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128-576: The agency is headquartered in Rio de Janeiro and manages several institutes and facilities throughout Brazil. It has five regional districts, with headquarters in Angra dos Reis , Caetité , Fortaleza , Porto Alegre , and Resende , and a special office in Brasília . The Nuclear Energy Research Institute ( Portuguese : Instituto de Pesquisas Energéticas e Nucleares ; IPEN) is an agency managed by CNEN and associated to

256-410: A Contemporary architecture , it has a conical shape, with 96 meters of internal diameter and capacity to receive up to 20 thousand faithful. The splendor of the building, with straight and sober lines, is due to the changing stained glass windows carved on the walls up to the dome. Its design and execution was coordinated by Monsignor Ivo Antônio Calliari (1918–2005). Saint Sebastian is recognized as

384-506: A Portuguese expedition under explorer Gaspar de Lemos , captain of a ship in Pedro Álvares Cabral 's fleet, or under Gonçalo Coelho . Allegedly the Florentine explorer Amerigo Vespucci participated as an observer at the invitation of King Manuel I in the same expedition. In 1555, one of the islands of Guanabara Bay, now called Villegagnon Island , was occupied by 500 French colonists under

512-486: A skin color and phenotype continuum from pálido ( branco ) or fair-skinned, through branco moreno or swarthy Caucasian, mestiço claro or lighter skinned multiracial, pardo (mixed race) to negro or black . Pardo , for example, in popular usage includes those who are caboclos ( mestizos ), mulatos ( mulattoes ), cafuzos ( zambos ), juçaras (archaic term for tri-racials ) and westernized Amerindians (which are called caboclos as well), being more of

640-547: A tropical savanna climate ( Aw ) that closely borders a tropical monsoon climate ( Am ) according to the Köppen climate classification , and is often characterized by long periods of heavy rain between December and March. The city experiences hot, humid summers, and warm, sunny winters. In inland areas of the city, temperatures above 40 °C (104 °F) are common during the summer, though rarely for long periods, while maximum temperatures above 27 °C (81 °F) can occur on

768-442: A (partially) closed nuclear fuel cycle . Water is a nontoxic, transparent, chemically unreactive (by comparison with e.g. NaK ) coolant that is liquid at room temperature which makes visual inspection and maintenance easier. It is also easy and cheap to obtain unlike heavy water or even nuclear graphite . Compared to reactors operating on natural uranium , PWRs can achieve a relatively high burnup . A typical PWR will exchange

896-479: A CANDU reactor or any other heavy water reactor when ordinary light water is supplied to the reactor as an emergency coolant. Depending on burnup , boric acid or another neutron poison will have to be added to emergency coolant to avoid a criticality accident . PWRs are designed to be maintained in an undermoderated state, meaning that there is room for increased water volume or density to further increase moderation, because if moderation were near saturation, then

1024-465: A PWR cannot exceed a temperature of 647 K (374 °C; 705 °F) or a pressure of 22.064 MPa (3200 psi or 218 atm), because those are the critical point of water. Supercritical water reactors are (as of 2022) only a proposed concept in which the coolant would never leave the supercritical state. However, as this requires even higher pressures than a PWR and can cause issues of corrosion, so far no such reactor has been built. Pressure in

1152-405: A PWR design. Nuclear fuel in the reactor pressure vessel is engaged in a controlled fission chain reaction , which produces heat, heating the water in the primary coolant loop by thermal conduction through the fuel cladding. The hot primary coolant is pumped into a heat exchanger called the steam generator , where it flows through several thousand small tubes. Heat is transferred through

1280-470: A PWR is not suitable for most industrial applications as those require temperatures in excess of 400 °C (752 °F). Radiolysis and certain accident scenarios which involve interactions between hot steam and zircalloy cladding can produce hydrogen from the cooling water leading to hydrogen explosions as a potential accident scenario. During the Fukushima nuclear accident a hydrogen explosion damaging

1408-455: A PWR. It can, however, be used in a CANDU with only minimal reprocessing in a process called "DUPIC" - Direct Use of spent PWR fuel in CANDU. Thermal efficiency , while better than for boiling water reactors , cannot achieve the values of reactors with higher operating temperatures such as those cooled with high temperature gases, liquid metals or molten salts. Similarly process heat drawn from

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1536-464: A barrier to the humid wind that comes from the Atlantic. The city has had rare frosts in the past. Some areas within Rio de Janeiro state occasionally have falls of snow grains and ice pellets (popularly called granizo ) and hail . Drought is very rare, albeit bound to happen occasionally given the city's strongly seasonal tropical climate. The Brazilian drought of 2014–2015, most severe in

1664-407: A conical shape, with an internal diameter of 96 meters and a capacity to hold up to 20,000 worshippers. The splendor of the building, with its straight and sober lines, is due to the changing stained glass windows carved into the walls up to the dome . Its design and execution were coordinated by Monsignor Ivo Antônio Calliari (1918–2005). Saint Sebastian is recognized as the patron saint of

1792-543: A final defeat was imposed on the French forces and they were decisively expelled from Brazil for good. The city of Rio de Janeiro proper was founded on 1 March 1565 by the Portuguese, led by Estácio de Sá , including Antônio de Mariz  [ pt ] . It was named São Sebastião do Rio de Janeiro , in honor of St. Sebastian, the saint who was the namesake and patron of the Portuguese then-monarch Sebastião . Rio de Janeiro

1920-635: A football when she joined him. And shortly after her arrival, in September 1894, the first football match in Brazil took place in the field beside the textile factory. It was a five-a-side match between British workers, and took place six months before the first game organized by Charles Miller in São Paulo. However, the Bangu Football Club was not formally created until 1904. At the time Brazil's Old Republic

2048-646: A given temperature set by the position of the control rods. In contrast, the Soviet RBMK reactor design used at Chernobyl, which uses graphite instead of water as the moderator and uses boiling water as the coolant, has a large positive thermal coefficient of reactivity. This means reactivity and heat generation increases when coolant and fuel temperatures increase, which makes the RBMK design less stable than pressurized water reactors at high operating temperature. In addition to its property of slowing down neutrons when serving as

