Insights into safety attitudes at U.S. nuclear plants from onsite evaluations of operating events

In 1990, the United States Nuclear Regulatory Commission's (U.S. NRC) Office for Analysis and Evaluation of Operational Data (AEOD) established a program to conduct onsite evaluations of human performance in operating events. About 20 such evaluations have been conducted. In addition, AEOD staff have participated in event reviews conducted by U.S. NRC augmented inspection teams. By interviewing key operations personnel and understanding their actions and related decisions during an operating event, insight can be gained into the site's safety culture. Further investigation, evaluation, and understanding of the root causes of the factors that influenced operator performance can yield insight into the licensee's priorities, decision-making processes, communications, and effectiveness of problem identification and corrective action processes, including management effectiveness. This paper provides an overview of AEOD's onsite human performance evaluation program and results from these evaluations. While the results from an individual site visit do not provide a detailed safety culture assessment, such visits do yield insight into a site's safety culture. By incorporating these techniques into routine event investigations, it is possible to identify emerging safety culture issues. (author)