ALARA. As low as (is) reasonably achievable.
Alluvial. A general term for clay, silt, sand, gravel, or similar unconsolidated detrital material, deposited during comparatively recent geological time by a stream or other body of running water.
Alpha (α) decay. Radioactive decay in which an alpha particle (nucleus of the 4He atom, consisting of two protons and two neutrons) is emitted.
Anatexis. The partial melting of preexisting rock. It implies in situ partial melting.
Anticline. A fold, generally convex upward, whose core contains the stratigraphically older rocks.
Aquifer. A body of rock that contains sufficient saturated permeable material to conduct groundwater and to yield significant quantities of water to wells and springs.
Aureole. A zone surrounding an igneous intrusion in which the country rock shows the effects of contact metamorphism.
Backfill. Waste rock or aggregate used to support the roof or walls of a mine after removal of ore.
Basalt. A general term for dark-colored mafic igneous rocks, commonly extrusive but locally intrusive (e.g., as dikes), composed chiefly of calcic plagioclase and clinopyroxene; the fine-grained equivalent of gabbro.
Basement. The crust of the Earth below sedimentary deposits, extending downward to the Mohorovicic discontinuity. In many places the rocks of the complex are igneous and metamorphic and of Precambrian age, but in some places they are Paleozoic, Mesozoic, or even Cenozoic.
Bench. The horizontal step or floor along which coal, ore, stone, or overburden is worked or quarried.
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Glossary ALARA. As low as (is) reasonably achievable. Alluvial. A general term for clay, silt, sand, gravel, or similar unconsolidated detrital material, deposited during comparatively recent geological time by a stream or other body of running water. Alpha (α) decay. Radioactive decay in which an alpha particle (nucleus of the 4He atom, consisting of two protons and two neutrons) is emitted. Anatexis. The partial melting of preexisting rock. It implies in situ partial melting. Anticline. A fold, generally convex upward, whose core contains the stratigraphi- cally older rocks. Aquifer. A body of rock that contains sufficient saturated permeable material to conduct groundwater and to yield significant quantities of water to wells and springs. Aureole. A zone surrounding an igneous intrusion in which the country rock shows the effects of contact metamorphism. Backfill. Waste rock or aggregate used to support the roof or walls of a mine after removal of ore. Basalt. A general term for dark-colored mafic igneous rocks, commonly extrusive but locally intrusive (e.g., as dikes), composed chiefly of calcic plagioclase and clinopyroxene; the fine-grained equivalent of gabbro. Basement. The crust of the Earth below sedimentary deposits, extending down- ward to the Mohorovicic discontinuity. In many places the rocks of the complex are igneous and metamorphic and of Precambrian age, but in some places they are Paleozoic, Mesozoic, or even Cenozoic. Bench. The horizontal step or floor along which coal, ore, stone, or overburden is worked or quarried. 300
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301 GLOSSARY Beta (β) decay. Nuclear decay in which a β particle (an electron ejected from a radioactive nucleus) is emitted or in which orbital electron capture occurs. Breccia. A coarse-grained clastic rock, composed of angular broken rock frag- ments held together by a mineral cement or in a fine-grained matrix; it dif- fers from conglomerate in that the fragments have sharp edges and unworn corners. Calcrete. A term for a pedogenic calcareous soil, for example, limestone con- sisting of surficial sand and gravel cemented into a hard mass by calcium carbonate precipitated from solution and redeposited through the agency of infiltrating waters. Caldera. A large, basin-shaped volcanic depression, more or less circular or cirquelike in form, formed by collapse during an eruption. Carbonate. Sediments or rocks formed by the biotic or abiotic precipitation from aqueous solution of carbonates of calcium, magnesium, or iron, for example, limestone and dolomite. Aqueous carbonate species include CO2, H2CO3, and the HCO3– and CO32– ions. Cataclasite. A fine-grained, cohesive rock with angular fragments that have been produced by the crushing and fracturing of preexisting rocks as a result of mechanical forces in the crust, normally lacking a penetrative foliation or microfabric. Cohort. A group of individuals having a statistical factor (such as age or risk) in common. Compaction. Any process, such as burial or desiccation, by which a soil mass loses pore space and becomes denser; or the densification of a soil by mechanical means, accomplished by rolling, tamping, or vibrating, usually at controlled water content. Conglomerate. A coarse-grained clastic sedimentary rock, composed of rounded to subangular fragments larger than 2 mm in diameter (granules, pebbles, cobbles, boulders) typically containing fine-grained particles (sand, silt, clay) in the interstices, and commonly cemented by calcium carbonate, iron oxide, silica, or hardened clay. Dewatering. The removal of water from a drowned shaft or waterlogged work- ings by pumping or drainage as a safety measure or as a preliminary step to resumption of development in the area. Diagenesis. The sum of all chemical and physical changes in minerals during and after their initial accumulation, a process limited on the high-temperature, high-pressure side by the lowest grade of metamorphism. Dike. A tabular igneous intrusion that cuts across the bedding or foliation of the country rock. Dissolved load. The part of the total stream load that is carried in solution, such as chemical ions yielded by erosion of the landmass during the return of rainwater to the ocean.
