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98-842: The town stretches predominantly from the eastern ridge of the almost 900-m-high Fastenberg to where the Breitenbach, which forms part of the border with the Czech Republic, empties into the river Schwarzwasser. The nearest high mountains to the town are the 1019-m-high Auersberg , the 1043-m-high Blatenský vrch (in the Czech Republic) and the 913-m-high Rabenberg . Communities in Aue-Schwarzenberg bordering on Johanngeorgenstadt are Breitenbrunn , Eibenstock and Sosa . The Czech community of Potůčky also borders on Johanngeorgenstadt. Johanngeorgenstadt consists of

196-528: A description of this process of reactor control). As little as 15 lb (6.8 kg) of uranium-235 can be used to make an atomic bomb. The nuclear weapon detonated over Hiroshima , called Little Boy , relied on uranium fission. However, the first nuclear bomb (the Gadget used at Trinity ) and the bomb that was detonated over Nagasaki ( Fat Man ) were both plutonium bombs. Uranium metal has three allotropic forms: The major application of uranium in

294-479: A distribution of uranium oxidation species in various forms ranging from most oxidized to least oxidized. Particles with short residence times in a calciner will generally be less oxidized than those with long retention times or particles recovered in the stack scrubber. Uranium content is usually referenced to U 3 O 8 , which dates to the days of the Manhattan Project when U 3 O 8

392-582: A district of Eibenstock since 1994. North of the Auersberg lies the Sosa dam. Below the summit there is a parking lot. When ascending to the Auersberg, you cross the Johanngeorgenstadt district of Sauschwemme. The main type of rock is medium-grained granite , which includes tourmaline . Also included in the granite are silver, tin and iron compounds, which were mined as early as the 16th century. At

490-539: A few parts per million in soil, rock and water, and is commercially extracted from uranium-bearing minerals such as uraninite . Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 is the only naturally occurring fissile isotope , which makes it widely used in nuclear power plants and nuclear weapons . However, because of the low abundance of uranium-235 in natural uranium (which is, overwhelmingly, mostly uranium-238), uranium needs to undergo enrichment so that enough uranium-235

588-566: A form of invisible light or rays emitted by uranium had exposed the plate. During World War I when the Central Powers suffered a shortage of molybdenum to make artillery gun barrels and high speed tool steels, they routinely used ferrouranium alloy as a substitute, as it presents many of the same physical characteristics as molybdenum. When this practice became known in 1916 the US government requested several prominent universities to research

686-741: A fuel in the nuclear power industry and in Little Boy , the first nuclear weapon used in war . An ensuing arms race during the Cold War between the United States and the Soviet Union produced tens of thousands of nuclear weapons that used uranium metal and uranium-derived plutonium-239 . Dismantling of these weapons and related nuclear facilities is carried out within various nuclear disarmament programs and costs billions of dollars. Weapon-grade uranium obtained from nuclear weapons

784-690: A higher incidence of cancer . An excess risk of lung cancer among Navajo uranium miners, for example, has been documented and linked to their occupation. The Radiation Exposure Compensation Act , a 1990 law in the US, required $ 100,000 in "compassion payments" to uranium miners diagnosed with cancer or other respiratory ailments. During the Cold War between the Soviet Union and the United States, huge stockpiles of uranium were amassed and tens of thousands of nuclear weapons were created using enriched uranium and plutonium made from uranium. After

882-497: A lesser degree uranium-233, have a much higher fission cross-section for slow neutrons. In sufficient concentration, these isotopes maintain a sustained nuclear chain reaction . This generates the heat in nuclear power reactors and produces the fissile material for nuclear weapons. The primary civilian use for uranium harnesses the heat energy to produce electricity. Depleted uranium ( U) is used in kinetic energy penetrators and armor plating . The 1789 discovery of uranium in

980-448: A much more complicated and far more powerful type of fission/fusion bomb ( thermonuclear weapon ) was built, that uses a plutonium-based device to cause a mixture of tritium and deuterium to undergo nuclear fusion . Such bombs are jacketed in a non-fissile (unenriched) uranium case, and they derive more than half their power from the fission of this material by fast neutrons from the nuclear fusion process. The main use of uranium in

1078-459: A plutonium-based device (see Trinity test and " Fat Man ") whose plutonium was derived from uranium-238. Little Boy became the first nuclear weapon used in war when it was detonated over Hiroshima , Japan , on 6 August 1945. Exploding with a yield equivalent to 12,500 tonnes of TNT , the blast and thermal wave of the bomb destroyed nearly 50,000 buildings and killed about 75,000 people (see Atomic bombings of Hiroshima and Nagasaki ). Initially it

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1176-405: A reaction by piling together 360 tonnes of graphite , 53 tonnes of uranium oxide , and 5.5 tonnes of uranium metal, most of which was supplied by Westinghouse Lamp Plant in a makeshift production process. Two types of atomic bomb were developed by the United States during World War II : a uranium-based device (codenamed " Little Boy ") whose fissile material was highly enriched uranium , and

