August 2013 Plutonium Mountain Inside the 17-year mission to secure a dangerous legacy of Soviet nuclear testing By Eben Harrell & David E. Hoffman Project on Managing the Atom
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Belfer Center for Science and International Affairs | Harvard Kennedy School 5 gesturing beyond the gates of Semipalatinsk-21 toward Degelen Mountain, “is a monster.” The Soviet Union conducted 209 nuclear tests at Degelen Mountain, in 181 tunnels. Most tests in- volved small- or medium-sized nuclear explosions. 8
pan and Sary-Uzen, and used giant steel drums known as “Kolbas” to contain other tiny nuclear explosions. 9 A full-blown nuclear explosive test does not consume most of the fissile materials in the weapon; instead, the material is atomized in the blast, and typically mixed with tons of rock. In many tunnels, including most of the vertical shafts at Balapan, it would be so difficult to recover any plutonium or HEU that the material did not present a serious threat. However, in experiments not involving a major nuclear explosion, or experiments that did not work, including many in the tunnels at Degelen Mountain, the plutonium or HEU remained underground, poten- tially vulnerable to theft. 10 In the early 1990s, local citizens once employed to build the tunnels at Degelen Mountain began to scavenge the tunnels, using mining equipment to steal everything they could find, including copper from the electrical wiring, and rails once used to transport nuclear devices far under- ground. 11
were other dangers, too. Five of the scavengers, sleeping in tunnels, died from gas inhalation poisoning due to improper venting of a diesel generator. 12 In the winter of 1995, Kairat Kadyrzhanov, a metallurgist living in Semipalatinsk-21, confronted the scavengers at Degelen to alert them that radiation might be present in the tunnels. “My wife and children are starving,” one of the scavengers told Kadyrzhanov, as he recalled it. “What am I supposed to do?” Scavenging in the testing site was not technically illegal—newly empowered local officials, desperate to do everything possible to spur local economic growth, had issued regional mining licenses for nonferrous metals without indicating permitted locations. 13 Kady- rzhanov and his scientist colleagues tried to enlist the few remaining Russian troops to help. The soldiers did not have ammunition, fuel, or even appropriate clothing; they were in no position to do anything. Kadyrzhanov went back to the area later in an attempt to reason with the scav- engers. He noticed that the scavenging operation had blossomed into a full-blown enterprise: the scavengers now employed heavy mining machinery and protected their worksite by carrying guns. In the ensuing months, reports began to surface of radioactive copper popping up in metals markets in neighboring China. Kadyrzhanov and other Kazakh scientists became increasingly concerned; they felt a catastrophe was threatening to unfold on their doorstep. 14
In total, the Soviet Union conducted 456 tests at Semipalatinsk and another 130 tests at the Novaya Zemlya test site in the Far North. Yet another 129 tests were conducted outside these two test sites, including 33 elsewhere in Kazakhstan. Overall, 156 tests were for industrial and peaceful nuclear purposes. Mikhailov, “USSR Nuclear Weapons Tests,” pp. 1-10. 9 Hecker, “Dealing with Kazakhstan’s Soviet Nuclear Legacy,” p.16. 10 Hecker, “Dealing with Kazakhstan’s Soviet Nuclear Legacy,” p. 17. See also: “Degelen Mountain Tunnel Neutralization Proj- ect – 1996,” http://youtu.be/kPLQ4yEXFPc (accessed January 22, 2013). 11 Russian, U.S., and Kazakhstan officials reported to us that many of the scavengers had an employment history with Degelen Enterprise, the organization commissioned to construct the tunnels during the Cold War by the Soviet Union. 12 Interview with Sergey Lukashenko, the director of Kazakhstan’s Institute of Radiation Safety and Ecology, October 2012. 13 Interviews with Kazakh and Russian officials, October 2012. 14 Interview with Kairat Kadyrzhanov, October 2012. See also, Ellen Barry, “Old Soviet Nuclear Site in Asia Has Unlike- ly Sentinel: The U.S.,” The New York Times, May 21, 2011 http://www.nytimes.com/2011/05/22/world/asia/22kazakhstan. Plutonium Mountain: Inside the 17-year mission to secure a dangerous legacy of Soviet nuclear testing 6
The United States began a voluntary suspension of nuclear weapons tests on October 31, 1958. The Soviet Union joined after two tests in November. On December 29, 1959, President Eisen- hower said that he would honor the suspension, but the United States would continue to carry out research and development, including “laboratory-type experiments.” At the time, the United States was headed toward building smaller, lighter nuclear warheads that would fit atop ballistic missiles. These and other weapons required safety testing to make sure they would not produce a fission explosion if an accident resulted in detonation of the chemical high explosives used in the weapon.
