In February 1996, Iraq gave the United Nations a report that purported to cover an Iraqi program to develop and test a nuclear radiation bomb in 1987. The report, which was labeled “top secret,” explained the design of the bomb and the steps Iraq took to develop it. Iraq had irradiated zirconium oxide in a nuclear research reactor, placed the irradiated material inside a cylinder made of lead, inserted the cylinder into a high-explosive aerial bomb, dropped the bomb on a test range, and measured the radiation that the bomb created after it exploded and dispersed the zirconium oxide into the air and soil. The principal radioactive isotope that would result from irradiating natural zirconium oxide is zirconium-95, which has a 64-day half life.
The apparent reason for making the bomb was to irradiate enemy military units or to contaminate areas such as airports, railroad stations, bridges, and fortified defense installations. The levels of radiation achieved, however, were not high enough to accomplish any significant military objective.
To better understand the report, a number of points should be kept in mind. First, each irradiated charge loses its potency quickly through radioactive decay. The report states that the bombs cannot be stored for more than a week or two without losing their effectiveness. Thus, a reactor is needed to continuously irradiate new charges while a bombing campaign is going on. The Russian-supplied IRT 5000 reactor in which Iraq made the charges has been destroyed and Iraq has no other known reactor in which to irradiate charges.
Second, the report reveals that the bomb produced only minimal levels of radiation. Measurements following the third test (the most successful, conducted in calm wind conditions) found that the maximum level of radiation was only 3 milli rem per hour at a distance of 10 meters from the point of impact. According to the report, this is only equal to the dose allowed to be received internationally by radiation workers (i.e., the occupational dose). [This is roughly the same as the occupational dose in the United States, which is five rem per year]. Such a dose, by definition, would have little or no health effect over the lifetime of the person receiving it, even if the person worked eight hours per day, five days per week within 10 meters of the bomb crater, which is highly unlikely. There would be no short-term impact on troops.
Third, the report contains errors and internal contradictions. It does not, in the opinion of an experienced U.S. nuclear weapon expert, “reflect the participation of competent technical personnel.” From other Iraqi technical documents, the UN inspectors know that Iraq did have competent technical personnel within the country. It is unclear why the report did not benefit from the aid of such personnel. The report uses incorrect methods to estimate dose rates, which resulted in an overestimation of the doses that would be received. The report also fails to explain why zirconium oxide was chosen as the material to be irradiated when other materials would be more suitable.
Fourth, the report makes confusing claims about effectiveness. The report claims on page 2 that “the required charge to cover one square kilometer is 71 charges.” This claim comes in the context of “hitting the enemy” with a dose of 200 rem in a target “occupying 12 square kilometers.” It appears impossible, however, to produce an average dose of 200 rem over one square kilometer with 71 bombs each of which produces a dose of only 3 millirem (a millirem is one thousandth of a rem) per hour 10 meters from the point of impact. The numbers don’t add up. A person spending an entire lifetime on the edge of a bomb crater would still not get a dose of 200 rem. In addition, the report says that “calculations show” that “hitting a point with 33 bombs will lead to the deaths of all personnel within a ten-meter radius of the center, given normal weather conditions…the cause of death will be exposure to radiation.” It is important to remember that each bomb contains about a ton of high-explosives. One can visualize a group of people, standing in a circle between the goal line and twenty yard line of a football field, receiving 33 one-ton bombs within the circle. After the first bomb hit, very few of these persons would have to worry about the second bomb, let alone radiation doses.
Fifth, UN inspectors visited the Iraqi test site with radiation monitors and found nothing. One inspector who was there in the early 1990’s reported that the level of radioactivity was so low that it was difficult to obtain a reading.