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In an accidental release of radioactive materials to the environment, the contaminative influence of animal products due to the inhalation of air and the ingestion of soil of cattle, both of which are considered as minor contaminative pathways in most radioecological models but may be important ones, was investigated with the improvement of the Korean radioecological model DYNACON. Although mathematical models for both contaminative pathways have been established for considering all animal products and incorporated into the model, investigation was limited to milk. As a result, it was found that both pathways are influential in the contamination of milk during the non-grazing period of dairy cows. Precipitation was an influential factor in milk contamination due to the ingestion of soil, especially for 137Cs. In the case of an accidental release during the grazing period of dairy cows, the contaminative influence due to the inhalation of air was negligible irrespective of the existence of precipitation during an accidental release.

A three-dimensional wind field and an atmospheric dispersion model have been developed for real-time accident generation of a wind field over the whole domain using several measured data. A Lagrangian particle model was used for the calculation of the concentration distribution of the radionuclides in the atmosphere. The field tracer experiment near the Younggwang nuclear power plant was carried out for the purpose of analyzing the site-specific environmental characteristics and validating the atmospheric dispersion model in May 1996. The calculated concentration the most important factors for calculating the concentration of the released particles in the dispersion model. Several numerical experiments using the measured wind data were performed to get more accurate concentration distributions compared with the results of the field tracer experiment of SF6. The developed numerical models are being used as a basic tool for emergency preparedness in Korea.