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The Destructive Effects of a Nuclear Suitcase Bomb

by Roland Watson

The dust is settling on the conflict in Afghanistan and not one major figure from the Taliban or
Al-Qaida has been found. Bin Laden remains elusive and, according to some reports, he may
have moved to the Pashtun-dominated area of Pakistan weeks ago.

In that sense, Operation Enduring Freedom is so far a failure. And that leaves one vital question still open. Does Bin Laden still own the fabled nuclear suitcase bomb?

We can safely assume that nothing of that nature was found in the Tora Bora complex. One does
not abandon equipment that cost millions of dollars, especially if a heavy American attack on
Afghanistan was worked into Bin Laden’s war game tactics prior to September 11th.

The answer, in my opinion, is somewhere between probably and not likely. But, whatever one’s view is, the major question is concerned with what these devices are capable of. The answer to that depends on a number of different factors which I shall explore below. A likely scenario of bomb parameters will be used and we shall arrive at a set of numbers, which will show only too clearly what an undesirable visitor such a device would be to an American city.

Yield

The first parameter to establish is the explosive yield of the device. Based on the various media
reports and articles I have examined, the alleged nuclear "backpacks" or "suitcases" would
appear to be in the one to ten kiloton range. As a benchmark, the uranium fission bomb dropped
on Hiroshima was just over ten kilotons. However, the majority of the articles tend towards the
lowest figure of one kiloton and that is the number I will assume.

Delivery

The mode of detonation is very influential as to the range of the effects of the nuclear explosion
and is partly dependent on the intentions of the terrorists. High altitude airbursts are normally
intended for Electromagnetic Pulse (EMP) effects – i.e. to knock out electronic command and
control equipment. But this is not useful to terrorists and is useless anyway for such a low-yield
device.

A ground burst minimises blast and thermal damage due to the shielding of successive buildings
and hills but maximises the production of fallout particles. These particles are vacuumed up into
the initial fireball, which vaporises and then irradiates them before they condense back into solids
and float down to earth within hours.

Finally, a low altitude airburst would balance blast, heat, and fallout damage into one infernal
combination and has the dubious but added "bonus" of the Mach Effect, which is a reinforced
blast wave, created when a fireball blast wave meets the initial blast wave reflected from the
ground in the manner of constructive interference.

Which method would a terrorist choose? I suggest the low altitude airburst since it is emotive
pictures of decimated sectors of cities and high numbers of immediate casualties that they want
the world to witness. For sure, fallout from a ground burst could kill many more over the
following months and years, but that does not generate the razor-sharp publicity that a terrorist
hungers for.

But could a terrorist pull off a low altitude airburst? The only conceivable way to do this is to
carry the weapon over ground zero in a light aircraft. Getting the aircraft would probably be
quite easy as would be the loading of the device. Flying the aircraft over the city is more difficult,
but once again the nefarious deed could be executed before the military were alerted, scrambled
a fighter jet, and engaged the enemy. The likelihood of a USAF fighter catching such a plane is
also diminished if a lower-priority city is chosen. In that respect, I will assume a low-altitude
airburst. If they can kidnap and fly three out of four Boeing jets into their intended targets in one
day, they can do this as well.

A ground detonation is still entirely possible from inside a hidden building or a ship coming into
port (though half the energy of the blast could be directed towards the ocean) and these would
be easier operations. But this is primarily a question of what the terrorists believe is desirable and
achievable rather than what is easiest.

Target and Environment

Which is the unlucky American city? Certainly, it will be a city and it will be American as far as
an Islamic fanatic with an extremely rare and potent weapon is concerned. New York? Los
Angeles? San Francisco? New York has had a hard time of it with the two WTC attacks and
the downing of flight 587 (yes, I believe it was a terrorist attack), so we may be forgiven for
thinking the next attack will happen elsewhere.

However, the Eastern seaboard is the favoured route for bringing in smuggled items and
terrorists will not want to spend critical time in long, hazardous journeys westwards. We know
that some of the WTC terrorists were based and trained in Florida and that the alleged terrorist
on trial just now was caught in the mid-southern state of Oklahoma (ominously he had
undertaken Cessna flight training). I suggest that coastal cities further south or even into the Gulf
of Mexico may be at greater risk.

Furthermore, a city with a flat topology may be favoured above more contoured cities since hills
will deflect and absorb the blast waves as was the case in Hiroshima and Nagasaki attacks.
Hiroshima was a flatter city than Nagasaki and paid for this with a greater death toll and
destruction per square mile.

Seeking to get the last iota of destructive power out of their devilish device, the terrorists would
also favour southern cities because of the hotter conditions and better atmospheric conditions. In
other words, clear, sunny skies are better "tinderbox" conditions as would that time of day since
Bin Laden would want clear conditions for the infamous mushroom cloud to be recorded by the
world’s media.

Ultimately, I have no topological maps of southern US cities to make such judgements, but the
reader can draw their own conclusions. So far, all this is deductive common sense, but I now
move onto the actual effects based on a warm sunny morning in such an American city. The
range given in feet and miles will be for the actual distance from ground zero and assumes the
fireball centre to be 200 feet above it.

Fireball

On that fateful morning, the citizens close to ground zero will note the unremarkable drone of a
light aircraft flying above their buildings. It is the last thing they ever hear.