2176-444: A heavy pressure vessel and hence increases construction costs. The higher pressure can increase the consequences of a loss-of-coolant accident . The reactor pressure vessel is manufactured from ductile steel but, as the plant is operated, neutron flux from the reactor causes this steel to become less ductile. Eventually the ductility of the steel will reach limits determined by the applicable boiler and pressure vessel standards, and

2304-562: A million slaves arrived in Rio de Janeiro through Valongo Wharf , which is now a World Heritage Site . The Port of Rio de Janeiro was the largest port of slaves in America. When Prince Pedro proclaimed the independence of Brazil in 1822, he decided to keep Rio de Janeiro as the capital of his new empire while the place was enriched with sugar cane agriculture in the Campos region and, especially, with

2432-426: A moderator). The pressure in the primary coolant loop is typically 15–16 megapascals (150–160  bar ), which is notably higher than in other nuclear reactors , and nearly twice that of a boiling water reactor (BWR). As an effect of this, only localized boiling occurs and steam will recondense promptly in the bulk fluid. By contrast, in a boiling water reactor the primary coolant is designed to boil. Light water

2560-423: A moderator, water also has a property of absorbing neutrons, albeit to a lesser degree. When the coolant water temperature increases, the boiling increases, which creates voids. Thus there is less water to absorb thermal neutrons that have already been slowed by the graphite moderator, causing an increase in reactivity. This property is called the void coefficient of reactivity, and in an RBMK reactor like Chernobyl,

2688-465: A monthly basis. Along the coast, the breeze, blowing onshore and offshore, moderates the temperature. Because of its geographic situation, the city is often reached by cold fronts advancing from Antarctica , especially during autumn and winter, causing frequent weather changes. In summer there can be strong rains, which have, on some occasions, provoked catastrophic floods and landslides. The mountainous areas register greater rainfall since they constitute

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2816-515: A neo-gothic church was created, which still exists as the Saint Sebastian and Saint Cecilia Parish Church. Street cinemas and cultural buildings also appeared. In May 1894, Thomas Donohoe , a British worker from Busby , Scotland, arrived in Bangu. Donohoe was amazed to discover that there was absolutely no knowledge of football among Brazilians. So he wrote to his wife, Elizabeth, asking her to bring

2944-439: A population of the order of 1.29 million inhabitants being released without treatment in streams or rivers. With regard to industrial pollution, highly toxic wastes, with high concentrations of heavy metals – mainly zinc and cadmium – have been dumped over the years by factories in the industrial districts of Santa Cruz , Itaguaí and Nova Iguaçu , constructed under the supervision of State policies. The Marapendi lagoon and

3072-542: A quarter to a third of its fuel load every 18-24 months and have maintenance and inspection, that requires the reactor to be shut down, scheduled for this window. While more uranium ore is consumed per unit of electricity produced than in a natural uranium fueled reactor, the amount of spent fuel is less with the balance being depleted uranium whose radiological danger is lower than that of natural uranium. The coolant water must be highly pressurized to remain liquid at high temperatures. This requires high strength piping and

3200-469: A reduction in density of the moderator/coolant could reduce neutron absorption significantly while reducing moderation only slightly, making the void coefficient positive. Also, light water is actually a somewhat stronger moderator of neutrons than heavy water, though heavy water's neutron absorption is much lower. Because of these two facts, light water reactors have a relatively small moderator volume and therefore have compact cores. One next generation design,

3328-514: A result, temperatures over 40 °C (104 °F), that may happen about year-round but are much more common during the summer, often mean the actual "feels-like" temperature is over 50 °C (122 °F), when there is little wind and the relative humidity percentage is high. According to data from the Brazilian National Institute of Meteorology (INMET), since 1931, the absolute minimum temperature recorded in Rio de Janeiro

3456-539: A rich and influential Catholic tradition. The Roman Catholic Archdiocese of São Sebastião do Rio de Janeiro is the second largest archdiocese in Brazil after São Paulo . The Rio de Janeiro Cathedral was inaugurated in 1979, in the central region of the city. Its installations have a collection of great historical and religious value: the Archdiocesan Museum of Sacred Art and the Archdiocesan Archive. In

3584-419: A school in the poor suburb of Rio de Janeiro, the "pardos" there were found to be on average about 80% European, and the "whites" (who thought of themselves as "very mixed") were found to carry very little Amerindian and/or African admixtures. The results of the tests of genomic ancestry are quite different from the self made estimates of European ancestry. In general, the test results showed that European ancestry

3712-420: A shaft used for propulsion . Direct mechanical action by expansion of the steam can be used for a steam-powered aircraft catapult or similar applications. District heating by the steam is used in some countries and direct heating is applied to internal plant applications. Two things are characteristic for the pressurized water reactor (PWR) when compared with other reactor types: coolant loop separation from

3840-459: A skin color rather than a racial group in particular. Different ethnic groups contributed to the formation of the population of Rio de Janeiro. Before European colonization, there were at least seven different indigenous peoples speaking 20 languages in the region. A part of them joined the Portuguese and the other the French. Those who joined the French were then exterminated by the Portuguese, while

3968-500: A territory of 1,721 km . The Cathedral of São Sebastião do Rio de Janeiro , or Metropolitan Cathedral , was inaugurated in 1979 in the central region of the city. Its facilities house a collection of great historical and religious value: the Archdiocesan Museum of Sacred Art and the Archdiocesan Archive. The Banco da Providência and the Archdiocesan Caritas are also based there. In a contemporary architectural style, it has

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4096-632: Is 349.4 mm, recorded on February 26, 1971, at the former station in the Engenho de Dentro neighborhood. According to the 2010 IBGE Census , there were 5,940,224 people residing in the city of Rio de Janeiro. Since 1960, when it was surpassed by São Paulo , the city of Rio de Janeiro has been the second-most populous city in Brazil. The 2022 census revealed the following numbers: White Brazilian (45.4% or 2,821,619); Mixed (38.7% or 2,403,895); Black (15.6% or 968,428); Asian (10,514 or 0.2%); Indigenous (6,531 or 0.1%). The population of Rio de Janeiro

4224-461: Is a regional institute of CNEN responsible for radioactive waste management and deposit, and nuclear technology in the Central-West Region of Brazil. The Northeast Regional Center of Nuclear Science ( Portuguese : Centro Regional de Ciências Nucleares do Nordeste ; CRCN-NE) is a regional institute of CNEN responsible for inspection and control of facilities and radioactive materials in

