عنوان مقاله [English]
Risks in various industries including oil, gas, petrochemical and power plants can have irreparable consequences. Power plants are always exposed to many risks due to the use of flammable materials as fuel and various activities, therefore identifying risks is necessary to prevent accidents. The purpose of this research is to investigate the most important potential risks in the activities of Bampur Gas Power Plant. In this research, by using the FMEA method, the risk assessment of site visit activities, loading and repairs, cutting and working with millstones has been done. After that, hierarchical analysis of criteria and options was done using Waspas software, and finally, the obtained options were prioritized. The obtained results indicated the identification of 16 risk cases, and the hierarchical analysis of the options with the Waspas software showed that the highest preference was given to the option of working with a grinding stone and then visiting the site with a weight of 0.411 and 0.388, and the lowest weight was given to the activity Repairs amount to 0.340.
The failure of a system or the occurrence of accidents due to the use of complex systems in today's society can cause disturbances at different levels and even be considered as a threat to society and the environment. That's why everyone is looking for a secure system with low risk probability. This is where the term risk appears to indicate the probability of occurrence and its severity. It is the risk outcome that determines what damage will be caused to the system by the occurrence of each hazard and what environmental consequences it will have afterwards. Based on the definition, risk is defined as the degree of probability and severity of the occurrence of the risk and its consequences. The World Standard Organization's definition of risk includes the possibility of an accident and its consequences. According to the report of the International Organization (ILO), 2 million occupational accidents leading to death and 266 million non-fatal accidents occur every year, the economic consequences of which are equal to 4% of the gross national product. Risk assessment and management is one of the important pillars of HSE management. Organizations must constantly evaluate risks related to HSE. In order to identify specific risks, assess and control risks to an acceptable level, activities must be evaluated. The use of risk assessment as a systematic and organized method to identify risks and risk assessment for risk ranking is to reduce the risk to an acceptable level. Risk assessment has different methods with a range of quantitative and qualitative methods. Due to the importance of identifying and prioritizing the main risks, there are many methods to perform these tasks, and the failure mode and effect analysis method (FMEA) is one of these methods. The FMEA method is one of the main techniques used to identify and analyze relevant risks that are effective in improving safety. In this method, the indicators of a given system are basically used for qualitative analysis. Systems or subsystems of an assembly are examined to assess the effects of potential faults on other system components to identify potential faults. In addition to determining the risk levels of various processes, risk assessment enables us to make appropriate decisions to take the necessary measures to protect people. Safety, because of its general and universal value, all cultures should do their best to maintain and implement it. Risk, safety and its strategies are necessary to implement comprehensive risk and safety management among other countries and organizations. The information obtained from the risk assessment has three basic applications, including determining the points that need to be optimized in terms of occupational safety and health in order to reduce their risk to an acceptable risk, prioritizing the degree of importance of risks to allocate various limited resources, including financial, technical and human resources, it is in removing defects and improving conditions and finally determining the content of on-the-job training in the field of occupational health and safety. Among the existing methods, the method of analysis of failure modes and its effects (FMEA) is a method that has recently been widely used in order to investigate the potential of defects in various products, processes, designs and services. This method analyzes the components of the system and relates the conditions of the components to the conditions of the system and tracks the defects of the components in order to determine its effect on the system. The WASPAS method was proposed by Zavadskas in 2012. This method is one of the relatively new methods of multi-criteria estimation with very high accuracy, which is actually a combination of two methods, the weighted addition model and the weighted multiplication model (WPS3). The accuracy of the WASPAS method is higher than any of the two mentioned methods. The purpose of FMEA is to determine the causes of defects in systems and provide solutions to reduce or eliminate identified defects in order to increase process reliability.
The present research is of the type of present research based on evaluation-analytical method; And it is survey type. In this research, using the FMEA method, the most important potential risks of the power plant were analyzed based on pseudo-accidents and power plant accidents. For each potential risk, risk probability, risk severity, risk discovery probability and finally risk rating were determined according to table (1). The focus of the FMEA method is prevention-based and completely subjective. This method requires predicting errors and providing a solution to prevent errors. After determining the risk rating of each activity, using WASPAS software, hierarchical analysis of criteria and options was done, and finally, the prioritization of options was determined. One of the parameters that can be considered in choosing a multi-criteria decision-making method is the accuracy of these models. Also, these researchers suggest that the combination of two models can increase the accuracy of the results of the models. The accuracy of the results of multi-indicator decision making models (WSM) (weighted summation model) and WPS (weighted production model) is relatively well known. Also, the accuracy of composite models has been analyzed by researchers. The results of researchers' studies have confirmed that the accuracy of the combined model is much higher compared to the accuracy of these models before being combined. One of these combined models is the cumulative weight production evaluation model (Wasps). This model can be highly effective in complex decision-making problems, and the results obtained from this model are highly accurate. The model process is as follows:
First step: obtaining and standardizing the decision matrix;
The second step: calculating the variance of the values of the initial normalized criteria
Third step: calculation of variances
Fourth step: Calculate Qi and to rank the options
The purpose of this research was to identify and analyze potential risks in the power plant using the combination of FMEA and Waspas methods. In total, site visit activities, repairs, loading, cutting and using grinding stones; A total of 16 risks were identified, and among the 16 identified risks, noise pollution and vibration in the power plant were assigned the highest degree of risk probability with the number 7 and 5, respectively. The highest risk intensity number is number 9, which includes the activities of visiting the combustion chamber, air cutting, repairs and loading. The most important control measures proposed to reduce the risk of loading activity are periodic inspection of equipment and use of rigger. For the site visit activity, the proposed measures include rotating visits of the personnel to the site and placing a camera and an emergency way in the place of the combustion chamber. Suitable control measures for repair activities are the use of personal protective equipment and periodic inspection of the used equipment. Considering the preference of working with a grinding stone due to the possibility of breaking the grinding plate and other things, safety glasses and helmets should be used when working with it. Bahrami et al. (2017) conducted a research titled environmental risk assessment of Kermanshah Petrochemical Complex using FMEA method. that the result of the research was the expression of more fuzzy noise pollution, which is in line with some of the results of the present research.