Whether the blinding, split second flash of a hundred suns registers with them is unlikely because
the intense heat that kills them also travels at the speed of light. As the fireball expands rapidly to
its maximum diameter of 460 feet, its centre rages at a temperature of 10,000,000° C for its
brief lifetime. Note that temperatures in the WTC attacks were unlikely to have exceeded
5,000° C.

Metallic objects up to 450 feet from ground zero of the initial flash will vaporise. Metallic objects
up to 670 feet away will melt. It is needless to guess what happens to people caught out in the
open at these ranges – they cease to exist in any meaningful sense of the word and join the raw
material for the later fallout.

At 1400 feet from ground zero, rubbers and plastics will ignite and melt whilst wood will char
and burn. For victims out in the open, 3rd degree burns are inflicted up to 0.4 miles away, 2nd
degree burns up to half a mile away and 1st degree burns at up to nearly a mile away. It is at the
extremity of this range that we have the "open oven door effect" which needs no further
explanation.

Blast

The bomb will expend about 35% of its energy as this radiated heat; a further 50% is absorbed
by the atmosphere and becomes a juggernaut blast wave roaring across the city centre at speeds
of up to the limit of sound.

Coastal cities used to visiting hurricanes will not have witnessed the boiling winds we describe
here. As a comparison, a hefty hurricane-like wind velocity of 116 miles per hour will hit
residents at just under half a mile from the blast, whilst those experiencing less damaging winds of
70 mph at under 0.6 miles will feel fortunate.

Meanwhile, those buildings which survived the melting effects of the heat radiation will be
finished off by the high winds further into the city centre as winds approaching 670 mph will level
or badly damage even steel concrete structures within 740 feet of the blast. No one inside this
perimeter can hope to survive unless they are in good underground shelters.

Where the wind speed drops to 380 mph at about 1050 feet, tall multi-storey buildings will be
lucky to be left standing and survivors of the heat pulse will suffer potentially fatal lung injuries.
As the speed drops to 225 mph at about 1650 feet, most dwelling houses will be wrecked and
the streets blocked by debris. Flying fragments become the killer rather than sheer air pressure at
these distances.

What the initial radiation pulse did not ignite, the blast does by igniting new fires due to damaged
power lines, gas mains and oil tanks. Asphyxiation can also occur at these ranges as much of the
air is devoted to fuelling uncontrollable firestorms, which have no mercy on wooden housing.

Fallout

As I said, this factor will not be so important to devastation-minded terrorists, but the statistics
bear witness to further death and misery. The main figure here is the LD-50 dose level which will
kill at least 50% of humans exposed to it for an hour or longer. This value is 400 Rads for
humans and the victim can die within 30 days. Assuming a weather wind velocity of 15 mph
which gives a simple ellipse pattern of fallout, then this lethal dosage can extend downwind for up
to several miles but will be confined to a maximum width of only several hundred feet on
average.

It is to be noted that an instant gamma ray burst of 400 Rads from the fireball burst will also have
this effect up to about 700 feet from ground zero, but the victim would surely be dead from heat
and blast effects already.

Aftermath

As the winds drop to gale force at just under a mile, and the glow of the fireball abates, the grim
spectacle is over within minutes. We are confronted with a scene of complete devastation within
hundreds of feet of ground zero. As the four mile high mushroom cloud silently presides over its
work, rescue services will find this a radiation-infested no-go area for months and will
concentrate on helping those who have survived further away from ground zero.

Those who are capable of moving will be directed to get out of the immediate area to escape the
fallout which is beginning to rain down like snow along the wind patterns of the day. The
wreckage on roads as well as every possible vehicle taking to the road at the same time will
hamper evacuation procedures as will the transportation of the wounded and infirm.

People located about three-quarters of a mile or more from ground zero will have survived with
mainly minor injuries, their immediate task is to play their part in helping friends and relatives to
evacuate and beyond that lies the task of rebuilding and repairing homes as well as shattered
lives. Though only people in the immediate area of the fallout will be in danger, panic and
ignorance will no doubt lead to widespread evacuation across the whole city.

Based on the Hiroshima bombing and scaling down for bomb yields, one could expect fatalities
of up to 20,000 and a similar number of injured. If the contours of the land are favourable then
these number could drop by half as in the case of Nagasaki. Other factors such as the time of
day (e.g. not all people at work yet), accessibility to good medical facilities, evacuation
efficiency, and weather conditions all have a large part to play in the final casualty figures.

Conclusion

America is at war with international terrorism and will have to prepare itself against all that its
enemies can throw against it. In the larger scheme of things, terrorists can only inflict minimal
damage to the American continent as a whole – forty thousand casualties out of nearly 290
million people is 1 in 7250. As a comparison, a resident of the U.S.A. dies every 13 seconds or
20,000 will die of natural and unnatural causes every 3 days.

But these are not the cold-blooded statistics which interest the average citizen. Out of 77 major
American cities, they may feel the odds are closer to 1 in 77 rather than 1 in 7250. This is all
about psychology and a feeling of security and these terrorists know that only too well.

The protection of Heaven may yet prevent such devices being used, but one suspects that it is
more a case of "In the CIA we trust" rather than "In God we trust"!

January 4 , 2002