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137-681: Mackenzie Delta may refer to: The delta of the Mackenzie River , where it empties into the Arctic Ocean, in the Northwest Territories, Canada Mackenzie Delta (electoral district) , a territorial electoral district for the Legislative Assembly of Northwest Territories, Canada Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with

274-524: 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

411-471: 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

548-539: 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

685-556: 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

822-717: 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

959-677: 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

1096-497: 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

1233-448: 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

1370-459: 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

1507-405: 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

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1644-413: 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

1781-525: 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

1918-521: A steady decline since the 1960s. Water mammals such as beavers and muskrats are extremely common in the Mackenzie Delta and surrounding areas of muskeg. The Mackenzie estuary is also a calving area for beluga whales . The Mackenzie valley is believed to have been the path taken by prehistoric peoples during the initial human migration from Asia to North America more than 10,000 years ago. However, archaeological evidence of human habitation along

2055-412: 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,

2192-530: 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

2329-552: 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

2466-533: Is 1,738 kilometres (1,080 mi) long, flowing north-northwest from Great Slave Lake into the Arctic Ocean , where it forms a large delta at its mouth. Its extensive watershed drains about 20 percent of Canada. It is the largest river flowing into the Arctic from North America , and including its tributaries has a total length of 4,241 kilometres (2,635 mi), making it the thirteenth longest river system in

2603-519: 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

2740-806: Is a river in the Canadian boreal forest . It forms, along with the Slave, Peace, and Finlay, the longest river system in Canada , and includes the second largest drainage basin of any North American river after the Mississippi . The Mackenzie River flows through a vast, thinly populated region of forest and tundra entirely within the Northwest Territories in Canada, although its many tributaries reach into five other Canadian provinces and territories . The river's main stem

2877-519: 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

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3014-520: 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

3151-626: Is considered to be some of the best northern farmland in Canada, due to the high concentration of minerals found in the soil. These conditions are expected to be improved even more by trends in climate change, such as warmer temperatures and a longer growing season. According to the British Columbia Environmental Network, "there is enough agricultural capability in the Peace River Valley to provide vegetables to all of northern Canada". The only functioning oil pipeline in

3288-781: 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

3425-418: 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

3562-519: Is forested (mostly boreal forest ). Wetlands comprise about 18%, or about 324,900 km (125,400 sq mi), of the basin. More than 93% of forested areas are virgin old-growth forest . However, human activities such as oil extraction have threatened water quality in the headwaters of the Mackenzie River. In addition, a warming climate in northern parts of the watershed is melting permafrost and destabilizing soil through erosion. Most of

3699-426: Is formed by the confluence of the two rivers and flows 415 kilometres (258 mi) due north into Great Slave Lake, at Fort Resolution , Northwest Territories. The Slave is by far the largest river flowing into the lake, with an annual flow of 108 km (87 million acre-feet). It contributes about 77% of the overall inflow, and forms a large delta where it enters the lake. Other rivers entering Great Slave Lake are

3836-485: 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

3973-528: Is known as Mills Lake. After heading west for about 100 km (62 mi) the Mackenzie narrows and turns northwest through a long stretch of fast water and rapids, past the village of Jean Marie River . At Fort Simpson it is joined by the Liard River , its biggest direct tributary, from the west. The Liard drains a large area in the southern Yukon and northern BC and carries a large amount of sediment during

4110-552: Is nearly 210 km (130 mi) from north to south, and ranges in width from 50 to 80 km (31 to 50 mi). It is the second biggest Arctic delta in the world, after the Lena River delta in Russia. Most land in the Mackenzie delta consists of permafrost , with great depths to bedrock. A characteristic feature of the delta is its numerous pingos , or hills of earth-covered-ice – some 1,400 of them. The Peel River , carrying much of

4247-427: 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

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4384-424: 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

