Office for Nuclear Regulation

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Hunterston B - Planned Inspection

Executive summary

Purpose of Intervention

This was a planned inspection of EDF Energy Nuclear Generation Ltd.’s (NGL’s) Hunterston B Power Station, undertaken as part of the planned intervention strategy for the Operating Facilities Division (OFD) of the Office for Nuclear Regulation (ONR).

The work was carried out in accord with the planned inspection programme contained in the Hunterston B Integrated Intervention Strategy (IIS).

Interventions Carried Out by ONR

During this intervention, the following key activities were undertaken:

Explanation of Judgement if Safety System Not Judged to be Adequate

From the inspection, ONR judged that the Fuel Assemblies system met the requirements of the safety case.

From the inspection related to tanks and buried systems on the site ONR judged this meets relevant good practice.

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

Licence Condition 10 (Training) - ONR sampled the training records of a number of personnel involved in the management, maintenance and inspection activities associated with the Fuel Assemblies system. We judged that the personnel undertaking the activities were suitably qualified and experienced.  We therefore assigned a rating of Green (no formal action) for LC 10 compliance.

Licence Condition 23 (Operating Rules) - The Technical Specifications inspected adequately specified the limits and conditions of operation and reflected those specified in the safety case.  It was evident from the sample of surveillance records and compliance check sheets inspected that the Technical Specifications were complied with during operations.  We therefore assigned a rating of Green (no formal action) for LC 23.

Licence Condition 24 (Operating Instructions) - ONR examined a sample consisting of a plant item operating instruction (PIOI) and maintenance instructions (MIs).  We judged these documents to be of an adequate standard and therefore assigned a rating of Green (no formal action) for LC 24.

Licence Condition 27 (Safety Mechanisms, Devices and Circuits) - Interlocks associated with protection of personnel during handling of Fuel Assemblies were considered as safety related mechanisms.  We examined a sample of completed maintenance and test records and confirmed that they were adequately maintained and tested on a regular basis.  We judged that a rating of Green (no formal action) was appropriate for LC 27.

Licence Condition 28 (Examination, Inspection, Maintenance and Testing) - ONR examined maintenance instructions and work order cards.  Based on the sample we confirmed that maintenance was being carried out by suitably qualified and experienced persons with appropriate oversight for its safety significance. ONR judged that the Fuel Assembly plant and equipment was being suitably maintained, inspected and tested.  We therefore assigned an IIS rating of Green (no formal action) for LC 28.

Licence Condition 34 (Leakage and Escape of Radioactive Material and Radioactive Waste) - We focused upon the primary circuit gas monitoring equipment in place to detect radioactivity associated with fuel assemblies, which is an indicator of the condition of the fuel whilst in the reactor. We confirmed that this detection was available and examined the instructions for action if radioactivity is detected and the related compliance record sheet. We judged that a rating of Green (no formal action) was appropriate for LC 34.

From the inspection on tanks and buried systems, ONR was satisfied with the discussions and explanations given and judged that a rating of Green (no formal action) was appropriate for LC28.

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

From the evidence sampled during this SBI-15 inspection against LCs 10, 23, 24, 27, 28 and 34, we consider that the Fuel Assemblies System met the requirements of the safety case.

From the discussions, explanations and demonstrations held during the LC28 inspection related to tanks and buried systems, we consider the implementation of the arrangements meets relevant good practice.

There are no findings from this inspection that could significantly undermine nuclear safety.  At present, no additional regulatory action is needed over and above the planned interventions at Hunterston B Power Station as set out in the Integrated Intervention Strategy, which will continue as planned.