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136-649: The Husab Mine (formerly the Rössing South Mine ), operated under the Husab Uranium Project , is a uranium mine near the town of Swakopmund in the Erongo region of western-central Namibia . The mine is located approximately 5 kilometres (3.1 mi) south of the larger Rössing uranium mine and 45 kilometres (28 mi) from Walvis Bay . Swakop Uranium believes the Husab Mine has

272-587: A nuclear reactor , where a metres-thick water layer is used as effective shielding. There are two sources of high energy particles entering the Earth's atmosphere from outer space: the sun and deep space. The sun continuously emits particles, primarily free protons, in the solar wind, and occasionally augments the flow hugely with coronal mass ejections (CME). The particles from deep space (inter- and extra-galactic) are much less frequent, but of much higher energies. These particles are also mostly protons, with much of

408-517: A body to a point high enough to ionize small fractions of atoms or molecules by the process of thermal-ionization (this, however, requires relatively extreme radiation intensities). As noted above, the lower part of the spectrum of ultraviolet, called soft UV, from 3 eV to about 10 eV, is non-ionizing. However, the effects of non-ionizing ultraviolet on chemistry and the damage to biological systems exposed to it (including oxidation, mutation, and cancer) are such that even this part of ultraviolet

544-613: A fluorescence on a nearby plate of coated glass. Within a month, he discovered the main properties of X-rays that we understand to this day. In 1896, Henri Becquerel found that rays emanating from certain minerals penetrated black paper and caused fogging of an unexposed photographic plate. His doctoral student Marie Curie discovered that only certain chemical elements gave off these rays of energy. She named this behavior radioactivity . Alpha rays (alpha particles) and beta rays ( beta particles ) were differentiated by Ernest Rutherford through simple experimentation in 1899. Rutherford used

680-504: A functional group ( amidoxime group ) that selectively adsorbs heavy metals, and the performance of such adsorbents has been improved. Uranium adsorption capacity of the polymer fiber adsorbent is high, approximately tenfold greater in comparison to the conventional titanium oxide adsorbent. One method of extracting uranium from seawater is using a uranium-specific nonwoven fabric as an adsorbent. The total amount of uranium recovered from three collection boxes containing 350 kg of fabric

816-402: A generic pitchblende radioactive source and determined that the rays produced by the source had differing penetrations in materials. One type had short penetration (it was stopped by paper) and a positive charge, which Rutherford named alpha rays . The other was more penetrating (able to expose film through paper but not metal) and had a negative charge, and this type Rutherford named beta . This

952-469: A health hazard if used improperly. Exposure to radiation causes damage to living tissue; high doses result in Acute radiation syndrome (ARS), with skin burns, hair loss, internal organ failure, and death, while any dose may result in an increased chance of cancer and genetic damage ; a particular form of cancer, thyroid cancer , often occurs when nuclear weapons and reactors are the radiation source because of

1088-409: A higher orbital level or if the photon is extremely energetic, it may knock an electron from the atom altogether, causing the atom to ionize. Generally, larger atoms are more likely to absorb an X-ray photon since they have greater energy differences between orbital electrons. The soft tissue in the human body is composed of smaller atoms than the calcium atoms that make up bone, so there is a contrast in

1224-436: A material medium. This includes: Radiation is often categorized as either ionizing or non-ionizing depending on the energy of the radiated particles. Ionizing radiation carries more than 10 electron volts (eV) , which is enough to ionize atoms and molecules and break chemical bonds . This is an important distinction due to the large difference in harmfulness to living organisms. A common source of ionizing radiation

1360-436: A method of extraction that does not produce the same occupational hazards, or mine tailings, as conventional mining. With regulations in place to ensure the use of high volume ventilation technology if any confined space uranium mining is occurring, occupational exposure and mining deaths can be largely eliminated. The Olympic Dam and Canadian underground mines are ventilated with powerful fans with radon levels being kept at

1496-455: A sandstone body. Peneconcordant sandstone uranium deposits, also called Colorado Plateau –type deposits, most often occur within generally oxidized sandstone bodies, often in localized reduced zones, such as in association with carbonized wood in the sandstone. Precambrian quartz-pebble conglomerate-type uranium deposits occur only in rocks older than two billion years old. The conglomerates also contain pyrite. These deposits have been mined in

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1632-465: A significant degree, and is sometimes referred to as vacuum ultraviolet . Although present in space, this part of the UVA spectrum is not of biological importance, because it does not reach living organisms on Earth. There is a zone of the atmosphere in which ozone absorbs some 98% of non-ionizing but dangerous UV-C and UV-B. This ozone layer starts at about 20 miles (32 km) and extends upward. Some of

1768-414: A temperature at or below room temperature would thus appear absolutely black, as it would not reflect any incident light nor would it emit enough radiation at visible wavelengths for our eyes to detect. Theoretically, a black-body emits electromagnetic radiation over the entire spectrum from very low frequency radio waves to x-rays, creating a continuum of radiation. The color of a radiating black-body tells

1904-467: A very low to practically "safe level" in uranium mines. Naturally occurring radon in other, non-uranium mines, also may need control by ventilation. Heap leaching is an extraction process by which chemicals (usually sulfuric acid ) are used to extract the economic element from ore which has been mined and placed in piles on the surface. Heap leaching is generally economically feasible only for oxide ore deposits. Oxidation of sulfide deposits occurs during

2040-629: A violent part of the universe's early history. The kinetic energy of particles of non-ionizing radiation is too small to produce charged ions when passing through matter. For non-ionizing electromagnetic radiation (see types below), the associated particles (photons) have only sufficient energy to change the rotational, vibrational or electronic valence configurations of molecules and atoms. The effect of non-ionizing forms of radiation on living tissue has only recently been studied. Nevertheless, different biological effects are observed for different types of non-ionizing radiation. Even "non-ionizing" radiation

2176-454: A wavelength less than about 10  m (greater than 3 × 10  Hz and 1240 eV ). A smaller wavelength corresponds to a higher energy according to the equation E = h c / λ . ( E is Energy; h is the Planck constant; c is the speed of light; λ is wavelength.) When an X-ray photon collides with an atom, the atom may absorb the energy of the photon and boost an electron to

2312-434: Is radioactive materials that emit α, β, or γ radiation , consisting of helium nuclei , electrons or positrons , and photons , respectively. Other sources include X-rays from medical radiography examinations and muons , mesons , positrons, neutrons and other particles that constitute the secondary cosmic rays that are produced after primary cosmic rays interact with Earth's atmosphere . Gamma rays, X-rays, and

