Assessment of safety barrier performance in Natech scenarios

The impact of natural hazards on chemical and process facilities may lead to catastrophic technological accidents defined as Natech events. In the present study, a performance assessment of safety barriers during extreme natural events as floods and earthquakes was carried out. Assessing the performance of safety barriers during such complex scenarios is a key issue to identify the final consequences and the evolution of Natech events. Due to the scarcity of available data, an anonymous survey was carried out, involving more than 40 experts of different nationalities and background. Categories of safety barriers highly vulnerable to the impact of natural events were identified. Baseline values for performance modification factors describing how barrier performance may be affected by floods and earthquakes were obtained from the expert elicitation procedure. The results may support the probabilistic analysis of Natech scenarios, in order to achieve a more accurate assessment of final consequences and of possible escalation.