4352-506: Is about 6,000,000. The population of the greater metropolitan area is estimated at 11–13.5 million. Residents of the city are known as cariocas . The official song of Rio is " Cidade Maravilhosa ", by composer André Filho . The city has parks and ecological reserves such as the Tijuca National Park, the world's first urban forest and UNESCO Environmental Heritage and Biosphere Reserve; Pedra Branca State Park , which houses

4480-430: Is far more important than the students thought it would be. The "pardos" for example thought of themselves as 1 ⁄ 3 European, 1 ⁄ 3 African and 1 ⁄ 3 Amerindian before the tests, and yet their ancestry on average reached 80% European. Other studies showed similar results Religion in Rio de Janeiro is diverse, with Catholic Christianity being the majority religion. According to data from

4608-402: Is generated per unit of uranium ore even though a higher burnup can be achieved. Nuclear reprocessing can "stretch" the fuel supply of both natural uranium and enriched uranium reactors but is virtually only practiced for light water reactors operating with lightly enriched fuel as spent fuel from e.g. CANDU reactors is very low in fissile material. Because water acts as a neutron moderator, it

4736-432: Is more dense (more collisions will occur). The use of water as a moderator is an important safety feature of PWRs, as an increase in temperature may cause the water to expand, giving greater 'gaps' between the water molecules and reducing the probability of thermalization — thereby reducing the extent to which neutrons are slowed and hence reducing the reactivity in the reactor. Therefore, if reactivity increases beyond normal,

4864-401: Is not possible to build a fast-neutron reactor with a PWR design. A reduced moderation water reactor may however achieve a breeding ratio greater than unity, though this reactor design has disadvantages of its own. Spent fuel from a PWR usually has a higher content of fissile material than natural uranium. Without nuclear reprocessing , this fissile material cannot be used as fuel in

4992-402: Is noted for its production of radioisotopes for nuclear medicine . The Radiological Protection and Dosimetry Institute ( Portuguese : Instituto de Radioproteção e Dosimetria ; IRD) is an institute of CNEN responsible for radiological protection and dosimetry of ionizing radiation , and conducts inspection of radioactive use in the industry , power plants and other areas. Since 1976,

5120-527: Is on an 18–24 month cycle. Approximately one third of the core is replaced each refueling, though some more modern refueling schemes may reduce refuel time to a few days and allow refueling to occur on a shorter periodicity. In PWRs reactor power can be viewed as following steam (turbine) demand due to the reactivity feedback of the temperature change caused by increased or decreased steam flow. (See: Negative temperature coefficient .) Boron and cadmium control rods are used to maintain primary system temperature at

5248-405: Is still seen in many parts of the city (and many other parts of the state of Rio de Janeiro), including architecture and language . Most Brazilians with some cultural contact with Rio know how to easily differentiate between the local dialect, fluminense , and other Brazilian dialects. People of Portuguese ancestry predominate in most of the state. The Brazilian census of 1920 showed that 39.7% of

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5376-595: Is the second-largest center of research and development in Brazil, accounting for 17 percent of national scientific output according to 2005 data. Despite the high perception of crime, the city actually has a lower incidence of crime than most state capitals in Brazil. Rio de Janeiro is one of the most visited cities in the Southern Hemisphere and is known for its natural settings, carnival , samba , bossa nova , and balneario beaches such as Barra da Tijuca , Copacabana , Ipanema , and Leblon . In addition to

5504-538: Is under the control of the state through INB, which is a subsidiary of the National Nuclear Energy Commission, although the Brazilian government has recently announced that it is prepared to move ahead with private sector involvement in the nuclear fuel cycle. Rio de Janeiro Rio de Janeiro ( Portuguese: [ˈʁi.u d(ʒi) ʒɐˈne(j)ɾu] ), or simply Rio , is the capital of

5632-465: Is used as the primary coolant in a PWR. Water enters through the bottom of the reactor's core at about 548  K (275 °C; 527 °F) and is heated as it flows upwards through the reactor core to a temperature of about 588 K (315 °C; 599 °F). The water remains liquid despite the high temperature due to the high pressure in the primary coolant loop, usually around 155 bar (15.5  MPa 153  atm , 2,250  psi ). The water in

5760-513: The 2016 Summer Olympics and the 2016 Summer Paralympics , making the city the first South American and Portuguese-speaking city to ever host the events, and the third time the Olympics were held in a Southern Hemisphere city. The Maracanã Stadium held the finals of the 1950 and 2014 FIFA World Cups, the 2013 FIFA Confederations Cup , and the XV Pan American Games . The city will host

5888-795: The Brazilian Institute of Geography and Statistics (IBGE), in 2010 the population of Rio de Janeiro had 3,229,192 Roman Catholics (51.1%), 1,477,021 Protestants (23.4%), 372.851 Spiritists (5.9%), 37,974 Jehovah's Witnesses (0.6%), 75,075 Buddhists (0.2%), 52,213 Umbanda (0.8%), 21,800 Jews (0.3%), 25,743 Brazilian Catholic Apostolic Church (0.4%), 16,776 new eastern religious (0.2%), 28,843 Candomblé (0.4%), 3,853 Mormons (<0.1%), 5,751 Eastern Orthodox Christians (<0.1%), 7,394 spiritualists (0.1%), 964 Muslims (<0.1%), 5,662 esoteric (<0.1%) and 802 Hindus (<0.1%). 858,704 had no religion (13.5%), and 113,530 followed other forms of Christianity (1.8%). Rio de Janeiro has had

6016-522: The Brazilian War of Independence began. This is one of the few instances in history that the capital of a colonizing country officially shifted to a city in one of its colonies. Rio de Janeiro subsequently served as the capital of the independent monarchy, the Empire of Brazil , until 1889, and then the capital of a republican Brazil until 1960 when the capital was transferred to Brasília . Rio de Janeiro has