4521-407: 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

4658-658: Is significantly deeper than Great Bear. The third major lake, Athabasca, is less than a third that size with an area of 7,800 km (3,000 sq mi). Six other lakes in the watershed cover more than 1,000 km (390 sq mi), including the Williston Lake reservoir , the second-largest artificial lake in North America, on the Peace River. The river discharges more than 325 cubic kilometres (78 cu mi) of water each year, accounting for roughly 11% of

4795-441: 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

4932-585: 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

5069-525: Is very young in geologic terms – its channel formed over a period of no more than several thousand years as the ice sheet retreated. Prior to the ice ages, only the Peel River tributary flowed through what is now the Mackenzie Delta into the Arctic Ocean. The other tributaries of the Mackenzie combined into the "Bell River" which flowed east into Hudson Bay. During glaciation the weight of the ice sheet depressed northern Canada's terrain to such an extent that when

5206-595: The 1825–1827 Mackenzie River expedition . The following year he traced the coast west until blocked by ice while John Richardson followed the coast east to the Coppermine River . In 1849 William Pullen reached the Mackenzie from the Bering Strait. In the following decades the North West Company established forts on the river, the precursors of present-day settlements such as Fort Simpson (formerly Fort of

5343-522: The Arctic Red River from the southwest at Tsiigehtchic , where traffic on the Dempster Highway crosses via ferry/ice bridge. About 30 kilometres (19 mi) northwest of Tsiigehtchic is Point Separation, the head of the vast Mackenzie River Delta, whose branching channels, ponds and wetlands spread across more than 12,000 square kilometres (4,600 sq mi) of the coastal plain. The delta

5480-843: The Athabasca River all the way to the delta, though with several areas such as the huge rapids on the Slave River requiring portages . The route taken by gold seekers started in Edmonton and followed the Athabasca, Slave and Mackenzie Rivers as far as the Peel River , then up the Peel and its tributary the Rat River to the headwaters of the Porcupine River , which flows to the Yukon River . Many who attempted

5617-727: The Bering Strait ; and the Fraser River and Columbia River systems, both of which empty into the Pacific Ocean . Lowland divides in the north separate the Mackenzie basin from the Arctic Ocean watersheds of the Anderson , Horton , Coppermine and Back Rivers. In the east, the Mackenzie borders on the Hudson Bay watersheds of the Thelon and Churchill Rivers, and to the south it is bordered by

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5754-577: The Gwichya Gwich'in . In 2008, Canadian and Japanese researchers extracted a constant stream of natural gas from a test project at the Mallik methane hydrate field in the Mackenzie Delta. This was the second such drilling at Mallik: the first took place in 2002 and used heat to release methane. In the 2008 experiment, researchers were able to extract gas by lowering the pressure, without heating, requiring significantly less energy. The Mallik gas hydrate field

5891-402: 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

6028-492: 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

6165-624: The Northern Interior of BC, is the ultimate source of the Mackenzie River via the Finlay – Peace River system, which stretches 1,923 kilometres (1,195 mi) through BC and Alberta. The 1,231-kilometre (765 mi) Athabasca River originates further south, in Jasper National Park in southwest Alberta. Together, the Peace and Athabasca rivers drain a significant portion of the eastern slope of

6302-466: 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

6439-552: The Rocky Mountains and the central Alberta prairie. The Peace contributes the majority of the water, about 66 km (54 million acre-feet ) per year, and the Athabasca contributes 25 km (20 million acre-feet). The Peace and Athabasca meet at the Peace-Athabasca Delta , a vast inland delta at the western end of Lake Athabasca , which also takes runoff from the northern third of Saskatchewan. The Slave River

6576-728: The Saskatchewan – Nelson River system, which also empties into Hudson Bay. The Mackenzie system is hydrologically connected to the Hudson Bay watershed via Wollaston Lake , which is not only the source of the Fond du Lac tributary of Lake Athabasca, but also of the Cochrane River , which flows east into the Churchill River. The eastern portion of the Mackenzie basin is dominated by vast reaches of lake-studded boreal forest and includes many of

