APPENDIX D
Glossary


10 CFR Part 71:

Title 10, Part 71 of the Code of Federal Regulations, Packaging and Transportation of Radioactive Material. These regulations were promulgated by the U.S. Nuclear Regulatory Commission.

10 CFR Part 72:

Title 10, Part 72 of the Code of Federal Regulations, Licensing Requirements for the Independent Storage of Spent Nuclear Fuel, High-Level Radioactive Waste, and Reactor-Related Greater than Class C Waste. These regulations were promulgated by the U.S. Nuclear Regulatory Commission.

49 CFR Part 173:

Title 49, Part 173 of the Code of Federal Regulations, Shippers—General Requirements for Shipments and Packagings. These regulations were promulgated by the U.S. Department of Transportation.


A1:

The maximum activity of special form radioactive material permitted in a Type A package as provided in Appendix A of 10 CFR Part 71.

A2:

The maximum activity of normal form radioactive material permitted in a Type A package as provided in Appendix A of 10 CFR Part 71.

Absorbed dose:

The quantity of ionizing radiation deposited into an organ or tissue, expressed in terms of the energy absorbed per unit mass of tissue. The basic unit of absorbed dose is the rad or its SI equivalent the gray (Gy).

Acceleration:

The rate of change of velocity of an object.

Accelerometers:

Devices that measure the acceleration of an object.

Accident conditions of transport:

Severe conditions that well exceed normal conditions of transport. Such conditions could result in the application



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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States APPENDIX D Glossary 10 CFR Part 71: Title 10, Part 71 of the Code of Federal Regulations, Packaging and Transportation of Radioactive Material. These regulations were promulgated by the U.S. Nuclear Regulatory Commission. 10 CFR Part 72: Title 10, Part 72 of the Code of Federal Regulations, Licensing Requirements for the Independent Storage of Spent Nuclear Fuel, High-Level Radioactive Waste, and Reactor-Related Greater than Class C Waste. These regulations were promulgated by the U.S. Nuclear Regulatory Commission. 49 CFR Part 173: Title 49, Part 173 of the Code of Federal Regulations, Shippers—General Requirements for Shipments and Packagings. These regulations were promulgated by the U.S. Department of Transportation. A1: The maximum activity of special form radioactive material permitted in a Type A package as provided in Appendix A of 10 CFR Part 71. A2: The maximum activity of normal form radioactive material permitted in a Type A package as provided in Appendix A of 10 CFR Part 71. Absorbed dose: The quantity of ionizing radiation deposited into an organ or tissue, expressed in terms of the energy absorbed per unit mass of tissue. The basic unit of absorbed dose is the rad or its SI equivalent the gray (Gy). Acceleration: The rate of change of velocity of an object. Accelerometers: Devices that measure the acceleration of an object. Accident conditions of transport: Severe conditions that well exceed normal conditions of transport. Such conditions could result in the application

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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States of thermal and mechanical forces that have the potential to damage the vital containment functions of the package. Accident consequence value: The estimated collective dose that would be received by a population as a result of an accident scenario. Accident scenario: A postulated sequence of events during a transportation accident that result in the application of elevated thermal and mechanical loads to a transportation package. Accident source term: The amount of radioactive material released from a loaded transportation package in an accident. Actinides: Any of a series of chemically similar radioactive elements with atomic numbers ranging from 89 (actinium) through 103 (lawrencium). This group includes uranium (atomic number 92) and plutonium (atomic number 94). Activity: The rate of decay of a radioactive isotope. Acute radiation exposure: A radiation exposure that occurs over a relatively short period of time (e.g., seconds to hours). A chest X-ray is an acute radiation exposure. Affected communities: Communities that are impacted by a transportation program, for example, communities along a route used to ship spent fuel and high-level waste. Agreement State: States that have assumed authority under Section 274b of the Atomic Energy Act to license and regulate by-product materials (radioisotopes), source materials (uranium and thorium), and certain quantities of special nuclear materials. Atoms for Peace Program: A U.S. program begun under the Eisenhower administration to supply research reactor technology and nuclear fuel to foreign nations that agreed to forgo the development of nuclear weapons. Bare-fuel packages: See Package. Becquerel: A unit of radioactive decay equal to 1 disintegration per second. Bounding accident scenarios: Physically realistic accident scenarios that would be expected to produce large thermal and mechanical loading conditions. Burn-up: A measure of the degree to which the uranium-235 in nuclear fuel has been used up (fissioned), which determines the amount of radioactivity and heat generation in the fuel after it has been removed from the reactor. BWR: Boiling water reactor, a type of nuclear reactor in which the reactor’s water coolant is allowed to boil to produce steam. The steam is used to drive a turbine and electrical generator to produce electricity. Byproduct material: Defined by the Atomic Energy Act as radioactive material (except special nuclear material) yielded in or made radioactive by exposure to the radiation incident to the process of producing or using

