exposures exceeding the maximum per.iissable precluded, Pre-shot safety planning was accomplished for each event to insure that men, material and facilities would not be subjected to avoidable hazards. Of prime consideration was the threat of radioactive fall-out resulting from the detonations, Prior to each test event a predicted fall-out area was established and only when this area was clear of inhabited locations was the detonation executed, Of the shot celays encountered during Operation FARDTACK, more than ninety per cent were due to undesirable fall-out indications, These fall-out areas were posted in the -ir Operations Center so that controllers could keep aircraft clear of the Pre-shot planning also cealt with danage predictions con- cerning blast, heat and water action, Cn tuo (2) events at Inivetok anc t danger areas, = at one (1) event at Bikini it was necessary to evecuate liaison time alrerctt to preclude blast danace and on one (1) event it was necessary to reqiire complete body covering for all personnel to precluce the vossibilit; cl ourns. <A constant progran was pursveu to insure thet no one ocservec Getonations with his naked eyes. The possibility of retinal burns constituted a continual threat throuch the entire operation, Through ac.a-2 predication and the precautionary -eesures dictatea by these predicticns, no unplanned danage occurred to aircraft anc only cinor cemeces vere in- flicted on base facilities. The most difficult Task Group 7.4 ra&iological problems of the operstion existed in the support of the cloud samling program. vrrior to the operation and based on the scheculec nuwoer of detonations planned for HARDTACK, maximum permissazle exposures of ten (10) roentgens equivalent man (rem) for cloud sammling and effects aircrews and five (5) rem for a2 t LOPIED/DOE LANL RC a /