1274-413: A shielding material. Due to its high density, this material is found in inertial guidance systems and in gyroscopic compasses . Depleted uranium is preferred over similarly dense metals due to its ability to be easily machined and cast as well as its relatively low cost. The main risk of exposure to depleted uranium is chemical poisoning by uranium oxide rather than radioactivity (uranium being only

1372-525: A shorter half-life and so is an extinct radionuclide , having long since decayed completely to Th. Further uranium-236 was produced by the decay of Pu , accounting for the observed higher-than-expected abundance of thorium and lower-than-expected abundance of uranium. While the natural abundance of uranium has been supplemented by the decay of extinct Pu (half-life 375,000 years) and Cm (half-life 16 million years), producing U and U respectively, this occurred to an almost negligible extent due to

1470-412: A sledgehammer and a cross-peen hammer sable per saltire. The official German blazon, however (“Geteilt von Silber über Rot; oben drei rote Gebäude mit Türmen, unten ein kleiner Silberschild, darin schwarze Schlägel und Eisen”), does not mention the black roofs seen in the sample coat of arms in this article, nor does it say exactly how the charges are to be configured. It does not say, for instance, that

1568-586: A water-spouting bear's head referring to the Electoral hunts in the town's environs. Also at the marketplace, the Schillerbrunnen (“Schiller Fountain”) is to be found. This was built in 1859, and dedicated on Friedrich von Schiller ’s one hundredth birthday. Other memorials at the marketplace are the light grey granite pedestal of the Warriors’ Memorial (1870/71) and several memorial stones to

1666-412: A weak alpha emitter ). During the later stages of World War II , the entire Cold War , and to a lesser extent afterwards, uranium-235 has been used as the fissile explosive material to produce nuclear weapons. Initially, two major types of fission bombs were built: a relatively simple device that uses uranium-235 and a more complicated mechanism that uses plutonium-239 derived from uranium-238. Later,

1764-535: A world total production of 48,332 tonnes. Most uranium was produced not by conventional underground mining of ores (29% of production), but by in situ leaching (66%). In the late 1960s, UN geologists discovered major uranium deposits and other rare mineral reserves in Somalia . The find was the largest of its kind, with industry experts estimating the deposits at over 25% of the world's then known uranium reserves of 800,000 tons. The ultimate available supply

1862-552: Is malleable , ductile , slightly paramagnetic , strongly electropositive and a poor electrical conductor . Uranium metal has a very high density of 19.1 g/cm , denser than lead (11.3 g/cm ), but slightly less dense than tungsten and gold (19.3 g/cm ). Uranium metal reacts with almost all non-metallic elements (except noble gases ) and their compounds , with reactivity increasing with temperature. Hydrochloric and nitric acids dissolve uranium, but non-oxidizing acids other than hydrochloric acid attack

1960-445: Is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table . A uranium atom has 92 protons and 92 electrons , of which 6 are valence electrons . Uranium radioactively decays , usually by emitting an alpha particle . The half-life of this decay varies between 159,200 and 4.5 billion years for different isotopes , making them useful for dating

2058-523: Is a naturally occurring element found in low levels in all rock, soil, and water. It is the highest-numbered element found naturally in significant quantities on Earth and is almost always found combined with other elements. Uranium is the 48th most abundant element in the Earth’s crust. The decay of uranium, thorium , and potassium-40 in Earth's mantle is thought to be the main source of heat that keeps

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2156-530: Is also fissile by thermal neutrons. These discoveries led numerous countries to begin working on the development of nuclear weapons and nuclear power . Despite fission having been discovered in Germany, the Uranverein ("uranium club") Germany's wartime project to research nuclear power and/or weapons was hampered by limited resources, infighting, the exile or non-involvement of several prominent scientists in

2254-520: Is believed to be sufficient for at least the next 85 years, though some studies indicate underinvestment in the late twentieth century may produce supply problems in the 21st century. Uranium deposits seem to be log-normal distributed. There is a 300-fold increase in the amount of uranium recoverable for each tenfold decrease in ore grade. In other words, there is little high grade ore and proportionately much more low grade ore available. Calcined uranium yellowcake, as produced in many large mills, contains

2352-785: Is difficult to precipitate uranium as phosphate in the presence of excess carbonate at alkaline pH. A Sphingomonas sp. strain BSAR-1 has been found to express a high activity alkaline phosphatase (PhoK) that has been applied for bioprecipitation of uranium as uranyl phosphate species from alkaline solutions. The precipitation ability was enhanced by overexpressing PhoK protein in E. coli . Plants absorb some uranium from soil. Dry weight concentrations of uranium in plants range from 5 to 60 parts per billion, and ash from burnt wood can have concentrations up to 4 parts per million. Dry weight concentrations of uranium in food plants are typically lower with one to two micrograms per day ingested through

2450-418: Is diluted with uranium-238 and reused as fuel for nuclear reactors. Spent nuclear fuel forms radioactive waste , which mostly consists of uranium-238 and poses a significant health threat and environmental impact . Uranium is a silvery white, weakly radioactive metal . It has a Mohs hardness of 6, sufficient to scratch glass and roughly equal to that of titanium , rhodium , manganese and niobium . It

