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96-645: Three Mile Island Nuclear Generating Station (commonly abbreviated as TMI ) is a shut-down nuclear power plant on Three Mile Island in Pennsylvania on the Susquehanna River just south of Harrisburg . It has two separate units, TMI-1 (owned by Constellation Energy ) and TMI-2 (owned by EnergySolutions). The plant was the site of the most significant accident in United States commercial nuclear energy when, on March 28, 1979, TMI-2 suffered

192-521: A steam turbine connected to a generator that produces electricity . As of September 2023 , the International Atomic Energy Agency reported that there were 410 nuclear power reactors in operation in 32 countries around the world, and 57 nuclear power reactors under construction. Building a nuclear power plant often spans five to ten years, which can accrue significant financial costs, depending on how

288-1088: A 10-megawatt solar array outside of Ocean City, Maryland . The array will provide the city with approximately 20% of its annual energy usage when completed. In October 2018, Constellation and the Tucson Unified School District completed a project that added solar generation capability to 82 of the district's buildings and facilities. The project is estimated to meet 47% of the district's electricity needs. In 2022, it became an independent company after Exelon split its utilities and power generation businesses. Former subsidiary Baltimore Gas & Electric remained part of Exelon. Constellation provides electric power to commercial and industrial customers. Its electricity supply business manages energy sales, dispatch, and delivery from Exelon's power generation portfolio to utilities, municipal co-ops, and energy retailers nationwide. As of 2018 , Constellation had around 360 megawatts of solar generation assets that are either in operation or under construction across

384-411: A 20-year agreement to purchase power from the facility once it resumes operation, aiming to support the energy demands of its expanding AI data centers. Constellation Energy will invest $ 1.6 billion in the plant’s upgrades, pending regulatory approval. The Nuclear Regulatory Commission's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Three Mile Island

480-460: A 550-MW facility near Odessa, Texas. The purchase added 1,100 MW of capacity. On April 28, 2011, Exelon announced its intention to purchase Constellation Energy. The merger was completed on March 12, 2012. On May 27, 2011, Constellation Energy announced its intention to purchase StarTex Power, a retail electricity provider in Houston, Texas; the purchase was completed on June 1, 2011. In 2018,

576-422: A closed-cycle cooling system for its main condenser using two natural draft cooling towers. Makeup water was drawn from the river to replace the water lost via evaporation in the cooling towers. Once-through the cooling towers, river water was used in the service water system, cooling auxiliary components and removing decay heat when the reactor was shut down. On February 17, 1979, TMI-1 went offline for refueling. It

672-465: A condenser. The condenser is a heat exchanger which is connected to a secondary side such as a river or a cooling tower . The water is then pumped back into the steam generator and the cycle begins again. The water-steam cycle corresponds to the Rankine cycle . The nuclear reactor is the heart of the station. In its central part, the reactor's core produces heat due to nuclear fission. With this heat,

768-442: A coolant is heated as it is pumped through the reactor and thereby removes the energy from the reactor. The heat from nuclear fission is used to raise steam, which runs through turbines , which in turn power the electrical generators. Nuclear reactors usually rely on uranium to fuel the chain reaction. Uranium is a very heavy metal that is abundant on Earth and is found in sea water as well as most rocks. Naturally occurring uranium

864-402: A facility has been completely decommissioned it is released from regulatory control, and the licensee of the station no longer has responsibility for its nuclear safety. Generally speaking, nuclear stations were originally designed for a life of about 30 years. Newer stations are designed for a 40 to 60-year operating life. The Centurion Reactor is a future class of nuclear reactor that

960-417: A net generating capacity of 819  MW e . The initial construction cost for TMI-1 was US$ 400 million , equal to $ 2.47 billion in 2018 dollars. Unit 1 first came online on April 19, 1974, and began commercial operations on September 2, 1974. TMI-1 was licensed to operate for 40 years from its first run, and in 2009, was extended 20 years, which means it could have operated until April 19, 2034. TMI-1 had

1056-404: A nuclear reactor heats the reactor coolant. The coolant may be water or gas, or even liquid metal, depending on the type of reactor. The reactor coolant then goes to a steam generator and heats water to produce steam. The pressurized steam is then usually fed to a multi-stage steam turbine . After the steam turbine has expanded and partially condensed the steam, the remaining vapor is condensed in

