Expanding the scope of DYLAM methodology to study the dynamic reliability of complex systems: the case of chemical and volume control in nuclear power plants

The aim of this paper is to show how the DYLAM methodology, normally used to study the reliability of relatively simple plants, can be extended to the dynamic analysis of complex systems. To realize this goal a first step of classical reliability analysis on the plant under study is necessary, in order to discover its most critical parts. Subsequently a dynamic reliability analysis by DYLAM may be performed, focusing on those parts identified as critical elements. We show an application of these concepts to the study of the chemical and volume control system of a nuclear power plant, whereby the reduction of the components to be studied by DYLAM has been obtained by a detailed qualitative engineering analysis of the plant layout. Some results are presented to demonstrate the potential of the methodology to model the interaction of physical and probabilistic analysis of the plant.