The Cobalt Bomb
Nuclear explosions seem horrible for many reasons. They were presented to an unprepared world as a dramatic surprise—as the climax to the slaughter of the Second World War. Their power of destruction is fantastic. Before we had adjusted our thinking to atomic bombs, an even more potent tool of warfare—the hydrogen bomb—was invented. Worst of all: To the fear of destruction there was added the dread of the unknown. It is not surprising that discussion of nuclear weapons has not proceeded on a purely rational level.
To the nightmare of the atomic and hydrogen bombs has been added—not as a reality but as a further threat—the cobalt bomb. The idea of such a bomb is to intensify the most terrifying aspect of nuclear explosions: the radioactivity. This radioactivity could be used to poison the enemy. It could get out of hand and poison everyone.
Cobalt⁶⁰ is a radioactive isotope of the fairly common metal cobalt. It can be easily produced by absorbing slow neutrons in the natural and stable cobalt⁵⁹. It has a half-life of five years and it emits penetrating gamma rays. These properties make it useful in cancer therapy.
Many cancerous growths are more sensitive to radiation than healthy tissue. Therefore radiation can be used to reduce—sometimes even to destroy—dangerous tumors. The penetrating rays of cobalt⁶⁰ can reach the cancer even deep inside the human body. The lifetime of cobalt⁶⁰ is long enough so that this substance is easily installed in hospitals.
But the same properties which make cobalt⁶⁰ useful also make it potentially dangerous. A nuclear explosion produces many neutrons and these could be absorbed in ordinary cobalt. The radioactivity produced in this way lives long enough to become widely distributed. Its ray can easily penetrate a foot of masonry and several hundred feet of air. A cobalt bomb would indeed be a most unpleasant object. (See pictures 7 and 8.)
One widely discussed possibility is that future nuclear tests will be used to develop a cobalt bomb or other bombs for radiological warfare. Actually tests have little to do with the cobalt bomb. Once one has a powerful nuclear weapon, such as a hydrogen bomb, it is relatively easy to make a radiological bomb. Further tests are not necessarily required. To the extent that any testing need be carried out, it is only necessary to activate a moderate amount of substance to find out in what way a certain bomb would function as a tool of radiological warfare. Tests of this kind would add only a negligible amount of radioactivity to the atmosphere. Therefore, in connection with the test program we need not worry about the cobalt bomb or any related experiment. The question of the cobalt bomb or radiological warfare in general is not whether it is feasible—it is—but rather whether it serves a useful military purpose.
It is not impossible that situations might arise in which radiological warfare could be militarily advantageous. Instead of cobalt, other materials may be placed near the nuclear bombs. In this way other radioactive substances can be produced. By an appropriate choice of such a substance one can get a radioactive material which, when deposited near the point of explosion, will contaminate the site for a time which can be adjusted to the military requirements. The lifetime of the radioactive material may be long enough to give an opportunity to the people to escape from the contaminated area. At the same time, one may precipitate almost all the activity near the explosion so that distant localities would not be seriously affected. It is conceivable, therefore, that radiological warfare could be used in a humane manner. By exploding a weapon of this kind near an island one might be able to force evacuation without loss of human life. No instrument, not even a weapon, is evil in itself. Everything depends on the way in which it is used.
Public opinion has all but persuaded itself that nuclear weapons will be used not for a military objective but to terrorize and kill the greatest number of people. This is technically feasible. In fact, it does not even require the atomic bomb. For the last hundred years this possibility has been with us. Bacteriological warfare may cause widespread destruction. Yet no one has resorted to this horrible way of making war. We do not believe that anyone will expose his enemy and ultimately himself to indiscriminate bacteriological or radiological destruction. Our guarantee against this danger is not that it cannot be done. Our guarantee is the better and saner part of human nature: the will to survive and the feeling of common decency.
Our Nuclear Future: Facts, Dangers and Opportunities · The Wunder Library — complete classics, free to read, with narration.