Modeling dispersion in the event of a leak ammonia storage in a hypothetical uranium hexafluoride production plant

Abstract

The primary use of ammonia in nuclear plants is in producing uranium hexafluoride (UF6), a critical compound for uranium enrichment (U-235). Ammonia’s widespread use across multiple industries has led to a steady increase in its production over the years. However, due to its toxic properties, conducting comprehensive studies on its dispersion is essential, as leaks can pose significant risks to human health and the environment. Tools like the Areal Locations of Hazardous Atmospheres (ALOHA) system are employed to model the dispersion patterns of hazardous gases, enabling the prediction of toxic substance releases and their spread. This study evaluates ammonia dispersion in scenarios involving tank punctures or valve ruptures, which can lead to accidental leaks, particularly in uranium hexafluoride production facilities. The meteorological factors considered in the dispersion modeling are wind speed, temperature, humidity, and prevailing wind directions. The results demonstrate that low wind speeds and high temperatures significantly impact ammonia dispersion, while fluctuations in humidity have a minimal effect. Furthermore, the observed findings indicate that the prevailing wind direction in the site tends to be most commonly from the East-Southeast (ESE). In this direction, dispersion extends towards vegetated areas and certain uranium hexafluoride production plant sections. However, the results highlight the wind direction variability over time, prompting further investigation into additional simulation scenarios.