6144-707: The G20 summit in 2024 , and the FIFA Women's World Cup in 2027 . [REDACTED] Portuguese Empire 1565–1815 [REDACTED] United Kingdom of Portugal, Brazil and the Algarves 1815–1822 [REDACTED]   Empire of Brazil 1822–1889 [REDACTED] Republic of Brazil 1889–present The region of Rio was inhabited by the Tupi , Puri , Botocudo and Maxakalí peoples. Europeans first encountered Guanabara Bay on 1 January 1502 (hence Rio de Janeiro, "January River"), during

6272-685: The Imperial Academy of Fine Arts , as well as the National Library of Brazil – with the largest collection in Latin America – and The Botanical Garden . The first printed newspaper in Brazil, the Gazeta do Rio de Janeiro , came into circulation during this period. When Brazil was elevated to Kingdom in 1815, it became the capital of the United Kingdom of Portugal, Brazil and the Algarves until

6400-483: The Northeast Region of Brazil. Nuclear energy accounts for about 4% of the Brazil's electricity. It is produced by two pressurized water reactors at Angra Nuclear Power Plant (Angra I and II). A third reactor, Angra III, with a projected output of 1,350 MW, is planned to be finished by the 2020s. By 2025 Brazil plans to build seven more reactors. Currently, all uranium exploration, production and export in Brazil

6528-539: The Oak Ridge National Laboratory for use as a nuclear submarine power plant with a fully operational submarine power plant located at the Idaho National Laboratory . Follow-on work was conducted by Westinghouse Bettis Atomic Power Laboratory . The first purely commercial nuclear power plant at Shippingport Atomic Power Station was originally designed as a pressurized water reactor (although

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6656-464: The Portuguese Royal Court moved to Brazil , Rio de Janeiro became the seat of the court of Queen Maria I of Portugal . She subsequently, under the leadership of her son the prince regent John VI of Portugal , raised Brazil to the dignity of a kingdom, within the United Kingdom of Portugal, Brazil, and Algarves . Rio remained as the capital of the pluricontinental monarchy until 1822, when

6784-478: The Rodrigo de Freitas Lagoon have suffered with the leniency of the authorities and the growth in the number of apartment buildings close by. The illegal discharge of sewage and the consequent deaths of algae diminished the oxygenation of the waters, causing fish mortality. There are, on the other hand, signs of decontamination in the lagoon made through a public-private partnership established in 2008 to ensure that

6912-798: The Southeast Region and the worst in decades, affected the entire metropolitan region's water supply (a diversion from the Paraíba do Sul River to the Guandu River is a major source for the state's most populous mesoregion). There were plans to divert the Paraíba do Sul to the Sistema Cantareira (Cantareira system) during the water crisis of 2014 in order to help the critically drought-stricken Greater São Paulo area. However, availability of sufficient rainfall to supply tap water to both metropolitan areas in

7040-534: The São Paulo State government and the University of São Paulo . The IPEN has a broad infrastructure of laboratories , a research reactor (IEA-R1), an industrial particle accelerator , and a compact cyclotron of variable energy. The IPEN is involved primarily in conducting research in the areas of nuclear materials and processes, nuclear reactors , applications of nuclear techniques, and nuclear safety. The IPEN

7168-794: The Tijuca National Park (Parque Nacional da Tijuca), the largest city-surrounded urban forest and the second largest urban forest in the world, has been a National Park. The largest urban forest in the world is the Floresta da Pedra Branca (White Rock Forest), which is located in the West Zone of Rio de Janeiro. Due to the high concentration of industries in the metropolitan region, the city has faced serious problems of environmental pollution. The Guanabara Bay has lost mangrove areas and suffers from residues from domestic and industrial sewage, oils and heavy metals. Although its waters renew when they reach

7296-449: The Tropic of Capricorn where the shoreline is oriented east and west; the city thus faces largely south. It was founded at the entrance to an inlet, Guanabara Bay (Baía de Guanabara), which is marked by a point of land called Sugar Loaf (Pão de Açúcar) – a "calling card" of the city. The population of the city of Rio de Janeiro, occupying an area of 1,182.3 km (456.5 sq mi),

7424-631: The World Youth Day in 2013 , the second World Youth Day in South America and first in Brazil. In the sports field, Rio de Janeiro was the host of the 2007 Pan American Games and the 2014 FIFA World Cup Final . On 2 October 2009, the International Olympic Committee announced that Rio de Janeiro would host the 2016 Olympic Games and the 2016 Paralympic Games , beating competitors Chicago , Tokyo , and Madrid . The city became

7552-632: The battleship Minas Geraes and threatened to fire on the city. Another military revolt occurred in 1922, the Copacabana Fort revolt , a march against the Old Republic's coronelism and café com leite politics . This revolt marked the beginning of Tenentism , a movement that resulted in the Brazilian Revolution of 1930 that started the Vargas Era . Until the early years of the 20th century,

7680-773: The state of Rio de Janeiro . It is the second-most-populous city in Brazil (after São Paulo ) and the sixth-most-populous city in the Americas. Founded in 1565 by the Portuguese , the city was initially the seat of the Captaincy of Rio de Janeiro , a domain of the Portuguese Empire . In 1763, it became the capital of the State of Brazil , a state of the Portuguese Empire . In 1808, when

7808-452: The supercritical water reactor , is even less moderated. A less moderated neutron energy spectrum does worsen the capture/fission ratio for U and especially Pu, meaning that more fissile nuclei fail to fission on neutron absorption and instead capture the neutron to become a heavier nonfissile isotope, wasting one or more neutrons and increasing accumulation of heavy transuranic actinides, some of which have long half-lives. After enrichment,

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7936-531: The uranium dioxide ( UO 2 ) powder is fired in a high-temperature, sintering furnace to create hard, ceramic pellets of enriched uranium dioxide. The cylindrical pellets are then clad in a corrosion-resistant zirconium metal alloy Zircaloy which are backfilled with helium to aid heat conduction and detect leakages. Zircaloy is chosen because of its mechanical properties and its low absorption cross section. The finished fuel rods are grouped in fuel assemblies, called fuel bundles, that are then used to build

8064-557: The French admiral Nicolas Durand de Villegaignon . Consequently, Villegagnon built Fort Coligny on the island when attempting to establish the France Antarctique colony. Eventually this French settlement became too much of a threat to the established Portuguese colony and in 1560 the order was made to get rid of them. A years-long military aggression was then initiated by the new Governor General of Brazil Mem De Sa, and later continued by his nephew Estacio De Sa. On 20 January 1567,

