Chapter 2 The Nuclear Testing Program The nucleartesting program has played a major role in developing new weapon systems and determining the effects of nuclear explosions. Rongerik Atoll. Twotests (“*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. INTRODUCTION 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 major role in developing new weaponsystemsand determiningtheeffects of nuclear explosions. equipment, and material.4 The Bikini Atoll, how- ever, 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 THE HISTORY OF NUCLEAR TESTING Sandstone (‘'X-ray,’’ ‘‘ Yoke,”* and *‘Zebra’’) were proof tests for new bomb designs. As plans developed to expandthe 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 NevadaTest Site was chosen in December 1950 by President Truman as a continental proving ground for testing nuclear weapons. A month later, the first test—code named **Able’’"—was conducted using a device dropped from a B-50 bomber over Frenchman Flat as part of 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 TNT.* 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 a five-test series called ‘‘Operation Ranger.”’ The five tests were completed within | 1 days at what was then called the ‘*Nevada Proving Ground.” 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 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 Staff was created, on November10, 1945, to arrange called hydrogen or fusion bombs). On October 31. the first series of nuclear test explosions. President Truman approvedthe plan on January 10, 1946. The Bikini Atoll was selected as the test site and the 1952, the United States exploded the 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 previoustest. 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 vanationin the experimental and theoretical valuesofthe explosive energy released by TNT (although the majority of values le 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 (2.205x 10° pounds), or a long kiloton (2.24x 10 pounds). It was agreed, therefore, during the Manhattan Project that the term ‘*kiloton’’ would referto the reicase of 10! (1,000,000,000,000) calonesof explosive energy. 3John Malik, *‘The Yields of the Hiroshima and Nagasaki Nuclear Explosions,’’ Los Alamos National Laboratory report LA-8819. 1985. 4The target consisted of a fleet of over 90 vessels assembled in the Bikini Lagoon including three captured German and Japanese ships: surplus U S cruisers, destroyers, and submarines: and amphibious craft. 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 Bikini Atoll on May 20, 1956. Extensive preparations were made forthe test that included the construcuon of aruficial islands to house measuring equipment The elaborate experiments required that the bomb be dropped in a precise Jocauon in space. To accomplish this, the Swategic Air Command held a competition for bombing accuracy. Although the winner hit the correct point in every practice run, during the test the bomb was dropped 4 miles off-target. ~1l-