An Integrated Model for Reactor Control Based on Discrete Function Theory

In this paper, we propose a model for the quantitative analysis of the reactor control system which consists of I and C systems, MMI and human operators. The proposed model is to produce the best quantitative measure for the safety of reactor control based on all available knowledge related to the reactor control. After dividing the I and C systems and MMI into the subsystems and identifying the major cognitive activities of human operators, key factors related to the subsystems and cognitive activities are identified. For the subsystems of the I and C systems and MMI, the three factors, hardware, information and design, are commonly found to be important. For human operators' cognitive activities, simple error, operators' knowledge and workload are found to be important. For the quantitative analysis, we introduce a method based on the discrete function theory to represent more than two states in a system, in an effort to overcome the limitations of conventional fault tree analysis. Based on the speculation on the states of a general system and human cognitive activities, the states of the key factors of each subsystem and cognitive activity are determined. Numerical analysis based on assumed values of 30 related parameters in the proposed model shows that the proposed model produces reasonable results. (author)