8192-712: The IRD possesses a Secondary Standard Dosimetry Laboratory, recognized by the International Atomic Energy Agency and the World Health Organization . The Nuclear Technology Development Center ( Portuguese : Centro de Desenvolvimento da Tecnologia Nuclear ; CDTN) is a nuclear research institute of CNEN. It originated in the Engineering School of the Federal University of Minas Gerais , and

8320-519: The Portuguese who lived in Brazil lived in Rio de Janeiro. Including all of the Rio de Janeiro, the proportion raised to 46.3% of the Portuguese who lived in Brazil. The numerical presence of the Portuguese was extremely high, accounting for 72% of the foreigners who lived in the capital. Portuguese born people accounted for 20.4% of the population of Rio, and those with a Portuguese father or a Portuguese mother accounted for 30.8%. In other words, native born Portuguese and their children accounted for 51.2% of

8448-554: The United States are considered Generation II reactors . Russia's VVER reactors are similar to US PWRs, but the VVER-1200 is not considered Generation II (see below). France operates many PWRs to generate the bulk of its electricity. Several hundred PWRs are used for marine propulsion in aircraft carriers , nuclear submarines and ice breakers . In the US, they were originally designed at

8576-614: The beaches, landmarks include the giant statue of Christ the Redeemer atop Corcovado mountain, named one of the New Seven Wonders of the World ; Sugarloaf Mountain with its cable car ; the Sambódromo (Sambadrome), a permanent grandstand-lined parade avenue which is used during Carnival; and Maracanã Stadium , one of the world's largest football stadiums . Rio de Janeiro was the host of

8704-435: The capital of Brazil was officially moved to Brasília. The territory of the former Federal District became its own state, Guanabara, after the bay that borders it to the east, encompassing just the city of Rio de Janeiro. After the 1964 coup d'état that installed a military dictatorship , the city-state was the only state left in Brazil to oppose the military. Then, in 1975, a presidential decree known as "The Fusion" removed

8832-509: The city to the north and south was facilitated by the consolidation and electrification of Rio's streetcar transit system after 1905. Botafogos natural environment, combined with the fame of the Copacabana Palace Hotel, the luxury hotel of the Americas in the 1930s, helped Rio to gain the reputation it still holds today as a beach party town. This reputation has been somewhat tarnished in recent years by favela violence resulting from

8960-409: The city was largely limited to the neighborhood now known as the historic city center (see below), on the mouth of Guanabara Bay. The city's center of gravity began to shift south and west to the so-called Zona Sul (South Zone) in the early part of the 20th century, when the first tunnel was built under the mountains between Botafogo and the neighborhood that is now known as Copacabana . Expansion of

9088-788: The city's patron saint , which is why it received the canonical name of "Saint Sebastian of Rio de Janeiro." Many Protestant creeds coexist in the city, Presbyterian , Congregational , Lutheran and Anglican Churches. In addition to evangelical churches such as the Baptist , Methodist , Seventh-day Adventist and Pentecostal churches, such as the Universal Church of the Kingdom of God , Assembly of God , Christian Congregation in Brazil and The Foursquare Church . Afro-Brazilian religions such as Umbanda and Candomblé find support in various social segments, although professed by less than 2% of

9216-550: The city's federative status and merged it with the State of Rio de Janeiro , with the city of Rio de Janeiro replacing Niterói as the state's capital, and establishing the Rio de Janeiro Metropolitan Region . In 1992, Rio hosted the Earth Summit , a United Nations conference to fight environmental degradation . Twenty years later, in 2012, the city hosted another conference on sustainable development , named United Nations Conference on Sustainable Development . The city hosted

9344-461: The city, which is why it received the canonical name "São Sebastião do Rio de Janeiro". Pressurized water reactor A pressurized water reactor ( PWR ) is a type of light-water nuclear reactor . PWRs constitute the large majority of the world's nuclear power plants (with notable exceptions being the UK, Japan and Canada). In a PWR, the primary coolant ( water ) is pumped under high pressure to

9472-598: The coast, and type of vegetation or land use. During the winter, cold fronts and dawn/morning sea breezes bring mild temperatures; cold fronts, the Intertropical Convergence Zone (in the form of winds from the Amazon Forest ), the strongest sea-borne winds (often from an extratropical cyclone ) and summer evapotranspiration bring showers or storms. Thus the monsoon-like climate has dry and mild winters and springs, and very wet and warm summers and autumns. As

9600-426: The core of the reactor. A typical PWR has fuel assemblies of 200 to 300 rods each, and a large reactor would have about 150–250 such assemblies with 80–100 tons of uranium in all. Generally, the fuel bundles consist of fuel rods bundled 14 × 14 to 17 × 17. A PWR produces on the order of 900 to 1,600 MW e . PWR fuel bundles are about 4 meters in length. Refuelings for most commercial PWRs

9728-544: The desired point. In order to decrease power, the operator throttles shut turbine inlet valves. This would result in less steam being drawn from the steam generators. This results in the primary loop increasing in temperature. The higher temperature causes the density of the primary reactor coolant water to decrease, allowing higher neutron speeds, thus less fission and decreased power output. This decrease of power will eventually result in primary system temperature returning to its previous steady-state value. The operator can control

9856-635: The entire population and forced entry into houses to kill mosquitoes and rats. The people of the city rebelled against Cruz's policy, in what would be known as the Vaccine Revolt . In 1910, Rio saw the Revolt of the Lash , where Afro-Brazilian crew members in the Brazilian Navy mutinied against the heavy use of corporal punishment , which was similar to the punishment slaves received. The mutineers took control of

9984-399: The fast fission neutrons to be slowed (a process called moderation or thermalizing) in order to interact with the nuclear fuel and sustain the chain reaction. In PWRs the coolant water is used as a moderator by letting the neutrons undergo multiple collisions with light hydrogen atoms in the water, losing speed in the process. This "moderating" of neutrons will happen more often when the water

10112-537: The first favelas . Inspired by the city of Paris , Passos built the Municipal Theatre , the National Museum of Fine Arts and the National Library in the city's center; brought electric power to Rio and created larger avenues to adapt the city to automobiles . Passos also named Oswaldo Cruz as Director General of Public Health. Cruz's plans to clean the city of diseases included compulsory vaccination of

