Unplanned Plant Shut-downs
EDF Energy Nuclear Generation’s vision is to be “Leading the Energy Change” and this is sought within the framework of defined values that guide the behaviour of the organisation and everyone within it. Unplanned shutdown policy is effectively incorporated within The Asset Management Policy (BEG/POL/012). The foundation of the Asset Management Policy is that safety is the overriding priority. Whether nuclear, radiological, environmental or industrial, safety is placed before commercial gain.
The asset management processes must, as a minimum, ensure compliance with applicable legislation, statutory and regulatory requirements. In addition, they should integrate with, and complement, Nuclear Generation’s health and safety, environmental and quality management systems.
The Asset Management Policy requires that processes deliver the following business imperatives:
- Achieve world class operational safety and excellence
- Improve our financial stability
- Pursue life extension for our Stations
- Supporting new nuclear build
Three policy standards are specified;-
- Asset operation, replacement, modification, refurbishment, maintenance, inspection, testing and performance monitoring will be to the approved and documented company standards.
- Continuous Improvement is delivered locally, at business unit, fleet process and fleet levels through the fleet performance improvement programme. Alignment is achieved through an integrated business planning process which includes the definition of key strategic focus areas for the fleet. The strategic focus areas for 2013 are:-
- Personal Ownership
- Optimising Investment & Project Value
- Outage Performance
- Lifetime extension
- Equipment Reliability
This forms the foundation of the company’s performance improvement programme.
- Asset management decisions should be informed by risk management information and analysis. In addition, they should be taken in the context of the following fleet differentiation strategy:
Unplanned shutdowns challenge the operational safety of a power plant. Consequently EDF Energy Nuclear Generation is primarily committed to their reduction and eventual elimination in order to promote Nuclear Safety, Radiation Protection and Public Safety performance. Furthermore reduced plant availability due to unplanned shutdowns has an adverse economic impact in terms of lost revenue and additional costs. EDF Energy Nuclear Generation adopts international best practices in this field. The international standards and performance criteria defined in the INPO, WANO, EPRI (Electric Power Research Institute) and IAEA (International Atomic Energy Agency) constitute the foundation used by EDF Energy Nuclear Generation.
According to worldwide industry accepted best practice, the implementation of a rigorous process-based approach to plant operational management is the most effective and robust means to ensure sustainably high safety and environmental performance including avoidance of Unplanned Shutdowns. Three of the most important processes are:
- Work Management
- Equipment Reliability
- Nuclear Professionalism (human error prevention)
EDF Energy Nuclear Generation has implemented Work Management best practices following the INPO guideline AP-928 and continues to implement best practices supporting Equipment Reliability as described by INPO guideline AP-913.
The Nuclear Professionalism programme, which includes both human performance and nuclear safety culture components, is in place throughout EDF Energy Nuclear Generation. This programme focuses on minimising the frequency and consequences of human errors through training, effective use of human error prevention tools, performance coaching and the identification and reduction of organisational weaknesses through investigations into events, incidents, near misses and performance trending of sub standard conditions.
Work management - INPO AP-928 Implementation
Work Management deals with the Identification, Planning, Scheduling, Execution and Closure of maintenance and maintenance related activities.
The guiding principles of an effective work management process are:
- To ensure nuclear safety and non-nuclear safety by providing timely identification, selection, planning, coordination, and execution of work necessary to maximise the availability and reliability of station equipment and systems
- To manage the risk associated with conducting work
- To identify the impact of work to the station and work groups and to protect the station from unanticipated transients due to the conduct of work
- To maximise the efficiency and effectiveness of station staff and material resources
Since a significant proportion of the maintenance and maintenance related activities are carried out during the periodic shutdowns (statutory outages), the quality of the outage planning and execution has a significant effect on the safety and reliability of the Nuclear Power Plant, and consequently on the occurrence of unplanned shutdowns.
Equipment reliability - INPO AP-913 Implementation
The Nuclear Industry has established a documented standardised best practice in the area of Equipment Reliability based upon Reliability-Centred Maintenance. This has been formalised under the INPO guideline AP-913. A System Health programme is being rolled out in EDF Energy Nuclear Generation to fully implement AP-913. This Equipment Reliability process represents the integration and coordination of a broad range of equipment reliability activities into one process for plant personnel to evaluate important station equipment, develop and implement long-term equipment health plans to manage their health, monitor equipment performance and condition, and make continuing adjustments to preventive maintenance tasks and frequencies based on local, fleet wide and industry wide equipment operating experience. All of which is focused on the principal goal of underpinning nuclear safety.
