phast modeling and hazop risk assessment for nto tank in liquid propellant stand

Testing processes of liquid fuels in propulsion engines are complex and associated with high risks. in this research, there are 37 risks identified by the hazop method in a static stand of bipropellant n2o4/mmh. 48% of these risks have a red and unacceptable high-risk class, and 37% of risks are in the propellant and high-pressure equipment. in this research after the risk assessment with hazop method modeling the hazard of mmh and nto in the test site using phast software. one of the most important results of this modeling is that the risk of leakage at the top of the tanks is much higher. in the design of stand tanks, the risk of leakage at the top of the tank can be reduced by increasing the diameter instead of increasing the height, and if tanks with a smaller l/d can be used, we will probably have a smaller radius of pollution. if leakage from the bottom of the tank in normal weather and wind velocity of 5 m/s, the probability of death worker up to 500 meters is 100%. if possible, if tanks with a smaller l/d can be used, we will probably have a smaller radius of pollution.