Office for Nuclear Regulation

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Planned intervention

Executive summary

Purpose of intervention

The purpose of this intervention was to conduct Licence Condition (LC) compliance inspections at EDF Energy Nuclear Generation Limited’s Torness Power Station in line with the planned inspection programme contained in the Torness Integrated Intervention Strategy (IIS) for 2015/16.

Interventions Carried Out by ONR

This intervention included compliance inspections against the following Licence Conditions (LCs):

The inspection undertaken utilised ONR guidance documents, NS-INSP-GD-022 Revision 2, NS-INSP-GD-026 Revision 2 and NS-INSP-GD-028 Revision 3, which require inspectors undertaking compliance inspections against LC22, 26 and 28 to consider both the arrangements that are in place together with their associated implementation.

Explanation of Judgement if Safety System Not Judged to be Adequate

No safety system inspection was undertaken, hence this is not applicable.

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

The LC22 inspection focussed on the implementation of arrangements at Torness Power Station for modifications that are scheduled to be implemented as part of a forthcoming Reactor 2 periodic shutdown. This enabled me to review a series of modifications in terms of their safety significance, the implications this may have on the provision of documentation to justify the safety of a proposed modification and its implementation during the shutdown and their current status.

My inspection found that, with one exception relating to a software upgrade for a plant computing system, all periodic shutdown-related modifications have reached an approved stage. It was established that work is now focussed on ensuring that other aspects of these modifications such as development of work instructions, engineering drawings, operating and maintenance instructions is completed in a timely manner in advance of their implementation. During this inspection I also sampled the scope change process that enables additional work to be added to the outage programme only when the design is complete and funding is available for the modification to be implemented.

I found that the arrangements for compliance with LC22 covered during this inspection provide an adequate demonstration of the approach taken to satisfy relevant arrangements for classification and implementation of modifications for the forthcoming outage in terms of safety significance, the provision of documentation to justify the safety of proposed modifications and their implementation.

I am satisfied that implementation of arrangements for compliance with LC22 at Torness Power Station are adequate and judge that the outcome of the sample inspection undertaken met with relevant expectations in ONR guidance.

The LC26 inspection was made against the arrangements at Torness Power Station in terms of the role of duly authorised persons in the control and supervision of work on safety-related plant and equipment by suitably qualified and experienced personnel. This considered a sample of safety-related activities to demonstrate the effectiveness of the control and supervision of suitably qualified and experienced personnel.

This inspection was carried out by sampling workface activities that were subject of safety documents and being undertaken by contract partners. The personnel seen were able to demonstrate to my satisfaction that the control and supervision arrangements were being implemented effectively from the perspective of the quality of the safety documents and work instructions provided by duly appointed persons at Torness through to the proper handover of these documents to nominated competent persons within the contract partner organisations.

Based on the sampling undertaken, I found that the implementation of the LC26 arrangements at Torness Power Station for the control and supervision of safety-related activities are effective.  The station appears to have fully implemented the arrangements described in both station and corporate level specifications and procedures.

I am satisfied that the arrangements for compliance with LC26 at Torness Power Station are applied to a good standard and judge that the outcome of the sample inspection undertaken satisfied relevant expectations in ONR guidance.

The LC28 inspection was made against the arrangements at Torness Power Station with regard to the approach taken for systematic examination, inspection, maintenance and testing of all plant which may affect safety. This included an overview of the measures used by the Work Management Department to track these activities and ensure that any backlog is effectively controlled. 

I found that compliance with LC28 was achieved by implementation and use of a maintenance, inspection and test schedule, which is a well-established scheme for examination, maintenance, inspection and testing of safety related plant items and systems. In this respect, I established that this schedule has the objective of defining processes and procedures for maintenance, inspection and testing that are commensurate with the safety significance of the equipment to ensure that resources can be deployed in an efficient and effective manner.

In addition, I found that there is another category of maintenance referred to as Routine Other that can be used to ensure that appropriate preventative maintenance is performed on equipment that has a lower level of safety significance. To clarify the implications of the maintenance for equipment assigned as Routine Other, I sampled the status given to graphite sampling apparatus and sawdust injection equipment and established that this equipment is currently subject to overhaul or calibration, respectively, and maintenance prior to use as it is not subject of a safety case claim.

I also reviewed the measures applied by the Work Management Group to track completion of maintenance activities and manage any backlog that may occur. The approach applied uses pre-determined tolerance(s) levels for timely completion of work that was confirmed by inspection of a compliance report that is prepared on a daily basis on activities related to the maintenance, inspection and test schedule. This demonstrated to my satisfaction that an acceptable level of control was being applied to maintain the backlog, which puts emphasis on the need for system owners and maintenance managers to provide deferral statements to justify delays in completion of work. The use of extensions and unavailability declarations was also discussed albeit that these measures are currently infrequently applied.

I am satisfied that implementation of arrangements for compliance with LC28 at Torness Power Station are adequate and judge that the outcome of the inspection met with relevant expectations in ONR guidance.

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 am satisfied that the arrangements and their implementation at Torness for LC26 demonstrated during this intervention are good whilst LC22 and LC28, respectively, are adequate and judge that the outcome of the sample inspections undertaken met expectations detailed within relevant ONR guidance.  I have therefore rated the respective LC26 element of my intervention an IIS rating of 2, good, and both the LC22 and LC28 elements with an IIS rating of 3, adequate.

There are no findings from this inspection that could significantly undermine nuclear safety and no change to the planned interventions and inspections of Torness Power Station.