The threats of chemical, biological, radiological, nuclear and explosive (CBRNE) hazards continue to advance. CBRN weapons are some of the most indiscriminate and deadly weapons in existence today, with capability to affect large population in wide geographical area and in short time. The release of Chemical, Biological, Radiological and Nuclear (CBRN) materials, whether deliberate or accidental, may have the potential to cause serious harm and severe disruption to the delivery of vital public services over a wide geographical area.
The relative ease with which malicious actors could obtain many of the materials and know-how and wide range of dissemination techniques makes them appealing to extremist groups. A greater proliferation through the internet of the knowledge necessary to make CBRNE threats, coupled with the trends of rapid innovation and improvisation witnessed in Iraq and Afghanistan with IEDs, will make threat prediction difficult. Weaponized materials can be delivered using conventional bombs (e.g., pipe bombs), improved explosive materials (e.g., fuel oil-fertilizer mixture) and enhanced blast weapons (e.g., dirty bombs).
Radiological warfare is any form of warfare involving deliberate radiation poisoning or contamination of an area with radiological sources. Radiological weapons are normally considered weapons of mass destruction (WMDs), although radiological weapons can be specific in who they target, such as the radiation poisoning of Alexander Litvinenko by the Russian FSB, using radioactive polonium-210.
Numerous countries have expressed an interest in radiological weapons programs, several have actively pursued them, and three have performed radiological weapons tests. “We define a radiological weapon as one intended to disperse radioactive material in the absence of a nuclear detonation. Although our focus in the article is on state-level programs, the definition is consistent with devices usually associated with non-state actors. To the best of our knowledge, no state or non-state actor currently possess RW, although a number of states previously have produced and tested them (e.g., the United States, the Soviet Union and Iraq), said Samuel Meyer, Sarah Bidgood, and William C. Potter.
Technological advances were among the major drivers of RW programs in both the US and the Soviet Union, and RW were initially pursued in tandem with nuclear weapons and chemical weapons (CW) programs. The anticipated promise of RW as a weapons innovation, however, never materialised in either country due to a combination of factors, including technical difficulties in the production and maintenance of the weapons, diminution in the perceived military utility of RW relative to both CW and nuclear weapons, and low threat perceptions about adversary RW capabilities.
The demise of the US RW program turned, in part, on the choice of the radioisotope for the weapon: tantalum-182 and the absence of a dedicated production infrastructure (priority was given to the production of plutonium-239, the fissile material for most of the nuclear bombs then being produced).
We are concerned, however, that the Russian Federation, despite its own unsuccessful history with RW, has shown renewed interest in advanced nuclear weapons that seek to maximise radioactive contamination. We also worry that some countries may conclude that RW serve their perceived national interests, especially in the absence of international legal restraints. It therefore is important, we believe, to revive US-Russian cooperation to ban radiological weapons and strengthen the norm against their use, , said Samuel Meyer, Sarah Bidgood, and William C. Potter.
The US government document: the Report of the Uranium Committee identified three possible military aspects of atomic fission, the first of which was “production of violently radioactive materials … carried by airplanes to be scattered as bombs over enemy territory.” The fission products from a conventional nuclear explosive weapon are as much a radiological weapon as weapons solely designed for the purpose of mass radiological warfare. The standard high-fission thermonuclear weapon is automatically a weapon of radiological warfare, as dirty as a cobalt bomb.
Nuclear Weapons are the most well-known example of radiological weapons. First developed by the United States during World War II, nuclear weapons are extremely explosive bombs that split atoms into pieces, releasing a huge amount of radioactive energy. Nuclear weapons present two dangers: the damage created by the explosion itself and its released radiation, and the radioactive material that would remain after the explosion. However, nuclear weapons are extremely difficult to build or buy-only a very small handful of nations have been able to obtain them. Furthermore, the international community is extremely concerned about their use and they are one of the most tightly protected and monitored items in the modern world. Therefore, the risk of a terrorist attack utilizing nuclear weapons is extremely small.
Another potential form of radiological terrorism is an attack on a nuclear facility, such as a nuclear power plant or truck transporting radioactive material. Such an attack would have consequences similar to a dirty bomb attack, which is described below.
Initially, gamma radiation from the fission products of an equivalent size fission-fusion-fission bomb are much more intense than Co-60: 15,000 times more intense at 1 hour; 35 times more intense at 1 week; 5 times more intense at 1 month; and about equal at 6 months. Thereafter fission drops off rapidly so that Co-60 fallout is 8 times more intense than fission at 1 year and 150 times more intense at 5 years. The very long-lived isotopes produced by fission would overtake the 60Co again after about 75 years. Other salted bomb variants that don’t use cobalt have also been theorized.
A far lower-tech radiological weapon than those discussed above is a “dirty bomb” / radiological dispersal device, which refers to a conventional explosive bomb with a radiological side effect due to strapping radiation sources to it, is a very inefficient way to spread radiation, and all such “weapons” have problems that render them likely impractical for military uses.
A “dirty bomb” is one type of a radiological dispersal device — also called an RDD — that combines conventional explosives, such as dynamite, with radioactive material. The terms dirty bomb and RDD are often used interchangeably. Most RDDs would not release enough radiation to kill people or cause severe illness. The conventional explosive itself would be more harmful to individuals than the radioactive material. However, depending on the situation, an RDD explosion could create fear and panic, contaminate property, and require potentially costly cleanup. Making prompt, accurate information available to the public may prevent the panic sought by terrorists.
