Human Reliability Analysis to consider Common Cause Failures for a Research Reactor during its Design Phase

J. BARÓN; J. NÚÑEZ MC LEOD; S. RIVERA

Puerto Rico, EUA

Congreso; European Safety and Reliability Conference - ESREL 2002; 2002

International Association for Probabilistic Safety Assessment and Management

An approach to treat dependent failures is presented in this paper. This approach is based on Fault Trees (FT) and Human Reliability Analysis (HRA) techniques. The approach is useful to treat all the dependent failures except the component functional dependencies and the layout(environmental) causes, which are easy to be included in the event trees and in the systems component models.The proposed approach assumes that the root causes for the remaining dependent failures comefrom the inadequacy of procedures, human actions or errors during design, maintenance, inspection or test. Starting from this assumption, three different generic FTs were derived for three types of dependent failures: “Design”, “Maintenance” and “Test, calibration and inspection”.The basic components of these FTs were procedure inadequacies, human actions, human errors,and their interactions. As for the application case, the reactor is still during its design phase, thereare not developed procedures. Being this the case, the hypothesis used to guarantee a certain level of confidence in the dependent failure models, were used as specifications on the quality and level of detail of the procedures, plant personnel interactions and human interdependencies requirements. In this way, the developed FTs were used to retrofit the procedures for design, maintenance and test.