EU Clearinghouse for NPP OEF

Transcription

1 EU Clearinghouse for NPP OEF Artur Mühleisen European Comission Directorate-General Joint Research Center Institute for Energy and Transport P.O. Box 2, Westerduinweg 3 NL-1755ZG Petten, The Netherlands Artur.Muehleisen@ec.europa.eu ABSTRACT EU Clearinghouse is dedicated to improving nuclear safety of EU nuclear power plants by supporting effective and efficient use of operating experience feedback. It is steered by EU nuclear safety authorities and operated by the European Commission. It provides a wide scope of services and products to its members and wider nuclear community. 1 INTRODUCTION Operating experience feedback (OEF) is one of the ways of improving nuclear safety of operating nuclear power plants. Several participants at the conference on Improving Nuclear Safety through Operating Experience Feedback that was held in Germany in 2006 [1] discussed the possibility and benefits of joined efforts at European level to enhance the effectiveness of OEF. As a result a regional initiative has been set up in 2008 in support of EU Member States nuclear safety regulatory authorities, but also EU technical support organizations, international organizations and the broader nuclear community, to enhance nuclear safety through improvement of the use of lessons learned from operational experience of nuclear power plants (NPPs) [2,3]. The experience of US NRC operating experience (OE) Clearinghouse showed that the establishment of a centralized OE clearinghouse for a particular region in the world can yield significant benefits due to optimized use of resources and improved feedback of lessons learnt. Due to differing regulatory regimes in the EU member countries, significant diversity of the NPP designs and different languages used, the establishment of the EU Clearinghouse was more complicated and challenging and needed strong support and commitment from the EU nuclear safety regulatory authorities. The Joint Research Centre (JRC) of the EC has been chosen to play a central role in establishing and running of EU Clearinghouse for OEF. The choice allowed use of well established JRC working mechanisms, means and technical expertise in the field to promote better cooperation and more effective use of the limited national resources and to strengthen the capabilities for operational experience analyses and dissemination of the lessons learnt. 2 OBJECTIVES The reduction of occurrence and significance of events in NPPs and their safe operation is EU Clearinghouse ultimate goal. The objectives of the EU Clearinghouse are to promote 201.1

2 201.2 and support effective and efficient implementation of operational experience feedback for improvement of safety of NPPs through [4]: Strengthening co-operation between EU Safety Authorities, Technical Support Organizations (TSO) and the international OEF community to collect, evaluate and share NPP operational events data and apply lessons learnt in a consistent manner throughout member countries. Establishment of European best-practice for assessment of operational events in NPPs. Coordination of OEF activities and maintenance of effective communication between experts from European regulatory authorities involved in OEF analyses and their TSO. Strengthening EU resources in operational experience. Support for the long-term EU research and policy needs on NPP Operational Experience Feedback. 3 ORGANISATION The European Network on Operational Experience Feedback for Nuclear Power Plants, called the EU Clearinghouse, is organized as a network operated by a central office located at Institute for energy and transport that is part of JRC of the European Commission. It gathers European Safety Authorities from EU countries that have operating NPPs and Switzerland. It is open to European TSO and international organizations. Its organizational scheme is presented in Fig. 1. Figure 1: EU Clearinghouse organizational scheme [4].