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302 URANIUM MINING IN VIRGINIA Dose-response. Of, relating to, or graphing the pattern of physiological response to varied dosage (as of a drug or radiation) in which there is typically little or no effect at very low dosages and a toxic or unchanging effect at high dos- ages with the maximum increase in effect somewhere between the extremes. Drift. A horizontal opening in or near an orebody and parallel to the course of the vein or the long dimension of the orebody. Effluent. A liquid discharged as waste, such as contaminated water from a factory or the outflow from a sewage works; water discharged from a storm sewer or from land after irrigation. Eh (redox potential). Measures the tendency of a chemical species to acquire electrons and be reduced. Reduction/oxidation potential of a compound is measured under standards conditions against a standard reference half-cell. In biological systems, the standard redox potential is defined at pH 7.0 versus the hydrogen electrode and partial pressure of hydrogen = 1 bar. Epithelium. A membranous cellular tissue that covers a free surface or lines a tube or cavity of an animal body and serves especially to enclose and pro- tect the other parts of the body, to produce secretions and excretions, and to function in assimilation. Equilibrium factor. The ratio of decay products to radon. Equivalent dose. An absorbed dose that is averaged over an organ or tissue and weighted for the radiation quality. Erosion. The general process or the group of processes whereby the materials of the Earth’s crust are loosened, dissolved, or worn away, and simultane- ously moved from one place to another, by natural agencies, which include weathering, solution, corrasion, and transportation, but usually exclude mass wasting; specifically the mechanical destruction of the land and the removal of material (such as soil) by running water (including rainfall), waves and currents, moving ice, or wind. Exposure. The condition of being subject to some detrimental effect or harmful condition. Exposure pathway. The route a substance takes from its source (where it began) to its end point (where it ends), and how people can come into contact with (or get exposed to) it. An exposure pathway has five parts: a source of con - tamination, an environmental medium and transport mechanism, a point of exposure, a route of exposure, and a receptor population. Felsic. A mnemonic adjective applied to an igneous rock having abundant light- colored minerals in its mode; also, applied to those minerals (quartz, feld - spars, feldspathoids, muscovite) as a group. Fluvial. Produced by the action of a stream or river.
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303 GLOSSARY Fractional crystallization. A differentiation process whereby previously formed crystals are physically separated from the magma and thus prevented from equilibrating with the liquid from which they grew, resulting in a series of residual liquids of more extreme compositions than would have resulted from equilibrium crystallization. French drain. A covered ditch containing a layer of fitted or loose stone or other pervious material. Gamma (γ) radiation. Electromagnetic radiation emitted in the process of nuclear transformation or particle annihilation. Gangue. The valueless minerals in an ore; that part of an ore that is not economi - cally desirable but cannot be avoided in mining. It is separated from the ore minerals during concentration. Geochronometer. A physical feature, material, or element whose formation, alteration, or destruction can be calibrated or related to a known interval of time. Grade. The classification of an ore according to the desired or worthless material in it or according to value. Granite. A plutonic rock in which quartz constitutes 10 to 50 percent of the felsic components and in which the alkali feldspar/total feldspar ratio is generally restricted to the range of 65 to 90 percent. Gray. The SI unit of absorbed radiation dose of ionizing radiation, defined as the absorption of one joule of ionizing radiation by one kilogram of matter. 1 Gy is equal to 100 rads. Ground control. Maintaining rock mass stability by controlling the movement of excavations in the ground, which can be either rock or soil. Groundwater. That part of the subsurface water that is in the saturated zone, including underground streams. Loosely, all subsurface water as distinct from surface water. Hardness. A property of water causing formation of an insoluble residue, primarily due to the presence of ions of calcium and magnesium, but also to ions of other alkali metals, other metals (e.g., iron), and even hydrogen. Hardness of water is generally expressed as parts per million as CaCO 3. Healthy worker effect. Phenomenon of workers usually exhibiting overall death rates lower than those of the general population due to the fact that the severely ill and disabled are ordinarily excluded from employment. Hematite. A common iron mineral: Fe2O3. Hematite occurs in splendent, metallic-looking, steel-gray or iron-black rhombohedral crystals, in reniform masses or fibrous aggregates, or in deep-red or red-brown earthy forms. It is found in igneous, sedimentary, and metamorphic rocks and is the principal ore of iron.
