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24 command and the emergency operations center (e.g., the state Categories, emergency management office or agency). A confounding Doses, variable is that there are no rapid identification methods for bi- Detection, and ological agents, as there are for radiological and chemical Decontamination. agents. The ability to successfully route all potentially exposed traffic to decontamination areas clearly depends on the time Basics it takes to recognize that the agent has been released. In the case of delayed detection of a release, effort may be needed Radioactivity is a property of unstable atoms. As unstable to identify, decontaminate, and provide medical assistance to atoms decay, they release or radiate energy in the form of contaminated travelers, vehicles, and cargo after they have particles or waves known as radiation. Radiation emanates in left the area of initial contamination. all directions from a radioactive material and can bounce off In some outdoor release cases, it may be safer for people to or reflect from surfaces or the air to get around a corner. The remain inside buildings (i.e., shelter-in-place) than to evacu- energy of the radiation determines whether or not it will pen- ate. If evacuation of an area is determined to be needed, evac- etrate a particular surface. Everyone is exposed to low levels uees would be directed to decontamination areas. In these of naturally occurring radiation. We are also exposed to radi- cases, transportation paths may be re-routed to expedite one- ation during certain medical procedures such as x-rays. way travel. Essentially all modes of transportation may assist Ultimately, radioactive atoms decay to a stable atom that in population evacuations, as well as in transporting first re- is no longer radioactive. The time for half of a specific ra- sponders and providing emergency response supplies. Fur- dioactive material to decay to this stable and non-radioactive thermore, any transportation modes with large buildings may form is called its half-life. Half-lives can vary from fractions be considered for use as temporary shelters. of a second to billions of years. After a period of ten half- If the released agent or a disease outbreak is contagious, lives, over 99.9 percent of a radioactive material has decayed isolation of those infected is essential for containment. In this to a non-radioactive stable substance. Therefore, radioactive case, potentially infected people would be directed to area materials with half-lives of up to hours decay too quickly to hospitals. Special routes may be designated for transport of pose significant long-term hazards to humans. Radioactive potentially infected people. If hospitals cannot handle all atoms have the identical physical and chemical properties those infected, quarters for quarantines may be necessary. In as their non-radioactive or stable counterparts. Thus, radio- a worst-case scenario, people may be asked to stay isolated active iron looks, feels, and behaves the same as normal sta- from others in their homes. In this extreme scenario, trans- ble iron. portation would essentially be reserved for first responders and providing supplies. Events 2.3 RADIOLOGICAL THREATS Responses to radiological events are driven primarily by the quantity, quality, and dispersion of the radiological re- Familiarity with the basic types of radiation that may pose lease. However, recognition of the types of possible radio- threats can help in developing appropriate emergency response logical events can help in assessing vulnerabilities and risk. plans. The effects of radiation releases range from increased Four general types of radiological events are described long-term cancer risks to acute radiation sickness and death. below: This section presents radiation fundamentals (2.3.1), emer- gency response information needs for decision-makers (2.3.2), Radiological Infrastructure Event. Radioactive material and radiological threats and the transportation system (2.3.3). may be released from any of the thousands of facilities in the United States that produce, handle, and store ra- 2.3.1 Radiation Fundamentals dioactive materials (e.g., nuclear reactors, medical cen- ters, factories, food irradiators, research laboratories, A general understanding of radiation, including the terms construction sites, military depots, uranium mines, nu- used when referring to radiological threats, can improve com- clear fuel fabricating facilities, and nuclear waste stor- munication when dealing with a radiological event. More in- age sites), or from radioactive materials in transport formation on radiation is available from many commonly between these facilities. Two particular types of release available sources, including the Internet. The radiation fun- events that have received substantial attention and re- damentals addressed are sponse planning in nuclear threat studies are Nuclear Reactor Incident. This involves the release of Basics, dangerous levels of radiation from a nuclear reactor. Events, In an extreme event, such as occurred in Chernobyl,