This gave rise to “hydronuclear” experiments, which involved using high explosives to crush fis- sile material, such as plutonium or HEU, without setting off a significant nuclear blast. It was re- alized that by reducing the amount of fissile material, the yield could be kept very low, much less than what most people envision when they think of a nuclear explosion. Such experiments are sometimes called “zero-yield” tests, but the energy released by fission, while small, is not neces- sarily zero. The United States began conducting hydronuclear tests on January 12, 1960. 15 In the United States, the tests were aimed at achieving a safety standard known as one-point safe. This was defined as the assurance that in the event of a detonation at any single point of the high- explosive system of a nuclear weapon, the chance of a nuclear energy release in excess of four pounds equivalent of TNT would be less than one in a million. The first U.S. hydronuclear ex- periments were carried out in a deep hole at Technical Area 49 on the grounds of the Los Alamos National Laboratory in New Mexico; subsequent work was also performed at the Nevada Test Site, primarily by the Lawrence Livermore National Laboratory. 16 The Soviet Union began its hydronuclear tests at the Semipalatinsk site in Kazakhstan in 1958, and over the next 32 years, the Soviets fired off 85 hydronuclear devices at three separate loca- tions. While the Semipalatinsk site was closed and considered secret, the Soviet activities were observed by U.S. intelligence satellites. For a number of years, the satellite photos showed a html?sq=kazakhstan&st=cse&adxnnl=1&scp=4&pagewanted=all&adxnnlx=1358883389-3cLkFKRLYih964BQBu0HqA&_r=0 (accessed July 28, 2013). 15 Robert N. Thorn and Donald R. Westervelt, “Hydronuclear Experiments,” Los Alamos National Laboratory, LA-10902- MS, February, 1987. Thorn and Westevelt note that the value of these tests was demonstrated in the 1966 accident when a B-52 bomber with nuclear weapons aboard collided in midair with a KC-135 tanker near the fishing village of Palomares, Spain. In one of the nuclear weapons that fell to the ground, the high explosive detonated, but there was not a fission explosion due to the safety measures that had been introduced. Along with hydronuclear tests, certain safety and reliability tests—termed “studies of accidental modes” in U.S. testing par- lance—were designed to ensure that the material did not fission at all. In the early days of the Cold War, such tests were quite crude: British scientists set nuclear weapons on fire in the Australian desert, according to John Carlson, the former director general of the Australian Safeguards and Nonproliferation Office. Carlson spoke to the authors in a September 2012 interview. More sophisticated experiments could potentially leave behind equally dangerous materials. So-called “popcorn tests,” for in- stance, were designed to test whether a nuclear warhead will detonate unintentionally if a conventional explosion occurs nearby. “One-point safety” experiments test whether a weapons’ physics package (i.e. plutonium and other elements that fuel a nuclear bomb) will ignite if only one section of the multiple conventional explosives arranged around it pre-detonated. These experiments involved a significant quantity of weapon-grade plutonium which was not dispersed by a large explosion and could potentially be recovered and used to make a bomb. 16 Thomas C. Reed and Danny B. Stillman, The Nuclear Express: A Political History of the Bomb and Its Proliferation, (Min- neapolis: Zenith Press, 2009) pp. 62-63. Yüklə 333,26 Kb. Dostları ilə paylaş:
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