Simulation of accidents in a chemical industry using the software package MAXCRED

A new and elaborate software package MAXCRED (MAXimum CREDible accident analysis) has been used for generating accident scenarios and estimating damage potential for a typical industry. Four different scenarios have been generated for explosions, fires, as well as toxic releases. The da­ mage they would cause has been estimated. The studies indicate that a confined vapour cloud explo­ sion followed by fire would be the worst disaster scenario and would also have the highest probability of leading to 'cascading' or 'domino' effects. ,I J I Use of hazardous materials in a process industry give rise to the probability of an accident or a chain of accidents. These accidents can be charac­ terized as large fires, explosions, generation of toxic cloud and dispersion of toxic gases. The as­ sessment of the possible intensity and damage potential of such accidents is difficult and tedious, mainly due to non-availability of sufficient back­ ground information. Maximum credible accident analysis (MCAA)1 - 3 is an approach to assess the damage potential of chemical plant or industrial complex to the surroundings and the environment. MCAA comprises of following main steps - (i) study of the plant to identify hazardous materials and their capacities, (ii) identification of vulnerable sections, (iii) visualization of different accident scenarios, (iv) damage calculation through mathematical mo­ deling, and (v) delineation of maximum credible accident scenario. Recently a software MAXCRED (MAXimum CREDible accident analysis) has been developed4• The package incorporates state-of-the-art mathe­ matical models, including some developed or modified by author for rapid quantitative and comprehensive MCAA. In this paper, MAXCRED has been used to visualize different accident scenarios in a typical chemical industry's storage unit situated in an in­ dustrial area near Madras. The results have been represented in terms of risk (damage* probability) contour maps on the accident site to enable easy and swift assessment of the maximum credible scenario. Besides demonstrating the utilizability of MAX­ CRED, this study also focusses attention on the need to bestow greater effort towards risk assess­ ment. These studies would generate safety con­ sciousness among plant managers and would also help in developing accident prevention strategies and installing damage control devices.