2448-403: Is a common synonym for infrared radiation emitted by objects at temperatures often encountered on Earth. Thermal radiation refers not only to the radiation itself, but also the process by which the surface of an object radiates its thermal energy in the form of black-body radiation. Infrared or red radiation from a common household radiator or electric heater is an example of thermal radiation, as

2584-486: Is also ionizing. Neutrons are categorized according to their speed/energy. Neutron radiation consists of free neutrons . These neutrons may be emitted during either spontaneous or induced nuclear fission. Neutrons are rare radiation particles; they are produced in large numbers only where chain reaction fission or fusion reactions are active; this happens for about 10 microseconds in a thermonuclear explosion, or continuously inside an operating nuclear reactor; production of

2720-610: Is aware of uncertainties and lack of precision of the models and parameter values", "Collective effective dose is not intended as a tool for epidemiological risk assessment, and it is inappropriate to use it in risk projections" and "in particular, the calculation of the number of cancer deaths based on collective effective doses from trivial individual doses should be avoided". Ultraviolet, of wavelengths from 10 nm to 125 nm, ionizes air molecules, causing it to be strongly absorbed by air and by ozone (O 3 ) in particular. Ionizing UV therefore does not penetrate Earth's atmosphere to

2856-841: Is broken. This leads to production of chemical free radicals . In addition, very high energy neutrons can cause ionizing radiation by "neutron spallation" or knockout, wherein neutrons cause emission of high-energy protons from atomic nuclei (especially hydrogen nuclei) on impact. The last process imparts most of the neutron's energy to the proton, much like one billiard ball striking another. The charged protons and other products from such reactions are directly ionizing. High-energy neutrons are very penetrating and can travel great distances in air (hundreds or even thousands of metres) and moderate distances (several metres) in common solids. They typically require hydrogen rich shielding, such as concrete or water, to block them within distances of less than 1 m. A common source of neutron radiation occurs inside

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2992-474: Is capable of causing thermal-ionization if it deposits enough heat to raise temperatures to ionization energies. These reactions occur at far higher energies than with ionization radiation, which requires only single particles to cause ionization. A familiar example of thermal ionization is the flame-ionization of a common fire, and the browning reactions in common food items induced by infrared radiation, during broiling-type cooking. The electromagnetic spectrum

3128-404: Is composed of photons, which have neither mass nor electric charge and, as a result, penetrates much further through matter than either alpha or beta radiation. Gamma rays can be stopped by a sufficiently thick or dense layer of material, where the stopping power of the material per given area depends mostly (but not entirely) on the total mass along the path of the radiation, regardless of whether

3264-459: Is concluded. Land reclamation after mining takes different routes, depending on the amount of material removed. Due to the high energy density of uranium, it is often sufficient to fill in the former mine with the overburden, but in case of a mass deficit exceeding the height difference between the previous surface level and the natural water table, artificial lakes develop when groundwater removal ceases. If sulfites, sulfides or sulfates are present in

3400-534: Is electromagnetic radiation with a wavelength between 0.7 and 300 μm, which corresponds to a frequency range between 430 and 1 THz respectively. IR wavelengths are longer than that of visible light, but shorter than that of microwaves. Infrared may be detected at a distance from the radiating objects by "feel". Infrared sensing snakes can detect and focus infrared by use of a pinhole lens in their heads, called "pits". Bright sunlight provides an irradiance of just over 1 kW/m at sea level. Of this energy, 53%

3536-435: Is extensively used to suppress airborne dust levels. Groundwater is an issue in all types of mining, but in open pit mining, the usual way of dealing with it – i.e. when the target mineral is found below the natural water table – is to lower the water table by pumping off the water. The ground may settle considerably when groundwater is removed and may again move unpredictably when groundwater is allowed to rise again after mining

3672-453: Is home to approximately 500 mineralized breccia pipes and Cripple Creek, Colorado, also is a site that contains breccia pipe ore deposits that is associated with a volcanic pipe. Olympic Dam mine , the world's largest uranium deposit, was discovered by Western Mining Corporation in 1975 and is owned by BHP . Uranium prospecting is similar to other forms of mineral exploration with the exception of some specialized instruments for detecting

3808-399: Is in principle no different from any other hard rock mining and other ores are often mined in association (e.g., copper, gold, silver). Once the ore body has been identified a shaft is sunk in the vicinity of the ore veins, and crosscuts are driven horizontally to the veins at various levels, usually every 100 to 150 metres. Similar tunnels, known as drifts, are driven along the ore veins from

3944-411: Is infrared radiation, 44% is visible light, and 3% is ultraviolet radiation. Microwaves are electromagnetic waves with wavelengths ranging from as short as 1 mm to as long as 1 m, which equates to a frequency range of 300 MHz to 300 GHz. This broad definition includes both UHF and EHF (millimetre waves), but various sources use different other limits. In all cases, microwaves include

4080-836: Is located in Swakopmund. Taurus is a subsidiary of the China General Nuclear Power Company (CGNPC), Uranium Resources Co. Ltd. and the China-Africa Development Fund . Taurus owns ninety percent of Swakop Uranium. The remaining 10% is owned by Epangelo Mining Company, the Namibian state-owned mining company. CGNPC's investment in Swakop Uranium is one of the biggest investments in Namibia since its independence, and by far

4216-408: Is made of trillions of atoms, only a small fraction of those will be ionized at low to moderate radiation powers. The probability of ionizing radiation causing cancer is dependent upon the absorbed dose of the radiation and is a function of the damaging tendency of the type of radiation ( equivalent dose ) and the sensitivity of the irradiated organism or tissue ( effective dose ). If the source of

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4352-403: Is more penetrating than alpha radiation but less than gamma. Beta radiation from radioactive decay can be stopped with a few centimetres of plastic or a few millimetres of metal. It occurs when a neutron decays into a proton in a nucleus, releasing the beta particle and an antineutrino . Beta radiation from linac accelerators is far more energetic and penetrating than natural beta radiation. It

4488-543: Is naturally present in the environment, since most rocks and soil have small concentrations of radioactive materials. Since this radiation is invisible and not directly detectable by human senses, instruments such as Geiger counters are usually required to detect its presence. In some cases, it may lead to secondary emission of visible light upon its interaction with matter, as in the case of Cherenkov radiation and radio-luminescence. Ionizing radiation has many practical uses in medicine, research, and construction, but presents

4624-432: Is now the accepted leading technique for uranium prospecting with worldwide applications for geological mapping, mineral exploration & environmental monitoring . Airborne gamma-ray spectrometry used specifically for uranium measurement and prospecting must account for a number of factors like the distance between the source and the detector and the scattering of radiation through the minerals, surrounding earth and even in