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25 hundreds of square miles and the health of millions of Nuclear Yield Incident. This refers to the detonation of a people may be threatened. In such an event, state nuclear weapon (i.e., atomic, hydrogen, or neutron bomb). agencies would work in tandem with the federal These detonations both produce and spread radiation and agency that regulates the reactor or the federal agency radioactive fallout (i.e., particles that descend through the that owns and operates the reactor to coordinate emer- air) as the result of either splitting atoms (fission) or fus- gency response. The Nuclear Regulatory Commission ing the nuclei of two atoms (fusion).7 The magnitude of regulates civilian nuclear reactors. The DOE and such an event would result in substantial federal (civil and DOD regulate the reactors they own and operate for military) agency response that would likely exert sizable research and nuclear weapons production. The licens- control on all emergency responses. Although state and ing of nuclear reactors requires establishment of evac- local transportation officials would be involved in such a uation plans coordinated with the appropriate state response, specific classified procedures have been devel- and local response agencies. oped to guide responders. Thus, this extreme event is not Radioactive Material Transportation Incident. This specifically considered in this document. refers to an accidental or deliberate release of radioac- tive material in transport. Large quantities of radioac- tive material are transported in special packages Categories (i.e., casks or containers) which, if breached, can result in significant radioactive release. DOE-licensed haulers Radiation refers to any form of energy that travels through for radioactive materials follow pre-approved routes space, such as light, heat, sound, and ionizing radiation. Ion- and must have an acceptable emergency response plan izing radiation is any type of radiation that can cause the par- for radioactive leaks that includes training and commu- ticles it strikes to become chemically charged (i.e., ionized). nication with the appropriate state and local response The radiation of concern in WMD is ionizing radiation, and agencies along the shipping route. The effect of such an throughout this report, all references to radiation are more event could be a radiological dispersal that resembles specifically referring to ionizing radiation. an inefficient dirty bomb, contaminating the nearby Ionizing radiation is produced by atoms that are unstable area, including the transportation infrastructure and because they have extra energy or mass. Unstable atoms, also population. referred to as radioactive materials, give off, or emit their Passive Radiological Dispersion. Radiation can be extra energy or mass to become more stable. The energy or spread passively, without the need of active dispersal mass that is emitted from radioactive materials can be cate- mechanisms. For example radioactive material can be gorized as alpha particles, beta particles, gamma rays and x- placed as pellets or liquid spilled in elevators, trains, rays, and neutrons. These different types of radiation have or other spaces. Depending on the type of radioactive different properties and therefore pose different hazards. material and the time of exposure, the health effects Alpha particles are relatively heavy, cannot travel far, and experienced by exposed people can be severe, but the cannot penetrate the skin, but these particles can cause dam- number of people and area affected would likely be rel- age if inhaled or ingested. Beta particles are lighter, can travel atively small. farther, and can penetrate the skin. Skin can receive a thermal Radiological Dispersal Device (RDD). This refers to the burn (or beta burn) if it is exposed to a large enough quantity use of a forceful (or active) method of spreading radia- of beta particles. Gamma rays and x-rays are electromagnetic tion into the environment. A dirty bomb (frequently energy that can penetrate farther than beta particles--for ex- mentioned in the media) is a prime example of an RDD. ample, up to 3 inches of lead. Gamma rays have a shorter A dirty bomb uses a conventional explosive, such as dy- wavelength than x-rays and thus have higher, more damaging namite, to scatter a radioactive material, such as spent energy. Gamma rays are only generated in nuclear processes, nuclear reactor fuel rods, or radioactive material from while x-rays can be generated by either nuclear processes industrial or hospital equipment (e.g., Cesium-137 or or electronic devices. Neutrons are the highest energy form Cobalt-60). The potential spread of radiation from an of radiation and penetrate the farthest. Neutrons are only re- RDD is far less than from a nuclear bomb (referred to as leased during a nuclear detonation or as part of a nuclear re- a nuclear yield incident, below), which produces radia- actor leak. Many radioactive materials emit more than one tion from a nuclear reaction. Analyses of many RDD type of radiation simultaneously. For example, the materials scenarios suggest that this type of event would probably considered most likely to be used in a dirty bomb, Cesium- have minimal prompt fatalities and little serious life- 137 and Cobalt-60, both emit beta particles and gamma rays. threatening radiation doses to the public. However, all Radiation that penetrates body tissues is referred to as analyzed scenarios have resulted in widespread, low- external direct exposure. For each type of radiation, the level contamination causing panic, terror, and signifi- 7 In addition to nuclear (ionizing) radiation, these reactions also release thermal radi- cant economic impacts. More details and examples of ation, and they are unique in their release of an immediate electromagnetic pulse, or RDD events are presented in Appendix A-4. surge of electrical power.

