Introducing External Hazard Factors in Quantitative Risk Analysis

The conventional procedure for the Quantitative Risk Assessment of industrial installations or industrial areas, as well as for Land Use Planning with respect to major accident hazards should include the accident scenarios triggered by external hazard factors. In particular, domino effects (also known as escalation or knock-on) due to i) nearby sites, ii) natural events as earthquakes or flooding; iii) intentional misoperation, due malicious acts of interference. An insight of these issues will be provided in the following, jointly to a discussion of the current and the future approaches available for the quantitative assesment of these external hazard factors in a QRA framework.