4760-409: Is often compared with ionizing radiation. Light, or visible light, is a very narrow range of electromagnetic radiation of a wavelength that is visible to the human eye, or 380–750 nm which equates to a frequency range of 790 to 400 THz respectively. More broadly, physicists use the term "light" to mean electromagnetic radiation of all wavelengths, whether visible or not. Infrared (IR) light

4896-441: Is practically limitless with respect to world-wide demand. That is to say, if even a portion of the uranium in seawater could be used the entire world's nuclear power generation fuel could be provided over a long time period. Some proponents claim this statistic is exaggerated. Although research and development for recovery of this low-concentration element by inorganic adsorbents such as titanium oxide compounds has occurred since

5032-736: Is radiation frequencies from 3 to 30 Hz (10 to 10  m respectively). In atmosphere science, an alternative definition is usually given, from 3 Hz to 3 kHz. In the related magnetosphere science, the lower frequency electromagnetic oscillations (pulsations occurring below ~3 Hz) are considered to lie in the ULF range, which is thus also defined differently from the ITU Radio Bands. A massive military ELF antenna in Michigan radiates very slow messages to otherwise unreachable receivers, such as submerged submarines. Thermal radiation

5168-531: Is sometimes used therapeutically in radiotherapy to treat superficial tumors. Beta-plus (β ) radiation is the emission of positrons , which are the antimatter form of electrons. When a positron slows to speeds similar to those of electrons in the material, the positron will annihilate an electron, releasing two gamma photons of 511 keV in the process. Those two gamma photons will be traveling in (approximately) opposite direction. The gamma radiation from positron annihilation consists of high energy photons, and

5304-530: Is stripped (or "knocked out") from an electron shell of the atom, which leaves the atom with a net positive charge. Because living cells and, more importantly, the DNA in those cells can be damaged by this ionization, exposure to ionizing radiation increases the risk of cancer . Thus "ionizing radiation" is somewhat artificially separated from particle radiation and electromagnetic radiation, simply due to its great potential for biological damage. While an individual cell

5440-414: Is technically not ionizing. The highest frequencies of ultraviolet light, as well as all X-rays and gamma-rays are ionizing. The occurrence of ionization depends on the energy of the individual particles or waves, and not on their number. An intense flood of particles or waves will not cause ionization if these particles or waves do not carry enough energy to be ionizing, unless they raise the temperature of

5576-407: Is the heat emitted by an operating incandescent light bulb. Thermal radiation is generated when energy from the movement of charged particles within atoms is converted to electromagnetic radiation. As noted above, even low-frequency thermal radiation may cause temperature-ionization whenever it deposits sufficient thermal energy to raise temperatures to a high enough level. Common examples of this are

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5712-696: Is the range of all possible electromagnetic radiation frequencies. The electromagnetic spectrum (usually just spectrum) of an object is the characteristic distribution of electromagnetic radiation emitted by, or absorbed by, that particular object. The non-ionizing portion of electromagnetic radiation consists of electromagnetic waves that (as individual quanta or particles, see photon ) are not energetic enough to detach electrons from atoms or molecules and hence cause their ionization. These include radio waves, microwaves, infrared, and (sometimes) visible light. The lower frequencies of ultraviolet light may cause chemical changes and molecular damage similar to ionization, but

5848-413: Is then pumped back to the surface and processed to extract the uranium compounds from solution. In conventional mining, ores are processed by grinding the ore materials to a uniform particle size and then treating the ore to extract the uranium by chemical leaching . The milling process commonly yields dry powder-form material consisting of natural uranium, " yellowcake ", which is nowadays commonly sold on

5984-434: Is used for thinner, flatter ore bodies. In this method the ore body is first divided into blocks by intersecting drives, removing ore while so doing, and then systematically removing the blocks, leaving enough ore for roof support. The health effects discovered from radon exposure in unventilated uranium mining prompted the switch away from uranium mining via tunnel mining towards open cut and in-situ leaching technology,

6120-691: The Blind River – Elliot Lake district of Ontario, Canada, and from the gold-bearing Witwatersrand conglomerates of South Africa. Unconformity-type deposits make up about 33% of the World Outside Centrally Planned Economies Areas' (WOCA) uranium deposits. Hydrothermal uranium deposits encompass the vein-type uranium ores. Vein-type hydrothermal uranium deposits represent epigenetic concentrations of uranium minerals that typically fill breccias, fractures, and shear zones. Many studies have sought to identify

6256-1334: The Elkon mine at 71,300 tU, the Brazilian Itataia complex at 67,240 tU, the Marenica project at 62,856 tU, the Langer Heinrich Mine at 60,830 tU, the Dominion mine at 55,753 tU, the Inkai Uranium Project at 51,808 tU, the Kiggavik project at 51,574 tU, the Rössing mine at 50,657 tU, the Australian Yeleerie project at 44,077, and the Trekkopje mine at 42,243 tU. Many different types of uranium deposits have been discovered and mined. There are mainly three types of uranium deposits including unconformity-type deposits, namely paleoplacer deposits and sandstone-type, also known as roll front type deposits. Uranium deposits are classified into 15 categories according to their geological setting and

6392-1114: The Olympic Dam mine at 2981 tU, the Arlit mine at 1808 tU, the Rabbit Lake mine at 1400 tU, the Akouta mine at 1435 tU, and the McClean Lake mine at 1400 tU. The world's largest deposits include the Olympic Dam mine at 295,000 tU, the Imouraren mine at 183,520 tU, the McArthur River mine at 128,900 tU, the Streltsovsk mine at 118,341 tU, the Novokonstantinovka mines at 93,630, the Cigar Lake Mine at 80,500 tU, Uzbekistan mines at 76,000 tU,

6528-541: The Sun and detected the infrared (beyond the red part of the spectrum), through an increase in the temperature recorded by a thermometer . In 1801, the German physicist Johann Wilhelm Ritter made the discovery of ultraviolet by noting that the rays from a prism darkened silver chloride preparations more quickly than violet light. Ritter's experiments were an early precursor to what would become photography. Ritter noted that

6664-472: The western US ), Precambrian unconformities (in Canada), phosphate , Precambrian quartz -pebble conglomerate , collapse breccia pipes (see Arizona breccia pipe uranium mineralization ), and calcrete . Sandstone uranium deposits are generally of two types. Roll-front type deposits occur at the boundary between the up dip and oxidized part of a sandstone body and the deeper down dip reduced part of

6800-400: The "cut and fill" or "open stoping" method, the space remaining following removal of ore after blasting is filled with waste rock and cement. In the "shrinkage" method, only sufficient broken ore is removed via the chutes below to allow miners working from the top of the pile to drill and blast the next layer to be broken off, eventually leaving a large hole. The method known as "room and pillar"