3 201.3 The EU Clearinghouse is directed by a Steering Committee. Its members are representatives of European Safety Authorities participating (either as members or observers) in the EU Clearinghouse and representatives of European Commission s Joint Research Centre (EC JRC). At the moment all WENRA members having operating NPPs are presented in the steering committee. Its main roles are to decide new fields of work, to approve the annual work program and deliverables of the EU Clearinghouse. A technical board supports the steering committee. Its main roles are to discuss and comment the work performed by the central office, to comment on the annual work program prepared by the EU Clearinghouse and to propose new fields of work. It is composed of representatives from the same authorities as represented in the steering committee plus of the representatives of European technical support organisations, the International Atomic Energy Agency (IAEA), the Nuclear Energy Agency (NEA) of the OECD, European Commission s Directorate General for Energy (EC ENER), industrial companies, and other invited nuclear safety authorities or organizations as decided by the Steering Committee. The central office coordinates and performs tasks as directed by the Steering Committee. The office is provided by the European Commission Joint Research Centre s Institute for Energy and Transport. The central office consists of a core group of permanent staff, detached national experts and visiting scientists. It complements some tasks by contributions on specific technical topics from EU Technical Support Organizations. 4 CLEARINGHOUSE S SCOPE OF WORK Since its founding in 2008 EU Clearinghouse provided products and services to its members and to wider nuclear community. Products and services include technical and scientific work to disseminate the lessons learned from past operating experience, background research in OEF, topical operational experience reports, reviews of draft IRS reports etc. for its members and also public information related to recent operational experiences and its work. 4.1 Topical reports At request of its steering committee EU Clearinghouse prepares 2-4 topical reports per year. Clearinghouse Topical Reports on Technical Issue are developed by a task team of experts led by a JRC staff member task leader. The subject is determined by the steering committee at a proposal of any Member State of the Clearinghouse. For the preparation of such reports a broad range of information is used: IRS data base; Licensee Event Reports from the US-NRC website, when relevant; Publicly available information on the subject; Input from the Clearinghouse Member States; Results from research & developments available at the EC JRC; Other sources as found appropriate. The preparation of topical reports requires detailed investigation of the subject and is supported by JRC research and technical analyses which may involve a number of JRC Clearinghouse staff members. Selected topical reports are supported by contribution from professional groups in Europe (these groups include experts from the European TSO Network and other research or industry institutions, as appropriate). The reports aim to provide user friendly information to the European Regulatory Authorities on NPP operational experience and, if possible, recommendations for improvement of the current safety related practices both at the NPPs and in the national regulatory authorities. The steering committee approves the

4 201.4 final report and decides on its dissemination (e.g. whether the reports can be made public). Topical reports are made available to IRS users. Topical reports include summary reports of events with similar features or causes, precursor studies of events at selected European nuclear power plants facilitating trend analyses and enabling better understanding of the main patterns in operational experience events, reports on significant events including information on corrective actions taken at European facilities in response to lessons learned etc. 4.2 Databases A well organized website based platform for exchange of information, including powerful search functions, is maintained by EU Clearinghouse for its members. It allows its members also to store information with access limited only to that particular member. An effort is underway to establish for EU Clearinghouse members an OEF database similar in its contents to IRS database but with increased and simplified search functions. The database will be used also for events that do not fulfill criteria to be reported to IRS yet might be of interest to EU Clearinghouse members. 4.3 Support to IRS reporting and use of IRS information Support to EU Regulatory Authorities in reporting to IRS consists in support to the original authors in categorizations of the European IRS reports (following the advice given in the IRS guidelines) to ensure consistent categorization and reduce the burden to the authors. Such support is provided on demand and timely (EU Clearinghouse should provide response within 14 days), consisting of ca reviews of draft IRS reports per year. The provided information/draft report is checked for: completeness, clarity and consistency with the IAEA/NEA Guidance for reporting of NPP operational events. The review also states whether the root cause analyses performed for the given event had identified all causes and whether the corrective actions and lessons learned are identified systematically and seemed sufficient. A check whether the reported event is described in a manner that can be understood by experts not familiar with the type of NPP at which this event has happened is also made. EU Clearinghouse evaluates the IRS reports received from outside EU and alerts the national regulatory bodies on most important events and significant corrective actions implemented, usually by issuing topical reports providing additional insight into safety issues raised by a particular IRS report(s). In addition to the IRS reports EU Clearinghouse collects and analyzes other information received from international sources as appropriate. 4.4 Information for public On freely accessible part of EU Clearinghouse website [4] general information on EU Clearinghouse activities is provided, including summaries of selected topical reports and information on EU Clearinghouse organized workshops as well as other OEF related information (EU Clearinghouse newsletter, prompt notification information). The newsletter, published every three months, provides feedback on operational experience from significant safety related events at NPPs worldwide. It is intended to be complementary to other international reporting systems such as the IAEA IRS system, rather than duplicate the information provided by it and to provide timely information to the Clearinghouse members about recent significant events with a real or potential impact on nuclear or radiation safety. The newsletter is prepared using explicitly only publicly available information and should provide operating experience information promptly, in advance of other reporting systems. Only events that are considered to be likely to have lessons

