Mathematical modeling for atmospheric dispersion of radioactive cloud passing over Jeddah

الملخص EN

Atmospheric dispersion has been performed for a hypothetical accidental airborne radionuclide release from any nuclear installation such as power reactor, research reactor or any facility which uses radioisotopes as its tools.

Estimate of release for various radionuclides are based on U.S Nuclear Regulatory Commission (NRC 1.183).

The normalized concentration distribution (NCD) of pollutants is calculated as a function of downwind horizontal distance up to 10 km from the release point.

These estimates have been performed for Jeddah city (Kingdom of Saudi Arabia) using Gaussian Plume Model (GPM).

The calculations have been evaluated for the atmospheric thermal stability class, B, (moderately unstable), which is, meteorologically, and according to Pasquill classification, the dominant stability category for Jeddah city.

The computer program Mathmatica" is used for this purpose Also, the effect of radioactive decay on The NCD of pollutants has been investigated.

The relevant meteorological data, namely, atmospheric thermal stability class, mean wind speed and direction and their frequency of occurrence for Jeddah city have been analyzed and presented.

The results indicate that the NCD is significantly affected by the radioactive decay factor, particularly, in cases of short-lived isotopes, where it reduces the concentration of cloud by different ratios depending on the half- life time of a radionuclide.