6936-696: The 1960s in the United Kingdom, France, Germany, and Japan, this research was halted due to low recovery efficiency. At the Takasaki Radiation Chemistry Research Establishment of the Japan Atomic Energy Research Institute (JAERI Takasaki Research Establishment), research and development has continued culminating in the production of adsorbent by irradiation of polymer fiber. Adsorbents have been synthesized that have

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7072-644: The Earth from outer space were finally definitively recognized and proven to exist in 1912, as the scientist Victor Hess carried an electrometer to various altitudes in a free balloon flight. The nature of these radiations was only gradually understood in later years. The Neutron and neutron radiation were discovered by James Chadwick in 1932. A number of other high energy particulate radiations such as positrons , muons , and pions were discovered by cloud chamber examination of cosmic ray reactions shortly thereafter, and others types of particle radiation were produced artificially in particle accelerators , through

7208-536: The GSC built a lighter weight, more practical unit in 1934. Subsequent models were the principal instruments used for uranium prospecting for many years, until geiger counters were replaced by scintillation counters . The use of airborne detectors to prospect for radioactive minerals was first proposed by G. C. Ridland, a geophysicist working at Port Radium in 1943. In 1947, the earliest recorded trial of airborne radiation detectors (ionization chambers and Geiger counters)

7344-458: The Husab mine, show an annual average rainfall of between 30–35 mm per annum. A hydrogeology report commissioned by Swakop Uranium concluded that the mining activities will have an effect on water levels. Although there are no farmers or settlements in the area, Swakop Uranium has drilled a number of groundwater monitoring holes around the pit, the waste rock dump, the tailings storage facility,

7480-461: The May, 2008 exchange rate, this was about $ 240/kg-U. In 2012, ORNL researchers announced the successful development of a new adsorbent material dubbed "HiCap", which vastly outperforms previous best adsorbents, which perform surface retention of solid or gas molecules, atoms or ions. "We have shown that our adsorbents can extract five to seven times more uranium at uptake rates seven times faster than

7616-1079: The National Radiation Protection Authority and is regularly audited to ensure compliance. There are four related deposits in the granite of the Damara Belt in the Erongo Region of western Namibia, namely at Rössing (SJ and Z20 deposits), the Ida Dome, at Goanikontes, and the Valencia. The Husab Uranium Project includes the Ida Dome 20 km south, with 9600 tU inferred resource at 0.02% (contiguous with Reptile's Ongalo ). Ida Dome has estimated reserves of 53 million tonnes of ore grading 0.018% uranium . The Valencia deposit has 2,731 t U proven reserves and 23,577 t U probable reserves, and at Goanikontes there are 3,187 t U proven reserves and 20,055 t U probable reserves. The scope of

7752-450: The SJ and Z20 deposits at Rössing have not been significantly proved. Uranium mine Uranium is mined by in-situ leaching (57% of world production) or by conventional underground or open-pit mining of ores (43% of production). During in-situ mining, a leaching solution is pumped down drill holes into the uranium ore deposit where it dissolves the ore minerals. The uranium-rich fluid

7888-587: The Sengier reopened the Sinkolobwe mine with U.S. Army Corps of Engineers ' resources, and a $ 13 million investment from the United States. Sengier reported that uranium ore had been extracted from the mine down to a depth of 79 meters, but that another 101 meters of ore was available for extraction. This amounted to 10,000 tons of up to 60% triuranium octoxide . The project also acquired most of

8024-679: The Shinkolobwe mine, but closed down in the late 1930s as the radium market diminished. In May 1940, the Nazis invaded Belgium and seized Union Minière's uranium ore stored there. On 18 September 1942, 1250 t of Shinkolobwe uranium ore for the Manhattan Project was purchased from Union Minière's Edgar Sengier , who had stockpiled the ore in an Archer Daniels Midland warehouse near the Bayonne Bridge , Staten Island . In 1943,

8160-792: The Soviet Republics of Kazakhstan and the RSFSR would later become some of the leading uranium producers in the world, immediately after the end of World War II the availability of large uranium deposits in the USSR wasn't yet known and thus the Soviets developed immense mining operations in their satellite states East Germany and Czechoslovakia which had known uranium deposits in the Ore Mountains. The deliberately opaquely named SDAG Wismut (the German term "Wismut" for Bismuth should give

8296-579: The UV rays were capable of causing chemical reactions. The first radio waves detected were not from a natural source, but were produced deliberately and artificially by the German scientist Heinrich Hertz in 1887, using electrical circuits calculated to produce oscillations in the radio frequency range, following formulas suggested by the equations of James Clerk Maxwell . Wilhelm Röntgen discovered and named X-rays . While experimenting with high voltages applied to an evacuated tube on 8 November 1895, he noticed

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8432-423: The United States. A large mass of breccia is called a breccia pipe or chimney and is composed of the rock forming an irregular and almost cylinder-like shape. The origin of breccia pipe is uncertain but it is thought that they form on intersections and faults.  When the formations are found solid in ground host rock called rock flour, it usually is often a site for copper or uranium mining. Copper Creek, Arizona,

8568-614: The Welwitschia fields as well as the Khan and Swakop Rivers to measure the effect of mining activities in the area. All the boreholes have their water levels measured monthly and strategic boreholes are sampled every three months for water quality. In order to reduce the dust produced by mining operations to acceptable levels, the Husab mine will employ a number of dust suppression methods such as using water, extraction fans, chemicals, and other suppressants. A dust suppressant will be used on

8704-422: The absolute temperature of that body. The radiation emitted covers the entire electromagnetic spectrum and the intensity of the radiation (power/unit-area) at a given frequency is described by Planck's law of radiation. For a given temperature of a black-body there is a particular frequency at which the radiation emitted is at its maximum intensity. That maximum radiation frequency moves toward higher frequencies as

8840-470: The absorption of X-rays. X-ray machines are specifically designed to take advantage of the absorption difference between bone and soft tissue, allowing physicians to examine structure in the human body. X-rays are also totally absorbed by the thickness of the earth's atmosphere, resulting in the prevention of the X-ray output of the sun, smaller in quantity than that of UV but nonetheless powerful, from reaching

8976-399: The advances made in the efficiency of seawater uranium extraction, it was suggested that it would be economically competitive to produce fuel for light water reactors from seawater if the process was implemented at large scale. Uranium extracted on an industrial scale from seawater would constantly be replenished by both river erosion of rocks and the natural process of uranium dissolved from

