A Study on the Application of Dynamic Risk Assessment in Chemical Process Industries

Abstract

In conventional Quantitative Risk Analysis (QRA) process it is unable to use the accident precursor information to revise the risk profile. One of the main disadvantages is its inability to update the risk during the life of a process. Dynamic risk assessment can be used to overcome this disadvantage. Dynamic risk assessment refers to a risk management framework where frequent updates of risk evaluation information are used to evaluate the risk outcome. This uses accident precursors such as near misses and incidents to estimate likelihood of all possible end states while conventional QRA uses on static basis considering only major accidents and events. So these updated risk profiles which results from dynamic risk assessment can lead to more accurate decision making. In this paper the dynamic risk assessment methodology is discussed in detail. First, potential accident scenarios are identified and represented in terms of an event tree, next, using the event tree and available failure data, end state probabilities are estimated. Subsequently, using the available accident precursor data, safety system failure likelihood and event tree end state probabilities are revised. Finally, the updated probabilities are used in revising the risk profile of the process system. It is more useful in chemical process industries as well as nuclear, aerospace and aviation industries where there is high likely hood of occurrence or several losses. In this research, the significance of dynamic risk assessment is demonstrated with respect to hydrocarbon storage tanks