Field Testing The Physical Proof of Design Principles by Bob Campbell, Ben Diven, John McDonald, Bill Ogle, and Tom Scolman edited by John McDonald or the past four decades, Los interplay of field testing and laboratory de- disguisedly an instrument of destruction, Alamos has performed full-scale sign is orchestrated to optimize device per- without hurting anyone? nuclear tests as part of the Labo- formance, to guarantee reliability, to analyze From the beginning, field testing of nu- F ratory’s nuclear weapons pro- design refinements and innovations, and to clear weapons has followed commonsense gram. The Trinity Test, the world’s first study new phenomena that can affect future guidelines that accord prudent and balanced man-made nuclear explosion, occurred July weapons. concern for operational and public safety, 16, 1945, on a 100-foot tower at the White The advent of versatile, high-capacity obtaining the maximum amount of Sands Bombing Range, New Mexico. The computers makes it possible to model the diagnostic information from the high-energy- actual shot location was about 55 miles behavior of nuclear weapons to a high degree density region near the point of explosion, northwest of Alamogordo, at the north end of similitude. However, subtle and im- and meeting the exacting demands of engi- of the desert known as Jornada del Muerto perfectly understood changes in design neering and logistics in distant (and some- which extends between the Rio Grande and parameters, such as small variations in mass, times hostile) environments. The extreme the San Andres Mountains. shape, or materials, have produced unex- boundaries of the arena of nuclear testing The actual detonation of a nuclear device pected results that were discovered only encompass tropical Pacific atolls and harsh is necessary to experimentally verify the through full-scale nuclear tests. Whereas the Aleutian islands, rocket-borne reaches into theoretical concepts that underlie its design symmetry and compression of mock fissile the upper atmosphere, and holes deep under- and operation. In particular, for modern material can be studied by detonating high ground. Since 1945, tests have occurred atop weapons, such tests establish the validity of explosives in a controlled laboratory en- towers, underwater, on barges, suspended sophisticated refinements that explore the vironment without producing a nuclear yield, from balloons, dropped from aircraft, lifted limits of nuclear weapons design. In addition, the actual performance of a weapon, by rockets, on the earth’s surface, and under- occasional proof tests are conducted of fully particularly one of the thermonuclear type, ground. The locations evoke the words of a weaponized warheads before entry into the cannot be simulated in any conceivable labo- once-popular song, “Faraway Places with stockpile, and from time to time weapons are ratory experiment and must be done in an Strange-sounding Names’’—Bikini, withdrawn from the stockpile for confidence actual nuclear test. Eniwetok, Amchitka, Christmas Island; and tests. Also, tests characterized by a high Field testing is the culmination of the nearer to home, at the Nevada Test Site degree of complexity are conducted to study imposing array of scientific and engineering (NTS), Frenchman Flat, Yucca Lake, and military vulnerability and effects. effort necessary to discharge the Labora- Pahute Mesa, among others. These names, Information from test detonations assures tory’s role in developing and maintaining no longer so strange sounding, have become that weapons designs which match their nuclear weapons technology to support the familiar parts of the test community’s lan- delivery systems can be produced in a man- United States national security policy of guage. ner consistent with the availability of fissile nuclear deterrence. Embedded therein is the At various times between June 1946 and material and other critical resources. The paradox: How do you test a bomb, un- November 1962, atmospheric and under- 164 Winter/Spring 1983 LOS ALAMOS SCIENCE second called for a strong underground test program. The third concerned maintenance of the capability to return to testing in the “prohibited environments’’—the atmos- phere, underwater, and space—should that be necessary, and the fourth recognized the need to monitor carefully the nuclear test activities of other nations. The first two safeguards provided new justification for underground testing, includ- ing tests purely scientific in nature. The third safeguard led to nonnuclear atmospheric physics tests in Alaska, northern Canada, and the Pacific region. The facilities and capabilities held in readiness for nuclear tests were used in many scientific endeavors, including solar eclipse expeditions and auroral studies. The fourth safeguard was responsible for triggering Laboratory ac- tivity in space, as Los Alamos developed a satellite test-monitoring capability that arose from the Vela program. This in turn has led to a number of first-rate scientific space Aerial view of subsidence craters from