9112-500: The air. In Australia, a Weathering Intensity Index has been developed to help prospectors based on the Shuttle Radar Topography Mission (SRTM) elevation and airborne gamma-ray spectrometry images. A deposit of uranium, discovered by geophysical techniques, is evaluated and sampled to determine the amounts of uranium materials that are extractable at specified costs from the deposit. Uranium reserves are

9248-436: The amounts of ore that are estimated to be recoverable at stated costs. As prices rise or technology allows for lower cost of recovery of known, previously uneconomic, deposits, reserves increase. For uranium this effect is particularly pronounced as the biggest currently uneconomic reserve – uranium extraction from seawater – is bigger than all known land based resources of uranium combined. From 2008 through at least 2024,

9384-515: The application. Enrichment requires conversion of the yellowcake into uranium hexafluoride and production of the fuel (again usually uranium dioxide, but sometimes uranium carbide , uranium hydride or uranium nitride ) from that feedstock. Before 1789, when Martin Heinrich Klaproth discovered the element, uranium compounds produced included nitrate, sulfate, phosphate, acetate and potassium- and sodium- diuranate . Klaproth detected

9520-606: The arduous task of rehabilitating the land impacted by mining was begun. The seventeen towns and mines under Wismut's control contributed 50 percent of the uranium used in the Soviet's first atomic bomb, Joe-1 , and 80 percent of the uranium used in the Soviet nuclear program. Of the 150,000 laborers, 1281 were killed in accidents and 20,000 suffered injuries. After Stalin's death in 1953, the Red Army turned over control of production to SDAG, and prison laborers were released, reducing

9656-560: The biological proclivities of the radioactive iodine fission product, iodine-131 . However, calculating the exact risk and chance of cancer forming in cells caused by ionizing radiation is still not well understood, and currently estimates are loosely determined by population-based data from the atomic bombings of Hiroshima and Nagasaki and from follow-up of reactor accidents, such as the Chernobyl disaster . The International Commission on Radiological Protection states that "The Commission

9792-499: The construction of a new school. The company has also established a trust, called the Swakop Uranium Foundation Trust that will focus on training and education, the environment, infrastructure, health, and entrepreneurial development. The trust has donated N$ 100,000 to the Namibian government's Drought Relief fund. Swakop Uranium has instituted a radiation management plan. This plan has been submitted to

9928-421: The crosscut. To extract the ore, the next step is to drive tunnels, known as raises when driven upwards and winzes when driven downward, through the deposit from level to level. Raises are subsequently used to develop the stopes where the ore is mined from the veins. The stope, which is the workshop of the mine, is the excavation from which the ore is extracted. Three methods of stope mining are commonly used. In

10064-698: The disseminated uranium deposit at Rossing , Namibia; uranium-bearing pegmatites , and the Aurora crater lake deposit of the McDermitt Caldera in Oregon. Disseminated deposits are also found in the states of Washington and Alaska in the US. Breccia uranium deposits are found in rocks that have been broken due to tectonic fracturing, or weathering. Breccia uranium deposits are most common in India, Australia and

10200-520: The element radium . Pierre advocated its usage as a cancer cure, which fostered a spa business for that town. In 1913, the Shinkolobwe , Katanga Province, was discovered. In 1931, the Port Radium deposit was discovered. Other significant discoveries included Beira Province , Tyuya Muyun , and Radium Hill . In 1922, Union Minière du Haut Katanga started producing medicinal radium from

10336-630: The element in pitchblende from the George Wagsfort mine, Ore Mountains , and established commercial use as glass coloring. Pitchblende from these mountains was mentioned as early as 1565, and 110 t of uranium was produced from 1825 until 1898. In 1852, the uranium mineral autunite from the Massif Central was identified. Around 1850, uranium mining began in Joachimsthal, Bohemia , where more than 620 t of uranium metal (tU)

10472-416: The energies; there is some overlap in the effects of specific frequencies . The word "radiation" arises from the phenomenon of waves radiating (i.e., traveling outward in all directions) from a source. This aspect leads to a system of measurements and physical units that apply to all types of radiation. Because such radiation expands as it passes through space, and as its energy is conserved (in vacuum),

10608-457: The energy away as radio waves; these are mostly termed interference. Different frequencies of radio waves have different propagation characteristics in the Earth's atmosphere; long waves may bend at the rate of the curvature of the Earth and may cover a part of the Earth very consistently, shorter waves travel around the world by multiple reflections off the ionosphere and the Earth. Much shorter wavelengths bend or reflect very little and travel along

10744-545: The energy of such waves by passing through, on the average, 500 ft (150 m). Alpha particles are helium-4 nuclei (two protons and two neutrons). They interact with matter strongly due to their charges and combined mass, and at their usual velocities only penetrate a few centimetres of air, or a few millimetres of low density material (such as the thin mica material which is specially placed in some Geiger counter tubes to allow alpha particles in). This means that alpha particles from ordinary alpha decay do not penetrate

10880-399: The entire super high frequency band (3 to 30 GHz, or 10 to 1 cm) at minimum, with RF engineering often putting the lower boundary at 1 GHz (30 cm), and the upper around 100 GHz (3 mm). Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Like all other electromagnetic waves, they travel at

11016-472: The form of uraninite which is the primary ore mineral that is mined at Husab. Swakop Uranium is an entity established in 2006 by Extract Resources, an Australian company listed on the Australian, Canadian, and Namibian stock exchanges, to explore, evaluate, develop, and produce uranium oxide . In April 2012, Swakop Uranium was acquired by Taurus Minerals Limited of Hong Kong . Swakop Uranium head office

11152-500: The geological process called weathering. Therefore, oxide ore deposits are typically found close to the surface. If there are no other economic elements within the ore a mine might choose to extract the uranium using a leaching agent, usually a low molar sulfuric acid. If the economic and geological conditions are right, the mining company will level large areas of land with a small gradient, layering it with thick plastic (usually HDPE or LLDPE ), sometimes with clay, silt or sand beneath

11288-417: The higher energy range of ultraviolet light constitute the ionizing part of the electromagnetic spectrum . The word "ionize" refers to the breaking of one or more electrons away from an atom, an action that requires the relatively high energies that these electromagnetic waves supply. Further down the spectrum, the non-ionizing lower energies of the lower ultraviolet spectrum cannot ionize atoms, but can disrupt

11424-542: The illusion of prospection for a metal the Soviets definitely weren't after) became the biggest employer in the Saxon Ore Mountains and remote mining towns like Johanngeorgenstadt swelled to ten times their population in a few years. The mining cost immense amounts of money and miners were on the one hand subject to heavier repression and surveillance but on the other hand allowed more generous supply with consumer goods than other East Germans. While production

