Countdown to Zero Day: Stuxnet and the Launch of the World's First Digital Weapon

by Kim Zetter

  Iran was one of the first countries to sign the treaty in 1968, and by 1974 it had established its own Atomic Energy Organization and developed a grand scheme to build twenty nuclear reactors with support from Germany, the United States, and France, who all stood to gain from the sale of equipment to the shah’s regime. The first two reactors were to be built at Bushehr. In 1975, German engineers with the Siemens subsidiary Kraftwerk Union broke ground on the $4.3 billion construction project, which was slated to be completed in 1981.17

  There were concerns at the time that Iran’s endgame might be nuclear weapons. The shah himself hinted at one point that his nuclear aims weren’t solely peaceful in nature, asserting in an interview that Iran would get nuclear weapons “without a doubt … sooner than one would think” if conditions in the Middle East made it necessary.18 But US leaders weren’t worried, because they considered the shah a friend and couldn’t seem to fathom a day when he or his regime wouldn’t be in power.19

  That day came pretty quickly, however, when the Islamic Revolution erupted in 1979 just as one of the reactor buildings at Bushehr was nearing completion. The revolutionaries who ousted the shah and seized power with the Ayatollah Ruhollah Khomeini took a narrow view of the behemoth reactors being erected at Bushehr, considering them a symbol of the shah’s alliance with the West. The United States, alarmed by the unstable political situation, withdrew support for the project, and the German government eventually forced Kraftwerk Union to pull out of its contract for Bushehr.20

  The subsequent Iran–Iraq war wasn’t kind to the abandoned reactors. Throughout the eight-year war, which ran from 1980 to 1988, Iraq bombed the two towers more than half a dozen times, leaving them in ruins.21 During the war, the commander of Iran’s Revolutionary Guard urged the Ayatollah Khomeini to launch a nuclear weapons program to fend off Iraq and its Western allies. But Khomeini refused, believing that nuclear weapons were anathema to Islam and a violation of its basic moral principles. He apparently changed his mind, however, after Saddam Hussein unleashed chemical weapons on Iranian troops and civilians, killing about 25,000 and injuring more than 100,000 others. Incensed by the UN’s passive reaction, and alarmed at rumors that Iraq was seeking to build nuclear weapons of its own, Khomeini decided to revive Iran’s nuclear program. This included developing a uranium enrichment program.22

  To launch the program, Iran turned to a Pakistani metallurgist named Abdul Qadeer Khan for help. Khan had been instrumental in helping Pakistan build its nuclear weapons program in the mid-1970s, using centrifuge technology he had stolen from Europe. Khan had worked for a Dutch company that conducted centrifuge research and development for Urenco, a consortium formed by Germany, Great Britain, and the Netherlands to develop centrifuges for nuclear power plants in Europe. As part of his job, Khan had access to sensitive centrifuge designs that he copied and took back to Pakistan. He also absconded with lists of suppliers, many of whom were willing to secretly sell Pakistan parts and materials to make the centrifuges for its program.

  Centrifuges are metal cylinders with rotors inside that can spin at speeds in excess of 100,000 revolutions per minute to enrich uranium hexafluoride gas, produced from uranium ore found in earth and seawater. The hexafluoride gas is piped into “cascades” of centrifuges—groups of centrifuges connected by pipes and valves. And as the rotors inside them spin, the centrifugal force separates the slightly lighter U-235 isotopes in the gas—the fissile isotopes needed for atomic energy—from the heavier U-238 isotopes, in a process likened to panning for gold.23 Gas containing the heavier isotopes gets pushed to the outer wall, while gas containing lighter isotopes gathers closer to the center. Coils wrapped around the outside of the centrifuge that are filled with heated water create a varying temperature that sets the gas in vertical motion, in an oval pattern along the wall of the centrifuge, to further separate the isotopes. Scoops divert the gas containing the concentration of lighter isotopes into other centrifuges at a “higher” stage in the cascade, where further separation occurs, while the heavier gas, the depleted uranium, is diverted into a second set of centrifuges in a lower stage of the cascade for further separation. When additional U-235 isotopes are separated from this gas, it gets fed back into the higher stages to be recombined with the other U-235 isotopes while the depleted gas is sent to “waste”—that is, the tail end of the cascade, where it gets discarded. This process gets repeated until gas containing the desired concentration of U-235 isotopes is achieved.24