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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States special nuclear material; and tailings or wastes produced by the extraction or concentration of uranium or thorium from any ore processed primarily for its source material content. Caliente corridor: A corridor in Nevada that has been selected by the U.S. Department of Energy for the construction of a rail line to Yucca Mountain. The corridor begins near Caliente, Nevada; passes north of the Nevada Test and Training Range; and then runs south to Yucca Mountain. Cancer incidence: Also known as the incidence rate. The rate of occurrence of cancer within a specified period of time per unit of population; for example, the number of cancers per year per 100,000 people. Cancer mortality: Also known as the mortality rate. The rate of death from cancer within a specified period of time per unit of population; for example, number of cancer deaths per year per 100,000 people. Canister-based packages: See Package. Cask: See Package. Centralized interim storage: See Interim storage. Certification tests: See Full-scale testing. Chronic radiation exposures: Radiation exposures that occur over extended periods of time (e.g., months to years). Exposure to natural background is a chronic radiation exposure. Closed fuel cycle: A nuclear fuel cycle in which spent fuel is processed to recover its usable contents. Cloud shine: Radiation exposure from airborne radioactive material. Collective dose: The sum of all radiation exposures received by all members of a specified population. Commercial spent fuel: Spent fuel produced from commercial nuclear power plants. Community: A group of people having similar characteristics, interests, or interactions; for example, people living in a particular geographic region, people with common cultural backgrounds, or people with common professional interests. Comparative risk: See Risk. Complementary cumulative distribution function (CCDF): Also known as the risk curve. A graphical representation of estimates of risk to a population from a particular accident scenario involving spent fuel and high-level waste. The estimate is developed through computer modeling studies. Compound CCDF: A graphical representation of the statistical properties (e.g., mean, median) of a group of complementary cumulative distribution functions. Containment effectiveness: The ability of a transportation package to con-

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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States tain its radioactive contents and maintain its radiation shielding effectiveness during routine use and under severe accident conditions. Conventional vehicular impact: Health and safety impacts that result from both normal transportation and transportation accidents involving spent fuel and high-level waste. These include the health impacts of transport vehicle exhaust emissions as well as traffic-related fatalities, injuries, and property damage. Conveyance: Any transport vehicle or vessel used to move spent fuel and high-level waste packages; for example, a truck and trailer or a locomotive and railcar. Criticality events: Self-sustaining nuclear reactions in spent fuel like those that occur when the fuel is in the reactor. Crud: Non-fixed radioactive contamination on the external surfaces of spent fuel assemblies. Curie: A unit of radioactive decay equal to 3.7 x 1010 (37 billion) disintegrations per second. Dedicated train: A train that transports only spent fuel or high-level waste and no other cargo. Demonstration tests: See Full-scale testing. Depleted uranium: Uranium from which much of the uranium-235 has been removed. Direct inhalation: See Inhalation. Direct socioeconomic impact: Loss of economic or social well-being as a direct result of transportation program operations; for example, economic losses from a transportation accident. DOE spent fuel: Spent fuel that is being managed by the U.S. Department of Energy, including spent fuel from defense reactors, research reactors, naval reactors, and some commercial power plants. Dose: See Radiation dose. Dose rate: See Radiation dose rate. Dry-cask storage: Packages used to store spent fuel in a dry state. Effective dose: The equivalent dose averaged over all organs that accounts for the varying sensitivity of different organs and tissues to the biological effects of ionizing radiation. The effective dose has the same units as the equivalent dose. Elastic limit: The maximum stress that can be applied to an object without causing permanent deformation. Emergency responder: A individual trained to provide assistance at the scene of an accident. Environmental justice: The fair treatment and meaningful involvement of people regardless of race, gender, national origin, or level of attained education in the development of laws, regulations, and policies that affect them.

