Section 5 UNCERTAINTY ANALYSIS The uncertainty in calculated film badge doses for typical crewmembersis estimated from the underlying parameters. The basic uncertainties in the topside environment include radiation intensities from fallout deposited on deck, shine from contaminated lagoon water, and shine from contaminated ships alongside. Uncertainties in the conversion from topside environmentto personnel dose include the time spent on deck, the positions of personnel (hence their exposure) on deck, and the shielding from fallout afforded to those below. Uncertainties in the radiation environment below dueto ship contamination are dominated by the modeled buildup levels and rates of the radioactive material accumulated on the ship's hull and interior saltwater systems. The average intensities therefrom in representative crew spaces and the crew's time spent below are additional sources of uncertainty in personnel dose. Intensity levels from fallout on deck are determined from shipboard radiological survey data, supplemented at late times by decay rates measured on Bikini Atoll. Individual meter readings on deck, whereavailable, are taken as accurate, their inherent error having a negligible influence on the overall uncertainty in dose. Average on-deck intensity as a function of timeis taken as accurate; the power law interpolation in time between surveys Closely approximates fission product decay at the times after burst considered. Powerlaw fitting is less accurate during fallout deposition and decontamination; however, the influence of this uncertainty is minimized because the typical crewmember was below during these intervals. Where intensities from neighboring islands are used in lieu of shipboard data, the corrections made to determine the topside environment minimize the systematic error from this source. Overall, error in on-deck intensity from fallout is usually small compared to other uncertainties. A possible uncertainty that is unquantfiable is whether decontamination took place subsequentto the latest shipboard intensity readings, if any. The ship logs did not always indicate decontamination activities; however, none are presumed without evidence. For exposures involving shine from contaminated water, the dominant uncertainty is that in the water intensity. Both the estimation of land-equivalent radiation levels from nearby islands and their variation over the space of the operating areas contribute to waterintensity uncertainty. The conversion factor from water to topside intensity is good to 10 percent, based on the data of Reference 12. Where actual waterintensities were reported, the shine therefrom is considered to be without error. Additional uncertainties in dose from those in decay and the land-waterintensity 83