  In 1987, after Iran revived its nuclear program, officials there contacted a German engineer-turned-black-marketeer, who was a key supplier of equipment for Pakistan’s illicit nuclear program. He helped arrange a secret meeting in Dubai between Iranian officials and other members of the Khan supply network. In exchange for $10 million, the Iranians walked away with two large suitcases and two briefcases filled with everything they needed to kick-start a uranium enrichment program—technical designs for making centrifuges, a couple of disassembled centrifuge prototypes, and a drawing for the layout of a small centrifuge plant containing six cascades.25 Apparently as a bonus, the marketeers threw in a fifteen-page document describing how to turn enriched uranium into uranium metal and cast it into “hemispheres,” the core component of nuclear bombs.26 Khan later told Pakistani television that he helped Iran develop its nuclear program because he thought if both Pakistan and Iran became nuclear powers, they would “neutralize Israel’s power” in the region.27

  The disassembled centrifuges the Iranians received were based on one of the designs Khan stole from Urenco. In Pakistan the centrifuge was known as a P-1, but in Iran it became known as the IR-1. Initially, Iran lacked money to do much of anything with the designs, but in 1988, after the Iran–Iraq war ended and its resources were freed up, the country began pouring money into an enrichment program, buying high-strength aluminum and other materials to build its own centrifuges, and secretly importing nearly two tons of natural uranium—including uranium hexafluoride gas—from China.28

  Khan later secretly gave Iran components for five hundred P-1 centrifuges, as well as instructions for setting up a quality-assurance program for making and testing the centrifuges. The latter was badly needed because Iran was having trouble with the centrifuges it had created from Pakistan’s prototypes. Sometimes they spun out of control and crashed; other times they didn’t work at all.29 By 1994, Iran had succeeded in operating only one centrifuge successfully at “nearly full speed.”30

  As a result, the Iranians accused Khan of selling them a bill of goods. So in 1996, he handed over drawings for Pakistan’s P-2 centrifuge, a more advanced centrifuge based on another design stolen from Urenco.31 The P-2 was much more efficient than the IR-1 and could enrich about two and a half times the amount of uranium in the same amount of time. It also used a rotor made from maraging steel—a more resilient material than the breakage-prone aluminum rotors in the IR-1.

  While Iran was busy developing its secret uranium enrichment program, its public nuclear program continued in parallel. In 1995, the country signed an $800 million contract with Russia to resume construction of a reactor at Bushehr. The two countries also discussed building a uranium enrichment plant to produce fuel for the reactor, but the Clinton administration intervened and convinced Russia to drop it. So Iran simply built a secret enrichment plant on its own.32

  Around this time, Europe began tightening export controls on dual-use equipment and components. The controls didn’t deter Iran, however; they just forced its covert program further underground. To protect research and production facilities from being discovered, officials began spreading the work out among various sites around the country, some of them on protected military grounds, others hidden in plain sight in unassuming offices and warehouses. As part of this effort, it moved its centrifuge-manufacturing operations out of the Tehran Nuclear Research Center, where it had been launched, and into factories that once belonged to the Kalaye Electric Company, a former watch factory in an industrial part of Te
hran that the Atomic Energy Organization had purchased as a front operation. It was the same company that Jafarzadeh would later mention at his press conference in 2002.

  Sometime around 1999, Iran conducted its first successful enrichment tests at the Kalaye factory using small cascades of centrifuges and some of the uranium hexafluoride gas purchased from China.33 It was a major breakthrough, proving once and for all the viability of a program that had taken a decade to develop. Officials with Iran’s Atomic Energy Organization went full tilt at this point, ordering workers to begin large-scale production of 10,000 centrifuges for a sprawling enrichment plant they planned to build at Natanz. At the same time, they began ramping up procurement efforts to obtain parts and materials in Europe and elsewhere.34 Sometime in 2000, workers broke ground on the complex at Natanz, and Iran was on its way to becoming a nuclear nation.

  * * *

  1 Alireza Jafarzadeh’s speech is available in C-SPAN’s library at: c-​spanvideo.​org/​program/​172005-​1. A nonofficial transcript of his comments is also available at: iranwatch.​org/​privateviews/​NCRI/​perspex-​ncri-​topsecretprojects-​081402.​htm.

