The exact implication of a few cryptic sentences by Atomic Energy Commission Chairman Lewis L. Strauss will long be debated in scientific, military and diplomatic circles, but their gist was clear: the U.S. had found a way to control, at least in some measure, the deadly and indiscriminate fallout produced by large nuclear explosions.
"Real progress," said Strauss last week, "has been made with respect to ... achievement of maximum effect in the immediate area of a target with minimum widespread fallout hazards.
"It has been confirmed that there are many factors, including operational ones, which do make it possible to localize, to an extent not hitherto appreciated, the fallout effect of nuclear explosions.
"Thus, the current series of tests [in the Pacific] has produced much of importance, not only from a military point of view, but from a humanitarian aspect. We are convinced that mass hazard from fallout is not a necessary complement to the use of large nuclear weapons."
The Army's Lieut. General James M. Gavin recently alarmed all Europe by predicting that an all-out nuclear attack on the Soviet Union might kill several hundred million people, as the fallout drifted capriciously with the wind, falling on friend and foe alike. If the AEC has achieved a "large nuclear weapon" with greatly reduced fallout, it will enable atomic strategists to lay down their pattern of death with greater precision, make the H-bomb a far more useful military weapon. A bomb exploded, for instance, over a Polish air base would be less likely to depopulate Berlin.
Operational Factors. The AEC did not explain how it controls H-bomb fallout, but it pointed the way to some speculation. Strauss's "operational factors" presumably refer chiefly to the altitude at which the weapons are exploded. The 1954 H-bomb test that made "7,000 square miles of territory ... so contaminated that survival might have depended on prompt evacuation" (according to the AEC's own reports) was exploded on a tower on a small coral island. Its fireball dug a deep crater and tossed millions of tons of pulverized coral into the air. This material, made highly radioactive by contact with the fireball, was the poisonous "atomic snow" that settled on boats, islands and water 220 miles away.
The high-yield H-bombs of the current test program were dropped from aircraft and exploded high above the surface. Thus their fireballs did not concentrate their fury on a small area of coral, but spread it over miles of water. As a result, not much pulverized material was carried upward. The total radioactivity produced by such a bomb may be large, but most of the potential fallout is distributed high in the stratosphere in the form of extremely fine particles or even single molecules. Such impalpable stuff is slow to fall. Not much would fall in any one place, and its strength would be much reduced by mere passage of time.
"Clean" Bombs. The Strauss statement implies, however, that H-bombs have been made "clean" by something besides "operational factors." Nuclear pundits are already speculating about how the bombs themselves may have been changed so as to yield less fallout.