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26 TABLE 2-11 Radiation Shielding, Range, and Exposure Pathways Alpha () Beta () Gamma () and X-ray Neutron Property or Hazard Radiation Radiation Radiation Radiation Shielding Protection Normal Less than 1/4 inch 2 to 12 inches of lead, or 3 2 to 6 feet of water, human skin of metal, glass, to 18 inches of iron/steel, or 4 to 8 feet of layer or concrete or 1 to 6 feet of concrete concrete Expected Range of 1 to 4 inches 1 to 18 feet in air Hundreds to thousands of Hundreds to Unshielded Radiation in air feet in air thousands of feet in air External Exposure Open wound Open wound Open wound adsorption, Open wound Pathway to Humans absorption absorption, and and external direct adsorption, and external direct external direct Internal Exposure Inhalation Inhalation and Inhalation and ingestion Inhalation and Pathway to Humans and ingestion ingestion ingestion protective shielding, expected range of unshielded radia- 0.5 rem. This is slightly higher than background levels tion, and damaging exposure pathways for human health caused by exposure to man-made sources, including medical are presented in Table 2-11. x-rays, CAT-scans, nuclear medicine, and so forth.8 Sub- A specific radioactive material, also called a radioisotope, stantial human health effects of radiation occur if the dose re- is identified by its element abbreviation and atomic weight. ceived exceeds 100 rem in a period of hours to weeks. The atomic weight is written either before or after the A short-term dose to the whole body that exceeds 300 rem element abbreviation. For example, radioactive cobalt is could be fatal to some people, depending on medical care. identified as 60Co, Co-60, Cobalt-60, or Co60. Radioisotopes Greater detail on human health effects, established public can exist as a single pure element or as a compound with dose limits, personal protection, and treatment after exposure other non-radioactive elements. For example, radioactive is presented in Appendix C. sodium combined with non-radioactive chlorine can produce radioactive table salt. Depending on the specific element or compound, radioisotopes can exist as a solid, liquid, or gas Detection at normal temperatures. Each radioisotope has a unique half-life and energy of emis- No type of radiation can be seen, felt, heard, smelled, or sion of one or more types of radiation. Energy of emission is tasted. Radiation can only be detected with appropriate in- measured in electron volts (ev). A higher energy emission re- struments. Since September 11, 2001, the design and avail- sults in greater penetration capability through shielding and the ability of radiation measurement instruments, called dosime- human body. In contrast, the quantity of a radioactive mater- ters, survey meters, detection meters, radiation meters, and ial is a measure of how many atoms decay in each second. This Geiger counters, has grown. One instrument can measure is called the activity and is expressed in units of Curies (Ci) or alpha, beta, and gamma radiation, but the direct measure- Bequerels (Bq) with 37 billion Bq = 1 Ci. ment of neutron radiation requires either another instrument or another probe to connect to an instrument. Almost all in- struments are portable and battery operated and can be as Doses small as a personal pager or as large as a loaf of bread. For the purpose of first-responder detection of significant radia- Radiation dose to humans is measured in units that quan- tion, a detector or meter that measures alpha, beta, and tify the damage that can be done because of the radiation gamma radiation dose rates from about 0.1 or 1 mrem/hour type, energy, and quantity a person has been exposed to. to 100 or 1000 rem/hour is adequate and can be purchased for These units are called rem or Sieverts ( 100 rem). Each of about $400 to $1,500. Field personnel who may be first at the these units may be prefaced with milli- (m) or micro (), scene of an event may be able to provide critical threat in- meaning one-thousandth and one-millionth, respectively. formation if they have the appropriate detection equipment. The average individual receives background levels of radia- tion at a rate of about 0.3 rem per year. Background radiation is naturally occurring radiation (alpha, beta, and gamma) Decontamination from radioactive materials in the soil, air, and water. There is no natural neutron radiation. Lifestyle choices such as living Almost all radiological events require some degree of at higher altitudes, frequent air travel, or residing in an area decontamination. Removal or decontamination of surface with high natural radioactivity in the soil and rocks can in- 8 National Research Council, 2005. Health Risks From Exposure to Low Levels of Ion- crease the natural radiation received by an individual. The izing Radiation: BEIR VII Phase 2 Committee to Assess Health Risks from Exposure average annual radiation dose in the United States is around to Low Levels of Ionizing Radiation. National Academies Press, Washington, D.C.