5 201.5 applicable to European NPPs are selected. The final selection of events reported in the newsletter is performed by a selection committee of suitably qualified and experienced personnel using engineering judgement. 4.5 Other Clearinghouse products for its members EU Clearinghouse supports exchange and use of OEF in its entirety, only main products are presented in detail above. In addition, for example, it also supports dissemination of OEF techniques, through organisation of related workshops and training courses and other services on an ad hoc basis according to its members requests. 4.6 Cooperation with international organisations EU Clearinghouse supports/cooperates with IAEA by active participation in its development of documents and guidelines related to operating experience and organisation of workshops. It is also a member/observer of OECD/NEA task group on defence in depth of electrical systems and grid interaction (Didelsys), working group on operating experience (WGOE), working group on human and organisational factors (WGHOF) and working group on the regulation of new reactors (WGRNR). Support to these international organisations in the area of operating experience through active cooperation and membership is upgraded by further in-depth studies and research, for example in areas of event analysis methods, construction and commissioning operating experience. 4.7 EC oriented Clearinghouse products As EU Clearinghouse central office is part of JRC Institute for energy and transport, its mission is also to provide customer driven scientific and technical support to EU institutions and member states. Technical reports related to OEF area are prepared on request of DG ENER, internally, only by EC JRC staff members of the Clearinghouse. The central office is also an important source of scientific support to other EC services in general nuclear safety area. 5 TOPICAL REPORTS PRESENTED A number of topical reports have been prepared [5] and made available to users of IAEA incident reporting system database (IRS). The added value of the reports is that besides providing important insights gained from the analysed events they also present information on activities/actions taken by different countries participating in the EU Clearinghouse as a result of the event and provide insights from evaluations of events reported in the IRS database that are similar to or have commonalities with the events that are subject of the topical reports. Topical reports, prepared in 2008, have been Report on the event of 25 July 2006 at the Forsmark Nuclear Power Plant Unit 1 in Sweden and the Countries' Responses to the Event [6] and Report on incidents related to reactivity management. Example of the Shika-1 event on June 18th 1999 and countries' responses to the event [7, 8]. The first report reviews the Forsmark-1 event of July 2006, as well as about 120 disturbances in the plant electrical systems that were reported to IRS and US Licensee Event Reports (LER) in the period It provides insights from the Forsmark event and illustrates vulnerabilities of the plant electrical system to over voltage transients. The analysis of international OE revealed a number of events that involved disturbances in the plant electrical systems. The report also summarizes international projects that were initiated by Forsmark event, lessons that can still be learned from the event and actions taken at nuclear power plants and regulatory authorities

