Any nuclear weapon exploding at or near ground level will pull radioactive particles (fallout) into the atmosphere where they will disperse downwind. Depending on the speed of the wind at the time of the formation of the fireball/mushroom cloud, fallout can travel signicant distances.
And the Bushies are trying to sell this as if this were a "safer" use of nuclear weapons.
This is a very bad idea.
Here's a very relevant article written in 2001:
"Tactical Nuclear Weapons" against Afghanistan?
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http://www.globalresearch.ca/articles/CHO112C.html>
START QUOTES:
Dubbed by the Pentagon as "the Big Ones", the GBUs ("guided bomb unit") are 5000lb laser guided bombs with improved BLU-113 warheads, capable of penetrating several meters of reinforced concrete. The BLU-113 is the most powerful conventional "earth penetrating warhead."
While the Pentagon's "Big Ones" are classified as "conventional weapons", the official statements fail to mention that the same "bunker buster bombs" launched from a B-52, a B-2 stealth bomber or an F-16 aircraft can also be equipped with a nuclear device. The B61-11 is the " nuclear version" of its "conventional" BLU-113 counterpart. The B61-11 was developed from the old "conventional" B61-7 "gravity bomb."
...snip...
Osama's nuclear device is labelled a "dirty bomb" conveying the impression that America's B611-11 is "clean" The "dirty bomb" is developed from nuclear waste.
America's tactical nuclear weapons are said to be "safe" in comparison to those of Osama. Administration statements suggest, in this regard, that a so-called "low-yield" earth penetrating tactical nuclear weapon such as the B61-11 would "limit collateral damage" and therefore be relatively safe to use.6
These new buzz words are being spread by the US media to develop public support for the use of "tactical nuclear weapons" against an an opponent which now possesses nuclear capabilities. Yet the the scientific evidence on this issue is unequivocal: the impacts on civilians of the "low yield" B61-11 would be devastating "because of the large amount of radioactive dirt thrown out in the explosion, the hypothetical 5-kiloton weapon ... would produce a large area of lethal fallout."7
END QUOTES.Here is a point everyone needs to keep in mind...the weapons dropped on Hiroshima and Nagasaki were crude 10-kiloton nuclear devices used in an air-burst mode. Both devices were exploded at about 2000 feet above their targets, producing the maximum effect of heat and radiation. Even though both weapons were used in an air-burst mode, a tremendous amount of fallout was produced from what was incinerated below in the main area of impact and sucked into the resulting mushroom cloud.
As noted above, the so-called nuclear bunker busters are 5-kiloton weapons and are designed to be used in a sub-ground mode. At first glance, one could assume they will produce roughly half the explosive yield of the 10-kiloton weapons used on Hiroshima and Nagasaki.
Not so fast.
It has been almost 60 years since the two 10-kiloton bombs were used on Japan. During that time, nuclear weapon design technology and materials used has improved dramatically, making today's 5-kiloton weapon capable of producing a blast at least TWICE that of the crudely designed and manufactured Japanese bombs.
Think about that for a few seconds, and then think about the amount of fallout that will be created from a ground-burst 5-kiloton nuclear device. Because of the fact that they will be exploding just below the surface of the ground, these devices will pull an amazing amount of radioactive material into the atmosphere...many times the amount created by the two Japanese bombs. Any people living downwind will be affected by the fallout from such a device...the closer to the target, the worse the effects.
Repeat. This is a very bad idea.