Pierre Mottet

The use of liquefied natural gas, methanol, methane and hydrogen as fuels brings up issues regarding safety and acceptable risk. The potential hazards associated with an accidental release and dispersion should be evaluated. The article reports the results of different methods of modelling releases and dispersion of dangerous gases and vapors in cases of major accidents in industrial or urban zones. To describe these methods we introduce how parameters (such as amount of release gas, atmospheric conditions, buildings, tanks cracks, diameter etc.) at an industrial or urban site affect dispersion and show how these parameters can be parametrized in effects models. Effect evaluation is an important part for mitigation factors, such as water sprays, foam systems, and sheltering or evacuation, which tend to reduce the magnitude of potential effects in real incidents. The goal of this article is to present the results of modelling using these standard methods in the area of modelling of releases and dispersions of dangerous chemical substances in urban zones in cases of major accident.