Journal of Health and Safety at Work

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Introduction: Pollutants in gas turbine air intake can cause erosion ،corrosion، fouling as well as reduction of power and efficiency of turbine and noticeable economic losses. In order to select the appropriate filtration system, air monitoring of turbine inlet and its filtration is essential. Therefore, this study was performed to assess the quality of gas turbines inlets in a gas power plant in Tehran.

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Material and Method: In this cross- sectional study, the concentration of particulates contained in air intake of 4 types of gas turbines, including: Fiat, Assec, Hitachi and mitsubishi were evaluated in second-half of spring season. For this means, 12 series of air samples were collected using 8 stages cascade Impactor, model AN -200 made by OGAWA company on cellulose – ester filters . The dust concentrations were determined gravimetrically in different ranges of sizes . Then the concentrations of 8 metals including Sodium, Potassiumu Lead, Mercury, Aluminum ,Copper and Cadmium were measured using ,Atomic Absorption Spectroscopy method and the data were statistically analyzed by SPSS Software, version16.

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Results: The results showed that the mean of particulate concentration with the diameter less than 4.7 µ were 64% ,66% ,60% ,67% for Fiat, Assec, Hitachi, mitsubishi respectively and it was 64.25% totally. The concentrations of all assessed metals in particulates less than 4.7 µ were greater than of larger than 5 µ. There were not any differences between particulate concentration in the inlet of Fiat and Hitachi (P>0.05), while in the case of other gas turbine intakes , there were statistically significant differences (P<0.05).

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Conclusion: Based on mass distribution of particles, the highest concentration belongs to particles with diameter of less than 4.7 µ. These particles could damage turbine blades, especially due to the presence of sodium and potassium as corrosive elements in this range (200 µg/m3). Therefore,this range of particle size must be considered in selecting the air intake filtration system.

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Introduction: Fire and explosion are the most common consequences of natural gas pipeline accidents. The results of previous studies showed a higher rate of accidents in natural gas transmission lines. Given that a large number of people living in the vicinity of natural gas pipelines with a higher severity of related accidents. The aim of current study was to estimate risks using the method of quantitative calculation of risk and simulation of natural gas pipeline leakage using areal locations of hazardous atmospheres (ALOHA) in natural gas power generation.  
Material and Methods: The method of quantitative calculation of risk was used to identify and prioritize risks. The simulation of the consequences of natural gas pipeline leakage was done by ALOHA software. Calculations of individual and social risks were performed based on statistical data obtained from the literature.
Results: The most serious effect of natural gas pipeline leakage was heat radiation effect of jet flame. Considering three leakage apertures in the natural gas pipeline 80, 130, and 300 mm, individual risks for each leakage aperture were 0.073, 0.114, and 0.569 and the number of deaths was 115, 400, and 3386, respectively. Increases in the leak aperture can lead to an increase in the number of deaths and decrease in the cumulative rate of accidents.
Conclusion: The most serious consequence of natural gas pipeline leakage was heat radiation effect of jet flame. The individual risk and social risk are beyond the acceptable risks range.

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Introduction: Many general indicators have been proposed to assess an organization’s safety performance. However, due to their holistic nature, these indicators may not always reflect safety-specific aspects of an organization’s performance. In other words, the nature of an organization’s activities necessitates the use of specific criteria to better reflect safety performance. This study aimed to identify and measure key safety performance indicators using the Delphi method in Alborz Province Electric Power Distribution Company.
Material and Methods: This descriptive, survey-based study utilized the Delphi method to collect the opinions of 11 safety experts in the electric power distribution industry. Opinions were gathered in four phases, and key indicators were determined in the last phase of the study. These indicators were subsequently used to evaluate the safety performance of Alborz Electric Power Distribution Company for three months.
Results: This study identified and documented 34 safety activities. The expert group proposed 20 indicators in the first phase of the Delphi method. In the second and third phases, four and one indicators were eliminated, respectively, because they did not receive the required score. The content validity ratio (CVR) and content validity index (CVI) were calculated for the remaining 15 indices in the fourth phase. The results revealed that the mean quarterly performance scores of Alborz Province electric power distribution districts and departments in 2016, including Nazarabad, Savojbolagh, Mehrshahr, Fardis, West, East, Taleghan, and Eshtehard, were 78.9, 54.7, 78.8, 75.9, 75.7, 80.8, 61, and 83.5 out of 100 points, respectively.
Conclusion: The Delphi method is useful for identifying key safety performance indicators. The indicators discovered using this technique are active indicators (pre-accident) that are crucial in determining Alborz Electric Power Distribution Company’s safety performance. These indicators are suggested for use in evaluating the safety performance of other electric power distribution companies.