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1152-483: A nuclear station is smaller than the fuel cost for operation of coal or gas plants. Since most of the cost of nuclear power plant is capital cost, there is almost no cost saving by running it at less than full capacity. Nuclear power plants are routinely used in load following mode on a large scale in France, although "it is generally accepted that this is not an ideal economic situation for nuclear stations". Unit A at

1248-516: A number of long-established projects are struggling to find financing, notably Belene in Bulgaria and the additional reactors at Cernavodă in Romania , and some potential backers have pulled out. Where cheap gas is available and its future supply relatively secure, this also poses a major problem for nuclear projects. Analysis of the economics of nuclear power must take into account who bears

1344-413: A partial meltdown . According to the U.S. Nuclear Regulatory Commission (NRC) report, the accident resulted in no deaths or injuries to plant workers or in nearby communities. Follow-up epidemiology studies did not find causality between the accident and any increase in cancers. One work-related death has occurred on-site during decommissioning. The reactor core of TMI-2 has since been removed from

1440-615: A physical load-following energy supply contract. Constellation delivers approximately 730 billion cubic feet (21 billion cubic metres) of natural gas annually to customers, making it one of the ten largest natural gas marketers in the United States. The company oversees trading, transport, and storage of physical gas supply, pricing, hedging, and risk management. Constellation Technology Ventures (CTV), Constellation's venture capital fund, invests in start-up companies with emerging energy technologies. Their portfolio includes Proterra , ChargePoint and Aquion Energy Constellation

1536-444: A previous goal aimed to reduce nuclear electricity generation share to lower than fifty percent by 2025, this target was postponed to 2035 in 2019 and ultimately discarded in 2023. Russia continues to export the most nuclear power plants in the world, with projects across various countries: as of July 2023, Russia was constructing 19 out of 22 reactors constructed by foreign vendors; however, some exporting projects were canceled due to

1632-591: A significantly different evaluation of the economics of new nuclear power stations. Following the 2011 Fukushima nuclear accident in Japan , costs are likely to go up for currently operating and new nuclear power stations, due to increased requirements for on-site spent fuel management and elevated design basis threats. However many designs, such as the currently under construction AP1000, use passive nuclear safety cooling systems, unlike those of Fukushima I which required active cooling systems, which largely eliminates

1728-577: A single day. The massive drop led the New York Stock Exchange to halt trading in Constellation. The next day, as the stock fell as low as $ 13 a share, the company announced it was hiring Morgan Stanley and UBS to advise it on "strategic alternatives" suggesting a buyout. On September 17, 2008, Constellation accepted an offer of $ 4.7 billion by MidAmerican Energy , a subsidiary of Berkshire Hathaway , but ultimately canceled

1824-413: A slight decrease from the 2653 TWh produced in 2021. Thirteen countries generated at least one-quarter of their electricity from nuclear sources. Notably, France relies on nuclear energy for about 70% of its electricity needs, while Ukraine , Slovakia , Belgium , and Hungary source around half their power from nuclear. Japan , which previously depended on nuclear for over a quarter of its electricity,

1920-427: A small enough volume to become supercritical. Most reactors require continuous temperature control to prevent a core meltdown , which has occurred on a few occasions through accident or natural disaster, releasing radiation and making the surrounding area uninhabitable. Plants must be defended against theft of nuclear material and attack by enemy military planes or missiles. The most serious accidents to date have been

2016-482: A three-year research study of offshore floating nuclear power generation. In October 2022, NuScale Power and Canadian company Prodigy announced a joint project to bring a North American small modular reactor based floating plant to market. The economics of nuclear power plants is a controversial subject, and multibillion-dollar investments ride on the choice of an energy source. Nuclear power stations typically have high capital costs, but low direct fuel costs, with

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2112-580: A worldwide perspective, long-term waste storage costs are uncertain. Construction, or capital cost aside, measures to mitigate global warming such as a carbon tax or carbon emissions trading , increasingly favor the economics of nuclear power. Further efficiencies are hoped to be achieved through more advanced reactor designs, Generation III reactors promise to be at least 17% more fuel efficient, and have lower capital costs, while Generation IV reactors promise further gains in fuel efficiency and significant reductions in nuclear waste. In Eastern Europe,