Through the equipment reliability process the equipment that is critical for nuclear safety and operation is systematically identified and the performance is meticulously tracked. Risk based maintenance techniques are then selected and used to define the preventive maintenance programs and the life cycle management strategies to be adopted in order to maximise reliability and availability. This is done at both system and component levels, and is used to anticipate and prevent ageing and degradation effects impacting on nuclear safety and reliability. The process focuses on improving equipment reliability and availability which results in increased nuclear safety margins.
All events leading to an unplanned shutdown derive directly or indirectly from human errors. The objective of having a structured Nuclear Professionalism programme is to prevent safety and reliability related events and incidents and maximise nuclear safety margins. This is done by systematically identifying and addressing organisational weaknesses which lead to error likely situations, promoting fundamental behaviours that reduce human error, and by developing a nuclear safety culture which instils a defence-in-depth philosophy supplementing and reinforcing the nuclear professionalism of individuals.
The Nuclear Professionalism programme is founded on the following principles:
- Humans are fallible, even the strongest performers make mistakes.
- Error-traps are predictable, manageable, and preventable.
- Human Performance tools are used to minimise the frequency and severity of errors.
- Individuals achieve high levels of performance based largely on the encouragement and reinforcement received from supervisors, peers, and direct reports.
- Understanding the reasons human errors occur and applying the lessons learned from past errors can prevent events.
- Organisational processes and values determine and influence individual behaviour.
- Performance improves when members of the organisation learn from their successes and failures.
EDF Energy Nuclear Generation has deployed and continues to deploy extensive initiatives following these principles and based on feedback of experience from the best performers in the Nuclear Industry worldwide.
The programmes have been developed starting from values and expectations that are supported by appropriate Error Prevention Tools and adequate training programmes.
Both the tools and training programs are tailored to each specific working category, including executives, managers, supervisors and engineers/technicians/staff.
A coaching programme has been implemented, and this is supported by a Nuclear Professionalism learning clock programme. This monitors the frequency of notable events and the learning which ensues. This is done at station and department level with the objective of promoting continuous improvement and learning.
All events and incidents are promptly investigated according to a dedicated procedure to determine and address the root causes and underlying organisational weaknesses. Trending of causes is also conducted to judge programme effectiveness and help guide future plans.
All company processes including those described above (Work Management, Equipment Reliability and Nuclear Professionalism) apply Continuous Improvements methodologies. The Continuous Improvement approach is based on the INPO Operational Excellence model (ref) and is prescribed in the EDF Energy Nuclear Generation Quality Management System procedures. Issues and emerging trends are identified, analysed, solution options are studied and prioritised and the highest value activities are implemented through business plans, improvement plans, asset management plans and other arrangements. Finally an effectiveness review is conducted to ensure that the intended results have been delivered.
A good example of this is the development of the Nuclear Leadership Academy. The need to further improve nuclear leadership competencies of supervisors and managers was identified through in-depth analysis into underlying root causes of many safety and reliability conditions in 2008/09. In 2010 a Nuclear Leadership Academy was established to provide this training and development for nuclear leaders. The Nuclear Leadership Academy programme has been tailored for the specific needs of the organisation and is based on international best standards. Training the first group of nuclear leaders through this academy began towards the end of 2010.,It’s pedigree as a centre of excellence for nuclear leadership training and development is recognised by supervisors and managers in the business. Further development of the nuclear leadership programmes continues and its long term success will be judged on the impact it contributes towards improved plant safety and reliability performance.
In this way all aspects of the companies people, plant and organisational resources are continuously updated, developed and re-engineered (where appropriate) in the pursuit of nuclear excellence.
Corrective Action Programme
The Corrective Action Programme (CAP) is a cornerstone of Continuous Improvement and organisational learning.
An effective CAP is fundamental to the effective management of plant safety and reliability. The objective of the CAP is to identify, document, evaluate, and trend undesirable conditions (problems) and to take actions to correct problems and their causes. The aim is to proactively identify sub standard conditions and practices at a local, low consequence level and take positive action to prevent more significant consequence events arising and adverse trends developing.
The CAP establishes the processes to ensure that deficiencies, non-conformities, weaknesses with a process, documents, or a service, or conditions that adversely impact, or may adversely impact plant operations, personnel, nuclear safety, the environment, or equipment and component reliability, are promptly identified and resolved in accordance with their inherent risk to nuclear safety and reliability.
