Chapter 2 The Nuclear Testing Program The nuclear testing program has played a major role in developing new weapon systems and determining the effects of nuclear explosions. INTRODUCTION Rongerik Atoll. Two tests (*‘Able’’ and ** Baker’) were detonated on Bikini in June and July of 1946 as part of **Operation Crossroads,’’ a series designed to study the effects of nuclear weapons on ships, equipment, and material.4 The Bikini Atoll. however, was found to be too small to accommodate support facilities for the next test series and so *‘Operation Sandstone’’ was conducted on the nearby Enewetak Atoll. The tests of Operation In the past four decades, nuclear weapons have evolved into highly sophisticated and specialized devices. Throughout this evolution. the nuclear testing program has played a majorrole in developing new weaponsystems and determiningthe effects of nuclear explosions. THE HISTORY OF NUCLEAR TESTING Sandstone (‘‘X-ray,’’ *‘ Yoke,” and ‘*Zebra’’) were prooftests for new bomb designs. Asplans developed to expand the nuclear arsenal. the expense, security, and logistical problems of testing in the Pacific became burdensome. Attention turned toward establishing a test site within the continental United States. The Nevada Test Site was chosen in December 1950 by President Trumanas a continental proving groundfor testing nuclear weapons. A month later, the first test—code named **Able’’"—was conducted using a device dropped from a B-50 bomberover Frenchman Flat as part of a five-test series called ‘‘Operation Ranger.’ The five tests were completed within 1! days at what was then called the **‘ Nevada Proving Ground."' On July 16, 1945 the world’s first nuclear bomb (code named ‘‘Trinity’’) was detonated atop a 100-foot steel tower at the Alamogordo Bombing Range, 55 miles northwest of Alamogordo, New Mexico.' The explosion had a yield of 21 kilotons (kts), the explosive energy equal to approximately 21,000 tons of TNT2 The following month, Ameri- can planes dropped two atomic bombs (‘‘Little Boy,”’ 13 kilotons; ‘‘Fat Man,°’ 23 kilotons) on the Japanese cities of Hiroshima and Nagasaki, ending World War II] and beginning the age of nuclear weapons.? Within weeksafter the bombing of Hiroshima and Nagasaki, plans were underwayto study the effects of nuclear weapons and explore further design possibilities. A subcommittee of the Joint Chiefs of Staff was created, on November 10, 1945, to arrange the first series of nuclear test explosions. President Truman approved the plan on January 10, 1946. The Bikini Atoll was selected as the test site and the Although the Nevada Test Site was fully operational by 1951, the Pacific continued to be used as a test site for developing thermonuclear weapons(also called hydrogen or fusion bombs). On October 31. 1952, the United States explodedthe first hydrogen (fusion) device on Enewetak Atoll.* The test. code named ‘* Mike,’ had an explosive yield of 10.400 kilotons—over 200 times the largest previous test. Bikinians were relocated to the nearby uninhabited 'The Alamogordo Bombing Range is now the White Sands Missile Range. 2A kiloton (kt) was originally defined as the explosive equivalent of 1,000 tons of TNT. This definition, however, was found to be imprecise for two reasons.First, there is some variation in the experimentalandtheoretical values of the explosive energy released by TNT (although the majonity ofvalues lie in the range from 900 to 1,100 calories per gram). Second, the term kiloton could refer to a short kiloton (2x 10® pounds), a metric kiloton (2.205% 10° pounds), or a long kiloton (2.24x 10° pounds). It was agreed, therefore, during the Manhattan Project that the term ‘‘kiloton’’ would refer to the release of 10!2 (1,000,000,000,000) calories of explosive energy. 3John Malik, ‘‘The Yields of the Hiroshima and Nagasaki Nuclear Explosions,’’ Los Alamos National Laboratory report LA-8819. 1985 ‘The target consisted ofa fleet of over 90 vessels assembled in the Bikini Lagoon including three captured German and Japanese ships: surplus US. cruisers, destroyers, and submarines; and amphibiouscraft. 5The first test of an actual hydrogen bomb (rather than a device located on the surface) was ‘*Cherokee'’ which was dropped from a plane over Bikim Atoll on May 20, 1956. Extensive preparations were made forthe test that included the construcuonofartificial islands to house measuring equipment The elaborate experiments required that the bomb be dropped in a precise location in space. To accomplish this, the Strategic Air Command held a competition for bombing accuracy. Although the winner hit the correct point in every practice run, dunng the test the bomb was dropped 4 miles of f-target. -l1-