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16 Working Safely in a Radiological Area
being dispersed; this can cause powders to clump together (for example) into larger
particles that will behave differently when passing through the air than will powders.
The physical conditions of a blast can also cause solid sources (e.g. metal alloys
or ceramics) to fragment and spall, creating a large number of higher-activity bits
of radioactivity scattered through the area affected by the blast. These fragments
can create localized hot spots within the Hot Zone, can be embedded in the flesh
of persons within a few hundred meters of the explosion, and can pose a risk to
responders who might encounter them or try to pick them up, potentially leading to
skin burns and other tissue damage.
The explosive dissemination of radioactive materials, especially if that material
is in a physical form that is easily dispersible (e.g. liquid or powder), is likely to
blast the radioactive material to altitudes of a few hundred meters or higher, putting
the dust and debris into higher-level winds which will carry it further than would be
the case at lower levels. This also increases the amount of radioactivity available to
be inhaled over a large area, increasing the number of people exposed to airborne
radioactivity. This wider spread of radioactivity can also cause the contamination
of infrastructure close to the site of the explosion as well as areas further afield,
including sewer systems as firefighting water flushes the contamination away from
the scene and into storm sewers and the city’s waste water treatment system.
The explosive dispersion of radioactivity can also lead to injuries (cuts, scrapes)
through which radioactivity can be absorbed into the bloodstream as well as radioactive particles that can be driven into the body by the force of the explosion.
This increases the possibility of a radioactive intake with the resulting internal
contamination and exposure to those close enough to the blast to be affected.
On top of these radiological effects, the explosion of an RDD can cause physical
damage to proximate areas—the damage to utility lines, roads and bridges, and the
contamination of additional areas can hamper the movement of responders and their
equipment into the affected area as well as the movement of injured persons from
the area to receive medical care. While these are not, in and of themselves, radiation
safety concerns, they can cause increased radiation exposure to persons who are
contaminated or affected by embedded fragments of radioactive materials.
16.3 Other Safety Considerations Relevant
to a Radiological “Dirty Bomb”
Any explosion creates risks, and larger explosions create more and greater risks, and
focusing on the radiological aspects of an attack can take one’s attention away from
the non-radiological threats. While the NCRP [4] listed a number of these in Report
#161, most that are relevant here were discussed in Chaps. 6 and 7 of this book.
However, there are additional concerns that are relevant to emergency responders
that either were not raised by the NCRP or that have not been discussed here—or
both.
16 Working Safely in a Radiological Area
being dispersed; this can cause powders to clump together (for example) into larger
particles that will behave differently when passing through the air than will powders.
The physical conditions of a blast can also cause solid sources (e.g. metal alloys
or ceramics) to fragment and spall, creating a large number of higher-activity bits
of radioactivity scattered through the area affected by the blast. These fragments
can create localized hot spots within the Hot Zone, can be embedded in the flesh
of persons within a few hundred meters of the explosion, and can pose a risk to
responders who might encounter them or try to pick them up, potentially leading to
skin burns and other tissue damage.
The explosive dissemination of radioactive materials, especially if that material
is in a physical form that is easily dispersible (e.g. liquid or powder), is likely to
blast the radioactive material to altitudes of a few hundred meters or higher, putting
the dust and debris into higher-level winds which will carry it further than would be
the case at lower levels. This also increases the amount of radioactivity available to
be inhaled over a large area, increasing the number of people exposed to airborne
radioactivity. This wider spread of radioactivity can also cause the contamination
of infrastructure close to the site of the explosion as well as areas further afield,
including sewer systems as firefighting water flushes the contamination away from
the scene and into storm sewers and the city’s waste water treatment system.
The explosive dispersion of radioactivity can also lead to injuries (cuts, scrapes)
through which radioactivity can be absorbed into the bloodstream as well as radioactive particles that can be driven into the body by the force of the explosion.
This increases the possibility of a radioactive intake with the resulting internal
contamination and exposure to those close enough to the blast to be affected.
On top of these radiological effects, the explosion of an RDD can cause physical
damage to proximate areas—the damage to utility lines, roads and bridges, and the
contamination of additional areas can hamper the movement of responders and their
equipment into the affected area as well as the movement of injured persons from
the area to receive medical care. While these are not, in and of themselves, radiation
safety concerns, they can cause increased radiation exposure to persons who are
contaminated or affected by embedded fragments of radioactive materials.
16.3 Other Safety Considerations Relevant
to a Radiological “Dirty Bomb”
Any explosion creates risks, and larger explosions create more and greater risks, and
focusing on the radiological aspects of an attack can take one’s attention away from
the non-radiological threats. While the NCRP [4] listed a number of these in Report
#161, most that are relevant here were discussed in Chaps. 6 and 7 of this book.
However, there are additional concerns that are relevant to emergency responders
that either were not raised by the NCRP or that have not been discussed here—or
both.