2548-485: Is found in hundreds of minerals, including uraninite (the most common uranium ore ), carnotite , autunite , uranophane , torbernite , and coffinite . Significant concentrations of uranium occur in some substances such as phosphate rock deposits, and minerals such as lignite , and monazite sands in uranium-rich ores (it is recovered commercially from sources with as little as 0.1% uranium ). Like all elements with atomic weights higher than that of iron , uranium

2646-575: Is found the memorial dedicated on 8 September 1901 to the Ore Mountain poet and singer, school principal Christian Friedrich Röder (1827–1900); it includes a larger-than-life bust. Also worth seeing is the Platz des Bergmanns (“Miner’s Square”) with its music pavilion. In the New Town (Neustadt) stands a Saxony postal milestone from 1728, which once stood at the market. In Wittigsthal, next to

2744-427: Is only naturally formed by the r-process (rapid neutron capture) in supernovae and neutron star mergers . Primordial thorium and uranium are only produced in the r-process, because the s-process (slow neutron capture) is too slow and cannot pass the gap of instability after bismuth. Besides the two extant primordial uranium isotopes, U and U, the r-process also produced significant quantities of U , which has

2842-424: Is present. Uranium-238 is fissionable by fast neutrons and is fertile , meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor . Another fissile isotope, uranium-233 , can be produced from natural thorium and is studied for future industrial use in nuclear technology. Uranium-238 has a small probability for spontaneous fission or even induced fission with fast neutrons; uranium-235, and to

2940-407: Is produced through the thermal decomposition of uranium halides on a hot filament. It is estimated that 6.1 million tonnes of uranium exists in ores that are economically viable at US$ 130 per kg of uranium, while 35 million tonnes are classed as mineral resources (reasonable prospects for eventual economic extraction). Australia has 28% of the world's known uranium ore reserves and

3038-441: Is then calcined to remove impurities from the milling process before refining and conversion. Commercial-grade uranium can be produced through the reduction of uranium halides with alkali or alkaline earth metals . Uranium metal can also be prepared through electrolysis of KUF 5 or UF 4 , dissolved in molten calcium chloride ( CaCl 2 ) and sodium chloride ( Na Cl) solution. Very pure uranium

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3136-600: Is used for X-ray targets in the making of high-energy X-rays. The use of pitchblende , uranium in its natural oxide form, dates back to at least the year 79 AD, when it was used in the Roman Empire to add a yellow color to ceramic glazes. Yellow glass with 1% uranium oxide was found in a Roman villa on Cape Posillipo in the Bay of Naples , Italy, by R. T. Gunther of the University of Oxford in 1912. Starting in

3234-605: The Anton-Günther-Weg , which was dedicated in 1995 and which crosses the border . Also popular are outings to the Czech Republic, among these a trip to the 1043-m-high Plattenberg. Johanngeorgenstadt was included in the postal road system of the Electorate of Saxony as the town lay on a pass in the Ore Mountains. Hearkening back to this time are the postal milestone from 1728 before the post office in

3332-402: The Manhattan Project , another team led by Enrico Fermi was able to initiate the first artificial self-sustained nuclear chain reaction , Chicago Pile-1 . An initial plan using enriched uranium-235 was abandoned as it was as yet unavailable in sufficient quantities. Working in a lab below the stands of Stagg Field at the University of Chicago , the team created the conditions needed for such

3430-497: The Megatons to Megawatts Program . An additional 4.6 billion tonnes of uranium are estimated to be dissolved in sea water ( Japanese scientists in the 1980s showed that extraction of uranium from sea water using ion exchangers was technically feasible). There have been experiments to extract uranium from sea water, but the yield has been low due to the carbonate present in the water. In 2012, ORNL researchers announced

3528-475: The Oklo Fossil Reactors . The ore deposit is 1.7 billion years old; then, uranium-235 constituted about 3% of uranium on Earth. This is high enough to permit a sustained chain reaction, if other supporting conditions exist. The capacity of the surrounding sediment to contain the health-threatening nuclear waste products has been cited by the U.S. federal government as supporting evidence for

3626-721: The Shippingport Atomic Power Station in Pennsylvania , which began on 26 May 1958. Nuclear power was used for the first time for propulsion by a submarine , the USS Nautilus , in 1954. In 1972, French physicist Francis Perrin discovered fifteen ancient and no longer active natural nuclear fission reactors in three separate ore deposits at the Oklo mine in Gabon , Africa, collectively known as

3724-465: The United States (2.5%), Argentina (2.1%) and Ukraine (1.9%). In 2008, Kazakhstan was forecast to increase production and become the world's largest supplier of uranium by 2009; Kazakhstan has dominated the world's uranium market since 2010. In 2021, its share was 45.1%, followed by Namibia (11.9%), Canada (9.7%), Australia (8.7%), Uzbekistan (7.2%), Niger (4.7%), Russia (5.5%), China (3.9%), India (1.3%), Ukraine (0.9%), and South Africa (0.8%), with

