There are many different types of bombs
which disperse ionizing radiation. The atomic bomb, in which a fission reaction
results in a high energy output and extreme and direct destruction is the type
of device that first comes to mind when discussing a 'nuclear' weapon. But
there is a variety of radioactive weapons, bombs which kill, perhaps less
dramatically than with one huge blast, but which potentially kill with just as
deadly a force and perhaps with even more suffering. These bombs are called
'dirty' and 'dirty' is all about 'fallout'.
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| A Nuclear Explosion |
But 'fallout' usually refers to the
'residual radioactive material propelled into the upper atmosphere following a
nuclear explosion', so-called because it 'falls out' of the sky after the
explosion and energy pulse of the blast have passed. This radioactive dust and
ash may also originate from a damaged nuclear plant. The radioactive dust
consists of material either directly vaporized by a nuclear blast or charged by
exposure and, whatever the source, results in contamination of soil and water
supplies, possible leading to devastation of the exposed environment that lasts
years after the event.
With a dirty bomb, there is no true
'falling out' of dust from the sky but, in effect, the same result occurs in
perhaps a more restricted area and possibly with more severe localized levels
of radiation exposure.
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| Dirty Bomb |
The main difference between a
nuclear blast and a dirty bomb is not necessarily the ultimate degree of
radioactive damage inflicted but the fact that a dirty bomb is easier to make,
easier to conceal, easier to transport and easier to detonate.
A dirty bomb combines
radioactive material (which can be obtained readily from multiple sources) with
conventional explosives. The purpose of the weapon is to contaminate the area
around the explosion site with radioactive material, hence the term 'dirty'.
The dirty bomb is essentially a 'radiological
dispersal device' (RDD). The explosion itself, using conventional
explosives (dynamite) would likely have lethal effects, at least locally.
Studies suggest that not enough radiation could be dispersed in high enough
concentrations to cause severe illness or death.
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| A Simple Dirty Bomb with TNT |
A test explosion of a 'dirty bomb' and
subsequent calculations done by the United States Department of Energy found
that even if nothing is done to clean up the affected area and everyone stays
in the affected area for one year, the radiation exposure would be high but not
fatal.
Analysis of the fallout from the
Chernobyl disaster (see post: Man-Made and Natural Nuclear
Disasters) shows that the effect on many people in the surrounding area,
(although not those in close proximity) was extremely low.
So is a dirty bomb a weapon of mass
destruction or rather a weapon of mass terror? Certainly as a source of
terror, a dirty bomb would be effective. The device would be high-profile (any
blast would be noticed and investigated) but not insidious or stealthy as other
terrorist techniques could be (see post: The Terrorist With a Demon Core). But,
in the case of a dirty bomb, time and money would be needed to address
the contamination problem and there would always be the uncertainty of what the
longer term future held for the people exposed.
And what if multiple bombs were
detonated in close proximity to one another, at or near the same time? Many
devices could essentially create a true fallout effect, increasing the number
of people exposed as well as possibly increasing the degree of their exposure.
As of 2012, a dirty bomb is
only a speculative radiological weapon in that no such device has ever been
successfully deployed (yet). But since the attacks on the World Trade Center in
New York City in September 2001, the fear that terrorist groups could use
dirty bombs has increased significantly.
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| Izmaylovsky Park |
There have been a few cases of threatened dirty
bombs. On two occasions, caesium-containing devices were found, neither of
which was detonated.
The first attempt of radiological terror
was carried out in November 1995 by a group of Chechen separatists,
who buried a mass of caesium-137, wrapped in explosives at the Izmaylovsky
Park in Moscow. A Chechen rebel leader alerted the media, the bomb was
never activated.
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| Chechnya |
In December 1998, the Chechen Security Service, discovered a container filled with radioactive materials (caesium, once again) attached to an explosive mine, hidden near a railway line in the suburban area Argun, ten miles east of the Chechen capital of Grozny.
In August, 2008, a large Iranian cargo
ship, the MV Iran Deyanet was hijacked by Somali pirates. American
government sources largely ignored the event but the hijacking became headline
news in Russia. In the 21st century, Somalia, with its 1800 miles of
coastline has become an international terrorist haven as well as a safe
haven for pirates plying their trade as far away as the coast of India.
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| Caesium Dirty Bomb-Russia |
On August 2, it was reported that three
vessels, one Iranian, one Japanese and one German, along with 57 crew members
were hijacked by pirates in the Gulf of Aden, the stretch of water
connecting the Red Sea and the Indian Ocean near Somalia.
