NPP safety automation systems analysis. State of the art

This report describes the state of the art of formal methods and models applied in safety evaluation of nuclear and other industrial safety systems. Special attention is drawn to a technique called model checking that is a set of methods for analysing whether a model of a system fulfils its specifications by examining all of its possible behaviours. The report describes the scope and requirements for safety evaluation and introduces typical safety assessment approaches. The Safety Case concept is also described and discussed how it could be combined with model checking. (orig.)