A technique of dose estimation and reconstruction of acute and chronic intakes of Pu-241 and Am-241 by inhalation

The estimation of the time and the level of intake of Pu-241 and Am-241 is the focal point of this study. The computer program Stella II simulates a biokinetic model, the mathematical representation of the behavior of these radionuclides in the human body, and these results are further analyzed. The research performed for the thesis is the critical examination of the biokinetic model for the Pu-241 and the Am-241 nuclide and the validation/verification through comparison with established models for the same initial conditions. The simulations, represented through pulses, allow the study of the behavior of the radionuclides in regard to various intakes and provide more realistic intake situations. The intake scenarios here include acute single intakes of varying strengths, and long term chronic intakes of varying strengths. Observations of the simulations show that the activities in the compartments of the models are unique functions of time and that the ratios of the activities in various bioassay compartments are also unique functions of time. These characteristics of the unique curves are the basis for the study and provide information about the time the intake occurred, as well as the strength of the intake.