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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States Equivalent dose: The absorbed dose averaged over the organ or tissue of interest multiplied by a weighting factor that accounts for the differences in the biological effects per unit of absorbed dose for different types of radiation. The basic unit of equivalent dose is the rem or its SI equivalent the sievert (Sv). Essentially unyielding surface: A surface that, because of its large mass and stiffness, absorbs minimal energy when impacted with other objects. Event trees: A graphical illustration of the sequence of events leading to an accident along with the probability of occurrence of each event. Each branch of the tree depicts the sequence of events that leads to the accident outcome depicted at the end of the branch. The probability of that accident is equal to the product of the probabilities of each segment along the branch. Exclusive use: Defined in 10 CFR 71.4 as “sole use by a single consignor of a conveyance for which all initial, intermediate, and final loading and unloading are carried out in accordance with the direction of the consignor or consignee. The loading and unloading must be carried out by personnel having radiological training and resources appropriate for the safe handling of the consignment.” Extraregulatory conditions: Accidents that impose thermal or mechanical loads on transportation packages that exceed those generated in the hypothetical accident conditions specified in 10 CFR Part 71. Federal repository: A federally operated underground facility for the permanent disposal of spent fuel and high-level waste. Fissile: Capable of being fissioned with thermal (low-energy) neutrons, the primary process in most nuclear reactors. The two most important fissile materials in spent fuel are uranium-235 and plutonium-239. Fission: The splitting of a nucleus into at least two fragments accompanied by the release of neutrons and energy. Free-drop test: One of the hypothetical accident conditions in 10 CFR Part 71 involving the free fall a transportation package from a height of 9 meters (about 30 feet) onto a flat, essentially unyielding horizontal surface, with the package striking the surface in the position expected to produce maximum damage. Fuel assembly: A bundle of fuel rods arranged in a square array. Fuel basket: A latticed container that is inserted into a transportation package or dry-storage cask and is designed to hold spent fuel assemblies in a fixed configuration. Fuel cladding: The thin-walled metal tube, usually fabricated from a zirconium alloy, that forms the outer jacket of a nuclear fuel rod. Fuel pellets: Small cylinders of uranium, usually in an oxide form, that provide the fuel for a nuclear reactor. Fuel rod: Sometimes referred to as a fuel element or fuel pin. A long, slen-

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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States der, sealed tube that holds uranium fuel pellets. Fuel rods are bundled in square-arrays bundles called fuel assemblies. Full-scale testing: Tests carried out on full-scale transportation packages or package components. Tests carried out to simulate the hypothetical accident conditions specified in 10 CFR Part 71 are referred to as certification tests. Tests carried out to simulate other severe accident conditions are often referred to as demonstration tests. Fully engulfing fire: An optically dense, hydrocarbon-fuel fire that is sufficiently large to completely engulf a transportation package. g: The acceleration imparted by Earth’s gravity field; 1 g is equal to 9.8 meters per second squared or 32 feet per second squared. Galactic cosmic radiation: Radiation originating from distant stars and galaxies. General trains: Also known as general service trains. Trains that carry other freight in addition to spent fuel or high-level waste. Generic package: A conceptual package design that incorporates the salient features of packages that have been certified for actual service. Generic package designs have been constructed for use in package performance modeling studies. Gray literature: Foreign or domestic open-source material that usually is available through specialized channels and may not enter normal channels or systems of publication, distribution, bibliographic control, or acquisition by booksellers or subscription agents. Greater-than-Class-C waste: Radioactive waste that contains concentrations of certain radionuclides above the Class C limits in 10 CFR 61.55. Ground shine: Radiation exposure from material deposited on the ground. Hazardous Materials Incident Reporting System: A computerized database maintained by the U.S. Department of Transportation that contains information on incidents involving the interstate transportation of hazardous (including radioactive) materials by air, highway, rail, and water. Health and safety risks: In the context of this report, risks that arise from exposures of people to radiation as a direct result of spent fuel and high-level waste transport. Heavy-haul truck: As used by the U.S. Department of Energy, an overweight truck that is capable of transporting a full-size rail package. High-income economy countries: Defined by the U.S. Department of Energy to include Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Israel, Italy, Japan, Netherlands, Spain, Sweden, Switzerland, Taiwan, and the United Kingdom. High-level radioactive waste (HLW): Defined in Title 42 of the U.S. Code as the highly radioactive waste material resulting from the reprocessing of spent nuclear fuel, including liquid waste produced directly in repro-