For those conditions considered significant, or repetitive in nature, these processes ensure that appropriate levels of management are notified, causes identified, and actions taken to prevent recurrence. They also ensure that the actions taken to address the identified issues are verified to be complete and effective through formal effectiveness reviews which are scheduled usually 6 months to 1 year later.
- Plant staff are expected to identify and report all problems affecting safety by entering a ‘Condition Report’ (CR) into the system. CRs requiring immediate attention are reported immediately to the Shift Manager or Line Supervisor as appropriate.
- Daily, CRs raised during the previous 24 hours are screened according to their safety and reliability significance, organisational ownership is assigned and actions to be taken to correct the issue are placed.
- Where further investigation is required the level of investigation to be performed (root cause or apparent cause) is defined based on the safety and/or reliability significance and a lead investigator assigned. The lead investigator is trained in root cause investigation and/or apparent cause investigation. For root cause investigations they will normally lead a team of experts to collect facts, determine what happened, why it happened and what organisational weaknesses failed to prevent the problem developing into a consequential condition. The potential extent of condition is considered and this helps determine the extent of corrective and preventative actions required. Extent of condition is considered locally, at other stations in the fleet and internationally. Where there are potential international implications reports are submitted through international bodies such as the WANO, INPO and the Nuclear Plant Event Reporting (NUPER) database. A final report is compiled which includes a corrective and preventative action plan. This report is subject to oversight from the location Corrective Action Review Board (CARB). The CARB is comprised of senior management and independent company oversight representatives and takes the final judgement on the adequacy of the investigation and appropriateness of the proposed corrective and preventative action plan.
- Preventative actions are targeted at the root causes of problem, taking into account the potential extent of condition and are designed so that the benefits outweigh the costs. In certain cases, interim mitigation measures are taken to limit exposure to hazards and to restore adequate confidence while final corrective actions are being generated or deployed. Personnel involved in the original issue receive feedback on what was done. This is important to the reinforcement of prompt reporting behaviour and is vital to appropriate organisational learning. Condition report priorities are regularly reviewed so that resources are applied to those actions with the greatest importance to the organisation.
- Routine programme health reporting, which includes CAP trending analysis is carried out in order to identify degrading conditions early before an adverse trend in safety or reliability performance develops. A standard coding system is used so that effective trend analysis can be done subsequently. Finally, the information from the CAP is combined with industry-wide information exchanges and integrated within the Operational Experience Feedback process.
Operational Experience Feedback (OEF)
Together with CAP, the effective sharing and utilisation of experience is a fundamentally important process established by the nuclear industry from the lessons learned initially following the Three Mile Island accident in 1979, and subsequently developed. The Operating Experience (OPEX) processes cover the reviewing, screening, disseminating of internal and external nuclear industry event notices or other operating experience for applicability to specific EDF Energy Nuclear Generation facilities. It also provides the basis for external communication of events from within the organisation for the benefit of the worldwide nuclear community through the WANO global Event Reporting system. (An “event” is defined as any significant deviation from the normal expected functioning of a plant.).
The Operational Experience (OE) teams produce internal reports, newsletters and briefings for staff about to consider work activity or plant manoeuvres. Of particular value is the “Just-In-Time Briefing” process where the OE is collated and presented to operators and staff at the point of work and immediately prior to the activity.
At the global level, WANO (and INPO) maintain a database of events reported by every nuclear power plant on the secure WANO members’ website. WANO has established specific reporting information categories, including causes, corrective actions and learning points. Members are encouraged to report events promptly, so that others can benefit from their experience.
The WANO OPEX Central Team conducts analysis and monitors events across WANO to identify significant issues. Based on the number and significance of events, the Operating Experience Central Team writes Significant Operating Experience Reports (SOERs), Significant Event Reports (SERs) or Just-in-Time briefings (JITs). These reports warrant focused member attention and provide analysed information and learning points that can be applied across all plant types.
For effectiveness management purposes, there are OE Process performance indicators, regular self assessments and effectiveness reviews of the OE process.
Unplanned plant shutdowns
The unplanned automatic trip rate (UATR) is the number of unplanned automatic trips per 7,000 hours of operation as defined by the WANO. A low figure indicates that the reactor is controlled well within its safety limits and is operating reliably.
Increased focus has been given to equipment reliability to ensure that learning from unplanned automatic trips is embedded across the fleet. The overall UATR for all our nuclear stations at the end of the calendar year 2012 was 0.64.