morteza cheraghi - Department of Health, Safety & Environment (HSE), Faculty of Environment, University of Tehran, Tehran, Iran
babak omidvar - Department of Health, Safety & Environment (HSE), Faculty of Environment, University of Tehran, Tehran, Iran
amir banadkooki - Department of Health, Safety & Environment (HSE), Faculty of Environment, University of Tehran, Tehran, Iran

One of the most important tools for safety management is risk assessment in order to identify risks and provides risk reduction measures. The purpose of this study is to prioritize a power plant risks by using both fuzzy multi criteria decision making methods and five factors of risk assessment. In conventional methods, risk assessment was used to assess identified hazardous activities/unsafe conditions with two or three factors such as occurrence probability, injury magnitude and the undetectability which hazard risk number was gained by multiplying these factors. For eliminating disadvantages of conventional methods, a method is presented by this paper that uses five factors (occurrence probability, injury magnitude, undetectability, sensitivity to maintenance non-execution, and sensitivity to personal protective equipment non-utilization) to increase the accuracy of assessment. In this method, the risk of each hazard is obtained using fuzzy TOPSIS method and also fuzzy AHP is used to determine weight factors. In this risk evaluation model, triangular fuzzy numbers are used to cover the uncertainty in experts opinion. Finally, the results obtained from an industrial example verify the capability of the presented method.

Risk Assessment; Risk Factor; Fuzzy Logic; TOPSIS; AHP