MODEL FOR ESTIMATING Pii TRANSPORT AND DOSE 49 i 



TABLE 7 Parameters for Calculating Radiation Doses from 

 Transuranium Radionuclides 



*Includes energy from daughter products with half-times less than 1 yr. 



fr^ is radioactive half-hfe of radionuclide, days. 



JGIT is gastrointestinal tract (principally, lower large intestine). Mass of contents of lower large 

 intestine is 150 g. 



§ICRP-II used 1000 g for mass of lungs. All other models use 500 g. Effective energy to lymph 

 nodes and all portions of the respiratory tract are assumed equal to lung. Masses for these organs are: 

 nasopharyngeal region, 1.35 g; tracheobronchial region, 400 g; abdominal lymph nodes, 10 g. 



applied to plutonium or other transuranic elements, is shown in Fig. 3. This model 

 distinguishes between insoluble and readily soluble compounds that are inhaled. In the 

 absence of other data, it is assumed that 25% of a soluble compound is exlialed, 50% is 

 swallowed and reaches the gastrointestinal tract (GIT) almost immediately, and 25% is 

 immediately transferred directly to the blood. 



