CONSEQUENCE EVALUATION OF CHLORINE GAS RELEASE FROM THE INDUSTRIAL AREA OF BHAGWANPUR (UTTARAKHAND) AND DURGAPUR (WEST BENGAL)

Abstract

The accidental release of toxic, flammable and hazardous chemicals from chemical plants are causing serious threats to lives, properties and environment. The situation becomes more damaging if the plant is located in a densely populated area. Different chemicals are used for the production of variety of chemical products. Among all these, extreme use of chlorine gas in the manufacturing of chemicals and products possess great risk of chlorine gas leakage from storage tank. Chlorine gas is irritating to eyes and it cause respiratory problems on inhalation and being denser than air it remains on the ground for long time. During sudden release the gas will disperse in the atmosphere depending on the process and meteorological conditions prevailing at that time. In this paper with the help of ALOHA model the areas of Bhagwanpur (Uttarakhand) and Durgapur (West Bengal) which can be affected during the dispersion of chlorine gas have been calculated. It is mainly based on the principles of fluid dynamics. The methodology discussed in this paper is useful to predict the probable threat zones of chlorine gas dispersion for the concentrations 350 ppm, 125 ppm, and 15 ppm during summer, monsoon, post monsoon and winter season for the two areas. The rate of maximum indoor and outdoor concentration of chlorine gas in terms of time from the source at a distance of 2 km is also calculated. With the help probit analysis mortality rate for the three concentrations are calculated. The situation can be very critical during winter and post monsoon season. The mortality rate is also a matter of concern as it indicates 49.20 % of mortality rate for 350 ppm concentration for an exposure period of 15 minutes. The results from the scenarios are further analyzed and compared for the same and can be used in the analysis of consequences and risk assessments by the respective sectors in order to minimize the potential impact from such incident in future.