3822-439: The age of the Earth . The most common isotopes in natural uranium are uranium-238 (which has 146 neutrons and accounts for over 99% of uranium on Earth) and uranium-235 (which has 143 neutrons). Uranium has the highest atomic weight of the primordially occurring elements. Its density is about 70% higher than that of lead and slightly lower than that of gold or tungsten . It occurs naturally in low concentrations of

3920-604: The break-up of the Soviet Union in 1991, an estimated 600 short tons (540 metric tons) of highly enriched weapons grade uranium (enough to make 40,000 nuclear warheads) had been stored in often inadequately guarded facilities in the Russian Federation and several other former Soviet states. Police in Asia , Europe , and South America on at least 16 occasions from 1993 to 2005 have intercepted shipments of smuggled bomb-grade uranium or plutonium, most of which

4018-432: The oceans may contain 10  kg (2 × 10  lb). The concentration of uranium in soil ranges from 0.7 to 11 parts per million (up to 15 parts per million in farmland soil due to use of phosphate fertilizers ), and its concentration in sea water is 3 parts per billion. Uranium is more plentiful than antimony , tin , cadmium , mercury , or silver, and it is about as abundant as arsenic or molybdenum . Uranium

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4116-413: The railway to Schwarzenberg began running, and from 1899 until its closure in 1945 the railway ran through to Neudek ( Nejdek ) and Karlsbad (Karlovy Vary). There are bus connections to Schwarzenberg and by way of Eibenstock to Rodewisch . With the reopening of the railway on 30 June 1991 and the opening of a pedestrian border crossing, which may also be used by motorscooters, it became possible to reach

4214-681: The 18th century. After the two free years were up in 1656, the Elector of Saxony gave up excise , “Schock” (an old currency in Saxony) and drinking taxes until the beginning of the 18th century owing to the pervasive poverty in the town. The great famine in the Ore Mountains in 1771 and 1772 claimed roughly 650 lives in Johanngeorgenstadt. Already in 1651 in today's constituent community of Wittigsthal, an ironworks had come into service, and by 1828, Carl Gotthilf Nestler (1789–1864) had set up Saxony's first fully functional iron plate rolling mill in

4312-640: The Dean of the Sapienza University of Rome , Orso Mario Corbino , named ausenium and hesperium , respectively. The experiments leading to the discovery of uranium's ability to fission (break apart) into lighter elements and release binding energy were conducted by Otto Hahn and Fritz Strassmann in Hahn's laboratory in Berlin. Lise Meitner and her nephew, physicist Otto Robert Frisch , published

4410-408: The Earth's outer core in the liquid state and drives mantle convection , which in turn drives plate tectonics . Uranium's concentration in the Earth's crust is (depending on the reference) 2 to 4 parts per million, or about 40 times as abundant as silver . The Earth's crust from the surface to 25 km (15 mi) down is calculated to contain 10  kg (2 × 10  lb) of uranium while

4508-481: The Haberlandmühle. In the 19th century also began the production of lace bands and as of 1860, of leather gloves . On 19 August 1867, a devastating great fire destroyed 287 of the town's 355 houses and claimed seven adults’ and five children's lives. Germany's first ski jump was built in 1929 near Johanngeorgenstadt. It bore the name “Hans-Heinz-Schanze”. In 1934, the formerly abandoned mining industry

4606-603: The New Town (Neustadt) in 1956 has been shut down for many years. Since 1927, at Hospitalstraße 5, there has been a youth hostel with 60 beds at its disposal. In 1986, the title “Most Beautiful Youth Hostel” ( Schönste Jugendherberge ) was bestowed upon it. Until 1990, the hostel bore the name Ernst Schneller, after a prewar Communist member of the Reichstag who died at the Sachsenhausen concentration camp . The gymnasium built in 1930 and 1931 on Eibenstocker Straße

4704-514: The New Town (Neustadt), although originally it stood at the marketplace, and also a full milestone opposite the powder tower and a quarter-mile stone in Steinbach, both of which date from 1725. There are furthermore several Kingdom of Saxony milestones near the town that were placed from 1858 onwards, for example on the old postal route from Auerbach by way of Carlsfeld and Wildenthal (today part of Eibenstock ) to Johanngeorgenstadt. In 1883,

4802-691: The Russian government approved a federal program for nuclear and radiation safety for 2016 to 2030 with a budget of 562 billion rubles (ca. 8 billion USD ). Its key issue is "the deferred liabilities accumulated during the 70 years of the nuclear industry, particularly during the time of the Soviet Union". About 73% of the budget will be spent on decommissioning aged and obsolete nuclear reactors and nuclear facilities, especially those involved in state defense programs; 20% will go in processing and disposal of nuclear fuel and radioactive waste, and 5% into monitoring and ensuring of nuclear and radiation safety. Uranium

4900-598: The border crossing and the visitor mine, is the mansion of the old Wittigsthal ironworks, from 1836. There is an old powder tower in the town known locally as the Pulverturm . A Naturbad (“natural” swimming pool), fed by the Schwefelbach, draws summertime visitors. The natural ice stadium not far from the pool at the ski jumps is open in the wintertime. The cross-country skiing centre in Schwefelwerk