6713-688: 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

6850-450: The Taltson , Lockhart and Hay Rivers , the latter of which also extends into Alberta and BC. The Mackenzie River issues from the western end of Great Slave Lake about 150 km (93 mi) south-west of Yellowknife . The channel is initially several kilometres wide but narrows to about 800 m (2,600 ft) at Fort Providence , which was historically an important ferry crossing in

6987-465: 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

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7124-439: 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

7261-592: 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

7398-432: 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

7535-498: The 3,200-kilometre (2,000 mi) journey died along the way or turned back before reaching the Yukon. Oil was discovered at Norman Wells in the 1920s, beginning a period of industrialization in the Mackenzie valley. Oil was initially shipped out by steamboats, supplying mines and towns across the NWT. This demand grew when gold was discovered on the northern shore of Great Slave Lake, leading to

7672-619: 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

7809-408: 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

7946-495: The Forks). A lucrative fur trade was carried out, as the Mackenzie basin teemed with beaver and muskrat. However, the short summer and harsh winter conditions limited trappers' activities. During the late 19th century Fort Simpson was regional headquarters for the Hudson's Bay Company . The first fur trappers were native, but starting in the 1920s increasing numbers of European trappers entered

8083-565: The Great Slave Lake region. By acting as a massive stabilizer on the water flow of the Peace River, Williston Lake reduces flood crests on the Peace, Slave and Mackenzie rivers as far downstream as Fort Good Hope . This has made the Peace Valley more suitable for farming, but has had significant impacts on downstream wildlife and riparian communities. The more stable annual flow slows down the spread of essential nutrients which builds up in

8220-514: The Liard River, it is 6,769 m /s (239,000 cu ft/s). At Norman Wells it is 8,446 m /s (298,300 cu ft/s), and at the Arctic Red confluence it is 8,926 m /s (315,200 cu ft/s). Mackenzie monthly mean discharge at Arctic Red River (m /s) As recently as the last glacial maximum about 30,000 years ago, the majority of northern Canada was buried under

8357-445: The Mackenzie River drainage basin encompasses nearly 20 percent of Canada. About 980,000 km (380,000 sq mi), or 54 percent of the basin, lies above Great Slave Lake. Permafrost underlies about three-quarters of the watershed, reaching up to 100 m (330 ft) deep in the Mackenzie Delta. As a whole, the Mackenzie basin receives only meager to moderate rainfall, averaging 410 millimetres (16 in) over

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8494-573: The Mackenzie River. Fort Providence lost 20 percent of its population, and some smaller villages and camps were completely wiped out. Steamboat service on the Mackenzie River began in the 1880s, and the number of vessels surged in the early 1900s as the Klondike Gold Rush brought a wave of prospectors to the Yukon. The Mackenzie River was one of the main routes into the northern interior, with sternwheelers transporting passengers, domestic supplies and industrial goods from as far upstream as

8631-498: The Mackenzie basin connects Norman Wells with Zama City , Alberta. Norman Wells was the main oil-producing area on the Mackenzie River until the 1970s, when new oil fields were discovered further north in the Mackenzie delta and the surrounding coastline. As of 2016, there were an estimated 166 billion barrels of oil reserves in this region. There is a proposal for a Mackenzie Valley Pipeline , which has not been built due to environmental concerns and falling oil and gas prices. During

8768-488: The Mackenzie is scant, despite the efforts of many researchers. Many archaeological sites have probably been destroyed by flooding, freeze-thaw and erosion. The Inuvialuit , Gwich'in and other Indigenous peoples have lived along the river for thousands of years; however, the oldest known evidence of continuous occupation stretches back only about 1300–1400 years, at the Gwich'in community of Tsiigehtchic . The Mackenzie provided

8905-477: The Mackenzie watershed is unbroken wilderness and human activities have little influence on the overall water quality, although there are some localized impacts. Some parts of the Mackenzie basin are rich in natural resources – oil and gas in the Northwest Territories and in central Alberta , lumber in the Peace River headwaters, uranium in Saskatchewan, gold and zinc in the Great Slave Lake area and tungsten in