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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States cessing and any solid material derived from such liquid waste that contains fission products in sufficient concentrations; and other highly radioactive material that the U.S. Nuclear Regulatory Commission, consistent with existing law, determines by rule to require permanent isolation. Highly enriched uranium (HEU): Uranium enriched in the isotope uranium-235 to concentrations greater than or equal to 20 percent. HIGHWAY: A U.S. Department of Energy computer model used to route highway shipments of radioactive materials. Highway route controlled quantity: Defined in 49 CFR 173.403 as a quantity within a single package that exceeds 3000 times the A1 or A2 values for special form and normal form radioactive material, respectively, or that contains 1000 terabecquerels (27,000 curies) of radioactivity, whichever is least. HTGR: High-temperature gas-cooled reactor, a type of nuclear reactor in which helium is used as the coolant instead of water. The helium is used to heat water to generate steam, which in turn drives a turbine and electrical generator to produce electricity. Hypothetical accident conditions: A series of package tests described in 10 CFR Part 71 that includes a free-drop test, puncture test, thermal test, and immersion test. Immersion test: One of the hypothetical accident conditions in 10 CFR Part 71 in which an undamaged package is subjected to a pressure head equivalent to immersion in 15 meters (about 50 feet) of water. Additionally, 10 CFR 71.61 specifies that for packages designed for transport of spent fuel with activity exceeding 37 petabecquerels (1 million curies), the undamaged containment system must be able to withstand an external water pressure of 2 megapascals (290 pounds per square inch) for one hour without collapse, buckling, or in-leakage of water. Impact limiters: Protective coverings attached to the ends of transportation packages that are designed to absorb mechanical forces and provide thermal protection for the package closure system. Incidents: (1) Any event that involves the actual or suspected release of radioactive material from or surface contamination of a transportation package. (2) An intentional criminal act intended to damage a transportation package or disrupt a shipment. Independent Spent Fuel Storage Installations (ISFSIs): See Interim storage. Ingestion: Radiation exposures resulting from the uptake of radioactive material into the body via the digestive tract. Inhalation: Exposures resulting from the uptake of material into the body via the respiratory tract. The exposures of interest in this report are from inhalation of radioactive materials. Interim storage: The temporary storage of spent fuel and high-level waste,

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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States either in pools or in dry casks. Facilities designed to store spent fuel or high-level waste from several different sites are also informally referred to as centralized interim storage facilities. INTERLINE: A Department of Energy computer model used to route rail shipments of radioactive materials. Intermodal transportation: Movement of spent fuel or high-level waste using a combination of rail, highway, and barge. INTERTRAN 2: An implementation of the RADTRAN code for international applications. Ionizing radiation: Radiation that is sufficiently energetic to ionize the matter (i.e., remove electrons from the atoms) through which it moves. Irradiated nuclear fuel: See Spent nuclear fuel. Large-quantity shipping programs: Transportation programs that ship on the order of hundreds to thousands of metric tons of spent fuel or high-level waste. Latent cancer: Cancerous lesions in a living organism that have not progressed to a stage to be detectable. Legal-weight truck: A truck having a total gross weight (i.e., including cargo) of 80,000 pounds (about 36 metric tons) or less. Low enriched uranium (LEU): Uranium enriched in the isotope uranium-235 to concentrations less than 20 percent. Magnox package: A transportation package used in the United Kingdom to transport spent fuel from Magnox reactors. Also referred to as a Magnox flask. Margin of safety: Also known as a safety margin. A philosophy for designing engineering structures that relies on conservative assumptions about the mechanical properties of the materials used in the structure and the applied loads that the structure must resist. Maximally exposed individual: The individual in a population who is expected to receive the largest radiation dose. Maximum reasonably foreseeable accident: Defined by the U.S. Department of Energy as an accident characterized by extremes of mechanical and thermal forces, and other conditions not specified, that leads to the “highest reasonably foreseeable consequences.” DOE defines any accident that has the chance of occurring more than 1 in 10 million times per year as being reasonably foreseeable. Mean collective dose risk: The collective dose received by the population from an accident times the probability of occurrence of that accident. Mixed oxide fuel: Nuclear fuel that contains uranium and plutonium. Mode: See Transportation mode. Modular Emergency Response Radiological Transportation Training (MERRTT): U.S. Department of Energy-developed training materials

