| 36 RADIOLOGICAL CLEANUP OF ENEWETAK ATOLL OPERATION CROSSROADS: JUNE-JULY 1946 Bikini Atoll was the one chosen as the site of Operation Crossroads, which wasto be the occasion of the first peacetime detonations of nuclear weapons.Theclimatic, wind, current, and harbor size requirements could be met. The selection was influenced by the fact that the population of the atoll was small and could be relocated easily and that Bikini was close to Kwajalein and Enewetak Atolls, both of which held military support facilities. Under the Presidential authority, the Navy also relocated the people of Enewetak to Meik Island in Kwajalein Atoll while the Bikini tests were being conducted.°4.55 Three tests were planned for Operation Crossroads, two of which— Able and Baker—were eventually carried out. The first of these was an aerial drop, and the second an underwater shot. The bombsweresimilar to those which had been used against the Japanesecities and which had produced yields of 13 KT at Hiroshima and 23 KT at Nagasaki. The yield, stated in KT (thousands of tons), expresses the explosive equivalent of a weight of TNT. For example, a nuclear bomb havinga yield of 25 KT would have the same explosive force as a single explosion of 25,000 tons of TNT. A ‘‘nominal”’ yield was one approximately equivalent to that of the bombs used against the Japanesecities. Test Able occurred on 30 June 1946. The bomb was dropped from a B-29 aircraft and exploded about 500 feet above the lagoon surface. The bomb detonated 1,500 feet west of the center target vessel. The vessel did not sink, but five other vessels were sunk and others were burned or damaged. The sunken ships were two attack transports, two destroyers, and a Japaneselight cruiser.°® The yield of the nuclear device of Test Able was 23 KT. Test Baker was performed with a nuclear device suspended 90 feet below a landing ship in the center of another array of ships in the lagoon. At detonation, a hollow column of water rose to a height of a mile above the surface of the lagoon. The U.S. battleship ARKANSAS, theaircraft carrier Saratoga, and the Japanese battleship Nagato were sunk, as well as other surface vessels and submarines. Some sank immediately and others took from 7-1/2 hours to 5 days to sink.°’ Test Baker also yielded the equivalent of 23 KT of TNT.58 Although these tests were successful, Bikini ifself demonstrated a numberof deficiencies as a test site. One was the lack of land area, which necessitated the use of surface vessels for planning, administration, scientific laboratory work, and for life support. A second was the combinationofisland orientation and wind direction, which prevented the installation of an adequate airstrip. _