4998-566: The bulk of the use, including common bathroom and kitchen tiles which can be produced in green, yellow, mauve , black, blue, red and other colors. Uranium was also used in photographic chemicals (especially uranium nitrate as a toner ), in lamp filaments for stage lighting bulbs, to improve the appearance of dentures , and in the leather and wood industries for stains and dyes. Uranium salts are mordants of silk or wool. Uranyl acetate and uranyl formate are used as electron-dense "stains" in transmission electron microscopy , to increase

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5096-417: The centres of Altstadt (called locally Sockendorf ), Mittelstadt, Neustadt, Schwefelwerk, Jugel (Ober- and Unterjugel), Henneberg, Wittigsthal, Pachthaus, Heimberg (with Külliggut), Steigerdorf (with Haberlandmühle), Steinbach and Sauschwemme. The former centre of Neuoberhaus is nowadays abandoned and has been overgrown by woods. Owing to the town's great elevation – the road to Neustadt reaches 892 m –

5194-409: The civilian sector is to fuel nuclear power plants . One kilogram of uranium-235 can theoretically produce about 20  terajoules of energy (2 × 10   joules ), assuming complete fission; as much energy as 1.5 million kilograms (1,500 tonnes ) of coal . Commercial nuclear power plants use fuel that is typically enriched to around 3% uranium-235. The CANDU and Magnox designs are

5292-549: The contrast of biological specimens in ultrathin sections and in negative staining of viruses , isolated cell organelles and macromolecules . The discovery of the radioactivity of uranium ushered in additional scientific and practical uses of the element. The long half-life of uranium-238 (4.47 × 10 years) makes it well-suited for use in estimating the age of the earliest igneous rocks and for other types of radiometric dating , including uranium–thorium dating , uranium–lead dating and uranium–uranium dating . Uranium metal

5390-442: The development of uranium mining to extract the radium, which was used to make glow-in-the-dark paints for clock and aircraft dials. This left a prodigious quantity of uranium as a waste product, since it takes three tonnes of uranium to extract one gram of radium. This waste product was diverted to the glazing industry, making uranium glazes very inexpensive and abundant. Besides the pottery glazes, uranium tile glazes accounted for

5488-476: The effects on either human beings or on the environment. A great deal of the Old Town had to be torn down between 1953 and 1960 owing to mining damage, and new residential areas were built. From 1952 to 1957, Johanngeorgenstadt was a district unto itself, but after this the town was integrated with the district of Schwarzenberg (now Aue-Schwarzenberg). The closure that began in 1990 of many businesses, such as

5586-465: The element very slowly. When finely divided, it can react with cold water; in air, uranium metal becomes coated with a dark layer of uranium oxide . Uranium in ores is extracted chemically and converted into uranium dioxide or other chemical forms usable in industry. Uranium-235 was the first isotope that was found to be fissile . Other naturally occurring isotopes are fissionable, but not fissile. On bombardment with slow neutrons, uranium-235 most of

5684-493: The feasibility to store spent nuclear fuel at the Yucca Mountain nuclear waste repository . Above-ground nuclear tests by the Soviet Union and the United States in the 1950s and early 1960s and by France into the 1970s and 1980s spread a significant amount of fallout from uranium daughter isotopes around the world. Additional fallout and pollution occurred from several nuclear accidents . Uranium miners have

5782-503: The field and several crucial mistakes such as failing to account for impurities in available graphite samples which made it appear less suitable as a neutron moderator than it is in reality. Germany's attempts to build a natural uranium / heavy water reactor had not come close to reaching criticality by the time the Americans reached Haigerloch , the site of the last German wartime reactor experiment. On 2 December 1942, as part of

5880-468: The first sample of uranium metal by heating uranium tetrachloride with potassium . Henri Becquerel discovered radioactivity by using uranium in 1896. Becquerel made the discovery in Paris by leaving a sample of a uranium salt, K 2 UO 2 (SO 4 ) 2 (potassium uranyl sulfate), on top of an unexposed photographic plate in a drawer and noting that the plate had become "fogged". He determined that

5978-506: The fissile component, and on 29 February 1940, Nier used an instrument he built at the University of Minnesota to separate the world's first uranium-235 sample in the Tate Laboratory. Using Columbia University 's cyclotron , John Dunning confirmed the sample to be the isolated fissile material on 1 March. Further work found that the far more common uranium-238 isotope can be transmuted into plutonium, which, like uranium-235,

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6076-611: The food people eat. Worldwide production of uranium in 2021 was 48,332 tonnes , of which 21,819 t (45%) was mined in Kazakhstan . Other important uranium mining countries are Namibia (5,753 t), Canada (4,693 t), Australia (4,192 t), Uzbekistan (3,500 t), and Russia (2,635 t). Uranium ore is mined in several ways: open pit , underground , in-situ leaching , and borehole mining . Low-grade uranium ore mined typically contains 0.01 to 0.25% uranium oxides. Extensive measures must be employed to extract

