time of entry. This time delay was caused by the pradtice of issuing film badges at Eniwetok and developing the film at Bikini and by a lack of night transportatjon in the lagoon. The practice of entry control by film—-badge exposqres left much to be desired, but it was the only method afail-~ able in the absence of reliable self-reading dosimetric devices. The practice of issuance and development of}film badges may have penalized many individuals because offinherent inaccuracies of the film badge in the presencefof low-energy radiation and low dosages. PRE-EVENT SAFETY MEASURES Hazard Zones A security zone, 150 x 300 nmi (278 x 556 km), was established around Enewetak and Bikini prior to CASTLE (Reference 26),* and this also served as a radsafe precaution area. The area was patrolled by P2V fhircraft and destroyers to assure that no unauthorized vessels were present. also diverted shipping from within a sector 500 nmi (926 km) The Navy From ground zero in an are extending from the southwest, clockwise to thefeast. volving primarily U.S. shipping, this was done on all shots H+24. In- fffom H-hour to ‘ After BRAVO, maximum cooperation with other nations was trol shipping in the hazard zone. ught to con- The area was officially ddsignated a danger zone and redefined as the sector centered on 12°N, 16 PE, from 240° clockwise to 95°, with a radial distance 450 nmi (833 km). subsector (designated Area Green) was defined as the region bounded by 10°15'N, 16°40'N, 160°10'E, and 170°20'E, which was subject to more itensive air and sea search prior to a shot than the rest of the danger z@ne. tionally, all U.S. shipping that passed within 600 nmi (1,11]} kini came under the operational control of CTG 7.3 Addi- km) of Bi- (for rads&fe diversion if necessary). * The area was bounded by 160935' to 166°16'E and 10°15' to posse 107