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304 URANIUM MINING IN VIRGINIA Hydrology. The science that deals with water (both liquid and solid), its proper- ties, circulation, and distribution, on and under the Earth’s surface and in the atmosphere, from the moment of its precipitation until it is returned to the atmosphere through evapotranspiration or is discharged into the ocean. In situ leaching/ in situ recovery (ISL/ISR). A hydrometallurgical process that treats ore for the recovery of minerals while the ore is in place underground. It is a mineral recovery technique where no mine waste piles or tailings impoundments are created. Intercalated. Said of layered material that exists or is introduced between layers of a different character; especially said of relatively thin strata of one kind of material that alternate with thicker strata of some other kind, such as beds of shale that are intercalated in a body of sandstone. Ionizing radiation. Any radiation consisting of directly or indirectly ionizing particles or a mixture of both, or photons with energy higher than the energy of photons of ultraviolet light or a mixture of both such particles and photons. Isotope. One of two or more species of the same chemical element, that is, having the same number of protons in the nucleus, but differing from one another by having a different number of neutrons. The isotopes of an element have slightly different physical and chemical properties, owing to their mass dif - ferences, by which they can be separated. Karst. A type of topography that is formed on limestone, gypsum, and other soluble rocks, primarily by dissolution. It is characterized by sinkholes, caves, and underground drainage. Leaching. Metallurgical process for dissolution of metals by means of an acid or alkaline solution. Lenticular. Resembling in shape the cross section of a lens, especially of a double-convex lens. Lining. A layer of clay, concrete, synthetic film, or other material, placed under or over all or part of the perimeter of a conduit, reservoir, or landfill to resist erosion, minimize seepage losses or the escape of gases, withstand pressure, and improve flow. Lithology. The description of rocks, especially in hand specimen and in outcrop, on the basis of such characteristics as color, mineralogic composition, and grain size. Load. The material that is moved or carried by a natural transporting agent, such as a stream, a glacier, the wind, or waves, tides, and currents; or the quantity or amount of such material at any given time. Mafic. Said of an igneous rock composed chiefly of one or more ferromagnesian, dark-colored minerals in its mode; also, said of those minerals. Matrix. The finer-grained material enclosing, or filling the interstices between, the larger grains or particles of a sediment or sedimentary rock; the natural material in which a sedimentary particle is embedded.
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305 GLOSSARY Maximum contaminant level (MCL). The maximum permissable level of a contaminant in water which is delivered to any user of a public water system. Meta-analysis. A method that takes results of two or more studies of the same research question and combines them into a single analysis. The purpose of meta-analysis is to gain greater accuracy and statistical power by taking advantage of the large sample size resulting from the cumulation of results over multiple studies. Meta-analysis typically uses the summary statistics from the individual studies, without requiring access to the full dataset. Key components of meta-analysis include ensuring the availability of a common metric across all studies and the use of appropriate algorithms for combining or averaging those metrics across studies and assessing statistical significance. Metaluminous. Said of an igneous rock in which the molecular proportion of aluminum oxide is greater than that of sodium and potassium oxides com - bined but generally less than of sodium, potassium, and calcium oxides combined. Metamorphism. The mineralogical, chemical, and structural adjustment of solid rocks to physical and chemical conditions that have generally been imposed at depth, below the surface zones of weathering and cementation, and differ from the conditions under which the rocks in question originated. Metasomatism. The open-system metamorphic process in which the original chemical composition of a rock is changed by reaction with an external source. The process is commonly thought to occur in the presence of a fluid medium flowing through the rock. Metasomatism may also occur by grain- boundary diffusion or by diffusion through a static fluid medium. Mylonite. A fine-grained, foliated rock, commonly with poor fissility and pos- sessing a distinct lineation. Nepheline syenite. A plutonic rock composed essentially of alkali feldspar and nepheline. It may contain an alkali ferromagnesian mineral, for example, an amphibole or a pyroxene. Nephrotoxicity. Resulting from or marked by poisoning of the kidney. Ore. The naturally occurring material from which a mineral or minerals of economic value can be extracted profitably or to satisfy social or political objectives. Overburden. Material of any nature, consolidated or unconsolidated, that over- lies a deposit of useful materials, ores, or coal, especially those deposits that are mined from the surface by open cuts. Oxidation. The complete, net removal of one or more electrons from a molecular entity. Peralkaline. Said of an igneous rock in which the molecular proportion of aluminum oxide is less than that of sodium and potassium oxides combined. Peraluminous. Said of an igneous rock in which the molecular proportion of aluminum oxide is greater than that of sodium and potassium oxides combined.