2208-424: Is about 1/3 of solar and 1/45 of natural gas and 1/75 of coal . Newer models, like HPR1000 , produce even less carbon dioxide during the whole operating life, as little as 1/8 of power plants using gen II reactors for 1.31g/kWh. Constellation Energy The company was known as Constellation Energy Group (former NYSE ticker symbol CEG), a Fortune 500 company and one of the largest electricity producers in

2304-464: Is anticipated to resume similar levels of nuclear energy utilization. Over the last 15 years, the United States has seen a significant improvement in the operational performance of its nuclear power plants, enhancing their utilization and efficiency, adding the output equivalent to 19 new 1000 MWe reactors without actual construction. In France, nuclear power plants still produce over sixty percent of this country's total power generation in 2022. While

2400-503: Is being designed to last 100 years. One of the major limiting wear factors is the deterioration of the reactor's pressure vessel under the action of neutron bombardment, however in 2018 Rosatom announced it had developed a thermal annealing technique for reactor pressure vessels which ameliorates radiation damage and extends service life by between 15 and 30 years. Nuclear stations are used primarily for base load because of economic considerations. The fuel cost of operations for

2496-650: Is estimated at $ 918 million. On September 20, 2024, citing a resurgence in the need for nuclear generated carbon free electricity, Constellation Energy announced plans to reopen Three Mile Island Unit 1 in 2028. It will be renamed the Christopher M. Crane Clean Energy Center, in honor of former Exelon Corporation CEO Chris Crane. Crane, who started his career in nuclear energy as a Reactor Operator with ComEd , retired from Exelon in December 2022 and died on April 13, 2024. As part of this plan, Microsoft entered into

2592-431: Is found in two different isotopes : uranium-238 (U-238), accounting for 99.3% and uranium-235 (U-235) accounting for about 0.7%. U-238 has 146 neutrons and U-235 has 143 neutrons. Different isotopes have different behaviors. For instance, U-235 is fissile which means that it is easily split and gives off a lot of energy making it ideal for nuclear energy. On the other hand, U-238 does not have that property despite it being

2688-590: Is the United States' leading nuclear power plant operator, with over 19,000 megawatts. Constellation owns and operates a portfolio of fossil fuel and other sources generating more than 12,000 megawatts (MW) of power. Constellation's two hydroelectric plants generate 1,600 MW of power. Constellation has 27 wind projects in ten states, totaling nearly 1,400 megawatts (MW). Constellation owns Constellation Generation Solutions (CGS). CGS functions as an industry-leading maintenance and technical services organization emphasizing precision and quality, structured to streamline

2784-429: Is the only nuclear facility that does not use a natural body of water for cooling, instead it uses treated sewage from the greater Phoenix metropolitan area. The water coming from the cooling body of water is either pumped back to the water source at a warmer temperature or returns to a cooling tower where it either cools for more uses or evaporates into water vapor that rises out the top of the tower. The water level in

2880-489: The BWR , the steam is directed into the suppression chamber and condenses there. The chambers on a heat exchanger are connected to the intermediate cooling circuit. The main condenser is a large cross-flow shell and tube heat exchanger that takes wet vapor, a mixture of liquid water and steam at saturation conditions, from the turbine-generator exhaust and condenses it back into sub-cooled liquid water so it can be pumped back to

2976-719: The Criterion Wind Project in Garrett County, Maryland , and to purchase 28 Clipper Liberty 2.5-MW wind turbines for the project. Construction was completed in December 2010. In May 2010, the firm acquired two natural gas combined-cycle generation facilities in Texas from Houston-based Navasota Holdings. The $ 365 million transaction included the Colorado Bend Energy Center, a 550-MW facility near Wharton, Texas, and Quail Run Energy Center,

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3072-759: The European Pressurized Reactor (EPR) in the United States. On December 19, 2005, FPL Group, Inc. announced the acquisition of Constellation Energy in a merger transaction valued at more than $ 11 billion, as well as the fact that it would adopt Constellation Energy as its name for the post-merger entity. The merger was canceled on October 25, 2006. In July 2008, Constellation Energy bought uranium trading firm Nufcor International from AngloGold Ashanti and FirstRand International . On September 15, 2008, after reports that Constellation had exposure to Lehman Brothers following that firm's bankruptcy filing, Constellation's stock price dropped 56% in

