SUMMARY

Releases from nuclear or radiological security events may result in significant internal radiation contamination through inhalation of particulate contaminants. Biokinetic models have been developed to model radionuclide time-dependent retention and excretion in the human body. Traditional biokinetic models employed for prospective dose assessment employ deterministic mathematical parameters for radionuclide deposition and transfer between organ/tissue regions. The Human Respiratory Tract Model (HRTM) developed by the International Commission on Radiological Protection (ICRP) utilizes deterministic quantities outlined in the ICRP Publication 66 and updated in Publication 130. The overarching goal of this study is to determine the variability from deterministic biokinetic/dosimetry models to represent the stochastic breadth of radionuclide metabolism in an exposed non-reference population from realistic source terms, yielding an expanded compendium of inhalation dose coefficients. Analysis is actuated in three phases: (1) Development of a physiologically-enhanced biokinetic and dose coefficient model based on ICRP 130 HRTM and associated systemic biokinetics; (2) Investigation of statistical importance of uncertain parameters in the HRTM; and (3) Conducting stochastic analysis utilizing Latin Hypercube Sampling. The impact of this study is to ultimately assess the biokinetic/dosimetric sensitivity of an expanded, representative, non-reference population for enhanced consequence management applications.