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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States that provide information on fundamental concepts and procedures for responding to radioactive materials transport incidents. Mostly rail scenario: U.S. Department of Energy’s preferred scenario for using trains to ship spent fuel and high-level waste to a federal repository at Yucca Mountain, Nevada. Mostly truck scenario: U.S. Department of Energy’s alternate scenario for using trucks to ship spent fuel and high-level waste to a federal repository at Yucca Mountain, Nevada. MTHM: Metric tons of heavy metal, where the heavy metal is usually uranium. This is a commonly used measure of fuel quantity. Natural background radiation: Radiation that exists naturally in the environment. It includes cosmic and solar radiation, radiation from radioactive materials present in rocks and soil, and radioactivity that is inhaled or ingested. Naval spent fuel: Spent fuel from nuclear submarines, ships, and training reactors belonging to the U.S. Navy. Nominal probability coefficient: The slope of the linear no-threshold relationship between radiation dose and effect, the latter usually expressed in terms of fatal cancer. Non-fixed surface contamination: Contamination that adheres to the outer surfaces of a package and can be detected by wiping. Normal conditions of transport: Transport conditions in which the package is subjected to minor mishaps due to rough handling or exposure to weather. Such minor mishaps would not be expected to compromise the vital containment functions of the package. Normal form radioactive material: Defined in 10 CFR Part 71 as radioactive material that is not special form radioactive material. Nuclear fuel cycle: The cradle-to-grave processes for obtaining, using, recycling, and disposing of uranium for nuclear applications such as electric power generation. Nuclear Waste Fund: A fund established by the U.S. government and funded through a 1.0 mil (0.1 cents) per kilowatt-hour fee on nuclear-generated electricity to pay for the costs of disposing of commercial spent fuel. Nuclear Waste Policy Act: A federal law passed in 1982 and amended thereafter that provides for the development of a federal program to develop and operate a federal repository for the disposal of spent fuel and high-level waste. Open fuel cycle: Also known as the once-through fuel cycle. A type of nuclear fuel cycle in which fuel is disposed of after it becomes spent, with no effort made to recover its usable components. Operational controls: Restrictions placed on individual shipments of spent

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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States fuel and high-level waste to reduce the likelihood and/or consequences of accidents. Other than high-income economy countries: Defined by the U.S. Department of Energy to include Argentina, Bangladesh, Brazil, Chile, Colombia, Greece, Indonesia, Iran, Jamaica, Malaysia, Mexico, Pakistan, Peru, Philippines, Portugal, Romania, Slovenia, South Africa, South Korea, Thailand, Turkey, Uruguay, Venezuela, and Zaire. Overweight truck: A truck exceeding the legal-weight limit of 80,000 pounds (approximately 36 metric tons) but within the range of weights that states approve for operation on public roads after issuance of special permits. Package: See Transportation package. Package closure system: The system of seals and lids on a transportation package that provides for an airtight closure to prevent the release of radioactive materials to the environment. Package dose rates: The dose rate on the external surface of the package. Package performance: The ability of a transportation package to maintain a high level of containment effectiveness in long-term routine use and under extreme mechanical and thermal loading conditions. Package Performance Study: A U.S. Nuclear Regulatory Commission study of package response to extreme thermal and mechanical loading conditions. PATRAN/PThermal: A commercial computer code used to model heat convection, conduction, and radiation transport processes. Perceptions: Defined by Webster’s Third New International Dictionary as the “integration of sensory impressions of events in the external world … as a function of nonconscious expectations derived from past experience.” Physical protection: Security measures to protect spent fuel and high-level waste shipments from malevolent acts. Plutonium (Pu): A naturally radioactive actinide element with atomic number 94. Private Fuel Storage, LLC: A private company that is developing a surface facility in Utah for the interim storage of commercial spent fuel. PRONTO 3D: A computer code developed by Sandia National Laboratories that has been used to model transportation package response to thermal and mechanical loading conditions. Publics: Groups of people differentiated by both demographic (ethnicity, income) and interest-based criteria. Puncture test: One of the hypothetical accident conditions in 10 CFR Part 71 in which a package is dropped through a distance of 1 meter (about 40 inches) onto the upper end of a 6-inch (15.2-centimeter) diameter solid, vertical, cylindrical mild steel bar mounted on an essentially unyielding

