4.1 RELATIVE ACTIVITY The basic fallout radiological data calculated for Shot Bravo was provided by Lawrence Livermore National Laboratory (LLNL) (Reference 11). were performed using the isotope generation and The calculations depletion code ORIGEN (Reference 12). Modifications to the ORIGEN-calculated results were made based on radiation chemistry data for Bravo available to LLNL. The LLNL-calculated data for Bravo thus reflect the device-specific characteristics (such as fissile nuclides, neutron energy, and light/heavy element production) that are necessary to correctly specify the radionuclide content of the fallout material. The unfractionated inventory is used because it high-sides organ doses derived from an iodine-based bioassay and because no specific level of fractionation can be substantiated. Plutonium nuclide information does not explicitly appear in Reference 11, but has been derived based on guidance from the author. 4.2 INVENTORY NORMALIZATION As previously mentioned, urine samples were collected from American servicemen and sent to US laboratories for analysis. the exposed These afford the Opportunity for a more accurate dose calculation than possible from first-principle physical considerations. On-site radiation surveys were late (D+9 days) and did not facilitate an internal exposure analysis (Reference 8). The urinalysis data collected by Dr. Payne S. Harris of the Los Alamos National Laboratory are the most useful for this dose calculation because they are based on a comparatively early (D+17 days) sample collection and are well documented (Reference 9), The urinalysis results reported by the Naval Radiological Defense Laboratory involved samples collected much later (D+44 days and after), for which the available documentation is weak (Reference 13). It is understood that urinalysis results were also reported by medical personnel at Tripler Army Hospital; however, apparently the sample collection times were so late that meaningful results were not reported (Reference 4). The urinalysis data reported by Dr. Harris for the American servicemen were based on a 10-man, pooled urine sample collected on 18 March 1954. The urine 17 3