9042-494: The Mountain River the Mackenzie flows due north until reaching The Ramparts , a limestone gorge barely 500 metres (1,600 ft) wide and up to 45 metres (148 ft) deep. Below The Ramparts is the village of Fort Good Hope , where the Mackenzie turns northwest again, soon crossing the Arctic Circle . The Mackenzie here flows slightly lower in elevation than the surrounding tundra , as a braided river between low bluffs about 3 to 5 km (1.9 to 3.1 mi) apart. It receives

9179-636: 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

9316-399: The Yukon. As of 2003 there were two operational gold mines in Yellowknife, and many more abandoned mines dot the region. Communities along the Mackenzie River depend on subsistence fishing, although there is also some commercial fishing on the river. Agriculture in the Mackenzie River basin is mainly concentrated in the Peace and Athabasca valleys to the south. The valley of the former river

9453-404: The basin, none of them endemic . The Mackenzie River has a similar range of fish fauna to the Mississippi River system. It is believed that the two river systems were connected during the Ice Ages by meltwater lakes and channels, allowing fish in the two rivers to interbreed. Fish in the Mackenzie River proper include the northern pike , several minnow species, and lake whitefish . Fish in

9590-566: 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

9727-409: 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

9864-549: 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

10001-442: 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

10138-602: The eastern and southern edges of the basin; these include uranium , gold , lead , and zinc . Agriculture remains prevalent along the south, particularly in the Peace River area. Various tributaries and headwaters of the river have been developed for hydroelectricity production, flood control and irrigation. Through its many tributaries, the Mackenzie River basin covers portions of five Canadian provinces and territories – British Columbia (BC), Alberta , Saskatchewan , Yukon , and Northwest Territories. Thutade Lake , in

10275-465: 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

10412-551: The enormous continental Laurentide Ice Sheet . The tremendous erosive powers of the Laurentide and its predecessors, at maximum extent, completely buried what is now the Mackenzie watershed under thousands of metres of ice and flattened the eastern portions of the watershed. When the ice sheet receded for the last time, it left a 1,100 km (680 mi) long proglacial lake , Lake McConnell , of which Great Bear, Great Slave and Athabasca Lakes are remnants. Today's Mackenzie River

10549-539: The entire basin, though mountain areas experience much higher precipitation, and areas near and north of the Arctic Circle receive much lower precipitation. The Mackenzie drainage basin is bordered by multiple major North American watersheds. Much of the western edge of the Mackenzie basin runs along the Continental Divide . The divide separates the Mackenzie watershed from that of the Yukon River , which flows to

10686-486: 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

10823-498: 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

10960-464: 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

11097-499: 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,

11234-605: 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

11371-551: The form of sediments, thus causing the river to become more polluted. Uranium Uranium 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

11508-527: The government-owned Marine Transportation Services . In 2016, Northern Transportation Company went bankrupt, and its assets were bought by the government of Northwest Territories. Barge traffic travels the entire length of the Mackenzie in long "trains" of up to fifteen shallow-draft vessels pulled by tugboats . Goods are shipped as far as the port of Tuktoyaktuk on the eastern end of the Mackenzie Delta, where they are transferred to oceangoing vessels and delivered to communities along Canada's Arctic coast and

11645-473: The ice retreated, the Mackenzie system was captured to lower elevations in the northwest, establishing the present flow direction to the Arctic. Fluvial deposits and other erosional evidence indicate that around the end of the Pleistocene , about 13,000 years ago, the Mackenzie channel was scoured by one or more massive glacial lake outburst floods unleashed from Lake Agassiz , formed by melting ice west of

11782-449: The ice-free season, the Mackenzie is a major transportation link through the vast wilderness of northern Canada, linking the many isolated communities along its course. Wide, calm sections of the river are frequently used to land seaplanes in the ice-free season. Canada's northernmost major railhead is located at the town of Hay River , on the south shore of Great Slave Lake. Goods shipped there by train and truck are loaded onto barges of

