A Fuzzy-Sets Based Approach for Modelling Uncertainties in Quantitative Risk Assessment of Industrial Plants Under Seismic Actions

This paper describes a fuzzy set based approach for dealing with uncertainties in the assessment of “NaTech” events triggered by earthquakes: and in particular with those related to seismic hazard and fragilities of the industrial plant components. The effects of these uncertainties on the Quantitative Risk Assessment (QRA) of local and societal risk indexes, caused by accidental scenarios triggered by seismic events, are evaluated for a case study refinery. The adopted QRA methodology allows for identification and consequence assessment of all the possible scenarios, including possible domino events. The procedure has been implemented in a GIS-based software tool in order to manage the high number of event sequences that are likely to be generated in large industrial facilities.