The MV Iran Devant had departed Nanjing, China on
July 28 and was headed to Rotterdam to deliver 42,500 tons of iron
ore and other 'industrial products' to an unidentified German client.
The Iranian bulk carrier and its 29 crew members, belonged to the Islamic
Republic of Iran Shipping Lines (IRISL), run by the Iranian Revolutionary
Guard.
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| Somalia on the Horn of Africa |
Forty Somali pirates, armed with AK-47s
and rocket-propelled grenades brought the MV Iran Deyanet to Eyl, a
fishing village in northeastern Somalia where a larger contingent of
pirates took control of the vessel – 50 on board and 50 patrolling on the
beach.
Attempts to inspect the ship's seven
cargo containers failed, the pirates unable to break into the holds and the
crew swearing they did not have access codes to the locks. The captain and
engineer of the ship at first said the containers held crude oil then changed
the story to say there were 'minerals' in the holds.
After several efforts, the pirates
succeeded in opening one of the containers and discovered packets of what was
described as a 'powdery fine sandy soil'. Those exposed to the powder became
sick and within days began to exhibit symptoms which looked like skin burns as
well as hair loss. Sixteen of the pirates died.
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| The MV Iran Deyanet |
According to Russian reports, the entire
cargo was radioactive sand obtained by Iran from China in exchange
for oil then sealed in containers. The plan had involved detonation of charges
on the ship after the crew had escaped in life boats. The planned blast would
have been taken high into the air where prevailing winds would then have pushed
the highly dangerous and radioactive cloud ashore.
The MV Iran Deyanet was, in
effect, a huge floating dirty bomb, intended to detonate after exiting the
Suez Canal at the eastern end of the Mediterranean and in proximity to the
coastal cities of Israel.
Because a dirty bomb has never been
successfully used, there is disagreement as to how deadly or destructive the
device would actually be. Many studies have suggested that a radiological
dispersal device such as a dirty bomb would not physically harm nor kill many
people. But one thing is certain. The detonation of a dirty bomb would have
tremendous psychological impact as well as economic impact on the target
population and country.
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| Goiania, Brazil |
But there have been 'accidental' dirty
bombs - radiological accidents really, which spread radioactivity in a manner
similar to that of a radiological dispersal device. One example is the accident
which took place in Goiania, Brazil between September 1987 and March
1988.
On September 13, 1987, two metal
scavengers broke into the radiotherapy clinic of an abandoned city
hospital and removed a radiotherapy source capsule containing powdered caesium-137
with a radioactivity of 50 T Bq. The two men took the component home and
began to take it apart with the plan to sell it for scrap metal.
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| Goiania Radiotherapy Source Capsule |
Later that day both men began to show
signs of radiation illness with vomiting, swollen hands and diarrhea. Work on
the container continued and within a few days, one of the men punctured the
1 mm thick window of the capsule, allowing caesium chloride powder
to leak out.
The powder glowed blue in the dark and
the man brought the container and powder back home to his family and friends to
show them this curiosity. Within 2 weeks, spread by contact, contamination
caused an increasing number of people to fall ill. Before the correct diagnosis
of acute radiation sickness was made, 249 people had been contaminated,
151 of whom showed signs of both external (ex skin burns) and internal
(vomiting, anemia). Twenty people became seriously ill and 5 people died.
The cleanup operation necessitated
topsoil removal from several sites and the demolition of several homes.
All the objects from within those houses were removed and
examined. The Goiânia incident to some extent demonstrates a
possible contamination pattern of radioactive dispersal, even without an
explosive device. The incident also shows how fatal even very small amounts of
ingested radioactive powder can be and raises concerns of how effective a
'dirty' device can be if a powdered alpha-emitting material (such as
polonium-210; see post: Radiation to Cure, Radiation to Kill) is used.
Although no dirty bomb has been
detonated to date, it is well-known that terrorist groups are actively pursuing
unsecured radiological material, and several of them may already possess
dirty-bomb capabilities. Significant amounts of radioactive materials are
stored in laboratories, food irradiation plants, oil drilling facilities,
medical centers, and many other sites throughout the world.