11560-450: The intensity of all types of radiation from a point source follows an inverse-square law in relation to the distance from its source. Like any ideal law, the inverse-square law approximates a measured radiation intensity to the extent that the source approximates a geometric point. Radiation with sufficiently high energy can ionize atoms; that is to say it can knock electrons off atoms, creating ions. Ionization occurs when an electron

11696-478: The inter-atomic bonds that form molecules, thereby breaking down molecules rather than atoms; a good example of this is sunburn caused by long- wavelength solar ultraviolet. The waves of longer wavelength than UV in visible light, infrared, and microwave frequencies cannot break bonds but can cause vibrations in the bonds which are sensed as heat . Radio wavelengths and below generally are not regarded as harmful to biological systems. These are not sharp delineations of

11832-409: The ionization (plasma) seen in common flames, and the molecular changes caused by the " browning " during food-cooking, which is a chemical process that begins with a large component of ionization. Black-body radiation is an idealized spectrum of radiation emitted by a body that is at a uniform temperature. The shape of the spectrum and the total amount of energy emitted by the body is a function of

11968-406: The ionizing radiation is a radioactive material or a nuclear process such as fission or fusion , there is particle radiation to consider. Particle radiation is subatomic particles accelerated to relativistic speeds by nuclear reactions. Because of their momenta , they are quite capable of knocking out electrons and ionizing materials, but since most have an electrical charge, they do not have

12104-522: The line of sight. Very low frequency (VLF) refers to a frequency range of 30 Hz to 3 kHz which corresponds to wavelengths of 100 000 to 10 000  m respectively. Since there is not much bandwidth in this range of the radio spectrum, only the very simplest signals can be transmitted, such as for radio navigation. Also known as the myriametre band or myriametre wave as the wavelengths range from 100 km to 10 km (an obsolete metric unit equal to 10 km). Extremely low frequency (ELF)

12240-425: The material is of high or low density. However, as is the case with X-rays, materials with a high atomic number such as lead or depleted uranium add a modest (typically 20% to 30%) amount of stopping power over an equal mass of less dense and lower atomic weight materials (such as water or concrete). The atmosphere absorbs all gamma rays approaching Earth from space. Even air is capable of absorbing gamma rays, halving

12376-536: The mine. Uranium mineralisation is hosted primarily within sheeted leucogranites that intruse the rocks at various stages during the Damara Orogeny . Formation of the uranium magmatic ore body is stratigraphically controlled with the Khan-Rossing boundary acting as a redox front. The abundance of iron oxides and sulfides provide reducing conditions for uranium to be oxidised and precipitate in

12512-509: The mine. The uranium in the Husab deposit is granite hosted, and currently consists of an administration and housing area and three open pits. The mine has the potential to produce 15 million pounds (6800 tonnes) of uranium oxide per annum. The Husab mine contains approximately 280 million tonnes of uranium ore. Mining is expected to last nearly 20 years. As of at least 2024, the China-Africa Development Fund and China Guangdong Nuclear Power Uranium Resources Co together own approximately 90% of

12648-485: The mine. Carbon dating shows that medium-sized plants can be as old as 1,000 years. The Husab Project is challenged to ensure that limited nearby water resources are not adversely affected by mining operations. The Namib Desert is a hyper- arid desert with an average rainfall of between 0–50 mm at Swakopmund and Gobabeb . Long-term records from the Rössing Uranium Mine , situated 5 km north of

12784-574: The mine. In the past mining companies would sometimes go bankrupt, leaving the responsibility of mine reclamation to the public. 21st century additions to US mining law require that companies set aside the money for reclamation before the beginning of the project. The money will be held by the public to insure adherence to environmental standards if the company were to ever go bankrupt. In-situ leaching (ISL), also known as solution mining, or in-situ recovery (ISR) in North America, involves leaving

12920-423: The more efficient acid leach. The Australian government has published a best practice guide for in situ leach mining of uranium, which is being revised to take account of international differences. The uranium concentration in sea water is low, approximately 3.3 parts per billion or 3.3 micrograms per liter of seawater. But the quantity of this resource is gigantic and some scientists believe this resource

13056-404: The most common isotopes of both types atoms present (hydrogen and oxygen) capture neutrons and become heavier but remain stable forms of those atoms. Only the absorption of more than one neutron, a statistically rare occurrence, can activate a hydrogen atom, while oxygen requires two additional absorptions. Thus water is only very weakly capable of activation. The sodium in salt (as in sea water), on

13192-415: The native groundwater in the orebody which is fortified with a complexing agent and in most cases an oxidant. It is then pumped through the underground orebody to recover the minerals in it by leaching. Once the pregnant solution is returned to the surface, the uranium is recovered in much the same way as in any other uranium plant (mill). In Australian ISL mines ( Beverley , Four Mile and Honeymoon Mine )

13328-448: The neutrons stops almost immediately in the reactor when it goes non-critical. Neutrons can make other objects, or material, radioactive. This process, called neutron activation , is the primary method used to produce radioactive sources for use in medical, academic, and industrial applications. Even comparatively low speed thermal neutrons cause neutron activation (in fact, they cause it more efficiently). Neutrons do not ionize atoms in

13464-512: The now-exposed rocks acid mine drainage can be a concern for those newly developing bodies of water. Mining companies are now required by law to establish a fund for future reclamation while mining is ongoing and those funds are usually deposited in such a way as to be unaffected by bankruptcy of the mining company. If the uranium is too far below the surface for open pit mining, an underground mine might be used with tunnels and shafts dug to access and remove uranium ore. Underground uranium mining

13600-734: The only four countries that have reported non-domestic uranium exploration and development expenses are: China, Japan, France, and Russia. The U.S. is investigating whether China is circumventing a ban on Russian uranium imports by exporting its uranium to the U.S. while importing enriched uranium from Russia. This inquiry follows a spike in Chinese uranium exports to the U.S. after the December 2023 ban, which aimed to cut off funding for Russia's war in Ukraine. As with other types of hard rock mining there are several methods of extraction. In 2016,

13736-429: The ore where it is in the ground, and recovering the minerals from it by dissolving them and pumping the pregnant solution to the surface where the minerals can be recovered. Consequently, there is little surface disturbance and no tailings or waste rock generated. However, the orebody needs to be permeable to the liquids used, and located so that they do not contaminate ground water away from the orebody. Uranium ISL uses

13872-413: The other hand, need only absorb a single neutron to become Na-24, a very intense source of beta decay, with half-life of 15 hours. In addition, high-energy (high-speed) neutrons have the ability to directly ionize atoms. One mechanism by which high energy neutrons ionize atoms is to strike the nucleus of an atom and knock the atom out of a molecule, leaving one or more electrons behind as the chemical bond