  2 Although nuclear nonproliferation specialists weren’t too concerned about plutonium from the light-water reactor at Bushehr being used to create nuclear weapons, because the material wasn’t ideal for that purpose, there were other concerns related to the reactor. Deputy Assistant Secretary of Defense Marshall Billingslea told the Senate on July 29, 2002, that there were concerns that Bushehr was “a pretext for the creation of an infrastructure designed to help Tehran acquire atomic weapons”—meaning that materials acquired for Bushehr might be used for secret nuclear activites instead.

  3 Heavy water is water with a high amount of the hydrogen isotope deuterium. Heavy water has nonweapons applications as a coolant and moderator in power plants and in research reactors for the production of medical isotopes. But spent fuel from such plants contains plutonium and other materials that, when reprocessed, can be used for nuclear weapons. Heavy-water reactors are a better source of plutonium than light-water reactors like Bushehr.

  4 For more information, see this page.

  5 Jafarzadeh said the NCRI received the intelligence just days before the press conference and that it came from members of the resistance inside Iran. “These are people who were directly associated or involved with this, [and] had access to information directly about these kinds of activities,” he told reporters in the room. “Certainly, these are people who have access to this information within the regime.” Asked if his group had shared the intelligence with US authorities, Jafarzadeh parsed his words carefully. The data “have been prov …,” he started to say, “have been available to the proper authorities in this country. I’m not aware of their reaction yet.” Two years later, CIA Director George Tenet said about these and other revelations from the NCRI, “I want to assure you that recent Iranian admissions about their nuclear programs validate our intelligence assessments. It is flat wrong to say that we were ‘surprised’ by reports from the Iranian opposition last year.” He was speaking at Georgetown University on February 5, 2004. A transcript of his talk is available at: https://​www.​cia.​gov/​news-​information/​speeches-​testimony/​2004/​tenet_​georgetownspeech_​02052004.​html.

  6 Israel secretly joined the ranks of nuclear powers in 1967.

  7 The NCRI’s lobbying campaign worked. With the aid and support of a number of US lawmakers, as well as former leaders of the FBI and CIA, the group got its name removed from the terrorist list in 2012. Supporters called the group a loyal ally of the United States and cited its role in helping expose Iran’s covert nuclear program as one of the reasons to remove it from the list.

  8 The other company was GeoEye.

  9 An IAEA source confirmed to me that the agency did commission the images.

  10 David Albright, Peddling Peril: How the Secret Nuclear Trade Arms America’s Enemies (New York: Free Press, 2010), 187.

  11 Author interview with Heinonen in June 2011.

  12 There are differing reports about what the IAEA knew when. According to Mark Hibbs, a former leading journalist on nuclear issues who is now a policy analyst, about two months before the NCRI’s press conference, the United States gave the IAEA coordinates for the suspect sites in Iran, which the United States had been tracking since at least the beginning of 2002 (Hibbs, “US Briefed Suppliers Group in October on Suspected Iranian Enrichment Plant,” Nuclear Fuel, December 23, 2001). David Albright of ISIS says, however, that although US sources gave the IAEA coordinates for sites, they didn’t say that the Natanz site was a uranium enrichment plant. Mohamed ElBaradei, in his book The Age of Deception, acknowledges that in mid-2002 the IAEA received information about the Natanz facility, but doesn’t say if the IAEA knew it was a uranium enrichment plant.

  13 Iranian officials would later say that the only reason they had concealed their activities at Natanz was because the West had tried to thwart their efforts to build a civilian nuclear program.

  14 A transcript of the CNN piece is available at http://​transcripts.​cnn.​com/​TRANSCRIPTS/​0212/​13/​lol.​07.​html.

  15 Digital National Security Archive, “US Supplied Nuclear Material to Iran,” January 29, 1980, available at nsarchive.​chadwyck.​com (registration required). See also Dieter Bednarz and Erich Follath, “The Threat Next Door: A Visit to Ahmadinejad’s Nuclear Laboratory,” Spiegel Online, June 24, 2011, available at spiegel.​de/​international/​world/​the-​threat-​next-​door-​a-visit-to-​ahmadinejad-s-​nuclear-laboratory-​a-​770272.​html.

