Overview of United States operating experience

The paper describes the United States Nuclear Regulatory Commission's (NRC) comprehensive programme to evaluate, assess and feed back operating experience. The programme's objectives are twofold. The first objective is to identify safety significant situations which, if left uncorrected, could result in potentially serious operating events. The second objective is to examine operating events from a trend or pattern perspective to find incidents of apparent low significance which may be significant to safety because of the frequency or distribution of the events. The NRC's programme for the analysis and evaluation of operating data has been successful in identifying many safety significant situations in which construction deficiencies, system interactions and common mode failure mechanisms had eluded plant safety analysis reviews. The paper describes some of the studies that were performed and reports that were produced. It also provides some examples which show how operating experience is being fed back to improve plant operating performance and to improve plant safety. The paper provides brief descriptions and findings from two NRC Office for Analysis and Evaluation of Operational Data operating experience feedback reports. Also included in the paper is a brief discussion on the NRC's Performance Indicator Program and some of the Program's findings. (author). 2 refs, 2 figs