A methodological framework applied to the choice of the best method in replacement of nuclear systems

The economic equipment replacement problem is a central question in Nuclear Engineering. On the one hand, new equipments are more attractive given their best performance, better reliability, lower maintenance cost etc. New equipments, however, require a higher initial investment. On the other hand, old equipments represent the other way around, with lower performance, lower reliability and specially higher maintenance costs, but in contrast having lower financial and insurance costs. The weighting of all these costs can be made with deterministic and probabilistic methods applied to the study of equipment replacement. Two types of distinct problems will be examined, substitution imposed by the wearing and substitution imposed by the failures. In order to solve the problem of nuclear system substitution imposed by wearing, deterministic methods are discussed. In order to solve the problem of nuclear system substitution imposed by failures, probabilistic methods are discussed. The aim of this paper is to present a methodological framework to the choice of the most useful method applied in the problem of nuclear system substitution.