Radionuclide migration modeling through the soil-plant system as adapted for Hungarian environment.

The migration of radionuclides released as fallout through the food-chain to humans was modelled using the MODELMAKER software. In the established dynamic environmental transfer model ETM-2002 with compartmental structure, the principal pathways of vegetable contamination were studied specifically for the Hungarian environment. These pathways were: direct deposition on plant surface, root uptake and deposition after resuspension from the soil surface. As result of the modeling the variation of activity-concentration with time was obtained in the compartments. The validation of the model was done by comparing the calculated results with those obtained in field experiments. A sensitivity analysis of the input parameters was also carried out and the parameters were categorized by their sensitivity index (SI). According to this study, the most sensitive parameters are the daily human intake of vegetable, the distribution coefficient, the transfer factor from soil to plant and the weathering half-time. The most probable distribution types for the parameter values were also determined based on Monte Carlo simulations.