Optimization of reliability target for main safety systems

Reliability allocation is an optimization process of minimizing the total plant costs subject to the overall plant safety goal constraints. Reliability allocation has been applied to determine the reliability characteristics of reactor systems, subsystems, major components and plant procedures that are consistent with a set of top-level performance goals: the core melt frequency, acute fatalities and latent fatalities. Reliability allocation is a kind of a difficult multi-objective optimization problem as well as a global optimization problem. The genetic algorithm, known as one of the most powerful tools for most optimization problems, is applied to the reliability allocation problem of a typical Pressurized Water Reactor in this paper. One of the main problems of reliability allocation is defining realistic objective functions. We used techniques derived from the Value Impact Analysis to define the realistic objective function in this paper