Meteorological Factors Affecting Chimney Design Parameters

The height of mechanical mixing layer is one of the parameter of the safety analysis report of any industrial (nuclear) facility due to its relation to the dispersion factor of pollutants. It can provide information about lower atmospheric dispersion, which is usually used to study the pollutants released from nuclear facility, risk analysis and emergency planning. Mixing layer height is difficult to measure; therefore, mathematical methods are introduced to calculate this layer. The analysis of the results showed that the height variation of the mechanical mixing layer for different seasons depends on the degree of unstable condition and wind speed, where the height of the mechanical mixing layer equals 2433 m at wind speed of 14.5 m/s and 1952 m at wind speed of 14 m/s and 1700 m at wind speed of 13 m/s. The purpose of this work is to calculate the mechanical mixing layer height (HABL)mech. using different mechanical models during stable/unstable conditions. This value is one of the key parameter of the safety analysis report of any nuclear facility and important in the prediction of pollutants concentration released from any nuclear facility and the scaling of turbulence. The suggested model successfully calculate the pollutants profiles during the monthly seasons study depends on the degree of instability conditions, wind speed and predicted the maximum height of mixing layer.