11919-419: The lake to rise, and the excess water can only flow out after the rivers have receded. The same phenomenon occurs at Great Slave Lake, which naturally regulates the flow from the Slave River into the Mackenzie. There are river gauges at several upstream points along the Mackenzie River. The average flow rate at the outlet of Great Slave Lake is 4,269 m /s (150,800 cu ft/s). At Fort Simpson, below

12056-442: The largest lakes in North America. By both volume and surface area, Great Bear Lake is the biggest in the watershed and third largest on the continent, with a surface area of 31,153 km (12,028 sq mi) and a volume of 2,236 km (536 cu mi). Great Slave Lake is slightly smaller, with an area of 28,568 km (11,030 sq mi) and containing 2,088 km (501 cu mi) of water, although it

12193-763: 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

12330-487: The major route into Canada's northern interior for European explorers as early as the late 18th century. Scottish explorer Alexander Mackenzie travelled the river in the hope it would lead to the Pacific Ocean , but instead reached its mouth on the Arctic Ocean on 14 July 1789. There is a story, likely apocryphal, that he named it "Disappointment River", but eventually it was named after him. No European reached its mouth again until Sir John Franklin on 16 August 1825 during

12467-404: The major route into Canada's northern interior for early European explorers. Economic development remains limited along the river. During the 19th century, fur trading became a lucrative business, but this was affected by harsh weather conditions. The discovery of oil at Norman Wells in the 1920s began a period of industrialization in the Mackenzie valley. Metallic minerals have been found along

12604-487: The massive cost and environmental impact. The Royal Canadian Mint honoured the 200th anniversary of the naming of the Mackenzie River with the issue of a silver commemorative dollar in 1989. In 1997, a cultural landscape along the section of the Mackenzie River at Tsiigehtchic was designated the Nagwichoonjik (Mackenzie River) National Historic Site of Canada due to its cultural, social and spiritual significance to

12741-534: 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

12878-455: The mid-twentieth century, more than 400,000 birds passed through during the spring and up to a million in autumn. Some 215 bird species in total have been catalogued in the delta, including species such as the whooping crane , peregrine falcon and bald eagle . The construction of the W.A.C. Bennett Dam on the Peace River has reduced the seasonal variations of water levels in the delta, causing damage to its ecosystem. Bird populations have seen

13015-491: 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

13152-473: The mine shut down in 1988, the railroad remains an important transportation link between the Mackenzie River waterway and the rest of Canada. In the 1950s the U.S. Army Corps of Engineers proposed the North American Water and Power Alliance (NAWAPA), a vast series of dams, tunnels and reservoirs designed to move 150 km (120,000,000 acre⋅ft) of water from northern Canada to southern Canada,

13289-422: 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

13426-570: 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

13563-453: The north. Year round, the Mackenzie's outflow has a major stabilizing effect in the local climate above the Arctic Ocean with large amounts of warmer fresh water mixing with the cold seawater. The average flow rate at the mouth is 9,910 m /s (350,000 cu ft/s), the second largest in Canada after the St Lawrence , and the fourteenth largest in the world. About 60 percent of

13700-457: The numerous islands to the north. In winter, the frozen channel of the Mackenzie River, especially in the delta region, is used as an ice road , firm enough to support large trucks, although travel between northern communities is mostly by dog sleds and snowmobiles. Although the Mackenzie River is wide and deep, navigation is "notoriously difficult" due to the locations of sandbars and shallows changing from year to year. In some narrower parts of

13837-531: The oil due to poor construction. It only operated for thirteen months, shutting down in 1945. Much abandoned equipment remains along the corridor today; part of the pipeline route has been designated the Canol Heritage Trail . In 1964 the Mackenzie Northern Railway (now a subsidiary of CN ) reached the shore of Great Slave Lake, to serve the new Pine Point zinc mine near Hay River. Although

