[en] Subject of the paper are the IAEA cooperative patterns of unusual events data treatment and utilization of the operating safety experience feedback. The Incident Reporting System (IRS) and the Analysis of Safety Significant Event Team (ASSET) are discussed. The IRS methodology in collection, handling, assessment and dissemination of data on NPP unusual events (deviations, incidents and accidents) occurring during operations, surveillance and maintenance is outlined by the reports gathering and issuing practice, the experts assessment procedures and the parameters of the system. After 7 years of existence the IAEA-IRS contains over 1000 reports and receives 1.5-4% of the total information on unusual events. The author considers the reports only as detailed technical 'records' of events requiring assessment. The ASSET approaches implying an in-depth occurrences analysis directed towards level-1 PSA utilization are commented on. The experts evaluated root causes for the reported events and some trends are presented. Generally, internal events due to unexpected paths of water in the nuclear installations, occurrences related to the integrity of the primary heat transport systems, events associated with the engineered safety systems and events involving human factor represent the large groups deserving close attention. Personal recommendations on how to use the events related information use for NPP safety improvement are given. 2 tabs (R.Ts)

[en] The IAEA/NEA Incident Reporting System (IRS) was established in the early 1980, its objective being to gain from operating experience achieved in countries with nuclear power programmes by means of exchanging information on events relevant to safety. Among the 2171 events in the database, 175 events (i.e. 8%) were identified as ''control room events''. It was decided to group these into three sets for further study: 65 events with common mode/cause failures (CCFs), 22 events with cognitive errors and 30 events with unforeseen interaction between NPP systems. It is expected that the pitfalls experienced in the IRS and the questions derived from this study will help to gain a better understanding of the needs and interests of specialists in advanced information methods and artificial intelligence in NPP control rooms. (author)

[en] In the safe operation of nuclear power plants reliable and attentive human behavior plays a major role. Apart from assisting the staff in the optimal performance of their duty from the managerial level to prevent undesired actions, it is also imperative to investigate actual events to determine their causes and implement remedial mechanisms. While analysis of single events can lead to specific conclusions related to the particular circumstances, the systematic screening of a collection of events will lead to generic insights and the identification of overall problem areas. The Incident Reporting System supported by the International Atomic Energy Agency (IAEA) is collecting reports on safety significant operational events on an international basis. Close investigation of these reported events revealed that in a large number of cases human intervention contributed to the initiation and/or development of these events. A systematic analysis developed within the IAEA termed Assessment of Safety Significant Events Technique (ASSET) was applied which provides a structured methodology to identify not only the direct cause explaining why an individual failed, but more important, provides insights into the root causes to determine why this latent deficiency was not detected earlier through the plant surveillance program. The generic lessons drawn from the collected insights on human behavior are presented and a brief description of one or more symptomatic events illustrating these lessons is given

[en] There is increasing recognition that operating safety feedback provides a unique opportunity for improving nuclear safety. Systems have been established in many countries to collect, analyze and disseminate data on safety-related events in nuclear power plants. The IAEA has set up the international Incident Reporting System (IAEA-IRS) whose main goals and features are described, including the first results of the development of a new mechanism for the prompt notification, collection, assessment and dissemination of operating safety experience of nuclear installations. (author) 1 fig., 7 tabs., 1 ref

[en] Analysis of reported events reveals that in a large number of areas human intervention contributed to the initiation and/or development of these events. Since an accident at any nuclear power plant can have a world-wide effect on public acceptance, the need for attentive and reliable human behavior assumes an even greater significance. The identification of areas where human interaction can have an impact on safe operation is mainly relying on the analysis of events reported to the nuclear community. Any substantial compilation of safety significant operational events such as contained in the IAEA-IRS (Incident Reporting System) is bound to provide valuable and factual insights into problem areas, their origin, development, impact and some remedial actions. Thus a systematic analysis has been carried out on over 200 events where a human contribution could be identified. Some events of particular interest will be discussed and furthermore generic lessons will be presented. In addition the Assessment of Safety Significant Event Technique (ASSET) developed within IAEA which provides a structured methodology to identify not only the direct cause explaining why an individual failed but more important, insights on the root causes explaining why this latent deficiency was not detected earlier through the plant surveillance programme was applied. (author)

[en] Since 1983 the Agency has been gathering information on NPP unusual events considered important for safety and accident prevention. The more than a thousand unusual events in the Incident Reporting System (IRS) contain considerably more lessons learned for the international operational experience feedback process. This summary of IRS recent events gives information on procedural failure (no single person is responsible for the accuracy of a procedure, the production of procedure is multifaceted). Emphasis in the IRS event patterns analysis was given to two aspects: Incomplete procedure (usually an equipment failure initiates a transient, and then the corresponding procedures failed to provide enough information); incorrect procedure (as with incomplete procedure, this problem usually occurs when trying to respond to a plant transient). (author). 2 tabs

[en] The main objectives of IAEA-IRS activity are to prevent repetition of unusual events in other NPPs, at other locations and to enhance the capability of the nuclear community to improve nuclear safety. This paper outlines the experience of international expertise in the analysis of data collection on unusual events in NPPs. Examples illustrate IAEA-IRS analysis activity in practice - trends and patterns identified by a human expert. The importance of the use of modern techniques simulating and supporting human decision-making processes for analysis of IRS information is briefly discussed

[en] The IAEA Incident Reporting System (IRS) is an international network to communicate lessons learned to reflect the operational safety experience of a variety of NPPs under different conditions around the world. A considerable part of IRS activity consists of topical studies based on system data collection and national studies of safety issues. IRS studies cover technical and human problems in NPP design, operation, surveillance and maintenance. This paper presents the most interesting results from IRS topical studies carried out over more than ten years, the time the system has been in existence. (author)

No abstract available

[en] The Incident Reporting System (IRS) is a global network through which IAEA Member States exchange experience to improve the safety of nuclear power plants. Even with extremely careful plant design and operation, many unplanned events can and do occur, though almost none of them result in serious accidents. Timely feedback of operational experience provides useful information on events which may prevent similar occurrences at other plants. This international sharing of operational experience is the impetus behind the IRS