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306 URANIUM MINING IN VIRGINIA Permeability. The property or capacity of a porous rock, sediment, or soil for transmitting a fluid; it is a measure of the relative ease of fluid flow under unequal pressure and is a function only of the medium. Permissible exposure limits. Regulatory limits on the amount or concentra- tion of a substance in the air, designed to protect workers against the health effects of exposure to hazardous substances. Phosphorite. A sedimentary rock with a high enough content of phosphate minerals to be of economic interest. Most commonly it is a bedded primary or reworked secondary marine rock composed of microcrystalline carbonate fluorapatite in the form of laminae, pellets, oolites, nodules, and skeletal, shell, and bone fragments. Pooled analysis. A method of analysis that combines primary data from several studies and then conducts analysis on the enlarged data set. Porphyry copper deposit. A large body of rock, typically porphyry, that con- tains disseminated chalcopyrite and other sulfide minerals. Such deposits are mined in bulk on a large scale, generally in open-pits, for copper and byproduct molybdenum. Most deposits are 3 to 8 km across, and of low grade (less than 1% Cu). Pregnant solution. A concentrated, purified uranium solution. Protore. In older writings, any primary mineralized material too low in tenor to constitute ore but from which ore may be formed through secondary enrichment. As commonly employed today, the rock below the sulfide zone of supergene enrichment; the primary material that cannot be produced at a profit under existing conditions but that may become profitable with techno - logical advances or price increases. Rad. A unit of absorbed radiation dose causing 0.01 joule of energy to be absorbed per kilogram of matter. It is equal to 1 centiGray (cGy). Radioactive decay. Nuclear decay in which particles or electromagnetic radia- tion are emitted or the nucleus undergoes spontaneous fission or electron capture. Radioactivity. The property of certain nuclides showing radioactive decay. Radionuclide. A nuclide (species of atom) that is radioactive. Radon progeny. The short-lived decay products of radon, an inert gas that is one of the natural decay products of uranium. The short-lived radon progeny (i.e., polonium-210, lead-214, bismuth-214, and polonium-214) are solids and exist in air as free ions or as ions attached to dust particles. Raffinate. The aqueous solution remaining after the metal has been extracted by the solvent; the tailing of the solvent extraction system. Reagent. A substance that is consumed in the course of a chemical reaction.
