THE 13765 AND For 137 Cs 60 an CO METHODOLOGY 60 Co, the methods of the ICRP 22,36,37 and the National Council on Radiation Protection and Measurements (NCRP)?® as developed by Killough and Rohwer in their INDOS code?? are used for the dose calculations. This code is used as published; otager 3 msnisanacasariacunatnineau TREETEN however, the output is modified to show the body burdens for each year. For 1370. which is of major importance in the Marshall Islands, the model for adults consists of two compartments with removal half-times of 2 and 110 d, with 10% of the intake going to the 2-d compartment and 90% to the 110-d compartment. These data are consistent with preliminary data obtained by BNL on the half-time of the long-term compartmentin the Marshallese.‘ The average results for ten Marshallese males showed a mean of 114 d (range: 76 to 178 d) for the long-term compartment. For 21 females the mean value is 83 d (range: 63 to 126d). The gut transfer coefficient for 13765 is 1. The half-time of 1376, in children is determined in two stages. The equation used to determine the half-time of 137 6 developed by Snyder at Oak Ridge Laboratory, is Ti 2 = 1.63 M, where M is the body mass in kilograms”! National The M as a function of age is determined using equations given by Spiers. > When the Snyder and Spiers equations are combined, the half-time as a function of age can be determined. The average half-time using the above approach for ages 5 through 10 is about 42d. Data from BNL whole-body counting for 14 Marshallese children in this age bracket is 43d. For ages I1 to 15, the Snyder-Spiers method gives an average half-time of about 70d, while the BNL data for nine adolescents in this age bracket is 69 d.77 TRANSURANIC RADIONUCLIDES METHODOLOGY Inhalation The inhalation model used for the various isotopes of plutonium and for 241 am is that of the ICRP Task Group.2!+#2 Parameters for the lung model are also those of the ICRP--the gut-to-blood transfer for plutonium isotopes is io"? and for 5 x 107" (see Ref. 23). Both 24! Am 24 am it is and plutonium are assumed to be class-W compounds. Ingestion . . . -4 For the ingestion pathway, the gut transfer coefficients are, as stated above, 10 241 for plutonium and 5 x 107" fo r Am. The critical organs are bone and liver with 100-y 37