Abstract
A mathematical model was proposed to estimate transportation and distribution of 90Sr in fallout at an aerated zone. The distribution of 90Sr in the aerated zone was estimated at two locations, Ibaraki and Yamagata, by using enviromental parameters such as fallout, precipitation, evaporation, distribution factor, diffusivity and field capacity, and the calculated 90Sr profiles were compared with observed profiles to examine the validity of the model. Sensitivity analysis and robustness analysis were applied for evaluating variational characteristics of the calculated profiles.
Some valuable resu1ts were obtained in this study under the limits considered. These are as follows: (1)The mathematical model would be applicable reasonably on the practical estimation of transportation and distribution of 90Sr in fallout at aerated zone; (2) Calculated 90Sr profile agreed satisfactorily with the observed one under the assumption of 90Sr in fallout at composition of more sorptive fraction and less sorptive; and (3) Distribution factor, diffusivity, precipitation and more sorptive 90Sr fraction were more sensitive to the calculated 90Sr profile than the another environmental parameters involved in the model.
