Development of an algorithm to evaluate plutonium metabolic model for systemic retention and excretion

Liver biliary secretion influences the plutonium (pu) content of feces. A mammillary model that incorporates the enterohepatic circulation is developed for the purpose of improving internal dose assessment amd bioassay models. This model uses a whole body uptake retention function to obtain the distribution of Pu in the body and the rates of elimination of Pu in urine and feces simultaneously. The development of the model relies on the fact that a retention function expressed by a sum of exponential terms can be depicted by a mammillary model involving the translocation of a contaminant between a central and various peripheral compartments. In this study, an algorithm is developed to compute the translocation rate constants that are consistent with the systemic retention function. The thesis provides a method that can be used to confirm and improve Pu metabolic models. This method can be extended to other elements and used to make estimates of intakes and internal radiation doses from excretion bioassay data. 70 refs., 18 figs., 12 tabs