6174-496: The glove, textile and furniture industries as well as machine building led to a great fall in the town's population to levels below those before the war. This in turn led to the demolition of many empty factories and residential blocks (especially in Neuoberhaus, Pachthaus and the midtown). These measures even affected one of the town's few cultural monuments: The mining warehouse building, built between 1806 and 1812 and spared by

6272-591: The great fire of 1867, was, with town council's approval, torn down. Development of population figures (from 1955 31 December) : 1815 to 1946 1950 to 1971 1974 to 2006 2008 to 2017 since 2018 1 29 October 2 31 August Of the 5,748 inhabitants on 31 December 2003, 2,751 were male and 2,997 female. The town's arms have their roots in the time when the town was founded. Johanngeorgenstadt's coat of arms might heraldically be described thus: Party per fess, above argent three buildings gules with towers, below gules an inescutcheon argent, therein

6370-736: The late Middle Ages , pitchblende was extracted from the Habsburg silver mines in Joachimsthal , Bohemia (now Jáchymov in the Czech Republic) in the Ore Mountains , and was used as a coloring agent in the local glassmaking industry. In the early 19th century, the world's only known sources of uranium ore were these mines. The discovery of the element is credited to the German chemist Martin Heinrich Klaproth . While he

6468-601: The metal from its ore. High-grade ores found in Athabasca Basin deposits in Saskatchewan , Canada can contain up to 23% uranium oxides on average. Uranium ore is crushed and rendered into a fine powder and then leached with either an acid or alkali . The leachate is subjected to one of several sequences of precipitation, solvent extraction, and ion exchange. The resulting mixture, called yellowcake , contains at least 75% uranium oxides U 3 O 8 . Yellowcake

6566-544: The middle of town is a Heimat-Stube , a museum of local lore. In the Bahnhofsgebäude (railway station building), built in 1898 and 1899 and remodelled after a fire in 1993, various exhibitions take place. There is also an “educational and entertaining” visitor mine in Wittigsthal called “Frisch Glück” Johanngeorgenstadt is where the Ore Mountain folk group De Randfichten comes from, although only one of

6664-491: The military sector is in high-density penetrators. This ammunition consists of depleted uranium (DU) alloyed with 1–2% other elements, such as titanium or molybdenum . At high impact speed, the density, hardness, and pyrophoricity of the projectile enable the destruction of heavily armored targets. Tank armor and other removable vehicle armor can also be hardened with depleted uranium plates. The use of depleted uranium became politically and environmentally contentious after

6762-422: The mineral pitchblende is credited to Martin Heinrich Klaproth , who named the new element after the recently discovered planet Uranus . Eugène-Melchior Péligot was the first person to isolate the metal, and its radioactive properties were discovered in 1896 by Henri Becquerel . Research by Otto Hahn , Lise Meitner , Enrico Fermi and others, such as J. Robert Oppenheimer starting in 1934 led to its use as

6860-606: The monumental painting “Hausandacht” (“House Prayer”) – also known as “Betender Bergmann” (“Praying Miner”) and “Bergmannsglaube” (“Miner’s Belief”) – and “Exulantenschicksal” (“Exulants’ Fate”) by artist August Herrmann (1885–1962). At the marketplace stands the Statue of the Town's Founder, Elector Johann Georg I of Saxony (1585–1656). It was carved out of Postelwitz sandstone in 1863 by sculptor Wilhelm Schwenk from Dresden and restored in 1984. Before it are some granite steps and

6958-483: The neighbouring Czech community of Potůčky . The Rathaus (Town Hall) is housed in a former barracks building on Eibenstocker Straße in the middle of town. The old town hall lay right on the marketplace, but it was destroyed in the great fire of 1867, and its successor was torn down in 1955. Right near the town administration is the Haus der Jugend (House of Youth) built in 2004. The Kulturhaus Karl Marx built in

7056-584: The newly discovered metal itself (in fact, that powder was an oxide of uranium ). He named the newly discovered element after the planet Uranus (named after the primordial Greek god of the sky ), which had been discovered eight years earlier by William Herschel . In 1841, Eugène-Melchior Péligot , Professor of Analytical Chemistry at the Conservatoire National des Arts et Métiers (Central School of Arts and Manufactures) in Paris , isolated

7154-656: The only commercial reactors capable of using unenriched uranium fuel. Fuel used for United States Navy reactors is typically highly enriched in uranium-235 (the exact values are classified ). In a breeder reactor , uranium-238 can also be converted into plutonium-239 through the following reaction: Before (and, occasionally, after) the discovery of radioactivity, uranium was primarily used in small amounts for yellow glass and pottery glazes, such as uranium glass and in Fiestaware . The discovery and isolation of radium in uranium ore (pitchblende) by Marie Curie sparked