Cobalt-60 and caesium-137 are
used in food disinfection, medical equipment sterilization, and cancer
treatments. In the USA, nearly 1500 pieces of radioactive material went
'missing' between October 1996 and September 2001. The vast majority
of the missing items contain tiny amounts of radioactive material and pose
little threat but there have been several instances where hospital equipment
has been lost or stolen, equipment that contains potentially lethal amounts of
radioactive cobalt or cesium.
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| Training for Attack With a Dirty Bomb |
The threat of a dirty bomb has been
taken seriously by the US government. From June 5 to June 7, 2009, 400 New York
Army and Air National Guardsmen as well as volunteers from the New York State
Guard converged on Albany to practise their skills in responding to a dirty
bomb attack on an American city.
The three-day exercise involved the
theoretical detonation of a high explosive device covered with radioactive
material outside the New York State Capital, covering downtown Albany with
radioactive contamination and forcing thousands of residents to shelter indoors
for two days. Scenarios have been worked out as to explosion and wind
distribution of radioactive materials from a dirty bomb.
Dispersal of fine radioactive particles
expose people down wind from the event and can cause contamination in several
ways:
1. Inhalation of radioactive dust by the population directly exposed to the radiation cloud. Particles containing cobalt or caesium will stay in the body and result in long term exposure.
2. Exposure to settled dust after the radioactive cloud has passed. Caesium or cobalt-containing ground dust (gamma particles) results in on-going exposure for residents; dust containing americium (alpha particles) may be whipped into the air again by traffic or wind and inhaled resulting in internal radiation exposure.
3. Contaminated food and water especially in rural areas where water collection regions may be vast and monitoring more difficult.
1. Inhalation of radioactive dust by the population directly exposed to the radiation cloud. Particles containing cobalt or caesium will stay in the body and result in long term exposure.
2. Exposure to settled dust after the radioactive cloud has passed. Caesium or cobalt-containing ground dust (gamma particles) results in on-going exposure for residents; dust containing americium (alpha particles) may be whipped into the air again by traffic or wind and inhaled resulting in internal radiation exposure.
3. Contaminated food and water especially in rural areas where water collection regions may be vast and monitoring more difficult.
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| Fukishima Dust Cloud |
Dust clouds from nuclear accidents
(similar to a dirty bomb) have been seen. Following the Fukishima accident in
2011, scientists performed testing which showed nuclear radiation raining down
on Tokyo from incinerators that were burning radioactive sludge and other
materials contaminated with radiation from the damaged nuclear plant in
Fukishima 65 kilometers away.
In the United States, aside from
radioactive devices used in medicine and industry, there is at least one other
potential source of radioactive material that may be useful to build a dirty
bomb.
The Gammator was a gamma
irradiator made by the Radiation Machinery Corporation during
the U.S. Atoms for Peace project of the 1950s and 1960s (see post:
Nuclear Waste). The Gammator was distributed by the Atomic Energy
Commission to schools, hospitals, and private firms to promote 'nuclear
understanding'. About 120-140 Gammators were distributed throughout the
U.S. and the whereabouts of several of them remain unknown.
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| The Gammator |
The Gammator weighed about 1,850
pounds and contained caesium-137 in a pen-sized pellet (400
curies of radioactivity). The device was well-shielded and safe when used
as intended (school science experiments) but the amount of nuclear
material was large enough to cause significant problems if used as the
radioactive component in a dirty bomb.
Between 120 and 140 Gammators were
distributed to schools across the country. Since the attacks of September 11,
2001, the US Department of Energy has been trying to
retrieve these devices. In 2004, Massachusetts Congressman Edward
Markey claimed that six Gammators had 'gone missing'.
So, how do you build a dirty bomb?
A terrorist organization (or even a
disaffected former employee) must first obtain radioactive material by stealing
it or buying it (legally or illegally). Radioactive material could come from
the millions of radioactive sources used worldwide in industry, for medical
purposes (Goiania, Brazil is a good example) and in research institutions.
Few of these sources provide the
isotopes (caesium-137, cobalt-60, americium-241, californium-252, iridium-192,
plutonium-238, polonium-210 (see post: Radiation to Cure, Radiation to Kill),
radium-226, strontium-90) which would be useful for this type of terrorist
weapon. It has estimated that within the U.S., approximately one
source of these isotopes are lost, abandoned or stolen every day of the
year. Within the countries of the European Union, the annual estimate is
70.
