The document has an innocuous title, "Applications of Nuclear Physics," as if it were part of an introductory college course.
Its authors are identified as Iraq's Atomic Energy Agency and two weapons research centers. Then come the words "TOP SECRET."
In 105 pages including charts and graphs, Iraqi authorities in 1987 described their efforts to develop bombs that would have used conventional explosives to scatter radioactive material produced in a nuclear research reactor. In three field tests, the designers determined that the one-ton device would indeed explode, and then detonated a bomb on the ground and dropped two from Iraqi aircraft.
"The explosion was awesome," the document says of the ground test. "We saw the blast wave moving out of the centre of the explosion in the form of a circle moving at great speed, then an awesome cloud of earth rose to a height of 200 meters approximately from the earth's surface, then it moved off in the wind direction at the wind's speed. We waited for 15 minutes after the explosion, then a group ... with all its protective equipment, moved into the area of the experiment and registered the readings for the rates of radiation dosage."
Iraq apparently provided the document to United Nations weapons inspectors who entered the country after the Persian Gulf war. It was released this week by the Wisconsin Project on Nuclear Arms, a nonprofit organization in Washington that tracks the spread of nuclear weapons.
"We received it from a source that we consider reliable and that would have had a professional reason to receive the document," said Gary Milhollin, the project's director, who confirmed it was from the United Nations and expressed confidence in its authenticity.
As chronicled by the document, Iraqi scientists successfully evaded international controls when it irradiated zirconium in a now-destroyed research reactor. After being made radioactive, the zirconium was packed into lead casings equipped with conventional explosives.
Iraq was at the time fighting to a standoff in a war against Iran. There is no clear evidence that development of the weapon continued. What follows are excerpts from the document, available in full at www.iraqwatch.com.
The purpose of this report is to study the possibility of using the vertical channels of the Tammuz reactor to irradiate quantities of the raw materials of zirconium (containing zirconium, hafnium, uranium, and iron in different proportions) ... to be used as charges in aerial bombs weighing approximately 1,000 kilograms each to give known weapons additional effectiveness by contaminating the areas in which these bombs are used through spreading radioactive material in a wide pattern in the air.
In order to define this effect and estimate the benefit of using it, a number of experiments were performed and theoretical calculations were made. In addition, the necessary industrial facilities were established, with complete cooperation between the Atomic Energy Agency and Al-Qa'qa' and Al-Muthanna Facilities of the Military Industrial Commission. We paid special attention to safety considerations and to safeguarding the reactor, since the operations diverged from traditional methods, and we took precautions against the dangers of radiation to the people who handle the charge after it is irradiated and until it is dropped on the enemy.
Theoretical calculations show that it is possible to irradiate a charge containing 2.4 kilograms of zirconium in some of the vertical columns in the reactor so that the charge will have a biological effect during an irradiation period ranging from 7 to 15 hours. After that, this quantity of zirconium was actually irradiated. ... It was confirmed through the experiment that the Al-Qa'qa' facility can produce charges with the exact specifications, and the charges can be put into the reactor channels without any great effect on the reactor itself. ...
The lead container (with the irradiated zirconium charge inside it) was placed inside the bomb surrounded on all sides by high-explosive material "T.N.T." Models of the containers were made, and it was confirmed through tests that the containers would not affect the bursting of the bomb or the scattering of the irradiated material in the area of the explosion. Aerial field tests of the bomb were also performed, with complete suc- cess. ...
It was clear from these tests that the optimum situation would be to produce an aerial explosion at a height of 10 to 40 meters, since it would be expected that the irradiated material would fall in an approximately 350-meter diameter circle, producing a clear biological effect on anyone in the area during the explosion or up to a week afterward. ...
The weapon will weaken enemy units from the standpoint of health and inflict losses that would be difficult to explain, possibly producing a psychological effect. Suggested uses are:
Areas where troops are expected to be massed
Fortified defense areas where the enemy is holding firm
Bridges and troop crossings
Any other areas the command decrees
The bursting of this bomb will cause the usual effects of the traditional bomb and will add a biological effect which will strike the enemy in the first degree with regard to external exposure, and the degree increases with internal exposure (inhalation). It is clear from our calculations 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.
The principal limitations are:
A. One batch of 17 charges can be irradiated in a day. The radioactive strength/danger lessens after 4 days. After that, it must be used in bombs and dropped on a target without delay because the effectiveness of the irradiation decreases with time. The period between irradiation and use cannot exceed one week. ...
B. Weather conditions should include as little wind as possible and normal conditions to ensure optimum distribution of the irradiated material in the air and on the ground. This is one limitation, because different weather conditions will greatly decrease the effectiveness of the biological factor to the limits of the first or second stage, and the effects will not appear until after a very long time has passed.
C. All of the work in its entirety must be in accordance with the [International Atomic Energy Agency] guidelines so that none of the workers makes a mistake which will expose him to radiation.
D. Because of the lack of technical awareness this work must be done in strict secrecy, even with regard to those doing the work, so as not to give rise to psychological feelings leading to hesitation because of a fear of radiation. Those in charge must be completely aware of their roles.
E. It must be certain that the bomb will explode by installing more than one fuse to detonate it so that if it does not explode in the air it will explode on the ground.
F. If the enemy were to carry out a specialist physical analysis of the dust/soil shortly after the explosion then it would be possible for him to arrive at the nature of the radioactive material, the degree of its effect etc. ...
Results of a test bombing
The experiment was carried out in the Western Firing Range ... on Monday, Dec. 12, 1987. ... [T]wo live projectiles were dropped at exactly 4 o'clock and the distance between their points of impact was less than 15 metres.
The cloud of the explosion rose approximately three hundred metres from the surface of the earth. The wind speed was fluctuating between 1-2 m/sec and the weather was calm. A group of the organisation left about half an hour after the explosion to allow sufficient time for the irradiated cloud to disperse and the direct readings of the level of radiation were recorded by using the portable equipment.
The equipment was increasingly affected as we approached the centre of the explosion and at a distance of 80 metres the readings were 150 pulses/sec. It then began to increase until it reached more than 15,000 pulses/sec near the centre of the explosion.