Air Force flights collected radioactive samples to the south of Hawaii between 8 and 10 April. The debris was widely dispersed throughout the area, but the maximum radiation levels were low (hundredths of a milliroentgen per hour). One flight reported a peak 170 nmi of Hawaii at H+56 at 14,000 feet (4.27 km). (315 km) This air sample collection point was directly along the path of the 40,000-foot (12.19-km) particle trajectory. southwest airborne A second radioactive sample was collected 100 nmi (185 km} southeast of Hawaii 26 hours later at 19,000 feet (5.79 km). Another less active sample was obtained off the coast of Southern Cali- fornia on 12 April. Aircraft operating from Guam made no collections of KOON debris. AIRCRAFT DECONTAMINATION. The decay period after the KOON shot was reduced from that of the ROMEO shot (to 20 hours) because of a possible early turnaround requirement. In addition, Table 41 indicates that the aircraft were generally only lightly contaminated compared to the two pre- vious shots. Citric acid washings were discontinued starting with KOON. The first survey of 0.007 R/hr on F-84G No. 049, some 48 hours after the first surveys on the other F-84s, inditates an intensity of about 0.730 R/hr on 7 March, which is reasonable by comparison with other aircraft. UNION The UNION device, with a yield of 6.9 MT, was detonated at 0610 on 26 April from a barge anchored in 120 feet (37 meters) of water in the Bikini Lagoon off Iroij Island. Preshot Preparation The UNION detonation was initially scheduled for 16 April. The appro- priate JTF 7 staff moved from Enewetak to the Bikini area on 15 April; at the midnight briefing, however, the weather was unfavorable and a 24-hour delay was ordered. By 1500 on 16 April, it became obvious that the wea- ther would not improve within the foreseeable future and the shot was postponed indefinitely, subject to the condition that the joint task force Maintain an 18-hour capability to conduct the test. 283 4d