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13 Developing a Radiological and Nuclear Interdiction Network
The manner in which these all work together and in which one level calls for
assistance or “hands off” to a different level of responder is described (in the US) in
what is called the Concept of Operations, often shortened to “CONOPS.”
There are some questions that must be answered if one is to develop an interdiction
network:
• What are the characteristics of the device(s) we are trying to interdict?
• Are we concerned about an internal threat (obtaining a source within the city that
will be attacked), an external threat, or both?
• Who will be operating the instruments that will be deployed and what level of
training and expertise do they have?
• What is the budget?
Each of these will be discussed in turn.
13.1 Device Characteristics
Alpha radiation cannot penetrate a sheet of paper and has a range of only a few
mm in air. Beta radiation can penetrate to a depth of about 1 cm in water and up
to six or seven meters in air. Detecting these radiations at a distance can be hard
enough when they are unshielded, and sources that emit alpha and beta radiation are
even more difficult as they are so easily shielded. Gamma and neutron radiation, on
the other hand, are highly penetrating, and gamma radiation has a range of up to
several kilometers in air. Thus, gamma- and neutron-emitting sources are detected
at a distance, and gamma radiation can be analyzed to identify the radionuclide(s)
that emitted it.
A higher-activity source is more difficult to shield and can be detected at a greater
distance compared to a source of lower activity. Radiation dose rate drops as the
inverse square of the distance to a source and the dose rate at any given distance is
proportional to the source activity. Thus, in order to detect Source B at twice the
distance as Source A, Source B must have four times the activity.
The device in question might or might not provide shielding for the radioactive
source to make it more difficult to detect from a distance. Shielding adds to the size
and weight of a device, possibly placing restrictions on the type of vehicle that can
be used for transportation and limiting the places where it can be hidden; shielding
a high-activity Co-60 source, for example, might require more than a ton of lead.
In addition, heavy shielding can absorb the energy of an explosion, reducing the
explosion’s impact. Thus, radiation shielding can increase the difficulty of detecting
a radioactive source, but at the cost of making the source more difficult to transport
and reducing the potential effectiveness of the weapon’s explosive component.
13 Developing a Radiological and Nuclear Interdiction Network
The manner in which these all work together and in which one level calls for
assistance or “hands off” to a different level of responder is described (in the US) in
what is called the Concept of Operations, often shortened to “CONOPS.”
There are some questions that must be answered if one is to develop an interdiction
network:
• What are the characteristics of the device(s) we are trying to interdict?
• Are we concerned about an internal threat (obtaining a source within the city that
will be attacked), an external threat, or both?
• Who will be operating the instruments that will be deployed and what level of
training and expertise do they have?
• What is the budget?
Each of these will be discussed in turn.
13.1 Device Characteristics
Alpha radiation cannot penetrate a sheet of paper and has a range of only a few
mm in air. Beta radiation can penetrate to a depth of about 1 cm in water and up
to six or seven meters in air. Detecting these radiations at a distance can be hard
enough when they are unshielded, and sources that emit alpha and beta radiation are
even more difficult as they are so easily shielded. Gamma and neutron radiation, on
the other hand, are highly penetrating, and gamma radiation has a range of up to
several kilometers in air. Thus, gamma- and neutron-emitting sources are detected
at a distance, and gamma radiation can be analyzed to identify the radionuclide(s)
that emitted it.
A higher-activity source is more difficult to shield and can be detected at a greater
distance compared to a source of lower activity. Radiation dose rate drops as the
inverse square of the distance to a source and the dose rate at any given distance is
proportional to the source activity. Thus, in order to detect Source B at twice the
distance as Source A, Source B must have four times the activity.
The device in question might or might not provide shielding for the radioactive
source to make it more difficult to detect from a distance. Shielding adds to the size
and weight of a device, possibly placing restrictions on the type of vehicle that can
be used for transportation and limiting the places where it can be hidden; shielding
a high-activity Co-60 source, for example, might require more than a ton of lead.
In addition, heavy shielding can absorb the energy of an explosion, reducing the
explosion’s impact. Thus, radiation shielding can increase the difficulty of detecting
a radioactive source, but at the cost of making the source more difficult to transport
and reducing the potential effectiveness of the weapon’s explosive component.