3168-496: The Russian invasion of Ukraine . Meanwhile, China continues to advance in nuclear energy: having 25 reactors under construction by late 2023, China is the country with the most reactors being built at one time in the world. Nuclear decommissioning is the dismantling of a nuclear power station and decontamination of the site to a state no longer requiring protection from radiation for the general public. The main difference from

3264-801: The Soviet Union . The world's first full scale power station, Calder Hall in the United Kingdom , opened on October 17, 1956 and was also meant to produce plutonium . The world's first full scale power station solely devoted to electricity production was the Shippingport Atomic Power Station in Pennsylvania , United States, which was connected to the grid on December 18, 1957. The conversion to electrical energy takes place indirectly, as in conventional thermal power stations. The fission in

3360-575: The Toys-R-Us distribution center in Flanders, New Jersey, what was then the largest rooftop solar array ever constructed. In March 2014, it agreed to acquire ETC ProLiance Energy, a supplier of natural gas to customers in several states. In November 2014, it completed its acquisition of Integrys Energy Services, a competitive retail electricity and natural gas subsidiary serving customers in 22 states. In September 2016, it completed its acquisition of

3456-678: The UAE launched the Arab region's first-ever nuclear energy plant. Unit 1 of the Barakah plant in the Al Dhafrah region of Abu Dhabi commenced generating heat on the first day of its launch, while the remaining 3 Units are being built. However, Nuclear Consulting Group head, Paul Dorfman, warned the Gulf nation's investment into the plant as a risk "further destabilizing the volatile Gulf region, damaging

3552-424: The 1970s and 1980s, when it "reached an intensity unprecedented in the history of technology controversies," in some countries. Proponents argue that nuclear power is a sustainable energy source which reduces carbon emissions and can increase energy security if its use supplants a dependence on imported fuels. Proponents advance the notion that nuclear power produces virtually no air pollution, in contrast to

3648-485: The 1979 Three Mile Island accident , the 1986 Chernobyl disaster , and the 2011 Fukushima Daiichi nuclear disaster , corresponding to the beginning of the operation of generation II reactors . Professor of sociology Charles Perrow states that multiple and unexpected failures are built into society's complex and tightly coupled nuclear reactor systems. Such accidents are unavoidable and cannot be designed around. An interdisciplinary team from MIT has estimated that given

3744-572: The Brussels supplementary convention, and the Vienna Convention on Civil Liability for Nuclear Damage . However states with a majority of the world's nuclear power stations, including the U.S., Russia, China and Japan, are not party to international nuclear liability conventions. The nuclear power debate about the deployment and use of nuclear fission reactors to generate electricity from nuclear fuel for civilian purposes peaked during

3840-547: The NRC placed all of the nation's nuclear power plants into the highest level of security. United Flight 93 crashed into a field (present-day Flight 93 National Memorial ) about 135 miles (217 km) west of Three Mile Island in Stonycreek Township , just outside Shanksville, Pennsylvania , with its actual target believed to have been Washington, D.C. On November 21, 2009, a release of radioactivity occurred inside

3936-480: The NRC. Exelon was operating Unit 1 at a financial loss since 2015. In 2017, the company said it would consider ceasing operations at Unit 1 because of high costs unless there was action from the Pennsylvania government. Unit 1 officially shut down at noon on September 20, 2019. Unit 1 decommissioning was expected to be completed in 2079 and would have cost $ 1.2 billion, but in September 2024, Constellation Energy,

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4032-520: The StarTex brand was discontinued; Constellation served its existing customers instead. In May 2011, the company acquired MXenergy, a residential and small business energy provider with approximately half a million customers. In December 2011, it announced the acquisition of ONEOK Energy Marketing Co., a natural gas company with customers in the Midwest. In 2011, it contracted to construct and operate for

4128-583: The TMI nuclear plant, then broke through an entry gate. He eventually crashed the car through a secure door and entered the Unit 1 turbine building. The intruder, who had a history of mental illness, hid in the turbine building and was apprehended after four hours. During and following the September 11, 2001 attacks , there was a concern that United Airlines Flight 93 was headed towards Three Mile Island. On that day,

4224-548: The United States, including Maryland, California, Arizona, New Jersey, and Texas. In 2011, Constellation was contracted to construct and operate what was then the largest rooftop solar array ever constructed for the Toys-R-Us distribution center in Flanders, New Jersey. The company's offsite renewables service (CORe) provides access to offsite renewable energy projects through a retail power contract. CORe combines location-specific renewable energy purchases and certificates with

