To begin the introduction to the topic
of radiological terrorism, here are important terms and concepts that will be
used throughout this tutorial.
Radioactivity is the property or condition of
some elements that results in the spontaneous transformation, or
decay, of the nucleus of an unstable atom. As the unstable atom tries to change to
a stable state, it releases excess energy in the form of
radiation. Substances that undergo this transformation
process are called radioisotopes, or more generally,
radioactive materials. Once the substances are processed into a usable form,
such as pellets or powder, they are called radioactive
sources.
There are two types of radiological terrorism: the malicious use
of a radiological device; and attacks on nuclear
facilities, such as nuclear power plants. Both types
have certain features in common, such as attempting to cause
radioactive contamination and playing off public fear
of radiation. The consequences of both types of attacks could also have
similarities, such as slightly elevated health risks or massive economic costs.
There are notable differences, however, several of which are described
below.
There are two options—active and passive—for terrorists who
wish to use radiological materials to cause fear among the public. The passive
option would involve the use of radioactive materials or objects in the form of
a radiation-emitting device (RED). A strong RED could be placed in high-profile
areas, such as highly trafficked urban sites and government facilities, which
could expose a large number of people to the intense radioactive source over a
short period of time. An alternative passive option would be the use of an RED
to harm a limited number of people over a long period of time. The active
option would involve the scattering of radioactive material over a large or
confined area using an RDD, as described below.
A radiological dispersal device (RDD) is not a nuclear bomb and does not
result in a nuclear explosion. Rather, an RDD is a device that contains
radioactive materials and some method by which those materials can be spread
over a wide area. The device can be built in a variety of sizes, and the
radiation can cause physical and environmental
contamination, economic damage, and some physical harm.
One type of RDD is popularly referred to as a "dirty bomb."
A dirty bomb uses the force of conventional explosives, such as TNT, to scatter
radioactive material. Use of this type of RDD could harm human health,
instill panic, complicate emergency response efforts, and deny access by
contaminating property.
|
A "dirty bomb" uses common explosives to
spread radioactive materials. |
An RDD can take other forms, such as an atmospheric device. An
atmospheric RDD is a system in which radioactive material is converted
into a form that is easily transported by air currents. This type of RDD
could be used, for example, to distribute radioactive particles through the
ventilation system of an office building to poison the workers
inside.
Rather than using a radiological device, terrorists
might opt to attack a nuclear facility. Nuclear facilities include nuclear power
plants, cooling ponds for spent nuclear fuel rods, nuclear reactors used for
research or other non-electricity purposes, nuclear reprocessing facilities, and
nuclear waste sites. Another potential scenario for attack is during the
transport of spent nuclear fuel. Among these options, this tutorial will focus
on threats to operational nuclear power plants.
|