  16 Anne Hessing Cahn, “Determinants of the Nuclear Option: The Case of Iran,” in Nuclear Proliferation in the Near-Nuclear Countries, eds. Onkar Marway and Ann Shulz (Cambridge: Ballinger Publishing Co., 1975), 186.

  17 Ali Vaez, “Waiting for Bushehr,” Foreign Policy, September 11, 2011.

  18 John K. Cooley, “More Fingers on Nuclear Trigger?” Christian Science Monitor, June 25, 1974. Iranian officials later denied that he made the statement.

  19 In fact, Iran discussed plans with Israel to adapt surface-to-surface missiles to fit them with nuclear warheads. See Paul Michaud, “Iran Opted for N-bomb Under Shah: Ex-Official,” Dawn, September 23, 2003. Also, according to Akbar Etemad, head of Iran’s Atomic Energy Organization under the shah, he had been tasked with creating a special team to track the latest nuclear research so that Iran would be ready to build a bomb if and when it was necessary. He disclosed the information during an interview with Le Figaro in 2003, according to Elaine Sciolino, “The World’s Nuclear Ambitions Aren’t New for Iran,” New York Times, June 22, 2003.

  20 John Geddes, “German Concern Ends a Contract,” New York Times, August 3, 1979. See also Judith Perera, “Nuclear Plants Take Root in the Desert,” New Scientist, August 23, 1979.

  21 Vaez, “Waiting for Bushehr.”

  22 Institute for Science and International Security, “Excerpts from Internal IAEA Document on Alleged Iranian Nuclear Weaponization,” October 2, 2009. The ISIS report is based on an IAEA internal document titled “Possible Military Dimensions of Iran’s Nuclear Program,” available at isisnucleariran.​org/​assets/​pdf/​IAEA_info_3October2009.​pdf.

  23 The U-235 isotope has three fewer neutrons than the U-238, which makes it lighter.

  24 Charles D. Ferguson, Nuclear Energy: What Everyone Needs to Know (New York: Oxford University Press, 2011).

  25 Dennis Frantz and Catherine Collins, The Nuclear Jihadist: The True Story of the Man Who Sold the World’s Most Dangerous Secrets (New York: Free Press, 2007), 156. The items were listed on a handwritten document the IAEA obtained that was described in IAEA Board of Governors, “Director General, Implementation of the NPT Safeguards Agreement in the Islamic Republic of Iran, GOV/2005/67” (report, September 2, 2005), 5.

  26 In November 2007, according to the IAEA Board of Governors, Iran gave the IAEA a copy of the fifteen-page document, “Implementation of the NP
T Safeguards Agreement and relevant provisions of Security Council resolutions 1737 (2006) and 1747 (2007) in the Islamic Republic of Iran” (report, February 22, 2008), 4. Iran claimed it had not requested the document but received it unsolicited from the black marketeers.

  27 Erich Follath and Holger Stark, “The Birth of a Bomb: A History of Iran’s Nuclear Ambitions,” Der Spiegel, June 17, 2010.

  28 IAEA Board of Governors, “Implementation of the NPT Safeguards Agreement in the Islamic Republic of Iran” (report, November 10, 2003), 5.

  29 In 1992, the former head of Iran’s Atomic Energy Organization, Masud Naraghi, left Iran and provided the CIA with some information about Iran’s program. Naraghi had helped negotiate the deal in 1987 between Iran and A. Q. Khan to obtain the first centrifuges for Iran’s enrichment program. He told the CIA, for example, that Iranian researchers were having trouble with the IR-1 centrifuges that they were trying to build from Khan’s design. See Frantz and Collins, Nuclear Jihadist, 202. See also Albright, Peddling Peril, 76–81.

  30 Nuclear Jihadist, 213.

  31 IAEA Board of Governors, “Director General, Implementation of the NPT Safeguards Agreement” (report September 2, 2005), 5.

  32 It’s believed that designs for a separate uranium conversion plant at Esfahan—for converting milled uranium ore into gas—may have come from China. In 1997, the Clinton administration announced that it had halted a deal that China had made to sell Iran a conversion facility, but Iran still obtained blueprints for the plant from the Chinese. See John Pomfret, “U.S. May Certify China on Curbing Nuclear Exports,” Washington Post, September 18, 1997.