Abstract

Decision making is considered as one of the major activitiesin any Risk Control strategies associated with the industry arena. Severalmethods are used to quantify the risk and subsequently map it according torespective importance. It becomes difficult to take critical decisions withvague information presented about the competing parameters. Layer of ProtectionAnalysis (LOPA) is a powerful analytical tool that can be used for riskassessment. It can be used for analyzing risk, catastrophic failures andassessing the adequacy of protection layers to mitigate process risk. It is ahazard analysis technique that includes hazard identification and hazardquantification and allows determining the risk associated with the varioushazardous processes by utilizing their severity and the likelihood of theevents being initiated. LOPA is carried out based on the information developedduring qualitative hazard evaluation procedures such as Hazard and Operabilitystudy (HAZOP) and Process Hazard Analysis (PHA). Fuzzy Layer of ProtectionAnalysis (Fuzzy LOPA) presents a new approach to risk assessment based on fuzzylogic and degrees of memberships. This work particularly focuses on applying aFuzzy Layer of Protection Analysis (Fuzzy LOPA) to mitigate the accidentscenarios associated with sodium hypochlorite plant in a chlor-alkali industryby providing various Independent Protection Layers (IPLs) to reduce the risklevels of the scenarios to acceptable limits. The protection provided helps inreducing the risks posed by the plant by a large amount in an effective manner.It is evident from this study, that the fuzzy LOPA methodology provides abetter risk estimation compared to classical LOPA and helps in prioritizing thepossible hazardous events of process industries and improves the overall safetyof the plant.

Keywords: Layer of Protection Analysis, FuzzyLOPA, Sodium Hypochlorite Plant, Chlor-Alkali Industry