Calculating the performance of engineering structures: national approach to the use of PSA in the Federal Republic of Germany

The deterministic and probabilistic approaches are discussed generally and characterized. Deterministic and probabilistic approaches are shown to be just different stages in iterative safety decision making. Both approaches have different advantages, which complement each other very efficiently. Advances in safety assessment have been achieved by a combination of probabilistic analyses and deterministic approaches. The fundamental principles for the national approach to the use of psa are illustrated in the Safety Criteria of the Ministry of the Environment of the Federal Republic of Germany. Scope and depth of application in accordance with the state of psa-development to supplement the deterministic approach to achieve 'sufficient reliability' and 'well balanced design'. The defence in depth concept has further been improved to an advanced probabilistic concept, which enables a more differentiated application of reliability engineering to provide optimal plant response to disturbances, transients or accidents. Examples for probabilistic approaches in regulatory guides, codes and standards are given. (author)