Posted on 12/20/2001 7:02:05 PM PST by fiftymegaton
Backpack nukes small but deadly Published 12/20/2001 6:55 PM
NEW YORK, Dec. 20 (UPI) -- Backpack nuclear devices are small, man-portable nuclear weapons with the explosive power of thousands of tons of TNT.
These weapons were designed to be carried by one or two people for use behind enemy lines in the event of a war. With yields of up to 10 kilotons, they are relatively tiny when compared to the 100- to 25,000-kiloton bombs found in the U.S. nuclear arsenal. But they are nevertheless still weapons of mass destruction -- the bomb detonated at Hiroshima was about 15 kilotons in explosive strength. One kiloton is the equivalent of 1,000 tons of TNT.
The most immediate effects of a nuclear explosion would be an intense flash of ultraviolet light and a fireball tens of millions of degrees hot that would set a large area ablaze. This would be followed seconds later by a shock wave that leveled buildings and turned debris into a torrent of deadly high-speed projectiles.
Ted Postol of the Security Studies Program at the Massachusetts Institute of Technology in Cambridge, Mass., estimates that even a 1 kiloton bomb would instantaneously leave a swath of destruction a half-mile in radius in which no one could survive the heat and blast. A 5-kiloton bomb and a 10-kiloton bomb would immediately create lethality zones about two miles in diameter.
In addition, the nuclear flash would be much brighter than the sun at noon. The intense light would cause blindness and permanent retinal injuries for anyone looking directly at the explosion in an area up to roughly eight miles from ground zero, assuming clear weather with high visibility.
The explosion of a backpack nuke at ground level would be limited in some ways. The blast would be mitigated to some degree by buildings, especially in an urban area. A ground-level explosion would also not produce an electromagnetic pulse or EMP as would an atomic burst well above ground -- from an incoming missile, for example. An EMP would shut down power grids and knock out unprotected electronics -- effectively cutting telecommunications, destroying computers and knocking out automobile engines.
Nonetheless, even a relatively small nuclear blast at ground level would produce an intense, deadly blanket of gamma ray-emitting radioactive fallout.
"The fireball breaks through the surface of the earth, carrying into the air large amounts of dirt and debris," explained theoretical physicist Robert Nelson at Princeton University in Princeton, N.J. "This material has been exposed to the intense neutron flux from the nuclear detonation, which adds to the radioactivity from the fission products."
Predicting radiation levels from early fallout is difficult and extremely dependent on factors such as weather, terrain and bomb design. Postol estimated that even with a 1-kiloton bomb, within an hour or so there would be a swath of fallout 2 1/2 to 3 miles long and maybe a quarter-mile wide. "Anyone who didn't get out of that would be exposed to a lethal dose of radiation," Postol said.
Because of the fallout, relief operations would be highly risky in the immediate aftermath of such an attack. First responders like paramedics and firefighters could be entering areas of very dangerous radiation.
In weapons tests with 5-kiloton bombs, about half of the total radioactivity produced was distributed in the fallout, while the other half was confined to the highly radioactive crater. "A rough estimate would be that as many people would die of fallout as would die from the initial blast, assuming that they couldn't immediately evacuate and be properly decontaminated," Nelson said in an interview with United Press International.
The number of casualties caused directly by the explosion is difficult to predict and dependent on the location of the device, whether there is any warning, as well as the time of day and the number of people at work or home.
Nonetheless, the officials -- who spoke to UPI during a recent briefing in Washington -- estimated that a 1-kiloton nuclear device exploded in Lower Manhattan could inflict between 80,000 and 200,000 casualties. A 10-kiloton device would kill at least twice as many they said.
Moreover, immediate casualties are likely to represent only a proportion of the eventual death toll.
Even if medical centers around the blast zone are still operable, it is likely that they will be overwhelmed, and there not will be enough empty beds for even the most critically injured.
In the days following the attack many of the injured would almost certainly die from lack of any medical care. Victims trapped in collapsed buildings or tunnels might not survive in time for rescue teams to save them. In addition, while early fallout comes down roughly a day after the explosion in an area around the blast site, delayed fallout knocked hundreds of miles into the atmosphere could spread radioactivity around the world for decades.
"A ground burst would have much more fallout than either Hiroshima or Nagasaki, because those were high altitude explosions," Nelson said.
Interesting that now the gummint is chatting about the possibility of nuke attacks, when we spent the last 16 years eliminating our civil defense capability. Look at the civil defense radiation meters on ebay and other places, search on CDV-717. We just got rid of about 100,000 units, and cities don't have the equipment. If someone popped a pit in a city, nobody whould know for days where the fallout plume was going.
Trust the Feds to keep you safe!
It even has a quicktime button.
Imagine what would have happened if an al-Qaeda terrorist detonated a 1 kT nuclear bomb at the foot of the World Trade Center towers instead of crashing two planes into the towers. Instead of circa 6,000 dead we may be talking 80,000 to 100,000 dead immediately from the blast and heat effects of the bomb and another 50,000 to 70,000 dead with three days from the remains of collapsed buildings and radiation poisoning. The lethal fallout--if it spreads eastwards over the Bronx, Brooklyn and Queens boroughs--would kill another 20,000 people directly exposed to the fallout within 10 days. Very likely, just about every building in the World Trade Center complex would razed to the ground, and the remains would be major radiation hazard for at least 25 years. We're talking a casualty figure of 300,000+ people given the density of Manhattan and the fallout path over eastern NYC boroughs.
Uranium 235 has a half-life of 71 million years and Pu239 has a half-life of 24,400 years, so an age of a few hundred years would not seriously deplete either core.
There may be other isotopes such as polonium (6 months) or tritium (about 12 years) that would limit life. If I were a weapons designer I'd design them so that they all required some depot level maintenance, to cover just such a circumstance of losing physical control of the devices. On the other hand a perverse engineering group could design them to last 50 or 100 years, just in case they had to survive a long time "underground" and several disarmament treaties.
In a world without strategic nukes for retaliation a small stockpile of little bombs would carry considerable weight.
If I remember correctly our old Davy Crockett had some limited life components.
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