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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States horizontal surface. The package is dropped onto the bar in a position that is expected to produce maximum damage. PWR: Pressurized water reactor, a type of nuclear reactor in which the reactor’s water coolant is kept at high pressure to prevent it from boiling. The heat from this water is transferred to a secondary water system that produces steam to drive a turbine and electrical generator to produce electricity. Quality assurance program: Defined in 10 CFR Part 71 as those planned and systematic actions necessary to provide adequate confidence that a system or component will perform satisfactorily in service. Radiation dose: The quantity of radiation deposited in an object divided by the mass of the object. The radiation dose of interest in this report is ionizing radiation. Ionizing radiation doses can be expressed as an absorbed dose, equivalent dose, or effective dose. Radiation dose rate: The quantity of ionizing radiation deposited into an object per mass of the object per unit time. Radiation exposure: The act of being exposed to radiation. Also referred to as irradiation. Radiation shine: Radiation emitted from a transportation package containing spent fuel or high-level waste. Radioactive: Elements that are unstable and transform spontaneously (i.e., decay) through the emission of ionizing radiation, a process known as Radioactive decay. Radioactive decay: See Radioactive. Radioactive Material Incident Report Database: A database maintained by Sandia National Laboratories that contains information about radioactive materials transportation incidents that have occurred in the United States since 1971. RADTRAN: A computer code developed by Sandia National Laboratories that has been used to estimate radiological exposures and consequences under both normal transport conditions and accidents. Railhead: The terminus of a rail line, usually within easy access of a public roadway or water port. Rail package: A transportation package designed to be transported by rail. Repository: See Federal repository. Research reactor: Small nuclear reactor used primarily to conduct research, to develop theoretical practices, and for education or medical purposes. These serve as sources of neutrons for spectrographic and radiographic applications and for the manufacture of radionuclides for medical and other uses. Research reactor spent fuel: Spent fuel produced from research reactors. Resuspension inhalation: Inhalation of radioactive materials that were deposited onto the ground and later resuspended in air.

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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States Risk: As used in this report, the potential for an adverse effect from the transport of spent fuel or high-level waste. This potential can be estimated quantitatively if answers to the following three questions can be obtained: (1) What can go wrong? (2) How likely is it? (3) What are the consequences? Risk can be expressed in absolute terms or in comparison to other types of risks. Risk curves: See Complementary cumulative distribution function. RISKIND: A computer code developed by Argonne National Laboratory that has been used to estimate local, scenario-specific radiological doses to maximally exposed individuals. Routine conditions of transport: Transport conditions that are free of minor mishaps (see Normal conditions of transport) or accidents (see Accident conditions of transport). Safeguards: Steps taken to ensure that special nuclear material is not stolen or otherwise diverted for possible use in nuclear explosives or for radiological sabotage. Safe havens: Preplanned locations where a transport vehicle can stop in case of an emergency and receive protection by police or other security forces. Safety: Measures taken to protect spent fuel and high-level waste during handling and transport from failure, damage, human error, and other inadvertent acts. Scale model: A dimensionally accurate representation of an object, usually at a reduced size, that is used for design and testing purposes. Security: In the context of this report, measures taken to protect spent fuel and high-level waste during handling and transport from sabotage, attacks, and theft. SI: International System of Units (from the French Système International d’Unités), also sometimes referred to as the metric system. Small-quantity shipping programs: Transportation programs that ship on the order of tens of metric tons of spent fuel or high-level waste. Social amplification of risk: Social processes that increase the consequences of a particular risk. Social process: A characteristic mode of social interaction. Such interactions shape the communities in which people live by influencing choices about where to purchase or rent a home, where to work, and where to send children to school. Social risk: Risks that arise from social processes and human perceptions. Societal risk: All risks that affect society, including the health and safety risks and social risks discussed in this report. Source materials: Defined in the Atomic Energy Act to include any combination of uranium and thorium, in any physical or chemical form, or ores that contain at least 0.05 percent by weight of uranium, thorium,

