Ilościowe miary ryzyka ukŁadów bloku energetycznego

There has been a growing interest in the analysis of the risk involved in the operation of complex technical systems and the consideration of this risk as an economic category in the financial accounts of industrial companies. The risk analysis is also used in conventional power engineering and has now become the starting point for planning basic diagnostic tests, maintenance and investment schemes. The first and most important stage of these tasks is the assessment of the level of technical risk involved in the existence and operation of such complex systems as power units. The paper presents a procedure of risk assessment for the mill installation of a power unit. The subsystems and elements of the installation are described, dangerous scenarios identified and the probability of the occurrence of the risk estimated. The quantitative measures of risk are calculated upon the characterization of the consequences of the damages. From the point of view of reliability, the mill installation is the so called: "k-out-of-n" system i.e. its is regarded as good if at least k of the n components are good. The probability of the failure of a single component of the installation, that is, of a single mill unit, was calculated by means of the fault tree method. The derived values of risk expressed in monetary terms make it possible to optimize preventive measures to avoid failures of the discussed system.