10240-545: The first South American city to host the event and the second Latin American city (after Mexico City in 1968 ) to host the Games. Since the early 2010s, Rio de Janeiro has been inscribed as a UNESCO World Heritage Site for its arts, urban culture and designed landscapes set around a natural environment. Rio de Janeiro is near the west end of a strip (from Cabo Frio to just east of Ilha Grande ) of Brazil's Atlantic coast close to

10368-524: The first power plant connected to the grid was at Obninsk , USSR), on insistence from Admiral Hyman G. Rickover that a viable commercial plant would include none of the "crazy thermodynamic cycles that everyone else wants to build". The United States Army Nuclear Power Program operated pressurized water reactors from 1954 to 1974. Three Mile Island Nuclear Generating Station initially operated two pressurized water reactor plants, TMI-1 and TMI-2. The partial meltdown of TMI-2 in 1979 essentially ended

10496-548: The flawed RBMK control rods design. These design flaws, in addition to operator errors that pushed the reactor to its limits, are generally seen as the causes of the Chernobyl disaster . The Canadian CANDU heavy water reactor design have a slight positive void coefficient, these reactors mitigate this issues with a number of built-in advanced passive safety systems not found in the Soviet RBMK design. No criticality could occur in

10624-716: The future is merely speculative. Roughly in the same suburbs ( Nova Iguaçu and surrounding areas, including parts of Campo Grande and Bangu) that correspond to the location of the March 2012, February–March 2013 and January 2015 pseudo-hail ( granizo ) falls, there was a tornado -like phenomenon in January 2011, for the first time in the region's recorded history, causing structural damage and long-lasting blackouts , but no fatalities. The World Meteorological Organization has advised that Brazil, especially its southeastern region, must be prepared for increasingly severe weather occurrences in

10752-511: The growth in new construction of nuclear power plants in the United States for two decades. Watts Bar unit 2 (a Westinghouse 4-loop PWR) came online in 2016, becoming the first new nuclear reactor in the United States since 1996. The pressurized water reactor has several new Generation III reactor evolutionary designs: the AP1000 , VVER-1200, ACPR1000+, APR1400, Hualong One , IPWR-900 and EPR . The first AP1000 and EPR reactors were connected to

10880-460: The heaters or emptying the pressurizer. Pressure transients in the primary coolant system manifest as temperature transients in the pressurizer and are controlled through the use of automatic heaters and water spray, which raise and lower pressurizer temperature, respectively. The coolant is pumped around the primary circuit by powerful pumps. These pumps have a rate of ~100,000 gallons of coolant per minute. After picking up heat as it passes through

11008-683: The highest point of Rio de Janeiro, the peak of Pedra Branca; the Quinta da Boa Vista complex; the Botanical Garden ; Rio's Zoo; Parque Lage ; and the Passeio Público , the first public park in the Americas . In addition the Flamengo Park is the largest landfill in the city, extending from the center to the south zone, and containing museums and monuments, in addition to much vegetation. Since 1961,

11136-411: The inhabitants of Rio, or a total of 267,664 people in 1890. As a result of the influx of immigrants to Brazil from the late 19th to the early 20th century, also found in Rio de Janeiro and its metropolitan area are communities of Levantine Arabs who are mostly Christian or Irreligious , Spaniards , Italians , Germans , Japanese , According to an autosomal DNA study from 2009, conducted on

11264-497: The lagoon waters will eventually be suitable for bathing. The decontamination actions involve the transfer of sludge to large craters present in the lagoon itself, and the creation of a new direct and underground connection with the sea, which will contribute to increase the daily water exchange between the two environments. However, during the Olympics the lagoon hosted the rowing competitions and there were numerous concerns about potential infection resulting from human sewage. Rio has

11392-485: The last half of the 19th century. At that time the number of slaves was drastically reduced and the city was developed, with modern drains, animal trams, train stations crossing the city, gas and electric lighting, telephone and telegraph wiring, water and river plumbing. Rio continued as the capital of Brazil after 1889, when the monarchy was replaced by a republic. On 6 February 1889 the Bangu Textile Factory

11520-510: The most deployed type of reactor globally, allowing for a wide range of suppliers of new plants and parts for existing plants. Due to long experience with their operation they are the closest thing to mature technology that exists in nuclear energy. PWRs - depending on type - can be fueled with MOX-fuel and/or the Russian Remix Fuel (which has a lower Pu and a higher U content than "regular" U/Pu MOX-fuel) allowing for

11648-471: The narcotics trade and militias . Plans for moving the nation's capital city from Rio de Janeiro to the center of Brazil had been occasionally discussed, and when Juscelino Kubitschek was elected president in 1955, it was partially on the strength of promises to build a new capital. Though many thought that it was just campaign rhetoric, Kubitschek managed to have Brasília and a new Federal District built, at great cost, by 1960. On 21 April of that year,

11776-465: The near future, since events such as the catastrophic January 2011 Rio de Janeiro floods and mudslides are not an isolated phenomenon. In early May 2013, winds registering above 90 km/h (56 mph) caused blackouts in 15 neighborhoods of the city and three surrounding municipalities, and killed one person. Rio saw similarly high winds (about 100 km/h (62 mph)) in January 2015. Temperature also varies according to elevation, distance from

11904-430: The neutron activity correspondingly. An entire control system involving high pressure pumps (usually called the charging and letdown system) is required to remove water from the high pressure primary loop and re-inject the water back in with differing concentrations of boric acid. The reactor control rods, inserted through the reactor vessel head directly into the fuel bundles, are moved for the following reasons: to start up

12032-584: The new coffee cultivation in the Paraíba Valley . In order to separate the province from the capital of the Empire, the city was converted in Neutral Municipality in 1834, passing the province of Rio de Janeiro to have Niterói as capital. As a political center of the country, Rio concentrated the political-partisan life of the Empire. It was the main stage of the abolitionist and republican movements in

12160-480: The nucleus of a boron-10 atom which subsequently splits into a lithium-7 and tritium atom. Pressurized water reactors annually emit several hundred curies of tritium to the environment as part of normal operation. Natural uranium is only 0.7% uranium-235, the isotope necessary for thermal reactors. This makes it necessary to enrich the uranium fuel, which significantly increases the costs of fuel production. Compared to reactors operating on natural uranium, less energy

