Iraq's Nuclear Program

Iraq faced the same two challenges that every other country trying to develop a nuclear weapon has faced. First came the need to produce a critical mass of "fissile material" - uranium 235 or plutonium - the heavy metals needed to fuel a first-generation fission bomb. The second challenge was to produce a device that could cause the uranium or plutonium to explode in a nuclear chain reaction. This second process is called weaponization. Iraq attacked both challenges simultaneously.

Iraq spread the work among four major groups, all of which operated within the Iraqi Atomic Energy Commission, and more specifically within the Commission's Department of Studies and Development (also known as Department 3000). Group I was responsible for producing uranium 235 by using diffusion barriers and centrifuges. Group II tried to do the same by using chemical and electromagnetic methods. Group III was responsible for computer modeling, and Group IV performed "special tasks," another term for weaponization. The program carried the code name Petrochemical 3 (PC-3)

In 1995, Iraq admitted to the IAEA that it had considered several implosion-type bomb designs. Iraq claimed that it gave no serious consideration to the simpler, gun-type uranium bomb that the United States dropped on Hiroshima. Iraq ran the computer codes pertinent to these designs on a Japanese NEC 750 computer located at Tuwaitha, which was moved to the National Computer Center after the Gulf war. Iraq also experimented with high explosives to produce implosive shock waves and developed a 32-point electronic firing system using detonators developed at Al Qaqaa. The firing system was tested and gave satisfactory results. For research purposes, Iraq also used flash X-ray systems (180, 600 and 1200 kV), and two gas guns (light gas and high-explosive-driven gas). Iraq used fiber optics with fast response electronic equipment, and high speed electronic streak cameras - all to diagnose and perfect a workable bomb design.

Iraq also admitted studying several approaches to building a neutron initiator, which supplies the neutrons necessary to set off a nuclear chain reaction. Iraq produced and recovered tritium by irradiating lithium, and produced and recovered polonium by irradiating bismuth.

A special unit in Al Qaqaa was created to help Group Four develop and manufacture the high-explosive lenses and detonators needed for the implosion device. This group developed manufacturing processes such as rigid die-pressing of mixed explosives and plastic-bonded explosives, atmospheric and vacuum casting of melt-cast explosives, and casting of explosive/polymer composites. By the end of 1990, Iraq could perform computer numerical controlled (CNC) machining of high explosives.

The Al Qaqaa team was also responsible for developing and producing plane wave lenses During 1990, the team produced lenses with various diameters (up to 120 mm) and lengths. These lenses were tested or used as plane wave generators for shock-wave experiments. Iraq also started working on spherical lenses as early as 1988, and experimented with various kinds of explosives, including Baratol, PETN, COM-B, TNT, RDX and HMX. Iraq revealed to IAEA-4 that hundreds of tons of HMX had been imported, and that Iraq had gained "considerable experience in casting such material." The HMX was used to make improved explosive lenses for the Iraqi bomb. The Al Qaqaa team also mastered the design of dedicated exploding bridge wire (EBW) detonators, after experimenting with several types. In fact, the U.S. Departments of Defense and Energy helped train three Iraqi scientists from Al Qaqaa at a quadrennial international detonation conference in Portland, Oregon, where nuclear weapon detonation technology and flyer plate technology were presented. The latter is used to control the force and shape of implosive shock waves.

More recently, UN inspectors have learned that Iraq's first bomb design, which weighed a ton and was a full meter in diameter, was replaced by a smaller, more efficient model. From discussions with the Iraqis, the inspectors have deduced that the new design weighs only about 600 kilograms and measures only 600 to 650 millimeters in diameter. That makes it small enough to fit on Iraq's Scud-type missiles, some of which are still unaccounted for. Iraq has mastered the key technique of creating an implosive shock wave, which squeezes a bomb's nuclear material enough to trigger a chain reaction. The new Iraqi design also uses a "flying tamper," a refinement that "hammers" the nuclear material to squeeze it even harder, so that bombs can be made smaller without diminishing their explosive force. The inspectors have determined that Iraq now has a successful bomb design and lacks only the material to fuel it.