A dirty bomb is in no way similar to a nuclear weapon or nuclear bomb. A nuclear bomb creates an explosion that is millions of times more powerful than that of a dirty bomb. The cloud of radiation from a nuclear bomb could spread tens to hundreds of square miles, whereas a dirty bomb’s radiation could be dispersed within a few blocks or miles of the explosion. A dirty bomb is not a “Weapon of Mass Destruction” but a “Weapon of Mass Disruption,” where contamination and anxiety are the terrorists’ major objectives.
Rather, radiological warfare with dirty bombs would be of vastly more use to terrorists spreading or intensifying fear. The release of radioactive material may involve no special “weapon” and include no direct killing of people from its radiation source, but rather could make whole areas or structures unusable or unfavorable for the support of human life. The elevated radiation levels in the targeted areas would make these areas dangerous to humans. An area, once contaminated with radiation, is often expensive to clean up. Decontamination of the built environment would take time.
There are many factors that limit the potential for a radiological or dirty bomb attack. Facilities that contain a large amount of radioactive material, such as nuclear power plants, are highly secure and their radiation is well contained. It would be very difficult to obtain enough radiological material to cause a significant amount of damage from a dirty bomb attack. The real danger of radiological weapons lies in the potential for people to react in fear and therefore create greater danger than actually present in the attack itself.
Impact of a Dirty Bomb
The extent of local contamination would depend on a number of factors, including the size of the explosive, the amount and type of radioactive material used, the means of dispersal, and weather conditions. Those closest to the RDD would be the most likely to sustain injuries due to the explosion. As radioactive material spreads, it becomes less concentrated and less harmful.
Since it would be extremely difficult for a terrorist to obtain an amount of radiation that would be very powerful or harmful, and since the radiation from a dirty bomb would be spread out over a large area after an explosion, the dose of radiation that each person in the surrounding area would receive would likely be so low that it would not be a cause for any concern. We naturally receive radiation all the time from sources like the sun, and the dose that a victim of a dirty bomb would receive would be no more than the typical dose we receive every year – not enough to result in a significant increase in the risk of cancer.
Prompt detection of the type of radioactive material used will greatly assist local authorities in advising the community on protective measures, such as sheltering in place, or quickly leaving the immediate area. Radiation can be readily detected with equipment already carried by many emergency responders. Subsequent decontamination of the affected area may involve considerable time and expense.
Immediate health effects from exposure to the low radiation levels expected from an RDD would likely be minimal. The effects of radiation exposure would be determined by:
- The amount of radiation absorbed by the body;
- The type of radiation (gamma, beta, or alpha);
- The distance from the radiation to an individual;
- The means of exposure-external or internal (absorbed by the skin, inhaled, or ingested); and the length of time exposed.
- The health effects of radiation tend to be directly proportional to radiation dose. In other words, the higher the radiation dose, the higher the risk of injury.
What concerns city and state officials most is the possibility of negative consequences resulting from panic, which would probably do more harm than the dirty bomb itself. Panic could lead to traffic accidents or stampedes resulting from anxious citizens fleeing the city, as well as stress and anxiety-related health problems. The key to safety is thus education: citizens who know their risks are less likely to panic and more likely to stay safe.
CBRN protection includes identifying threats and hazards and preventing or mitigating the effects of CBRN environments. Protective measures include individual protective equipment, detection devices, contamination mitigation technology as well as medical countermeasures.
In general, protection from radiation is afforded by: minimizing the time exposed to radioactive materials; maximizing the distance from the source of radiation; and shielding from external exposure and inhaling radioactive material.
Sources of Radioactive Material
Radioactive materials are routinely used at hospitals, research facilities, industrial activities, and construction sites. These radioactive materials are used for such purposes as diagnosing and treating illnesses, sterilizing equipment, and inspecting welding seams. The NRC together with the “Agreement States,” which also regulate radioactive material, administers more than 22,000 licenses of such materials. The vast majority of these materials are not useful in an RDD.
Control of Radioactive Material
NRC and state regulations require owners licensed to use or store radioactive material to secure it from theft and unauthorized access. These measures have been greatly strengthened since the attacks of Sept. 11, 2001. Licensees must promptly report lost or stolen risk-significant radioactive material. “Risk-significant” refers to radioactive sources that may pose a significant risk to the public and the environment if not properly used, protected, or secured. Local authorities also assist in making a determined effort to find and retrieve such sources. Most reports of lost or stolen material involve small or short-lived radioactive sources that are not useful for an RDD.
Past experience suggests there has not been a pattern of collecting such sources for the purpose of assembling an RDD. It is important to note that the radioactivity of the combined total of all unrecovered sources in the U.S. over the past eight years (when corrected for radioactive decay) would not reach the threshold for one high-risk radioactive source.
The U.S. Government is working to strengthen security for high-risk radioactive sources both at home and abroad. The NRC and its Agreement States have worked together to create a strong and effective regulatory safety and security framework that includes licensing, inspection, and enforcement.
NRC also works with other federal agencies, the International Atomic Energy Agency, and licensees to protect radioactive material from theft and unauthorized access. The agency has made improvements and upgrades to the joint NRC-DOE (Department of Energy) database that tracks the location and movement of certain forms and quantities of special nuclear material. In addition, in early 2009, the NRC deployed its new National Source Tracking System, designed to track high-risk sources in the United States on a continuous basis.