12288-494: The other part was assimilated. Rio de Janeiro is home to the largest Portuguese population outside of Lisbon in Portugal. After independence from Portugal, Rio de Janeiro became a destination for hundreds of thousands of immigrants from Portugal, mainly in the early 20th century. The immigrants were mostly poor peasants who subsequently found prosperity in Rio as city workers and small traders. The Portuguese cultural influence

12416-595: The population, many Cariocas simultaneously observe those practices with Roman Catholicism. The Roman Catholic Archdiocese of São Sebastião do Rio de Janeiro , the Metropolitan See of its respective Ecclesiastical Province , belongs to the Regional Episcopal Council Leste I of the National Conference of Bishops of Brazil (CNBB) (headquartered in Rio until 1977). Founded in 1676, it covers

12544-637: The power grid in China in 2018. In 2020, NuScale Power became the first U.S. company to receive regulatory approval from the Nuclear Regulatory Commission for a small modular reactor with a modified PWR design. Also in 2020, the Energy Impact Center introduced the OPEN100 project, which published open-source blueprints for the construction of a 100 MW electric nuclear power plant with

12672-432: The pressure drop across the turbine, and hence the energy extracted from the steam, is maximized. Before being fed into the steam generator, the condensed steam (referred to as feedwater) is sometimes preheated in order to minimize thermal shock. The steam generated has other uses besides power generation. In nuclear ships and submarines, the steam is fed through a steam turbine connected to a set of speed reduction gears to

12800-518: The pressure vessel must be repaired or replaced. This might not be practical or economic, and so determines the life of the plant. Additional high pressure components such as reactor coolant pumps, pressurizer, and steam generators are also needed. This also increases the capital cost and complexity of a PWR power plant. The high temperature water coolant with boric acid dissolved in it is corrosive to carbon steel (but not stainless steel ); this can cause radioactive corrosion products to circulate in

12928-419: The pressurized steam is fed through a steam turbine which drives an electrical generator connected to the electric grid for transmission. After passing through the turbine the secondary coolant (water-steam mixture) is cooled down and condensed in a condenser . The condenser converts the steam to a liquid so that it can be pumped back into the steam generator, and maintains a vacuum at the turbine outlet so that

13056-414: The pressurizer temperature and the highest temperature in the reactor core) of 30 °C (54 °F). As 345 °C is the boiling point of water at 155 bar, the liquid water is at the edge of a phase change. Thermal transients in the reactor coolant system result in large swings in pressurizer liquid/steam volume, and total pressurizer volume is designed around absorbing these transients without uncovering

13184-441: The primary circuit is maintained by a pressurizer, a separate vessel that is connected to the primary circuit and partially filled with water which is heated to the saturation temperature (boiling point) for the desired pressure by submerged electrical heaters. To achieve a pressure of 155 bars (15.5 MPa), the pressurizer temperature is maintained at 345 °C (653 °F), which gives a subcooling margin (the difference between

13312-423: The primary coolant loop. This not only limits the lifetime of the reactor, but the systems that filter out the corrosion products and adjust the boric acid concentration add significantly to the overall cost of the reactor and to radiation exposure. In one instance, this has resulted in severe corrosion to control rod drive mechanisms when the boric acid solution leaked through the seal between the mechanism itself and

13440-406: The primary system. Due to the requirement to load a pressurized water reactor's primary coolant loop with boron, undesirable radioactive secondary tritium production in the water is over 25 times greater than in boiling water reactors of similar power, owing to the latter's absence of the neutron moderating element in its coolant loop. The tritium is created by the absorption of a fast neutron in

13568-808: The purpose of training, research and radioisotope production. The Nuclear Engineering Institute ( Portuguese : Instituto de Engenharia Nuclear ; IEN) is a research unit of CNEN. Since 1962, IEN has been contributing to the national mastering of technologies in the nuclear field and its correlates. Its scope is generating and transferring knowledge and technology to the productive sector - public and private - with society as its final beneficiary. Patents publications, technology licensing, radiopharmaceuticals , materials essays and analysis, radioactive waste collecting, consulting and human resources formation are IEN's main products and services. The Central-West Regional Center of Nuclear Science ( Portuguese : Centro Regional de Ciências Nucleares do Centro-Oeste ; CRCN-CO)

13696-432: The reactor coolant and control the reactor power by adjusting the reactor coolant flow rate. PWR reactors are very stable due to their tendency to produce less power as temperatures increase; this makes the reactor easier to operate from a stability standpoint. PWR turbine cycle loop is separate from the primary loop, so the water in the secondary loop is not contaminated by radioactive materials. PWRs can passively scram

13824-422: The reactor core where it is heated by the energy released by the fission of atoms. The heated, high pressure water then flows to a steam generator , where it transfers its thermal energy to lower pressure water of a secondary system where steam is generated. The steam then drives turbines, which spin an electric generator. In contrast to a boiling water reactor (BWR), pressure in the primary coolant loop prevents

13952-455: The reactor core, the primary coolant transfers heat in a steam generator to water in a lower pressure secondary circuit, evaporating the secondary coolant to saturated steam — in most designs 6.2 MPa (60 atm, 900  psia ), 275 °C (530 °F) — for use in the steam turbine. The cooled primary coolant is then returned to the reactor vessel to be heated again. Pressurized water reactors, like all thermal reactor designs, require

14080-403: The reactor in case offsite power is lost to immediately stop the primary nuclear reaction. The control rods are held by electromagnets and fall by gravity when current is lost; full insertion safely shuts down the primary nuclear reaction. PWR technology is favoured by nations seeking to develop a nuclear navy; the compact reactors fit well in nuclear submarines and other nuclear ships. PWRs are

14208-428: The reactor, to shut down the primary nuclear reactions in the reactor, to accommodate short term transients, such as changes to load on the turbine, The control rods can also be used to compensate for nuclear poison inventory and to compensate for nuclear fuel depletion. However, these effects are more usually accommodated by altering the primary coolant boric acid concentration. In contrast, BWRs have no boron in

