The purpose of this intervention was to undertake Licence Condition (LC) compliance inspections at Sizewell B power station in line with the planned inspection programme contained in the Sizewell B Intervention Plan. The intervention was undertaken by the Office for Nuclear Regulation (ONR) nominated site inspector and a civil engineering assessor.
This intervention involved undertaking a safety case system based inspection of the Fuel Pond Cooling and Clean-Up Systems (FPCCS). Through examination of this system I performed compliance inspections against LC 10: Training; LC 23: Operating rules; LC 24: Operating instructions; LC 27: Safety mechanisms, devices and circuits; LC28: Examination, inspection, maintenance and testing and LC34: Leakage and Escape of Radioactive Material and Radioactive Waste. Our inspections were based on sampling the implementation of the arrangements in place against each licence condition.
The safety systems were judged to meet the requirements of the safety case and were adequate.
The inspection focused on FPCCS, which support the fuel pond demands at Sizewell B. The inspection assessed compliance with six site licence conditions and examined the linkage between the safety case requirements and the following areas: operating rules and instructions, staff training and competency, maintenance and availability of plant.
From an LC10 perspective, the training arrangements for the FPCCS provide a clear link clear to the safety case and the Technical Specifications. I consider the LC10 element of this inspection to be adequate, warranting an associated Integrated Intervention Strategy (IIS) rating of 3.
From an LC23 perspective, based on the evidence sampled during this inspection, the implementation of the technical specifications, commentaries, and schedules has been demonstrated to be consistent with the claims and arguments presented within the safety case for the FPCCS inspected. I consider the LC23 element of this inspection to be adequate, warranting an associated IIS rating of 3.
From an LC24 perspective, based on the evidence sampled during this inspection, I was content that the provisions in place as required by the FPCCS safety case were adequately implemented at Sizewell B. The operating rules under LC23 have been implemented through station and plant operating instructions, which was confirmed by sampling documents and records during the inspection. I consider the LC24 element of this inspection to be adequate, warranting an associated IIS rating of 3.
The duty holder was able to demonstrate an adequate level of compliance against LC 27 with no significant shortfalls indentified. I consider that the LC27 element of this inspection to be adequate, warranting an associated IIS rating of 3.
Examination, inspection, maintenance and testing under LC28 involved sampling a number of maintenance tasks including completed records and check sheets as well as consideration of asset condition as part of the plant inspection. I consider the LC28 compliance of this inspection to be adequate, warranting an associated IIS rating of 3.
Leakage and escape of radioactive material and radioactive waste under LC34 involved sampling maintenance tasks, as well as the system condition as part of the plant inspection. There are no concerns regarding the functionality of the systems, hence I consider the LC34 element of this inspection to be adequate, warranting an associated IIS rating of 3.
The licence conditions were inspected against ONR's published guidance requirements (as described in our technical inspection guides).
After considering all the evidence witnessed during each of the sample inspections undertaken against LCs 10, 23, 24, 27, 28 and 34 I consider that the FPCCS subject to this system based inspection meet the requirements of the safety case and its implementation is deemed adequate.
A number of minor observations were made as a result of this system based inspection, however, I am content that they will be addressed by NGL in accordance with their own arrangements.
There are no concerns regarding the system's performance in the short to medium term. However, the maintenance strategy does not contain the forward strategy of future asset condition. I placed an action on the Licensee to review the maintenance strategy to include their long term strategy, which has been raised as an issue within the ONR Issues Database.
There are no findings from this inspection that could significantly undermine nuclear safety.