Section 4 DOSE CALCULATIONS To determine the dose to personnel, consideration is given to the time spent topside and below decks and the radiation protection afforded by a ship. The daily, free-field integrated intensities (topside and below) from section 3 are adjusted to account for crew activities, either documented or assumed. The daily exposures (mR) are then converted to film badge equivalence (mrem). Results are presented as a daily cumulative dose to personnel through 31 May 1954, or into the post-operational period as necessary until shipboard dose accrual falls below 1 mrem per day. An estimate of personnel movements is critical in determining a film badge dose, especially during fallout deposition and at early times when topside intensities are relatively high and intensity levels are changing through decontamination. Only two of the ships considered herein experienced significant fallout from Shot BRAVO--COCOPAand PC-1546. A review of the ship's logs gives no indication that normal crew duties were interrupted on | and 2 March due to the fallout; however, because intensity levels were still relatively high on these two ships, it is necessary to account for specific periods of time on deck in order to calculate personnel doses. Shot ROMEOfallout, on the other hand, peaked at approximately 0001-0400 hours, 29 March, on several of the ships while anchored in Bikini Lagoon. Rad-safe measures, such as turning on the ship's washdown system, were generally accomplished at a time when virtually all of the crew wasalready below deck. By the time crews were mustered at approximately 0800, shipboard intensity levels had been reduced to where normal crew duties could be resumed without restriction; hence, it is not necessary to detail personnel rnovements onboard the task group ships following Shot ROMEOto estimate their dose. Fallout from the remaining four shots in the CASTLEseries did not seriously hamper normal crew activities on any of the ships considered herein; therefore, dose estimates for the crews of these ships are made withoutdetailing personnel movements onboard ship during periodsof fallout deposition. With the exception of 1-2 March on COCOPA and PC-1546, when actual times topside and below are used, the integrated intensities topside due to fallout (from tables in section 3) are multiplied by a time-averaged shielding factor to account for the time spent topside and below during a typical work day. As discussed in section 1, the time spent below was 60 percent of the day (14 1/2 hours). While below, the crew wasoffered shielding provided by the ship's structure. In Reference 1, it was determined that ship-shielding factors vary from approximately 0.06 to 71