Risk Assessment System for Verifying the Safeguards Based on the HAZOP Analysis

Abstract—In recent years, serious accidents in chemical plants frequently occurred in Japan. In order to prevent accidents and to mitigate process risks, to re-evaluate risks which consider the reliability of existed safeguards in chemical plants is needed. The chemical plant is obligated to provide and maintain a safe environment for people that live in such circumstances. Plant safety is provided through inherently safe design and various safeguards, such as instrumented systems, procedures, and training. HAZOP (Hazard and Operability Study) is used as one of effective measures to identify hazards in chemical plants. In this paper, a method is proposed to calculate the probability of occurrence of hazards in chemical plants already considering of existing safeguards. The developed system bases on the HAZOP analysis and reliability of safety equipment arrangement. The system can verify that the safeguards are adequate or not, and it will produce recommendations for further risk reduction. This system will become valid for risk management and present useful information to support for plant operation. Keywords—risk assessment; HAZOP analysis; safeguards I