More from David Bodansky’s Nuclear Energy (second edition), again, check out this readable book for more information.
There are any number of targets and tools terrorists, people targeting civilians, might consider. A partial list:
• places where people assemble, such as theaters, sports stadia, and cruise ships.
• choke points in transportation routes, such as bridges and tunnels.
• symbolic targets, such as the Statue of Liberty.
• national energy carriers: electric transmission lines, gas pipelines, and oil tankers [and refineries].
• food and water supplies: introducing poisons into food and water supplies on a large scale or in a seemingly random local manner.
• weapons of mass destruction: introducing biological, chemical, or nuclear materials into the environment quietly or using violent explosions. [This includes direct attacks on chemical plants.] The casualties might range from tens to tens of thousands, and conceivably much more.
Given the options, it is not clear how high a place nuclear terrorism occupies in planning by terrorist groups.
The following will consider threats involving nuclear weapons and materials, not because these are the most likely or most dangerous terrorist targets, but because they are important, and because there is widespread interest.
In the US, the threats will be of three kinds:
• nuclear bombs,
• radiological dispersion devices or dirty bombs, radioactive material spread into the environment by a conventional bomb, and
• attacks on nuclear power plants, either the reactors or the spent fuel.
A bomb could be stolen or built abroad, and delivered intact or in pieces, or could be constructed where it will be used. Drug smuggling gives an indication as to how easy getting uranium or plutonium (neither of which is very radioactive) into the country. According to a report issued jointly by the Project on Managing the Atom (Harvard’s Kennedy School of Government) and by the Nuclear Threat Initiative, a 10-kt bomb would
create a circle of near-total destruction perhaps 2 miles in diameter. Even a [one thousand ton] “fizzle”from a badly executed terrorist bomb would have a diameter of destruction nearly half as big. If parked at the site of the World Trade Center, such a truck-bomb would level every building in the Wall Street financial area and destroy much of lower Manhattan.
Terrorists could steal or receive as a gift a government-built bomb. There is not much worry about bombs in the US, Britain, China, France, and Israel because these weapons are well protected, and except for the US, inventories are small. The level of threat is “medium” for Pakistan and India, with their unstable political situation, and for Russia, with its large inventory and poor inventory controls. See Making the Nation Safer for more on this subject.
A moderately large and technically capable group that can’t get a bomb could make one if they could obtain enough fissionable material by theft or gift.
The Center for International Security and Cooperation compiles information on illicit traffic in nuclear materials. There are worries that undetected thefts have occurred, because so many incidents are known about: 3 kg of weapons grade uranium offered for sale in St. Petersburg in 1994, 2 kg disappearing in the Republic of Georgia, a fuel rod containing 0.19 kg enriched to 19.9% which the Italian mafia intended for an undisclosed buyer in the Middle East. The detected traffic in material from the former Soviet Union began westward into Europe, then switched to southward (Iraq, Iran, and Afghanistan) during 1999 – 2000.
To reduce the availability of nuclear weapons material:
• Ensure that weapons and weapons-grade material are protected in all countries with them, particularly the countries with the most, the US and Russia.
• Secure stocks of plutonium removed from dismantled weapons (intended for Yucca Mountain in the US and commercial reactors in Russia).
• dilute stocks of highly enriched uranium by diluting with natural or depleted uranium, and then using in nuclear power plants. [See WeSupportLee for more on this.]
• Improve security or remove plutonium and enriched uranium from vulnerable facilities.
For the immediate future, it seems unlikely that any terrorist group will have the missile capabilities to deliver a bomb to the United States. Further, if the missile were sent from a land base, its point of origin would likely become known, giving the potential host country a powerful incentive to prevent the activity.
[On the other hand, Castro was said not to worry about this problem during the Cuban missile crisis.]
Smuggling the bomb in should not be too hard, because bombs emit little radiation that would trigger a detection device. Methods to detect devices include the following:
• direct detection of radiation, primarily gamma rays or neutrons,
• radiography, passing the container or vehicle through a machine which makes elements with high atomic numbers (uranium or plutonium) stand out,
• induced fission, irradiating the bomb with neutrons and examining what is emitted, and
• muon radiography, now considered speculative, monitoring the path of cosmic rays through the vehicle to detect dense atoms, even in the presence of lead shielding. [See Los Alamos thinking on this possibility.]
The first method is simplest, but is probably not adequate, especially for the more likely uranium bombs. This is because the half-life of U-235 is 704 million years, so there isn’t much radioactivity to detect. Plutonium has a much shorter half-life, and would be easier to detect.
Radiological Dispersion Devices (RDD), or “Dirty Bombs”
Dirty bombs could be built easily by anyone with access to radioactive materials. Radionuclides from industry or medicine, such as radioactive cesium, cobalt, or strontium, could be dispersed by a conventional explosive.
What kind of government reaction is appropriate? How will the public respond to actions by the government? From Making the Nation Safer:
[T]he likely aim of an RDD attack would be to spread fear and panic and cause disruption. Recovery would therefore depend on how such an attack is handled by first responders, political leaders, the media, and general members of the public.
In general, public fear of radiation and radioactive materials appears to be disproportionate to the actual hazards. Although hazardous at high doses, ionizing radiation is a weak carcinogen, and its effects on biological systems are better known than those of most, if not all, toxic chemicals. Federal standards that limit human exposure to environmental ionizing radiation, which are based on the linear, nonthreshold dose-response relationship, are conservative and protective, and the government continues to fund R&D to improve scientific understanding of radiation effects on biological materials.
Attacks on Nuclear Power Plants
Nuclear power plants were designed to withstand the impact of a small plane [I'm sure that design requirements will change for new plants]. Even so, it is a difficult target for a 9/11-type attack because of the low height and small target. Alternatively, armed intruders could attempt to disable the normal and emergency cooling systems (presumably, the plant can be shut down at first sign of attack with no option for restarting), but the chance of success is poor.
Another target is the spent fuel in the cooling pool, but it is thought to be easy to restore cooling, and difficult to create an explosion that would cause a wide dispersal of the uranium pellets. If the fuel is densely packed, the fuel could melt and release Cs-137. The policy suggestion is to transfer 5-year old waste to dry storage. According to Making the Nation Safer,
these are very robust and would probably stand up to aircraft attacks as well.
Of course, nuclear power plants are not unique as targets. Again, from Making the Nation Safer,
The potential vulnerabilities of [nuclear power plants] to terrorist attack seem to have captured the imagination of the public and the media, perhaps because of a perception that a successful attack could harm large populations and have severe economic and environmental consequences. There are, however, many other types of large industrial facilities that are potentially vulnerable to attack, for example, petroleum refineries, chemical plants, and oil and liquefied natural gas supertankers. Their facilities do not have the robust construction and security features characteristic of [nuclear power plants], and many are located near highly populated urban areas. The committee has not performed a detailed examination of the vulnerabilities of these other types of industrial facilities and does not know how they compare to the vulnerabilities of [nuclear power plants]. It is not clear whether the vulnerabilities of [nuclear power plants] constitute a higher risk to society than the vulnerabilities of other industrial facilities.
Indeed, the attention paid to nuclear power plants may make other industrial targets and football stadia more attractive targets.
Also in this series
Part 1 Nuclear Bombs, Nuclear Energy, and Terrorism
Part 2 Today’s Bombs, Making a Bomb
Part 3 Making Bombs from Nuclear Waste
Part 5 Nuclear Proliferation—International Treaties
Part 6 The Bomb Spreads
Part 7 Nuclear Power and the Weapons Threat
Part 8 Wrapup on Nuclear Power Series