It is more important to realize safety management, medium-large accident prevention and risk prediction as accident of industry facilities can generate enormous physical and human damage because most energy plant might handle toxic substance. Especially, atmospheric dispersion system, which is able to simulate situation, have been used for release accident of toxic substance since the accident can show different of dispersion range and velocity according to release material, storage facility and atmospheric status. However those systems have been used generally in design step of industry facility and are difficult to deal with release accident quickly. Although some researches and cases have been studied for using real-time atmospheric information, there are insufficient system for processing quickly release accident. This paper aims to develop real-time smart atmospheric dispersion system that can deal with release accident quickly by enhancing distinct characteristics and efficiency of energy plant, and select release time and area using intelligent algorithm as accident prevention type.