Analysis of Human Error Trends at the Pickering A Nuclear Generating Station

Abstract

By studying the operating records from the Pickering A Candu reactor installation, an attempt was made to investigate the human errors that have taken place. While investigating these human errors particular attention was given to determining who was responsible for causing these events, why they were caused and the relevant frequency of these occurrences.

The material for this study consisted of all the Significant Event Reports (SER's) and Unusual Occurrence Reports (UOR's) prepared by Ontario Hydro for internal use, from January 18, 1970 to July 21, 1979 (excluding those reports that were unavailable due to security reasons). Of the 1374 reports filed during this period, 550 were attributed as being the result of human error in that human perception, decision making or forgetting was involved.

These reports involving human error were then further classified into 15 categories under four main sections as follows: I - operator error; II - maintenance error; III - administrative error, and IV - installation error.

In analyzing this data a certain amount of subjectivity was involved in interpreting and classifying the reports. Estimates of human error were based upon the judgment of the technical personnel in the organization completing the report.