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7 Physical Effects of Radiological Weapons
and burns (9). Broken glass accounted for 38% of the 2115 injuries for which
the cause could be determined, more than any other cause [12].
Parts of the truck in which the bomb was hidden were found up to several
hundred meters away.
7.6 Contaminated Area and Infrastructure
One of the major physical effects of a radiological attack will be the areas that will
be off-limits due to radiation dose rates and contamination levels. This can include
residential areas, bridges, roads, tunnels, stores, government buildings, transportation
hubs and equipment, port facilities, and much more. The loss of these facilities,
whether due to a radiological attack, extreme weather, or any other event will be
disruptive for some or all of a city’s residents.
Let’s consider an explosive RDD – a “dirty bomb”—that is set off in a crowded
area in a city center. We will assume that the radioactivity itself is in a dispersible
form—a powder or a liquid—to facilitate its spread. The majority of the radioactivity
will remain in that form, but some will work its way into cracks or crevices within
the container and some might clump together. When the explosives are detonated
the blast wave will pass through the container in which the radioactive material is
held; the heat and pressure will blast the contamination into the atmosphere along
with pieces of whatever containers hold the explosives and the radioactivity. As this
is happening, most of the radioactivity will be dispersed into the atmosphere, but
some will fuse with the materials blown apart by the explosion—the glass, plastic,
metal, and other materials of which the containers, the weapon, and (if appropriate)
the vehicles are constructed. This means that there will be an assortment of particle
sizes, a wide array of fragments of varying size and composition, and they will be
distributed across a variety of distances from the scene of the explosion. Larger
particles will tend to follow a ballistic trajectory and will typically travel up to a few
hundred meters unless they strike a building, vehicle, vegetation, or the like, with
the larger particles (several microns and larger in size) tending to settle to the ground
within several minutes [13].
Smaller particles are light enough to remain airborne for longer periods of time
and will tend to travel with the air currents. While this will tend to be downwind,
in an urban environment the winds can swirl around buildings and eddies can carry
particles upwind when the wind is blowing at an angle to the city’s grid of streets
and buildings. Aerosol-sized particles can travel a few to several tens of kilometers
downwind, spreading contamination wherever the plume settles to the ground.
Studies performed at Sandia National Laboratory [9] indicate that, for an explosive
RDD detonated at Wall Street in New York City, areas requiring remediation to meet
regulatory radiation exposure limits would cover the southern tip of Manhattan and
7 Physical Effects of Radiological Weapons
and burns (9). Broken glass accounted for 38% of the 2115 injuries for which
the cause could be determined, more than any other cause [12].
Parts of the truck in which the bomb was hidden were found up to several
hundred meters away.
7.6 Contaminated Area and Infrastructure
One of the major physical effects of a radiological attack will be the areas that will
be off-limits due to radiation dose rates and contamination levels. This can include
residential areas, bridges, roads, tunnels, stores, government buildings, transportation
hubs and equipment, port facilities, and much more. The loss of these facilities,
whether due to a radiological attack, extreme weather, or any other event will be
disruptive for some or all of a city’s residents.
Let’s consider an explosive RDD – a “dirty bomb”—that is set off in a crowded
area in a city center. We will assume that the radioactivity itself is in a dispersible
form—a powder or a liquid—to facilitate its spread. The majority of the radioactivity
will remain in that form, but some will work its way into cracks or crevices within
the container and some might clump together. When the explosives are detonated
the blast wave will pass through the container in which the radioactive material is
held; the heat and pressure will blast the contamination into the atmosphere along
with pieces of whatever containers hold the explosives and the radioactivity. As this
is happening, most of the radioactivity will be dispersed into the atmosphere, but
some will fuse with the materials blown apart by the explosion—the glass, plastic,
metal, and other materials of which the containers, the weapon, and (if appropriate)
the vehicles are constructed. This means that there will be an assortment of particle
sizes, a wide array of fragments of varying size and composition, and they will be
distributed across a variety of distances from the scene of the explosion. Larger
particles will tend to follow a ballistic trajectory and will typically travel up to a few
hundred meters unless they strike a building, vehicle, vegetation, or the like, with
the larger particles (several microns and larger in size) tending to settle to the ground
within several minutes [13].
Smaller particles are light enough to remain airborne for longer periods of time
and will tend to travel with the air currents. While this will tend to be downwind,
in an urban environment the winds can swirl around buildings and eddies can carry
particles upwind when the wind is blowing at an angle to the city’s grid of streets
and buildings. Aerosol-sized particles can travel a few to several tens of kilometers
downwind, spreading contamination wherever the plume settles to the ground.
Studies performed at Sandia National Laboratory [9] indicate that, for an explosive
RDD detonated at Wall Street in New York City, areas requiring remediation to meet
regulatory radiation exposure limits would cover the southern tip of Manhattan and