SUPER-NET, a multi-purpose tool for reliability and risk assessment

Abstract

The outcome of a Probabilistic Safety Assessment (PSA) consists of substantial amounts of written information describing the methods and assumptions used, as well as the results of the various analyses performed within the PSA. In addition, it contains a large body of computer-handled information, mainly the plant fault tree model. This model constitutes the back-bone of the PSA by summing up and including relevant parts of all other analyses performed. The living PSA concept implies keeping the PSA up to date with plant changes, and using it actively for creating a basis for decision-making in matters related to plant safety. Thus, the concept relies heavily on efficient computer tools for manipulation, evaluation and modification of the plant PSA model. ABB ATOM's SUPER-NET program package for reliability and risk analysis is specially designed to meet all these needs, both in performing the PSA and in making active use of it in analysis and enhancement of plant safety. It includes interacting programs dealing with, for example: —fault tree handling (input, editing, modification), —fault tree evaluation, —uncertainty analysis, —sensitivity analysis, —importance analysis, and —time dependent reliability analysis. This paper summarizes first the implications of the living PSA with respect to documentation, computer code requirements and need of a structured approach. This is followed by a description of SUPER-NET, its composition and working modes. Finally, examples of current applications of SUPER-NET are given, illustrating its usefulness for realization of the living PSA concept.