13974-650: 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

14111-482: 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

14248-557: 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

14385-498: The present-day Great Lakes . At its peak, Agassiz had a greater volume than all present-day freshwater lakes combined. This is believed to have disrupted currents in the Arctic Ocean and led to an abrupt 1,300-year-long cold temperature shift called the Younger Dryas . The Mackenzie carries a very large sediment load, transporting about 128 million tonnes each year to its delta. The Liard River alone accounts for 32 percent of

14522-539: The region. Beaver and muskrat populations were heavily depleted, especially in areas around and south of Great Slave Lake. Catholic missionary Henri Grollier founded missions at Fort Simpson, Fort Norman and Fort Good Hope between 1858 and 1859. During the late 19th century and early 20th century epidemics of introduced European diseases swept through Indigenous communities along the river, and thousands of native people lost their lives. One particularly severe influenza in 1928 killed as many as one in ten native people along

14659-404: The river, barges must be uncoupled and towed one by one through hazardous stretches, despite attempts to widen and deepening the channel by blasting. Although there are no dams along the main stem of the Mackenzie, many of its tributaries and headwaters have been developed for hydroelectricity production, flood control and irrigation. The W.A.C. Bennett and Peace Canyon hydroelectric dams on

14796-535: The runoff from the northern Yukon, joins in the delta at a point northeast of Fort McPherson . Below there, the Mackenzie diverges into several large channels with the largest heading north-northeast, emptying into the Beaufort Sea west of Tuktoyaktuk . The Mackenzie Delta contains a logjam with 400,000 caches of wood, which stores 3.4 million tons of carbon , equivalent to a year's emissions from 2.5 million cars. At 1,805,000 km (697,000 sq mi),

14933-508: The settlement of Yellowknife and the opening of several mines in the area. By the 1940s steamboats had been replaced by modern gas and diesel-powered craft, which continue to serve the river today. During World War II oil pumped in Norman Wells was shipped to Fairbanks , Alaska via the 1,000-kilometre (620 mi) Canol pipeline . The pipeline was considered a "fiasco", going five times over budget and losing as much as 20 percent of

15070-541: 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

15207-509: 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

15344-464: The southern half of the watershed are genetically isolated from those of the northern half due to large rapids on the Slave River preventing fish from swimming upstream. Migratory birds use the three major deltas in the Mackenzie River basin – the Mackenzie Delta and the inland Slave and Peace-Athabasca Deltas – as resting and breeding areas. The latter is located at the convergence of four major North American migratory routes, or flyways. As recently as

15481-471: The spring, the difference in discharge between the two halves of the watershed becomes even more marked. While large amounts of snow and glacial melt dramatically drive up water levels in the Mackenzie's western tributaries, large lakes to the east retard springtime discharges. Spring floods from the Peace-Athabasca system are significantly slowed by the delta area at the western end of Lake Athabasca causing

15618-496: 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,

15755-515: 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%),

15892-485: The summer melt – which does not fully mix with the clear water in the Mackenzie for almost 500 km (310 mi) downstream, with the resulting phenomenon of a clear current on the east bank and muddy water on the west bank. The river continues west-northwest until its confluence with the North Nahanni River , where it turns north towards the Arctic. It flows through open taiga with its wide valley bounded, on

16029-546: The summer, and used as an ice bridge in the winter for traffic along the Yellowknife Highway . In 2012 the Deh Cho Bridge was completed at a point about 10 km (6.2 mi) upstream, providing a safer permanent crossing. It is the only bridge across the main stem of the Mackenzie. West of Fort Providence the Mackenzie widens considerably, resembling a shallow, swampy lake more than a river; one large widening here

16166-402: The taiga consists of black spruce , aspen and poplar forest. In the north, the river's shores are lined with sparse vegetation like dwarf birch and willows , as well as extensive areas of muskeg and peat bogs . South of Great Slave Lake, there are much larger reaches of temperate and alpine forest, prairie, and fertile floodplain and riparian habitat. There are 53 fish species in