7252-495: The peak of mining activity, there were up to 300 mines on the Auersberg. These included the Churhaus Saxony. In addition to the aforementioned rocks, quartz and slate have been proven to occur in veins on the summit. This Saxony location article is a stub . You can help Misplaced Pages by expanding it . This Ore Mountains article is a stub . You can help Misplaced Pages by expanding it . Uranium Uranium

7350-487: The physical explanation in February 1939 and named the process " nuclear fission ". Soon after, Fermi hypothesized that fission of uranium might release enough neutrons to sustain a fission reaction. Confirmation of this hypothesis came in 1939, and later work found that on average about 2.5 neutrons are released by each fission of uranium-235. Fermi urged Alfred O. C. Nier to separate uranium isotopes for determination of

7448-557: The possibility that these organisms could be used in bioremediation to decontaminate uranium-polluted water. The proteobacterium Geobacter has also been shown to bioremediate uranium in ground water. The mycorrhizal fungus Glomus intraradices increases uranium content in the roots of its symbiotic plant. In nature, uranium(VI) forms highly soluble carbonate complexes at alkaline pH. This leads to an increase in mobility and availability of uranium to groundwater and soil from nuclear wastes which leads to health hazards. However, it

7546-550: The shorter half-lives of these parents and their lower production than U and Pu, the parents of thorium: the Cm/ U ratio at the formation of the Solar System was (7.0 ± 1.6) × 10 . Some bacteria, such as Shewanella putrefaciens , Geobacter metallireducens and some strains of Burkholderia fungorum , use uranium for their growth and convert U(VI) to U(IV). Recent research suggests that this pathway includes reduction of

7644-509: The soluble U(VI) via an intermediate U(V) pentavalent state. Other organisms, such as the lichen Trapelia involuta or microorganisms such as the bacterium Citrobacter , can absorb concentrations of uranium that are up to 300 times the level of their environment. Citrobacter species absorb uranyl ions when given glycerol phosphate (or other similar organic phosphates). After one day, one gram of bacteria can encrust themselves with nine grams of uranyl phosphate crystals; this creates

7742-655: The sons of the town. The two-metre-tall bronze figure formerly on the Warriors’ Memorial pedestal was melted down in the Second World War . At the corner of the marketplace at Karlsbader Straße once stood, until the town fire in 1867, the Löbelhaus in which the town's first mayor Johann Löbel the Elder lived. Here, in August 1785 Johann Wolfgang von Goethe spent the night on his way to Karlovy Vary. At Röderplatz

7840-509: The stabilization of political and economical turmoil of the early 1990s. For example, in 1993 there were 29 incidents ranking above level 1 on the International Nuclear Event Scale , and this number dropped under four per year in 1995–2003. The number of employees receiving annual radiation doses above 20 mSv , which is equivalent to a single full-body CT scan , saw a strong decline around 2000. In November 2015,

7938-515: The successful development of a new absorbent material dubbed HiCap which performs surface retention of solid or gas molecules, atoms or ions and also effectively removes toxic metals from water, according to results verified by researchers at Pacific Northwest National Laboratory . In 2005, ten countries accounted for the majority of the world's concentrated uranium oxides: Canada (27.9%), Australia (22.8%), Kazakhstan (10.5%), Russia (8.0%), Namibia (7.5%), Niger (7.4%), Uzbekistan (5.5%),

8036-580: The three musicians, Michael Rostig, actually still lives in town. Within the Erzgebirgszweigverein , a singing group led by retired teacher Eberhard Müller is active. The Evangelical Lutheran Stadtkirche (“Town Church”) was built in neo-Gothic style using the old tower stonework after the town fire destroyed the Exulantenkirche from the 17th century, and it was consecrated on 27 August 1872. Inside are found, among other things,

8134-513: The time splits into two smaller nuclei , releasing nuclear binding energy and more neutrons. If too many of these neutrons are absorbed by other uranium-235 nuclei, a nuclear chain reaction occurs that results in a burst of heat or (in some circumstances) an explosion. In a nuclear reactor, such a chain reaction is slowed and controlled by a neutron poison , absorbing some of the free neutrons. Such neutron absorbent materials are often part of reactor control rods (see nuclear reactor physics for

8232-446: The tools in the inescutcheon should be crossed (note, however, that this is implied if they are described as “ hammer and pick ”, the historical symbol of mining). Not far from Schwefelwerkstraße lies the recreation, dedicated on 30 October 1993, of a horse gin and a hat house that may be visited. Right near the horse gin is a lapidarium featuring historic border stones and other boundary-marking stones. Likewise on Schwefelwerkstraße in

8330-672: The town has been known by the affectionate nickname Johannsibirsk . On 23 February 1654 in Annaburg , the founding of Johanngeorgenstadt at the Fastenberg right on the border in the Amt of Schwarzenberg by Bohemian Protestant refugees driven from Horní Blatná was approved by Elector John George I of Saxony. By 1680, there were roughly 100 ore mines in the town and the surrounding area. Silver mining also branched into tin mining, reaching its high point about 1715 and declining during

