Summary Report on Events Related to the Supply of Nuclear Power Plants Components

This report presents the essential results of study performed by European Clearinghouse on Operational Experience Feedback in cooperation with IRSN and GRS aiming to analyze the impact of inappropriate components supplied to NPPs on safety. Study has been performed by means of extracting, systematizing and analyzing of adequate operational experience related information from event reports stored in the relevant data bases. Methodology of study includes identifying, highlighting and examining of circumstances, precursors, causes and safety significance of said events, as well as of most important corrective actions, lessons learned and recommendations. Trying to evaluate impact of different potential sources causing incidents the entire nuclear supply chain as a whole is covered, and all stages of this system including design, manufacturing, storage, transportation are taken into account in the developed system of 7 subfamilies. The main defence lines of the licensee designed to prevent penetration of substandard components such as thorough preparation of the procurement documentation, source inspection prior to authorizing release for delivery and inspection/testing of items on receipt are considered as well. Based on the results of performed analysis major contributors to the existing problem were identified. Among the analyzed subfamilies deficiencies in design cause about 42% of selected events and manufacturing faults cause 32%. The most frequently failing are mechanical (including hydraulic/ pneumatic) components (40 - 55% of relevant events) and electrical elements – they take 30 - 37% of total events number respectively. The worst vulnerable specific types of components are also identified: they are valves and seals among mechanical components, circuit breakers and relays among electrical components. Scrutinizing the lessons learned from the analyzed events and looking beyond the component-specific or condition-specific ones some generically applicable recommendations for preventing or decreasing the probability of supply to NPPs of inappropriate products and components are formulated.JRC.F.5-Nuclear Reactor Safety Assessmen

Comparative Analysis of Nuclear Event Investigation Methods, Tools and Techniques

Feedback from operating experience is one of the key means of enhancing nuclear safety and operational risk management. The effectiveness of learning from experience at NPPs could be maximised, if the best event investigation practices available from a series of methodologies, methods and tools in the form of a ‘toolbox’ approach were promoted. Based on available sources of technical, scientific, normative and regulatory information, an inventory, review and brief comparative analysis of information concerning event investigation methods, tools and techniques, either indicated or already used in the nuclear industry (with some examples from other high risk industry areas), was performed in this study. Its results, including the advantages and drawbacks identified from the different instruments, preliminary recommendations and conclusions, are covered in this report. The results of comparative analysis of nuclear event investigation methods, tools and techniques, presented in this interim report, are of a preliminary character. It is assumed that, for the generation of more concrete recommendations concerning the selection of the most effective and appropriate methods and tools for event investigation, new data, from experienced practitioners in the nuclear industry and/or regulatory institutions are needed. It is planned to collect such data, using the questionnaire prepared and performing the survey currently underway. This is the second step in carrying out an inventory of, reviewing, comparing and evaluating the most recent data on developments and systematic approaches in event investigation, used by organisations (mainly utilities) in the EU Member States. Once the data from this survey are collected and analysed, the final recommendations and conclusions will be developed and presented in the final report on this topic. This should help current and prospective investigators to choose the most suitable and efficient event investigation methods and tools for their particular needs.JRC.DDG.F.5-Safety of present nuclear reactor

Application and Selection of Nuclear Event Investigation Methods, Tools and Techniques

This final report presents the results gained in the last step of a project launched in the frame of technical task “Comparative study of event assessment methodologies with recommendations for an optimized approach in the EU” for 2010 -2011. It contains analysis and evaluation of the existing practices and some developed conclusions and recommendations to facilitate selection and implementation of relevant instruments to improve quality of nuclear event investigations. Study is based on the results of the performed survey with participation of experts from nuclear power plants and regulatory bodies representing 12 European countries and USA. Main attention was paid to analysis of the existing practices and organizational aspects of nuclear event investigation, as well as to qualitative evaluation of currently employed event investigation methods, tools and techniques. Some methodological inconsistencies, existing barriers, bottlenecks and emerging traps in event investigation process were identified and analyzed more thoroughly. In order to avoid the existing ambiguities and misunderstandings in system of terms and definitions, used in event investigation and root cause analysis concretely, the several improved definitions were suggested. Aiming to distinguish better event investigation instruments of different levels and applicability, the original system of classification of basic root cause analysis methods and tools was suggested. This system should facilitate comparison of characteristics and selection of the most relevant instruments for event investigation. Some methodological and practical recommendations how to conduct analysis overcoming the identified obstacles were put forward. The detailed recommendations for selection of root cause analysis methods and tools are presented as well.JRC.F.5-Nuclear Reactor Safety Assessmen