6 201.6 in different countries to prevent similar event. The second report investigates the 1999 Shika- 1 criticality event and shortcomings in reactivity management reported to IRS in the period The aim of the work was to identify reactivity control failure modes, the initiating factors and associated root causes and corrective actions. The report summarizes the actions taken at nuclear power plants and by the regulatory bodies in different countries to avoid repetition of similar events and identifies insights that might be useful to reduce the likelihood of operational events caused by shortcomings in reactivity management. In 2009 topical reports Analysis of Fuel Related Events [9] and Analysis of Maintenance Related Events [10] have been prepared. For the first report the whole IRS database was screened to identify, select and analyse fuel failure events. It analyses the main causes of actual and potential fuel failures in three situations: in-core, during handling, and during storage. The results of the analysis of the maintenance related events reported to IRS database during the period from January 2006 to September 2008 (60 reports with 85 maintenance related events) are subject of the second study. The study revealed that the continuous analysis of maintenance related events and efficient utilization of operational experience provide important insights for improving the safety and quality of maintenance, and for preventing the occurrence of events. In 2010 reports Report on the event of Olkiluoto-1 and Forsmark-2 of 2008 and Analysis of Construction and Commissioning events [11] have been prepared. Two events that are topic of the first report have been initiated by electrical disturbances that occurred at Olkiluoto-1 and Forsmark-2 NPPs in 2008 and involved safety related equipment. The report provides insights gained from these two events occurring less than 14 days apart from each other (between 30 May 2008 and 13 June 2008) including a description and a brief analysis, report on the corrective measures taken, identification of issues common to these two events, and a list of lessons learned and recommendations that may be applicable to other nuclear power plants, irrespective of their design. The second 2010 report is a comprehensive study on lessons learned from events related to the pre-operational phases of NPP. The report covers NPP events related to construction, commissioning and manufacturing (i.e. events that have its roots in a time prior to the start of commercial operation). The events considered are both issues detected during the pre-operational stages, and events detected during further operation of the plant. The report highlights lessons learned and recommendations for current and future construction programs. It summarizes the analysis of construction-related events reported to IRS database, LER and event reports collected by the WGRNR. Beyond the itemspecific lessons learned, this study identifies detailed generically applicable recommendations. These generic recommendations relate for instance to management of nonconformances, communication between the entities involved in construction, safety culture, quality control, management of temporary equipment and scope of commissioning tests. 6 CONCLUSIONS The EU Clearinghouse has been launched in 2008 and is in operation. It aims to enhance the benefits of operational experience feedback in its member countries through optimized use of resources. A central office has been set up at the JRC performing and organizing scientific and technical work for the benefits of the safety authorities participating in the project. Three years of operation of the EU Clearinghouse have shown the added value of the initiative that continues to provide useful service and products to its members.

7 201.7 REFERENCES [1] IAEA, Proceedings of Conference on Improving Nuclear Safety through Operating Experience Feedback, Cologne, Germany, June 2006 (published 2007). [2] V. Ranguelova, C. Bruynooghe, M. Noel, European clearinghouse on nuclear power plant operating experience feedback, Kerntechnik, 75 (1-2), 2010, p [3] M. Noel, European clearinghouse development areas and priorities in operating experience feedback for nuclear power plants, Nuclear technology & radiation protection, 25 (2), 2010, p [4] EU Clearinghouse, free access webpage. [5] EU Clearinghouse, members access webpages. [6] A. Duchac, M. Noel, Disturbances in the European Nuclear Power Plant Safety Related Electrical Systems, Nuclear Engineering and Design, 62 (3), 2011, p [7] C. Bruynooghe, M. Noel, European Clearinghouse: Incidents related to reactivity management. Failure modes and corrective actions, Progress in Nuclear Energy, 52 (5), 2010, p [8] C. Bruynooghe, M. Noel, European Clearinghouse - Contributing Factors to Incidents Related to Reactivity Management, Progress in Nuclear Energy, 52 (5), 2010, p [9] M. Martin Ramos, M. Noel, C. Bruynooghe, EU Clearinghouse on Operational Events for Nuclear Power Plants - International Operational Experience on In-Core Fuel Related Events, Nuclear Engineering International, 55 (674), 2010, p [10] U. Vuorio, M. Noel, M. Martin Ramos Maintaining Maintenance, Nuclear Engineering International, 56 (678), 2011, p [11] B. Zerger, M. Noel, Nuclear Power Plant Commissioning Experience, Progress in Nuclear Energy, 53 (6), 2011, p