Techno-Economic Analysis of Protection Barriers Against Fire-Induced Domino Effects in the Chemical and Process Industry

Domino effects triggered by fire are responsible for most of the cascading accidents which occurred in the chemical and process industry. Their occurrence is highly dependent on the performance of fire protection barriers, as well as on the primary fire scenario. Active and passive safety barriers are largely used to prevent or mitigate domino effects. However, a blinkered allocation approach of safety measures based on a subjective strategy, which does not consider cascading effects possibly triggered by an accident, can lead to a deployment of a safety plan that is not effective in effectively mitigating the consequences of a domino accident. In the present study, an innovative methodology supporting and optimizing the decision-making process for fire prevention in a chemical site has been developed. The methodology provides an optimal allocation of safety measures, aimed at preventing and mitigating fire escalation under budget constraints. A Cost-Effectiveness Analysis with an optimization algorithm is used to allocate a limited budget in terms of fire safety barriers. A novel tool, named Cost Variable Decision Tree, has been developed to support fire prevention investment decisions. The methodology is able to assess the economics of safety plan implementation, considering both the costs of safety measures and the hypothetical benefits deriving from avoided accidents. An illustrative case-study was carried out, confirming that the proposed methodology can effectively support the decision-making process addressing safety barriers allocation.