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307 GLOSSARY Recommended exposure limit. An occupational exposure limit recommended by the U.S. National Institute for Occupational Safety and Health as being protective of worker safety and health over a working lifetime if used in com- bination with engineering and work practice controls, exposure and medical monitoring, posting and labeling of hazards, worker training, and personal protective equipment. Reduction. The complete transfer of one or more electrons to a molecular entity. Rem. The “Roentgen equivalent in man,” a unit of radiation dose equivalent that is the product of absorbed radiation (rads) and a weighting factor. It is equal to 1 centiSievert (cSv). Runoff. That part of precipitation appearing in surface streams. It is more restricted than streamflow, because it does not include stream channels af- fected by artificial diversions, storage, or other human works. Sandstone. A medium-grained clastic sedimentary rock composed of abundant rounded or angular fragments of sand size with or without a fine-grained matrix (silt or clay) and more or less firmly united by a cementing mate- rial (commonly silica, iron oxide, or calcium carbonate); the consolidated equivalent of sand, intermediate in texture between conglomerate and shale. Sediment. Solid fragmental material that originates from weathering of rocks and is transported or deposited by air, water, or ice, or that accumulates by other natural agents, such as chemical precipitation from solution or secre - tion by organisms, and that forms in layers on the Earth’s surface at ordinary temperatures in a loose, unconsolidated form, for example, sand, gravel, silt, mud, till, loess, alluvium. Sievert. The SI unit for dose equivalent, which is the absorbed dose of ionizing radiation weighted with other factors. It is measured in J/kg. Silica. Silicon dioxide (SiO2), which occurs naturally in crystalline, amorphous, and impure forms (as in quartz, opal, and sand, respectively). Siliciclastic. Pertaining to clastic noncarbonate rocks which are almost exclu - sively silicon-bearing, either as forms of quartz or as silicates. Silicosis. Pneumoconiosis characterized by massive fibrosis of the lungs resulting in shortness of breath and caused by prolonged inhalation of silica dusts. Shotcrete. A mixture of portland cement, sand (commonly including coarse aggregate), and water applied by pneumatic pressure through a specially adapted hose and used as a fireproofing agent and as a sealing agent to pre- vent weathering of mine timbers and roadways. Skarn. An old Swedish mining term for silicate gangue (amphibole, pyroxene, garnet, etc.) of certain iron-ore and sulfide deposits of Archean age, particu - larly those that have replaced limestone and dolomite.
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308 URANIUM MINING IN VIRGINIA Stoping. Extraction of ore in an underground mine by working laterally in a se - ries of levels or steps in the plane of a vein. It is generally done from lower to upper levels, so that the whole vein is ultimately removed. The process is distinct from working in a shaft or tunnel or in a room in a horizontal drift, although the term is used in a general sense to mean the extraction of ore. Stratiform. Having the form of a layer, bed, or stratum; consisting of roughly parallel bands or sheets. Sulfate. A mineral compound characterized by the sulfate radical SO4. Anhydrous sulfates, such as barite, BaSO4, have divalent cations linked to the sulfate radical; hydrous and basic sulfates, such as gypsum, CaSO4∙2H2O, contain water molecules. Sulfide. A mineral compound characterized by the linkage of sulfur with a metal or semimetal, such as galena (PbS) or pyrite (FeS2). Suspended load. The part of the total sediment load that is carried for a consider- able period of time in suspension, free from contact with the bed; it consists mainly of clay, silt, and sand. Tailings. The gangue and other refuse material resulting from the washing, con - centration, or treatment of ground ore. Tectonics. A branch of geology dealing with the broad architecture of the outer part of the Earth, that is, the regional assembling of structural or defor- mational features, a study of their mutual relations, origin, and historical evolution. Tuberculosis. A usually chronic, highly variable disease that is caused by a bacterium of the genus Mycobacterium (M. tuberculosis), is usually com- municated by inhalation of the airborne causative agent, affects especially the lungs but may spread to other areas from local lesions or by way of the lymph or blood vessels, and is characterized by fever, cough, difficulty in breathing, inflammatory infiltrations, formation of tubercles, caseation, pleural effusion, and fibrosis. Unconformity. The structural relationship between rock strata in contact, char- acterized by a lack of continuity in deposition, and corresponding to a period of nondeposition, weathering, or especially erosion (either subaerial or subaqueous) prior to the deposition of the younger beds, and often (but not always) marked by absence of parallelism between the strata. Vein. An epigenetic mineral filling of a fault or other fracture in a host rock, in tabular or sheetlike form, often with associated replacement of the host rock; a mineral deposit of this form and origin. Water table. The surface between the zone of saturation and the zone of aeration; that surface of a body of unconfined groundwater at which the pressure is equal to that of the atmosphere. Watershed. The region drained by, or contributing water to, a stream, lake, or other body of water.
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309 GLOSSARY Waste rock. Barren or submarginal rock or ore that has been mined, but is not of sufficient value to warrant treatment and is therefore removed ahead of the milling processes. Working level. Any combination of short-lived radon daughters in 1 liter of air that will result in the ultimate emission of 1.3 × 105 MeV of potential alpha particle energy. Working level month. An exposure to 1 working level for 170 hours (2,000 working hours per year/12 months per year = approximately 170 hours per month). Yellowcake. Concentrated, high-purity (75-85%) uranium oxide (U3O8), which is used as the raw material for nuclear fuel fabrication.