16303-513: 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

16440-731: The title Mackenzie Delta . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Mackenzie_Delta&oldid=870281335 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Mackenzie River (Period of data: 1973-2011)10,300 m /s (360,000 cu ft/s) The Mackenzie River (French: Fleuve (de) Mackenzie ; Slavey : Deh-Cho [tèh tʃʰò], literally big river ; Inuvialuktun : Kuukpak [kuːkpɑk], literally great river )

16577-472: The total river flow into the Arctic Ocean. The river is frozen for most of the year, with the ice typically breaking up by early to mid-May in the south, and late May-early June in the north. Ice breaks up earlier on the tributaries, sometimes causing ice jams and flooding where they meet the Mackenzie. In the middle of the larger lakes, such as Great Slave, ice can persist as late as mid-June. The river typically freezes by late October or November, starting in

16714-481: The total, and the Peel River about 20 percent. Essentially all of the sediment is contributed by areas downstream of Fort Providence, since upstream sediment is trapped in Great Slave Lake. The Mackenzie River's watershed is considered one of the largest and most intact ecosystems in North America, especially the northern half. Approximately 63% of the drainage basin, or 1,137,000 km (439,000 sq mi),

16851-553: The upper Peace River were completed in 1968 and 1980 by BC Hydro . They have a combined capacity of more than 3,600 megawatts (MW). The reservoir of W.A.C. Bennett, Williston Lake , is the largest body of fresh water in BC and the ninth largest man-made lake in the world, with a volume of 70.3 km (57,000,000 acre⋅ft). Other smaller hydroelectric plants are located along the Snare and Taltson River tributaries, providing power to mines in

16988-716: 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

17125-528: 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

17262-487: The water comes from the western half of the basin, which includes the Rocky, Selwyn , and Mackenzie mountain ranges out of which spring major tributaries such as the Peace and Liard Rivers, which contribute 23 and 27 percent of the total flow, respectively. In contrast the eastern half, despite being dominated by marshland and large lakes, provides only about 25 percent of the Mackenzie's discharge. During peak flow in

17399-719: The west, by the Mackenzie Mountains and to the east by low hills of the Canadian Shield . This mostly uninhabited area is called the Mackenzie Lowlands; although partly forested, it is mostly covered by large areas of muskeg , swamps and many small lakes. A number of major tributaries join from the west, including the Root River, Redstone River and Keele River . Below the Keele River, the Mackenzie River flows north along

17536-577: The western United States and Mexico. The system would involve building massive dams on the Liard, Mackenzie, Peace, Columbia , and Fraser river systems and pumping water into a 650 km (400 mi) long reservoir in the Rocky Mountain Trench . The water would then flow by gravity to irrigate more than 220,000 km (85,000 sq mi) in the three countries and generate more than 50,000 MW of surplus energy. The projects were never built due to

17673-667: The western base of the Franklin Mountains before turning northwest, and receives the Great Bear River , the outflow of Great Bear Lake at Tulita . The Mackenzie widens considerably to about 6 to 7 km (3.7 to 4.3 mi) at Norman Wells , a major center of oil production. There is a narrows at the Mountain River confluence called the Sans Sault Rapids , where the Mackenzie falls about 6 metres (20 ft). Below

17810-537: 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

17947-446: The world . The ultimate source of the Mackenzie River is Thutade Lake , in the Northern Interior of British Columbia . The Mackenzie valley is believed to have been the path taken by prehistoric peoples during the initial human migration from Asia to North America over 10,000 years ago, despite sparse evidence. The Inuvialuit , Gwich'in and other Indigenous peoples lived along the river for thousands of years. The river provided

18084-650: 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

18221-577: 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

18358-480: Was first discovered by Imperial Oil in 1971–1972. As of 2001, approximately 400,000 people lived in the Mackenzie River basin – representing only one percent of Canada's population. Ninety percent of the population lived in the Peace and Athabasca River basins, mostly in Alberta. The cold northern permafrost regions beyond the Arctic Circle are very sparsely populated, mainly by Indigenous peoples . Most of

18495-494: 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

18632-481: 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

18769-450: 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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