An integrated approach for allocating engineered and procedural safety measures to mitigate fire-induced domino effects based on two-stage optimization

In a storage tank farm, domino accident is a high-impact low-probability event that can cause serious consequences. Safety measures are an important way to reduce the consequence of domino accidents, and reasonable allocation of safety measures can have a great effect. Safety measures are divided into three categories in a storage tank farm: inherent safety, engineered safety and procedural safety. The existing safety measure allocation method only targets a single type of safety measure. This paper proposes a two-stage optimization model that uses graph theory and event sequence diagram for the collaborative allocation of engineered and procedural safety measures, which enhances the effectiveness of risk management while saving investment in safety measures. The proposed approach consists of four main steps: analyzing domino vulnerability, optimizing allocation of safety barriers, modeling emergency response, and optimizing allocation of emergency team. A case study demonstrates the applicability and effectiveness of the method and it shows that collaborative allocation of safety barriers and emergency response can reduce the cost by 57% compared with the cost of only considering emergency response. This study provides engineers with a useful and easy-to-use method for the collaborative allocation of safety measures to reduce the risk of domino accident.