Indicators of plants performance during events identified by Recuperare method

The authors present a model developed for operating experience feedback analysis, built on the French HRA principles. This model puts emphasis on the recovery process during events and makes a classification of events based on the ways by which errors and recovery are linked. 900 events reported by EDF had been reviewed through this model. Some results are presented and some safety indicators of plants performance are proposed. This study opens up new lines of analysis for operating feedback and provides new safety indicators of plants performance. Although nuclear power plants do not all give the same type of information and some data are missing, the large amount of available data makes it possible to discern trends and profiles for the nature of incidents over a year. Thus, this method provides tools to establish an overview of incidents each year and to characterize equipment performance during correction of incident situations. Furthermore, the results can be used to draw up a log from one year to the next if certain relevant parameters are chosen, making allowing to form an overall opinion based on objective data as to the safety of facilities over the years. These data were analyzed using a very recent statistical method, i.e. PLS method, which overcomes the problem of missing data. The purpose of this new study was to attempt to 'predict' the detection times from factors that are contingent to the situation. The initial results are very encouraging and should be the subject of future articles. For the probabilistic studies, although use of these results in PSS is still a question, it should be noted that this approach appears promising for better: 1. identification of relevant data for analysis of dependency between faults and actors (cumulative situations and analysis of actor dependence allow study of the failure and recovery mechanisms); 2. specification of the pre-accident context; 3. analysis of pre-accident fault latency; 4. obtaining of a realistic idea of the times required for detection and action. (authors)