14008-497: The outer layers of dead skin cells and cause no damage to the live tissues below. Some very high energy alpha particles compose about 10% of cosmic rays , and these are capable of penetrating the body and even thin metal plates. However, they are of danger only to astronauts, since they are deflected by the Earth's magnetic field and then stopped by its atmosphere. Alpha radiation is dangerous when alpha-emitting radioisotopes are ingested or inhaled (breathed or swallowed). This brings

14144-514: The oxidant used is hydrogen peroxide and the complexing agent sulfuric acid. Kazakh ISL mines generally do not employ an oxidant but use much higher acid concentrations in the circulating solutions. ISL mines in the USA use an alkali leach due to the presence of significant quantities of acid-consuming minerals such as gypsum and limestone in the host aquifers. Any more than a few percent carbonate minerals means that alkali leach must be used in preference to

14280-614: The penetrating power of ionizing radiation. The exception is neutron particles; see below. There are several different kinds of these particles, but the majority are alpha particles , beta particles , neutrons , and protons . Roughly speaking, photons and particles with energies above about 10 electron volts (eV) are ionizing (some authorities use 33 eV, the ionization energy for water). Particle radiation from radioactive material or cosmic rays almost invariably carries enough energy to be ionizing. Most ionizing radiation originates from radioactive materials and space (cosmic rays), and as such

14416-546: The percentage of the mined uranium produced by each mining method was: in-situ leach (49.7 percent), underground mining (30.8 percent), open pit (12.9 percent), heap leaching (0.4 percent), co-product/by-product (6.1%). The remaining 0.1% was derived as miscellaneous recovery. In open pit mining, overburden is removed by drilling and blasting to expose the ore body, which is then mined by blasting and excavation using loaders and dump trucks. Workers spend much time in enclosed cabins thus limiting exposure to radiation. Water

14552-418: The pit, dump haul roads and other gravel site roads. The use of alternative suppression techniques has the potential to save up to 90% of the water that would otherwise have been required to achieve the same level of control. Swakop Uranium plans to engage in local procurement and recruitment where possible. The company grants bursaries for promising Namibian university students on an annual basis and has funded

14688-458: The plastic liner. The extracted ore will typically be run through a crusher and placed in heaps atop the plastic. The leaching agent will then be sprayed on the ore for 30–90 days. As the leaching agent filters through the heap, the uranium will break its bonds with the oxide rock and enter the solution. The solution will then filter along the gradient into collecting pools which will then be pumped to on-site plants for further processing. Only some of

14824-668: The population of laborers to 45,000. At its peak in 1953, the St. Joachimsthal mines had 16,100 inmates, half of whom were Soviet political prisoners. By 1975, 75% of global uranium ore production came from quartz - pebble conglomerates and sandstones located in the Elliot Lake area of Canada , Witwatersrand , and the Colorado Plateau . In 1990, 55% of world production came from underground mines, but this shrank to 33% by 1999. From 2000, new Canadian mines again increased

14960-713: The potential to become the second largest uranium mine in the world after the McArthur River uranium mine in northern Saskatchewan , Canada and the largest open-pit mine on the African continent. Mine construction started in February 2013. The Husab Mine started production towards the end of 2016 after completion of the sulfuric acid leaching plant. On 1 December 2011, the Namibian Ministry of Mines and Energy granted license to Swakop Uranium to develop

15096-461: The presence of radioactive isotopes. The Geiger counter was the original radiation detector, recording the total count rate from all energy levels of radiation. Ionization chambers and Geiger counters were first adapted for field use in the 1930s. The first transportable Geiger–Müller counter (weighing 25 kg) was constructed at the University of British Columbia in 1932. H.V. Ellsworth of

15232-656: The production from the Eldorado Mine (Northwest Territories) . According to Richard Rhodes , referring to German uranium research, " Auer , the thorium specialists ... delivered the first ton of pure uranium oxide processed from Joachimsthal ores to the War Office in January 1940. In June 1940 ... Auer ordered sixty tons of refined uranium oxide from the Union Miniére in occupied Belgium." While

15368-677: The proportion of underground mining, and with Olympic Dam it is now 37%. In situ leach (ISL, or ISR) mining has been steadily increasing its share of the total, mainly due to Kazakhstan. In 2009, top producing mines included the McArthur River uranium mine at 7400 tU, the Ranger Uranium Mine at 4423 tU, the Rössing uranium mine at 3574 tU, the Moiynkum Desert mines at 3250 tU, the Streltsovsk mine at 3003 tU,

15504-514: The radioisotope close enough to sensitive live tissue for the alpha radiation to damage cells. Per unit of energy, alpha particles are at least 20 times more effective at cell-damage as gamma rays and X-rays. See relative biological effectiveness for a discussion of this. Examples of highly poisonous alpha-emitters are all isotopes of radium , radon , and polonium , due to the amount of decay that occur in these short half-life materials. Beta-minus (β ) radiation consists of an energetic electron. It

15640-521: The remainder consisting of helions (alpha particles). A few completely ionized nuclei of heavier elements are present. The origin of these galactic cosmic rays is not yet well understood, but they seem to be remnants of supernovae and especially gamma-ray bursts (GRB), which feature magnetic fields capable of the huge accelerations measured from these particles. They may also be generated by quasars , which are galaxy-wide jet phenomena similar to GRBs but known for their much larger size, and which seem to be

15776-482: The same way that charged particles such as protons and electrons do (by the excitation of an electron), because neutrons have no charge. It is through their absorption by nuclei which then become unstable that they cause ionization. Hence, neutrons are said to be "indirectly ionizing". Even neutrons without significant kinetic energy are indirectly ionizing, and are thus a significant radiation hazard. Not all materials are capable of neutron activation; in water, for example,

15912-542: The single biggest investment by China in Africa. More than US$ 100-million (in excess of N$ 1-billion) was spent to reach the construction phase. A further amount of approximately US$ 2-billion (more than N$ 20-billion) was spent to bring the mine online. Swakop Uranium has an environmental management plan committed to caring for all species of fauna and flora found near, or within, its exploration and mining areas. Welwitschia mirabilis , an ancient plant, grows in areas around

16048-490: The source of uranium with hydrothermal vein-type deposits and the potential sources still remains a mystery, but are thought to include preexisting rocks that have been broken down by weathering and force that come from areas of long-term sediment build up. The South Chine Block is an example of a region that has been relying on vein-type hydrothermal uranium deposit demand for the past half century. Igneous deposits include nepheline syenite intrusives at Ilimaussaq , Greenland;

