Community Research and Development Information Service - CORDIS


The Abnormal Occurrences Reporting System of the Commission of the European Communities was developed by the Joint Research Centre. It collects in a unique format all safety relevant events from NPPs as recorded in the participating countries. The system has been set-up to provide an advanced tool for a synoptic analysis of a large number of events, identifying patterns of sequences, trends, multiple dependencies between incident descriptors and precursors to severe incidents. This paper gives an overview of the development of trend and pattern analysis techniques of two different types. The first type, event sequence analysis, exploits the notion that any incident can be decomposed into a sequence of interrelated steps or occurrences, which give the cause-consequence paths or nets. By searching the data for predefined (fuzzy) patterns of occurrences, underlying mechanisms of relevant incident mechanisms may be revealed. The second type, statistical methods, aims at revealing hidden, complex structures in the data, giving multiple dependencies between the incident elements and trends of these in time. Various statistical methods are highlighted, and illustrative examples of their application to the AORS data are presented.

Additional information

Authors: AMESZ J, JRC Ispra Estab. (IT);KALFSBEEK H W, JRC Ispra Estab. (IT)
Bibliographic Reference: Paper presented: CSNI/CEC Specialist Meeting on Trend and Pattern Analyses of Operational Data from Nuclear Power Plants, Roma (IT), April 3-7,1989
Availability: Available from (1) as Paper EN 34503 ORA
Record Number: 198910221 / Last updated on: 1994-12-01
Original language: en
Available languages: en
Follow us on: RSS Facebook Twitter YouTube Managed by the EU Publications Office Top