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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States or any combination thereof. Depleted uranium is considered to be a source material. Special form radioactive material: Defined in 10 CFR Part 71 as radioactive material that exists as a single solid piece or is encapsulated material that meets certain other requirements. Special nuclear material: Defined in the Atomic Energy Act as plutonium, uranium-233, or uranium enriched in the isotopes uranium-233 or uranium-235. These isotopes are fissile and can be used in nuclear explosive devices. Spent fuel: See Spent nuclear fuel. Spent fuel basket: See Fuel basket. Spent fuel pool: A water-filled pool that is used for storage of spent fuel assemblies after their removal from a nuclear reactor. Spent nuclear fuel: Fuel whose fissile radionuclides have been consumed by fission to a point where it is no longer efficient for its intended purpose (e.g., for producing heat, electricity, or neutrons). Standard contract: Created by the Nuclear Waste Policy Act, it specifies the responsibilities of the U.S. Department of Energy and owners of commercial spent fuel for handling, receipt, and transportation of spent fuel to a federal repository for permanent disposal. Stigma: An event or condition that marks a person, place, product, or technology as deviant, flawed, or undesirable. When the particular stigmatizing characteristic is observed, the person, place, product, or technology may be denigrated or avoided. Strain: The deformation of an object under an applied force. Thermal creep: Deformation of an object over an extended period of time when subjected to elevated temperatures. Thermal test: One of the hypothetical accident conditions in 10 CFR Part 71 in which a package is fully engulfed in a hydrocarbon-fuel fire with an average flame temperature of at least 800°C (1472°F) for a period of 30 minutes. Thermally induced creep: See Thermal creep. Thermomechanical conditions: Describes the mechanical forces and heat loads applied to a transportation package. Transportation Emergency Preparedness Program: A program developed to support training of federal, state, tribal, and local authorities in emergency preparedness and response to transportation incidents involving DOE radioactive materials shipments. Transportation mode: Describes the means by which spent fuel and high-level waste is transported, for example, by truck, train, or barge. Transportation operations: The spectrum of activities associated with the shipment of spent fuel and high-level waste.

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Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States Transportation package: In the context of this report, containers used for the transport of spent fuel or high-level waste, whether loaded or empty. Loaded packages are referred to as packages in international standards, whereas the containers themselves without their contents are referred to as packagings. The terms casks and flasks (the latter term is commonly used in the United Kingdom) are sometimes used synonymously with packages. This report distinguished between two types of transportation packages: bare-fuel packages in which the spent fuel and the fuel basket are placed directly into the package, and canister-based packages in which the spent fuel and fuel basket are placed into a welded steel canister that in turn is placed in the package. Transuranic waste: Radioactive waste containing long-lived radioactive transuranic elements (elements with atomic numbers greater than 92) such as plutonium in concentrations greater than 100 nanocuries per gram. Truck package: A transportation package designed to be transported by road. Type A package: A package designed for the transport of materials of limited radioactivity—for example, uranium hexafluoride and fresh nuclear fuel. Type B package: A package designed for the transport of larger quantities of material including spent fuel, high-level waste, and mixed oxide fuel. Type C package: A package designed for the air transport of quantities of radioactive material exceeding a defined threshold including, for example, plutonium and mixed oxide fuel. Uranium (U): A naturally radioactive actinide element with atomic number 92. Very long duration fires: Fires that burn for periods of hours (or longer), which can produce thermal loading conditions that exceed those for the regulatory thermal test specified in 10 CFR 71.73. Vitrification: A process for immobilizing radioactive waste, particularly high-level waste, in glass matrices. Vulnerable communities: Communities of people who, because of disproportionate exposures to other health-affecting substances, or because of ethnic, linguistic, or socioeconomic issues, may be less able to read or understand information from the authorities, to act in a first-responder role, to exit the area in a timely manner in an emergency, or to otherwise cope with an emergency.