Managing Domino Effects from a Design-Based Viewpoint

Risk-based design has an important role in the inherent prevention of domino effect, limiting the possibility of escalation by both physical distances between units and introduction of robust safety barriers. In this chapter, the role of design in reducing domino hazard has been explored. Layout definition was identified as a key factor for the prevention of escalation. Threshold values for escalation to be used in design activities were defined. Thus, criteria for the assessment of appropriate safety distances were developed and implemented in layout design. The integration of different strategies in accident mitigation was identified as the key in achieving safer plants with respect to domino accidents. Since conceptual tools alone frequently fail in solving the tradeoffs related to the conflicting needs in the design improvement, inherent safety metrics were introduced to support design activities.