An Approach for Inclusion of Organizational Factors Into Probabilistic Safety Assessment. Song-Hua Shen, Ali Mosleh, and Eli Goldfeiz, Dept. of Materials and Nuclear Eng., University of Maryland, College Park, MD 20742
This work presents a model for assessing the influence of organizational factors on nuclear power plant operator performance as well as reliability performance of components. This model is expected to include explicit accounting of organizational factors in probabilistic safety assessment of nuclear power plants. To accomplish this a simple model for representing the structural and behavioral aspects of organization is developed. Factors directly influencing the quality of plant personnel in their interaction with plant hardware have been identified and their relationships with the elements of the organization model are considered. Influence diagram approach is used to quantify the measures of influence of the organizational factors. A modular structure of the organizational factors has been introduced which simplifies the quantification of the measure of their impact on workers’ performance. The result of this quantification is used to determine the amount of increase in failure rate due to organizational factors. In addition the nature of dependencies of events modeled in probabilistic safety assessment due to organizational factors has been explored and a method for factoring these dependencies has been proposed. The case of the maintenance department of a nuclear power plant has been used to demonstrate the application of the methodology.