Consequence Modeling of Chlorine Release

This paper describes the Consequence Modeling of Chlorine release from a Chlor Alkali plant as a part of Process Hazard Analysis. The objective was to carry out a Quantitative Risk Assessment Study of the liquid Chlorine storage area of the Chlor Alkali plant and build up in-house capability to carry out such studies. QRA covered the following stages • Hazard Identification • Consequence Analysis • Frequency Analysis • Risk Analysis • Risk Management QRA provides valuable insights into the features of the industrial plant, highlighting those aspects where failures may result in harm to operators, members of the public, the environment and/or the asset itself. Hazard Identification was done in 2 phases, Safety Review of Plant and Hazard Identification using Indices method. Based on Safety review and CEI rating, scenarios were selected for modeling and consequence analysis. PHAST software was used for modeling discharge, dispersion and consequence analysis. The results were summarized and scenarios were classified on basis of Onsite and Offsite impact.

A consequence modeling of various Loss of Containment scenarios of Chlorine bullet using PHAST software is explained in detail in the paper along with the risk management recommendations. Competency development initiatives such as this were helpful in understanding of process hazards by the plant operating staff and helped in implementation of mitigation measures. Thus a robust Process Safety Management culture can be instituted.