Quality of Supplied Components - Impact to Nuclear Safety

This paper presents the essential results of a study performed by the European Clearinghouse on Operational Experience aiming to analyze the impact of inappropriate components supplied to Nuclear Power Plants (NPPs) on safety. Study has been performed by means of extracting, systematizing and analyzing of adequate operational experience related information from event reports stored in relevant data bases. The methodology of the study includes identifying, highlighting and examining of circumstances, precursors, causes and safety significance of said events, as well as of most important corrective actions, lessons learned and recommendations. All production stages (including design, manufacturing, storage, and transportation) are taken into account in our study as well as the main defence lines of the licensee designed to prevent penetration of substandard components. The major contributors and causes of the reported events are deficiencies in design and manufacturing causing 42% and 32% of events respectively. We highlighted that the most frequently failing groups were mechanical and electrical components and among them mostly valves, seals, circuit breakers and relays. The overwhelming majority of the supply-related events seems to be caused by the same group of common fundamental causes: inadequate quality/safety culture and deficiencies or ineffectiveness of management systems, of quality management or of quality assurance. By scrutinizing the causes and lessons learned from the events and looking beyond the component-specific or condition-specific ones, we formulated some generically applicable recommendations.JRC.F.5-Safety of present nuclear reactor

Kodėl Lietuva negali nestatyti Visagino AE? [Why Lithuania cannot give up the idea of building a Nuclear Power Plant in Visaginas]

„Būti ar nebūti atominei Lietuvoje?“ Atsakymas į šį klausimą yra kritinis Lietuvos energetikos ateičiai. Nuo sprendimo – ar vystyti vakarietiškas branduolines technologijas Visagine - priklauso ne tik dabartinės, bet ir ateities kartų gerovė ir perspektyvos. Šiame straipsnyje apžvelgsime, kodėl mes tiesiog neturime kitokios geresnes alternatyvos Lietuvoje.JRC.F.3-Energy securit

Human Based Roots of Failures in Nuclear Events Investigations

Objective: Improvement of quality of the event investigations in the nuclear industry through analysis of the existing practices, identifying and removing the existing Human and Organizational Factors (HOF) and management related barriers. Background: Accidents are still recurring despite the plenty of efforts to prevent them because human and organizational factors' issues are typically not well addressed. Methods: Survey based study of human and organizational factors limiting the effectiveness currently existing event investigation practices typical for nuclear industry of 12 European countries. Results: System of operational experience feedback from information based on event investigation results is not enough effective to prevent and even to decrease frequency of recurring events. The latent root causes of failures found through investigation are related to weaknesses in safety culture of personnel and managers. These weaknesses include focus on costs or schedule, political manipulation, arrogance, ignorance, entitlement and/or autocracy. The potential improvements could be targeted to increasing competencies and capabilities of event investigation teams, elaboration of comprehensive software, increasing level of independency of investigation, ensuring of positive approach, adequate support and impartiality of management. Conclusion: Effectiveness of event investigation and operational experience feedback process is not perfect mainly due to existing methodological, HOF-related and/or knowledge management related constraints. Upgrades in safety culture of organization’s personnel and its senior management especially seem to be an effective way to improvement. Application: Results of this study could be applicable in nuclear power plants as well as in other high-risk industries.JRC.F.5-Nuclear Reactor Safety Assessmen