16184-404: The speed of light. Naturally occurring radio waves are made by lightning, or by certain astronomical objects. Artificially generated radio waves are used for fixed and mobile radio communication, broadcasting, radar and other navigation systems, satellite communication, computer networks and innumerable other applications. In addition, almost any wire carrying alternating current will radiate some of

16320-404: The sulfuric acid. Heap leach is significantly cheaper than traditional milling processes. The low costs allow for lower grade ore to be economically feasible (given that it is the right type of ore body). US environmental law requires that the surrounding ground water is continually monitored for possible contamination. The mine will also have to have continued monitoring even after the shutdown of

16456-401: The surface area of the ocean floor, both of which maintain the solubility equilibria of seawater concentration at a stable level. Some commentators have argued that this strengthens the case for nuclear power to be considered a renewable energy . Radiation In physics , radiation is the emission or transmission of energy in the form of waves or particles through space or

16592-440: The surface. Gamma (γ) radiation consists of photons with a wavelength less than 3 × 10  m (greater than 10  Hz and 41.4 keV). Gamma radiation emission is a nuclear process that occurs to rid an unstable nucleus of excess energy after most nuclear reactions. Both alpha and beta particles have an electric charge and mass, and thus are quite likely to interact with other atoms in their path. Gamma radiation, however,

16728-406: The temperature of its radiating surface. It is responsible for the color of stars , which vary from infrared through red ( 2500 K ), to yellow ( 5800 K ), to white and to blue-white ( 15 000  K ) as the peak radiance passes through those points in the visible spectrum. When the peak is below the visible spectrum the body is black, while when it is above the body is blue-white, since all

16864-421: The temperature of the body increases. The frequency at which the black-body radiation is at maximum is given by Wien's displacement law and is a function of the body's absolute temperature. A black-body is one that emits at any temperature the maximum possible amount of radiation at any given wavelength. A black-body will also absorb the maximum possible incident radiation at any given wavelength. A black-body with

17000-544: The type of rock in which they are found. This geological classification system is determined by the International Atomic Energy Agency (IAEA). Uranium is also contained in seawater but at present prices on the uranium market , costs would have to be lowered by a factor of 3–6 to make its recovery economical. Uranium deposits in sedimentary rocks include those in sandstone (in Canada and

17136-437: The ultraviolet spectrum some of the dangers of ionizing radiation in biological systems without actual ionization occurring. In contrast, visible light and longer-wavelength electromagnetic radiation, such as infrared, microwaves, and radio waves, consists of photons with too little energy to cause damaging molecular excitation, and thus this radiation is far less hazardous per unit of energy. X-rays are electromagnetic waves with

17272-444: The ultraviolet spectrum that does reach the ground is non-ionizing, but is still biologically hazardous due to the ability of single photons of this energy to cause electronic excitation in biological molecules, and thus damage them by means of unwanted reactions. An example is the formation of pyrimidine dimers in DNA, which begins at wavelengths below 365 nm (3.4 eV), which is well below ionization energy. This property gives

17408-415: The uranium (commonly about 70%) is actually extracted. The uranium concentrations within the solution are very important for the efficient separation of pure uranium from the acid. As different heaps will yield different concentrations, the solution is pumped to a mixing plant that is carefully monitored. The properly balanced solution is then pumped into a processing plant where the uranium is separated from

17544-505: The uranium market as U 3 O 8 . While some nuclear power plants – most notably heavy water reactors like the CANDU – can operate with natural uranium (usually in the form of uranium dioxide ), the vast majority of commercial nuclear power plants and many research reactors require uranium enrichment , which raises the content of U from the natural 0.72% to 3–5% (for use in light water reactors ) or even higher , depending on

17680-464: The visible colors are represented from blue decreasing to red. Electromagnetic radiation of wavelengths other than visible light were discovered in the early 19th century. The discovery of infrared radiation is ascribed to William Herschel , the astronomer . Herschel published his results in 1800 before the Royal Society of London . Herschel, like Ritter, used a prism to refract light from

17816-406: The world's best adsorbents," said Chris Janke, one of the inventors and a member of ORNL's Materials Science and Technology Division. HiCap also effectively removes toxic metals from water, according to results verified by researchers at Pacific Northwest National Laboratory . In 2012 it was estimated that this fuel source could be extracted at 10 times the current price of uranium. In 2014, with

17952-399: Was >1 kg of yellowcake after 240 days of submersion in the ocean. The experiment by Seko et al. was repeated by Tamada et al. in 2006. They found that the cost varied from ¥15,000 to ¥88,000 depending on assumptions and "The lowest cost attainable now is ¥25,000 with 4g-U/kg-adsorbent used in the sea area of Okinawa, with 18 repetitionuses [ sic ]." With

18088-448: Was conducted by Eldorado Mining and Refining Limited . (a Canadian Crown Corporation since sold to become Cameco Corporation ). The first patent for a portable gamma-ray spectrometer was filed by Professors Pringle, Roulston & Brownell of the University of Manitoba in 1949, the same year as they tested the first portable scintillation counter on the ground and in the air in northern Saskatchewan . Airborne gamma-ray spectrometry

18224-473: Was never able to compete with global uranium market prices, the dual use nature of the mined material as well as the possibility to pay miners in soft currency but sell uranium for hard currency or substitute imports which would have had to be paid for in hard currency tipped the scales in favor of continuing mining operations throughout the Cold War. After German reunification , mining was wound down and

18360-764: Was produced from 1850 and 1898, with 10,000 tU produced before closure in 1968. In 1871, uranium ore mining began in Central City, Colorado , where 50 t were mined before 1895. In 1873, the uranium mining began in the South Terras mine, St Stephen-in-Brannel , Cornwall, producing most of the 300 tU from that area in the 19th century. In 1898, carnotite was first mined in the Uravan Mineral Belt , yielding 10 tU annually. In 1898, Pierre Curie and Marie Skłodowska-Curie took delivery of 1 t of pitchblende from St. Joachimsthal, from which Marie identified

18496-709: Was the radiation that had been first detected by Becquerel from uranium salts. In 1900, the French scientist Paul Villard discovered a third neutrally charged and especially penetrating type of radiation from radium, and after he described it, Rutherford realized it must be yet a third type of radiation, which in 1903 Rutherford named gamma rays . Henri Becquerel himself proved that beta rays are fast electrons, while Rutherford and Thomas Royds proved in 1909 that alpha particles are ionized helium. Rutherford and Edward Andrade proved in 1914 that gamma rays are like X-rays, but with shorter wavelengths. Cosmic ray radiations striking

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