8428-727: The use of such munitions by the US, UK and other countries during wars in the Persian Gulf and the Balkans raised questions concerning uranium compounds left in the soil (see Gulf War syndrome ). Depleted uranium is also used as a shielding material in some containers used to store and transport radioactive materials. While the metal itself is radioactive, its high density makes it more effective than lead in halting radiation from strong sources such as radium . Other uses of depleted uranium include counterweights for aircraft control surfaces, as ballast for missile re-entry vehicles and as

8526-528: The use of uranium in manufacturing and metalwork. Tools made with these formulas remained in use for several decades, until the Manhattan Project and the Cold War placed a large demand on uranium for fission research and weapon development. A team led by Enrico Fermi in 1934 found that bombarding uranium with neutrons produces beta rays ( electrons or positrons from the elements produced; see beta particle ). The fission products were at first mistaken for new elements with atomic numbers 93 and 94, which

8624-542: The whole facility (later, the town of Arco became the first in the world to have all its electricity come from nuclear power generated by BORAX-III , another reactor designed and operated by Argonne National Laboratory ). The world's first commercial scale nuclear power station, Obninsk in the Soviet Union , began generation with its reactor AM-1 on 27 June 1954. Other early nuclear power plants were Calder Hall in England, which began generation on 17 October 1956, and

8722-490: The winter here, with its long-lasting snow cover, often lasts half the year, making Johanngeorgenstadt one of Saxony's snowiest areas. Wind strengths of four to seven at any time of year are not a rarity, leading to the town's already becoming a well-loved summer resort by the late 19th century. Ever since the area was once mentioned in some 18th-century publications as the Sächsisches Sibirien (“Saxon Siberia”),

8820-680: The world's largest single uranium deposit is located at the Olympic Dam Mine in South Australia . There is a significant reserve of uranium in Bakouma , a sub-prefecture in the prefecture of Mbomou in the Central African Republic . Some uranium also originates from dismantled nuclear weapons. For example, in 1993–2013 Russia supplied the United States with 15,000 tonnes of low-enriched uranium within

8918-588: Was believed that uranium was relatively rare, and that nuclear proliferation could be avoided by simply buying up all known uranium stocks, but within a decade large deposits of it were discovered in many places around the world. The X-10 Graphite Reactor at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, formerly known as the Clinton Pile and X-10 Pile, was the world's second artificial nuclear reactor (after Enrico Fermi's Chicago Pile) and

9016-601: Was completed in 2004 with a new building and recognized as a Nordic-Aktiv-Zentrum of the German Skiing Federation. Here begins the ridge ski run by way of Weitersglashütte and Mühlleithen to Schöneck, much loved in winter. Furthermore, in the Külliggut lands there are lifts at skiers’ disposal. The widely wooded surroundings offer hiking enthusiasts a broad area for their pastime. Many marked trails lead to local sightseeing spots, among them in particular

9114-418: Was emptied on 13 April 1945 and the inmates were sent on a death march towards Theresienstadt . Following World War II, the town was part of East Germany until 1990. Beginning in 1945, through the founding of SAG Wismut and later SDAG Wismut ( Sowjetisch-Deutsche Aktiengesellschaft Wismut – Soviet-German Bismuth Corporation) uranium mining underwent growth that was both rapid and without much regard to

9212-556: Was from ex-Soviet sources. From 1993 to 2005 the Material Protection, Control, and Accounting Program , operated by the federal government of the United States , spent about US$ 550 million to help safeguard uranium and plutonium stockpiles in Russia. This money was used for improvements and security enhancements at research and storage facilities. Safety of nuclear facilities in Russia has been significantly improved since

9310-653: Was opened once again in late October 2004 as the Franz Mehring Sport and Meeting Place after renovation and expansion. Auersberg Auersberg is a mountain in the Ore Mountains in Saxony , southeastern Germany. Auersberg is 1,018 m (3,340 ft) above sea level. It is located in the district of Wildenthal not far from the Czech border southeast of Eibenstock and northwest of Johanngeorgenstadt . Auersberg belongs to Wildenthal, which has been

9408-526: Was taken up again. In the Second World War , with the seizure of owner Arthur Krautmann's “Deutsches Haus” hotel across from the railway station , the town became home to a military hospital . Furthermore, the town harboured a subcamp of the Flossenbürg concentration camp in which countless inmates died. Its prisoners were used as forced labour and were deported mostly from German-occupied Soviet Union , Poland and France . The Johanngeorgenstadt camp

9506-491: Was the first reactor designed and built for continuous operation. Argonne National Laboratory 's Experimental Breeder Reactor I , located at the Atomic Energy Commission's National Reactor Testing Station near Arco, Idaho , became the first nuclear reactor to create electricity on 20 December 1951. Initially, four 150-watt light bulbs were lit by the reactor, but improvements eventually enabled it to power

9604-454: Was working in his experimental laboratory in Berlin in 1789, Klaproth was able to precipitate a yellow compound (likely sodium diuranate ) by dissolving pitchblende in nitric acid and neutralizing the solution with sodium hydroxide . Klaproth assumed the yellow substance was the oxide of a yet-undiscovered element and heated it with charcoal to obtain a black powder, which he thought was

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