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| Russian Radioisotope Thermo-Electric Generator |
There exist thousands of such lost or
abandoned sources scattered throughout the world. There are also thousands of
'orphaned' sources in Russia, lost following the collapse of the
Soviet Union. Especially worrisome are the Russian strong beta-emitting
strontium-90 sources used as radioisotope thermo-electric generators used
in beacons in lighthouses in remote areas.
In December 2001, three woodcutters
in Georgia (former republic of the Soviet Union) found one such power generator
and dragged it back to their camp site to use it as a heat source. Within hours
they suffered from acute radiation sickness and required hospitalization. The
generator contained approximately 40 kilocuries of
strontium,equivalent to the amount of radiation released immediately after the
Chernobyl accident (see post: Man-Made and Natural Nuclear Disasters).
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| Twin Towers, September 9, 2011 |
There have been several incidents of
alleged intent to make and detonate a dirty bomb. many of these cases are
linked to Al-Qaeda since the airline bombing of the Twin Towers in
New York City in 2001.
On 8 May 2002, Jose Padilla (a.k.a. Abdulla
al-Muhajir) was arrested on suspicion that he was an Al-Qaeda terrorist
planning to detonate a dirty bomb in the US. Padilla had not obtained
radioactive material or explosives at the time of arrest but authorities did
uncover evidence that he was on reconnaissance for usable radioactive material
and possible locations for detonation. Later, the charges against José
Padilla were dropped.
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| Jose Padilla |
In 2006, Dhiren Barot of North
London pleaded guilty of conspiring to murder innocent people in both the
United Kingdom and the USA. using a dirty bomb. He had planned to target
underground parking lots in British and American cities. Experts say
if the plot to use the dirty bomb had been carried out it would have been
'unlikely to cause deaths, but was designed to affect about 500 people'.
In January 2009, an FBI report described
the results of a search of the Belfast, Maine home of white supremacist, James
G. Cummings, who had been shot and killed by his wife.
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| Dhiren Barot |
Investigators found four one-gallon
containers of 35 percent hydrogen peroxide, uranium, thorium, lithium metal,
aluminum powder, beryllium, boron, black iron oxide and magnesium as well as
literature on how to build dirty bombs and information about cesium-137,
strontium-90 and cobalt-60, radioactive materials.
In April 2009, the Security
Service of Ukraine arrested a legislator and two businessmen from the
Ternopil Oblast region. The security service seized in the undercover 3.7
kilograms of what was claimed by the suspects during the sale as plutonium-239,
used mostly in nuclear reactors and nuclear weapons, but was determined by
experts to likely be americium, a radioactive material commonly used in amounts
of less than 1 milligram in smoke detectors but which can also be used in
a dirty bomb.
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| James G. Cummings |
The suspects reportedly wanted 10 million US dollars for the
material, which had been produced in Russia and smuggled into Ukraine
through a neighboring country.
To make a dirty bomb, therefore, would not be easy but
certainly easier than building an atomic bomb.
A dirty bomb would require a
radioactive source that was 'sufficiently' radioactive to create direct
radiological damage at the explosion or at least to perform societal
damage or disruption (a Russian thermo-electric generator would work).
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| Security Service of Ukraine |
The device would need to be be
transportable with enough shielding to protect the carrier, but not so much
that it will be too heavy to manoeuver (strontium-90 in the back pack of a
suicide 'bomber' would work).
Finally, the source would need to be
sufficiently dispersible to effectively contaminate the area around the
explosion ('powdered' strontium-90 or caesium-137 has already been shown to be
effective).
It seems then that it really only
involves three (rather simple) steps:
1. obtain the radioactive material (ex. strontium-90);
2. transport the radioactive material to the target site (in a sealed and protected box or trunk); 3. pack the radioactive material around a detonation source (simple dynamite will do).
1. obtain the radioactive material (ex. strontium-90);
2. transport the radioactive material to the target site (in a sealed and protected box or trunk); 3. pack the radioactive material around a detonation source (simple dynamite will do).
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| Dirty Bomb in a Briefcase |
And what do you do if (or when) a dirty
bomb is detonated nearby?
Get out of the way of the dispersal
cloud.
Move across or up wind to escape the
area.
If in a house or car, stay inside, turn
off the air conditioning and heat and close the windows. If near the
blast, take cover inside in a lower inside room away from doors and windows.
Use a filter mask or breathe through
clothing and avoid breathing through a jacket which may be contaminated with
radioactive dust.
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| Dirty Bomb in a Backpack |
Click on the link below for a PBS video
on dirty bombs.
