Software reliability analysis in probabilistic risk analysis

HOLMBERG Jan-Erik

VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Finland (jan-erik.holmberg@vtt.fi)

Abstract: Probabilistic Risk Analysis (PRA) is a tool which can reveal shortcomings of the NPP design in general. PRA analysts have not had sufficient guiding principles in modelling particular digital components malfunctions. Digital I&C systems are mostly analysed simply and the software reliability estimates are engineering judgments often lacking a proper justification. The OECD/NEA Working Group RISK’s task DIGREL develops a taxonomy of failure modes of digital I&C systems. The EU FP7 project HARMONICS develops software reliability estimation method based on an analytic approach and Bayesian belief network.
Keyword: nuclear safety; software reliability; probabilistic risk analysis; Bayesian belief network