“nforeseen fallout of small radioactive particles (less than 5 microns) curred on the night of D+l and covered the atoll, raising radiation lev3 bY approximately 0.100 R/hr. The small radioactive fallout particles “2a more difficult to remove than the fallout from the larger BRAVO parti_:3. The secondary fallout stopped between 0700 and 0800 on D+2. Resid- .al topside levels for ships that received fallout are given in Table 32. Fallout contaminated the western quarter of the lagoon with radiation -v2ls comparable to those of BRAVO. Lagoon flushing through the south- 2St Dassage substantially increased background radiation levels in the “.cinity of Oroken, Bokaetoktok, and Bokdrolul. On shot day the low-intensity contamination moving to the southwest ‘as reported by Wilson 3, and accordingly an alert message was dispatched :0 the Enewetak garrison indicating the presence of a westerly movement of itantgen-range contamination approximately 60 nmi cf ground zero. (111 km) west-northwest Although calculations indicated the contamination would cass to the north of Enewetak, all personnel at that atoll were directed to remain on alert status until H+24. No significant fallout was subse- quently experienced, a fact verified by a report at 1900 from the Enewetak monitoring system indicating 0.001 R/hr maximum on Enewetak and Parry and Zero background on Lojwa. The low-intensity contacts southwest of ground zero were not considered significant for Ujelang. Fallout began on Enewetak Island on D+2 at 1500, with peak readings of 0.010 to 0.015 R/hr. high as 0.040 R/hr. There were also local “hot spots" with readings as These areas were posted with danger signs, and per- sonnel were not allowed to enter them. On D+5, the maximum intensity was 0.010 R/hr at Enewetak Island. On 31 March, the TG 7.3 unit on Kwajalein reported 0.009 R/hr maximums on the windward side of tree trunks, averages of 0.001 to 0.003 R/hr on beaches, and 0.001 to 0.004 R/hr on windward sides of buildings. erage Kwajalein background before 31 March was 0.00005 R/hr. 265 The av- Aircraft on