Journal of Nuclear Fuel Cycle and Waste Technology

A dynamic compartment model is presented to predict the contamination level of agricultural plant by 137Cs as a result of a soil deposition. The model considered the processes of a percolation, soil mixing by a plowing before transplanting, plant uptake, leaching to a deep soil, and fixation to a clay mineral. The effects of the soil properties (pH, clay mineral, organic matter content, and exchangeable K), which are spatially varied, on a plant uptake and the leaching rates of 137Cs in a root zone soil were modeled by the Absalom model. To test the validity of the model, the 137Cs aggregated transfer factors(TFa) for rice plants were compared with those observed from some simulated 137Cs soil deposition experiments, which were carried out with respect to rice plants cultivated in seventeen paddy soils of different properties for two consecutive years. Observed 137Cs TFa values of the rice plants did not show an evident trend for the pH and clay content of the soil properties, while they increased with an increasing organic matter content or a decreasing exchangeable K concentration. Predicted 137Cs TFa values of the rice plants were found to be comparable with those observed.

Keywords

137Cs,Absalom model,soil properties,dynamic compartment model