underground nuclear tests in Yucca Flat at the programs. NTS. The so-called Yucca Lake is in the background, and the Control Point complex At present, the Los Alamos test program is carried out by approximately 385 Labora- is to the right of the dry lake. tory employees from the Test Operations Office and various divisions, including WX, ground tests were conducted by the U.S. 1958 was ended abruptly in August 1961 P, ESS, MST, INC, M, X, and H. Their principally on Eniwetok and Bikini Atolls in when the Soviets resumed atmospheric test- efforts are supplemented by about 740 con- the Marshall Islands and on Christmas ing. During the period of nontesting, the U.S. tractor employees of the DOE’s Nevada Island and Johnston Atoll in the Pacific made substantial progress in its mathemati- Operations Office working at the NTS. Ocean; at the Nevada Test Site; and over the cal modeling capability, but because Notable among the contractors are the South Atlantic Ocean. Since November substantial preparations for atmospheric Reynolds Electrical Engineering Company 1962, even before the atmospheric test ban tests had not been made, it was not until the (REECo) for drilling and field construction, treaty of 1963 came into effect, all U.S. late spring of 1962 that atmospheric nuclear EG&G for technical support, Holmes and nuclear weapons tests have been under- experiments could be fielded. Underground Narver (H&N) for construction architecture ground, most of them at the NTS, as part of tests had been resumed in the early fall of and engineering; and Fenix and Scisson an ongoing weapons program. Three under- 1961. (F&S) for drilling architecture and engineer- ground tests were conducted on Amchitka In conjunction with ratification of the ing. The dedicated efforts of all these people Island in the Aleutians. Some tests for safety Limited Test Ban Treaty (LTBT) in October are necessary to execute nuclear tests as a studies, peaceful uses of nuclear energy, and 1963, the Joint Chiefs of Staff defined four vital element of the Los Alamos weapons test detection research were conducted on safeguards, which, with the strong support of program. the Nellis AFB Bombing Range in Nevada, Congress, were to have significant impact and at other locations in Colorado, Nevada, upon the Laboratory. Diagnostics and Testing Technology New Mexico, and Mississippi. The accom- The first safeguard was, in effect, a panying table summarizes testing activities. promise that the nuclear weapons labora- Before the Trinity test, estimates of its A nuclear test moratorium initiated in tories would be kept strong and viable. The yield varied from zero to 20 or more kilo- LOS ALAMOS SCIENCE Winter/Spring 1983 165 NUCLEAR WEAPONS TEST OPERATIONSa Announced U.S. Nuclear Operation Testsb Dates Location Trinity 1 July 1945 Alamogordo New Mexico June - July 1946 Bikini Atoll April - May 1948 Eniwetok Atoll January - February 1951 Nevada Test Site April - May 1951 Eniwetok Atoll October - November 1951 Nevada Test Site April - June 1952 Nevada Test Site October - November 1952 Eniwetok Atoll March - June 1953 Nevada Test Site February - May 1954 Bikini and Eniwetok Atolls February - May 1955 Nevada Test Site April 1955 East Pacific November 1955- January 1956 Nevada Test Site May - July 1956 Eniwetok and Bikini Atolls April 1957 Nevada Test Site May - October 1957 Nevada Test Site December 1957 Nevada Test Site February - March 1958 Nevada Test Site April - August 1958 Eniwetok and Bikini Atolls; Johnston Island August - September 1958 South Atlantic September - October 1958 Nevada Test Site September 1961- June 1962 Nevada Test Site; Carlsbad, New Mexico April 1962- October 1962 Christmas and Johnston Islands July 1962- November 1962 Johnston Island July 1962- June 1963 Nevada Test Site August 1963- June 1964 Nevada Test Site; Fallon, Nevada July 1964- June 1965 Nevada Test Site; Hattiesburg, Mississippi July 1965- June 1966 Nevada Test Site; Amchitka, Alaska July 1966- June 1967 Nevada Test Site; Hattiesburg, Mississippi July 1967- June 1968 Nevada Test Site; Dulce, New Mexico July 1968- June 1969 Nevada Test Site July 1969- June 1970 Nevada Test Site; Grand Valley, Colorado; Amchitka, Alaska October 1970- June 1971 Nevada Test Site July 1971- May 1972 Nevada Test Site; Amchitka, Alaska July 1972- June 1973 Nevada Test Site; Rifle, Colorado October 1973- June 1974 Nevada Test Site July 1974- June 1975 Nevada Test Site September 1975- August 1976 Nevada Test Site November 1976- September 1977 Nevada Test Site October 1977- September 1978 Nevada Test Site November 1978- September 1979 Nevada Test Site November 1979- September 1980 Nevada Test Site October 1980- September 1981 Nevada Test Site October 1981- September 1982 Nevada Test Site November 1982- Nevada Test Site World War II were August 5 and 9,1945, respectively. b All tests before August 5, 1963, and after June 14, 1979, have been announced. 166 Winter/Spring 1983 LOS ALAMOS SCIENCE Field Testing tude. Detectors and recording equipment have been developed to follow the later faster reacting devices.