14336-431: The reduced moderation of neutrons will cause the chain reaction to slow down, producing less heat. This property, known as the negative temperature coefficient of reactivity, makes PWR reactors very stable. This process is referred to as 'Self-Regulating', i.e. the hotter the coolant becomes, the less reactive the plant becomes, shutting itself down slightly to compensate and vice versa. Thus the plant controls itself around

14464-534: The return of the Portuguese Royal Family to Lisbon in 1821, but remained as capital of the Kingdom of Brazil . From the colonial period until the first independent era, Rio de Janeiro was a city of slaves. There was a large influx of African slaves to Rio de Janeiro: in 1819, there were 145,000 slaves in the captaincy. In 1840, the number of slaves reached 220,000 people. Between 1811 and 1831, 500,000 to

14592-448: The sea, the bay is the final receiver of all the tributaries generated along its banks and in the basins of the many rivers and streams that flow into it. The levels of particulate matter in the air are twice as high as that recommended by the World Health Organization , in part because of the large numbers of vehicles in circulation. The waters of Sepetiba Bay are slowly following the path traced by Guanabara Bay, with sewage generated by

14720-418: The second largest municipal GDP in the country, and 30th-largest in the world in 2008. This is estimated at R$ 343 billion. In the city are the headquarters of Brazilian oil, mining, and telecommunications companies, including two of the country's major corporations, Petrobras and Vale , and Latin America's largest telemedia conglomerate, Grupo Globo . The home of many universities and institutes, it

14848-426: The steady state operating temperature by addition of boric acid and/or movement of control rods. Reactivity adjustment to maintain 100% power as the fuel is burned up in most commercial PWRs is normally achieved by varying the concentration of boric acid dissolved in the primary reactor coolant. Boron readily absorbs neutrons and increasing or decreasing its concentration in the reactor coolant will therefore affect

14976-427: The steam system and pressure inside the primary coolant loop. In a PWR, there are two separate coolant loops (primary and secondary), which are both filled with demineralized/deionized water. A boiling water reactor, by contrast, has only one coolant loop, while more exotic designs such as breeder reactors use substances other than water for coolant and moderator (e.g. sodium in its liquid state as coolant or graphite as

15104-468: The sugar) than Salvador, Bahia , much farther northeast. On 27 January 1763, the colonial administration in Portuguese America was moved from Salvador to Rio de Janeiro. The city remained primarily a colonial capital until 1808, when the Portuguese royal family and most of the associated Lisbon nobles, fleeing from Napoleon 's invasion of Portugal, moved to Rio de Janeiro. The kingdom's capital

15232-409: The void coefficient is positive, and fairly large, making it very hard to regulate when the reaction begins to run away. The RBMK reactors also have a flawed control rods design in which during rapid scrams, the graphite reaction enhancement tips of the rods would displace water at the bottom of the reactor and locally increase reactivity there. This is called the "positive scram effect" that is unique to

15360-414: The walls of these tubes to the lower pressure secondary coolant located on the shell side of the exchanger where the secondary coolant evaporates to pressurized steam. This transfer of heat is accomplished without mixing the two fluids to prevent the secondary coolant from becoming radioactive. Some common steam generator arrangements are u-tubes or single pass heat exchangers. In a nuclear power station,

15488-489: The water from boiling within the reactor. All light-water reactors use ordinary water as both coolant and neutron moderator . Most use anywhere from two to four vertically mounted steam generators; VVER reactors use horizontal steam generators. PWRs were originally designed to serve as nuclear marine propulsion for nuclear submarines and were used in the original design of the second commercial power plant at Shippingport Atomic Power Station . PWRs currently operating in

15616-514: Was 53.2% female and 46.8% male . The black community was formed by residents whose ancestors had been brought as slaves, mostly from Angola and Mozambique , as well by people of Angolan, Mozambican and West African descent who moved to Rio from other parts of Brazil. Nearly half of the city's population is by phenotype mixed or black. White in Brazil is defined more by having a European-looking phenotype rather than ancestry, and two full siblings can be of different "racial" categories in

15744-527: Was 6.4 °C on August 18, 1933, at the meteorological station in the Bangu neighborhood (deactivated in March 2004). This same station, located in the city's hottest neighborhood, recorded a maximum temperature of 43.1 °C on January 14, 1984, which held the record for the highest temperature in the city until December 26, 2012, when 43.2 °C was recorded at the Santa Cruz station. The record for rainfall within 24 hours

15872-463: Was created in 1952 with the name of Institute of Radioactive Researches (IPR). It was the first institution in Brazil devoted entirely to the nuclear area. Its initial activities included the research of radioactive mineral occurrences, studies in nuclear physics field, metallurgy and in materials of nuclear interest. In 1960 the research Reactor TRIGA Mark 1 was inaugurated at the Institute, with

16000-408: Was established, the city lacked urban planning and sanitation , which helped spread several diseases, such as yellow fever , dysentery , variola , tuberculosis and even black death . Pereira Passos , who was named mayor in 1902, imposed reforms to modernize the city, demolishing the cortiços where most of the poor population lived. These people then moved to live in the city's hills, creating

16128-502: Was founded, with the name of Industrial Progress Company of Brazil (Companhia Progresso Industrial do Brasil). The factory was officially opened on 8 March 1893, in a complex with varying architectural styles like Italianate , Neo-Gothic and a tower in Mansard Roof style. After the opening in 1893, workers from Great Britain arrived in Bangu to work in the textile factory. The old farms became worker villages with red-bricks houses, and

16256-573: Was the name of Guanabara Bay. Until early in the 18th century, the city was threatened or invaded by several mostly French pirates and buccaneers, such as Jean-François Duclerc and René Duguay-Trouin . In the late 17th century, still during the Sugar Era, the Bandeirantes discovered gold and diamonds in the neighboring captaincy of Minas Gerais , thus Rio de Janeiro became a much more practical port for exporting wealth (gold, precious stones, besides

16384-523: Was transferred to the city, which, thus, became the only European capital outside of Europe . As there was no physical space or urban structure to accommodate hundreds of noblemen who arrived suddenly, many inhabitants were simply evicted from their homes. In the first decade, several educational establishments were created, such as the Military Academy, the Royal School of Sciences, Arts and Crafts and

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