The present paper illustrates the results of a Quantitative Risk Analysis (QRA) case study of a refinery. The main purpose of a QRA is to evaluate the risk levels (both individual and societal risk) of a process due to Loss Of Containment scenarios (LOCs). A QRA can be used to optimize the risk reduction measures to be implemented to comply with a given tolerable risk level. Moreover, the development of a detailed QRA is the best opportunity to perform a specific analysis addressing structural response due to overpressure impacts caused by explosions and also estimating the Time To Failure (TTF) of structures and equipment due to thermal radiation of fires.
Part II of this paper is focused on illustrating how a detailed analysis of QRA results can provide valuable information for characterizing potential domino-effects due to thermal radiation of fires at a given location. The analysis gathers three key sources of information: (1) thermal radiation as a function of the cumulative frequency of occurrence; (2) total number of LOCs which contribute to the impact of fires; and (3) the identification and characterization of each LOC scenario and associated individual frequency of occurrence. This information not only is valuable for ensuring the heat radiation for a subsequent analysis intended to estimate the TTF and associated conditions remaining in the system (e.g., Wall Dynamics Analysis), but also provides specific information of which LOCs contribute most to the heat radiation impacts. This information ensures which LOC scenarios need to be addressed for optimizing the risk reduction decision-making process. Additionally, the accurate estimation of potential equipment failure due to thermal radiation provides added value for predicting when and how impacts such as BLEVEs (Boiling Liquid Expanding Vapor Explosions) are expected to occur.