The cause/consequence diagram method as a basis for quantitative accident analysis

A graphical method for clearing up relevant accidents in complex nuclear installations is presented. The method is a proposal for an expedient presentation of the logical connections between a "spectrum" of accident causes and a "spectrum" of relevant consequences, e.g. expressed in terms of fission products released to the population. Besides being a tool used in connection with the clearing-up of these consequences and their causes, the method serves as a basis from which the probability of occurrence of the individual consequences may be evaluated. The main principle of the method involves the
concept of a "critical event", which for example may often be described as a transgression of the safety limit of a vital reactor parameter, followed by two fault tree methods used in a combined way to determine the logical connections between the causes of the critical event and the "incredible", but possible,
consequences of it.