Evaluation of safety barriers deduced from the HAZOP study of fired heater F201-101, ADRAR refinery, Algeria using ETA method

Abstract

This paper described the method of event tree analysis that is commonly used to identify, characterize and estimate the risk. Quantitative estimates for probability of breach or failure and the resulting consequences can be obtained using event trees. Qualitative depictions of potential failure modes and consequences can also be developed using event trees. An event tree analysis (ETA) is an inductive procedure that shows all possible outcomes resulting from an accidental (initiating) event. An event tree consists of a sequence of interconnected nodes and branches. Each node defines a random variable that represents an uncertain event or state of nature. Branches originating from a node represent each of branches to represent the likelihood for each event or condition. These probabilities are conditional on the occurrence of the preceding events to the left in the tree. Our work includes a HAZOP study to determine the necessary safety barriers as a first step. And as a second step is their evaluation using ETA method of fired heater F201-101, ADRAR refinery, Algeria. This particular method is well suited to estimating the risk stemming from process plant failure. Neither the initiators of industrial accidents nor the layers of protection that prevent them are typically complex, that is, they do not usually require analysis by redundant systems or the time for on-line repair. Thus, they can be accurately characterized with the probability multiplication methods that from the basis of event tree analysis.