Castle Bravo
The decision to carry out the Bravo test under the prevailing winds was made by Dr. Alvin C. Graves, the Scientific Director of Operation Castle. Graves had total authority over detonating the weapon, above that of the military commander of Operation Castle. Graves appears in the widely available film of the earlier 1952 test "Ivy Mike", which examines the last-minute fallout decisions. The narrator, the western actor Reed Hadley, is filmed aboard the control ship in that film, showing the final conference. Hadley points out that 20,000 people live in the potential area of the fallout. He asks the control panel scientist if the test can be aborted and is told "yes", but it would ruin all their preparations in setting up timed measuring instruments. In Mike, the fallout correctly landed north of the inhabited area but, in the 1954 Bravo test, there was a large amount of wind shear, and the wind that was blowing north the day before the test steadily veered towards the east.
Bokak Atoll
While en route from the US to Asia in April, 1953, LST 1138, later commissioned as , dropped anchor at Bokak to search for rumored Japanese stragglers. The landing party noted the remains of the wartime outpost, but found no signs of any current occupants.
In 1954, the experience of large scale fallout from the Castle Bravo nuclear test on Bikini Atoll led to a pre-planned aerial survey of atolls adjacent to the subsequent Castle Romeo test, timed at one and four hours after the shot. The aircraft were equipped with gamma radiation detectors designed to measure ground contamination from altitudes of . An overflight of Sibylla Island measured 1.0 mrem/hr (10 μGy) an hour after the shot, dropping to 0.4 mrem/hr (4 μGy) three hours later. In 1957, Bokak was surveyed as a site for nuclear weapons testing as a part of Operation Hardtack, but due the number of improvements required to develop it, was passed over in favor of reusing the Bikini, Enewetak, and Nevada test sites. The atoll came under renewed consideration for use during Operation Dominic, but by that time the potential for political fallout from nuclear testing within a United Nations Trust Territory was deemed too great.