead to discuss the statutory reactor outage 14 (RO14) scope and planning.

I observed a meeting of the nuclear safety operational review committee (NSORC).

I accompanied the ONR acting Chief Nuclear Inspector (CNI) on a visit to the station.

Explanation of Judgement if Safety System Not Judged to be Adequate

This system based inspection judged that the arrangements and their implementation, associated with the circulating water and auxiliary circulating water systems met the requirements of the safety case and are adequate..

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

Neither the DA nor EA systems are formally claimed in the safety case, have limited nuclear safety significance and do not contain any radioactive material. I therefore have not provided a rating against LC 23 (operating rules), LC 27 (safety mechanisms, devices and circuits) and LC 34 (leakage and escape of radioactive material) for this inspection. I judge compliance against the remaining Licence Conditions as follows:

From an LC10 perspective the training records reviewed provided good evidence that a systematic and structured approach to training is in place and could be demonstrated for the personnel sampled. I judge that the LC10 element of this inspection merits an IIS rating of 2 – Good Standard.

From an LC 24 element perspective the evidence sampled during the inspection adequately demonstrated that appropriate operating instructions were in place and were understood by the station personnel. Therefore, I judge that the LC24 element of this inspection merited an IIS rating of 3 – Adequate.

From an LC28 perspective it was demonstrated that adequate processes, procedures and records in place for the examination, inspection and testing of key areas of the plant. It is my opinion that the LC 28 element of this inspection merited an IIS rating of 3 – Adequate.

Overall, I judge that the DA and EA systems adequately meet the requirements of the safety case.

The NSORC exists to provide authoritative and independent advice to the Station Director on issues related to the design, safety case and technical specifications for Sizewell B. The NSORC acts as an additional barrier within the modification process and is considered to offer a valuable challenge from the perspective of the station input on practical considerations that may not get such a view elsewhere in the process.  The NSORC used at Sizewell B station is judged to be good practice.

The capability map review evaluates both the safety and security aspects of the stations on-site emergency preparedness and response arrangements. In my opinion the overall response given by the station staff to the review and challenges presented was positive.  I consider that the station prepared well for the review and has in general acknowledged or self-identified potential gaps and areas for improvement in capability.  I also found that in a number of areas the station was judged to have good practices in place.  ONR will complete the Sizewell B on-site capability map using the further evidence gathered during the inspection and existing evidence already available to ONR.  The capability map will be used to monitor improvements of the stations on-site emergency preparedness and response arrangements and demonstrate on-going the capability of the station to respond to an on-site event.

The ONR acting Chief Nuclear Inspector (CNI) visited the station to gain an overview of the site’s key performance measures and current matters of interest to the regulator including plant operation, safety and security arrangements.  The acting CNI found the visit informative and supportive of the current ONR strategy to influence improvements in nuclear safety and security.

The meeting with the ONR Project Inspector, station outage manager and project lead to discuss the Reactor Outage 14 (RO14) scope and planning was constructive and will assist in informing ONR’s regulatory intervention strategy.

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

After consideration of all the evidence during the sampling inspections undertaken against LCs 10, 23, 24, 27, 28 and 34, I consider that the arrangements and their implementation, associated with the DA and EA systems, meet the requirements of the safety case and are deemed adequate.  Three minor observations were made during the inspection, but these were either adequately resolved during the inspection or have been appropriately recorded with the Licensees action tracking system for future resolution.

There were no findings from this inspection that could undermine nuclear safety and accordingly no issues were raised during the inspection. No change to the planned interventions and inspections of Sizewell B are required.