Risk assessment and modeling of chlorine leakage consequences using fuzzy HAZOP technique and PHAST software

This study aims to develop strategies for risk management and accurately model the potential outcomes in hazardous zones.

The initial step of this study involved conducting HAZOP studies to identify all process nodes and deviations in an urban water-treatment plant located in Markazi province. Subsequently, all risks associated with the identified deviations were evaluated using a qualitative risk matrix. To enhance the scientific accuracy of the risk assessment results, the fuzzy HAZOP methodology was employed. Finally, the assessed risks were prioritized with precision, and PHAST software was utilized to visualize critical scenarios and determine the zones of catastrophic consequences.

The initial findings from the HAZOP investigations conducted in the chlorination unit of the treatment facility reveal a total of 41 deviations out of 55 identified risks. Out of these risks, 47 (85%) were classified as high risk (HR), while 8 (15%) were categorized as medium risk (MR). The results of the risk assessment clearly demonstrate that the risks are of significant concern, despite the presence of existing controls. Ultimately, eight scenarios were identified and extracted from the analysis.

Based on the research results, it is imperative that all chlorination facilities undergo redesigning to prevent corrosion, erosion, leakage, and rupture and to conduct risk-based inspections (RBI). Furthermore, regular chlorine leakage drills should be included to enhance emergency response and preparedness.