4320-402: The United States, until a merger with Exelon in 2012. When FERC approved the acquisition, Constellation Energy's energy supply business was re-branded as Constellation, an Exelon company. As part of the 2012 merger, Baltimore Gas and Electric , the regulated utility operated by Constellation Energy, became a regulated utility operating under Exelon Utilities. The current iteration of the company

4416-475: The United States. The China Syndrome , a movie about a nuclear disaster, which was released 12 days before the incident and received a glowing reception from the movie-going public, became a blockbuster hit. On January 22, 2010, officials at the NRC announced the electrical generator from the damaged Unit 2 reactor at TMI will be used at Shearon Harris Nuclear Plant in New Hill, North Carolina. The generator

4512-516: The accident in 1979, is expected to close in 2052. The NRC defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 10 miles (16 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination , and an ingestion pathway zone of about 50 miles (80 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity. The 2010 U.S. population within 10 miles (16 km) of Three Mile Island

4608-595: The average price of electricity in the area was $ 39/MWh. On June 20, 2017, Exelon Generation, the owners of Three Mile Island's Unit 1, sent to the Nuclear Regulatory Commission a formal notice of its intention to shut down the plant on September 30, 2019, unless the Pennsylvania legislature rescued the nuclear industry, which was struggling to compete as newfound natural gas resources drove down electricity prices. Exelon Generation's Senior Vice President Bryan Hanson noted that once Three Mile Island

4704-557: The chief viable alternative of fossil fuel. Proponents also believe that nuclear power is the only viable course to achieve energy independence for most Western countries. They emphasize that the risks of storing waste are small and can be further reduced by using the latest technology in newer reactors, and the operational safety record in the Western world is excellent when compared to the other major kinds of power plants. Opponents say that nuclear power poses many threats to people and

4800-414: The containment building of TMI-1 while workers were cutting pipes. Exelon Corporation stated to the public that "A monitor at the temporary opening cut into the containment building wall to allow the new steam generators to be moved inside showed a slight increase in a reading and then returned to normal. Approximately 20 employees were treated for mild radiation exposure." As of November 22, 2009, it

4896-493: The costs of fuel extraction, processing, use and spent fuel storage internalized costs. Therefore, comparison with other power generation methods is strongly dependent on assumptions about construction timescales and capital financing for nuclear stations. Cost estimates take into account station decommissioning and nuclear waste storage or recycling costs in the United States due to the Price Anderson Act . With

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4992-412: The deal on December 17, 2008, in favor of a $ 4.5 billion buyout from French power company Electricite de France (EDF) . In January 2009, Constellation Energy announced it would sell the majority of its London-based international commodities business to an affiliate of Goldman Sachs for an undisclosed price. In April 2010, Constellation Energy closed its agreement with Clipper Windpower to acquire

5088-424: The destruction of a turbine in operation from flying towards the reactor. In the case of a pressurized water reactor, the steam turbine is separated from the nuclear system. To detect a leak in the steam generator and thus the passage of radioactive water at an early stage, an activity meter is mounted to track the outlet steam of the steam generator. In contrast, boiling water reactors pass radioactive water through

5184-413: The direct ownership and operation of its Exelon Nuclear business unit. According to Exelon Corporation, "many people are surprised when they learn that Three Mile Island is still making electricity, enough to power 800,000 households" from its undamaged and fully functional reactor unit 1. Exelon viewed the plant's economics of $ 44/MWh as challenging due to the low price of natural gas at $ 25/MWh. As of 2016,

5280-458: The dismantling of other power stations is the presence of radioactive material that requires special precautions to remove and safely relocate to a waste repository. Decommissioning involves many administrative and technical actions. It includes all clean-up of radioactivity and progressive demolition of the station. Once a facility is decommissioned, there should no longer be any danger of a radioactive accident or to any persons visiting it. After

5376-534: The energy-intensive stages of the nuclear fuel chain are considered, from uranium mining to nuclear decommissioning , nuclear power is not a low-carbon electricity source despite the possibility of refinement and long-term storage being powered by a nuclear facility. Those countries that do not contain uranium mines cannot achieve energy independence through existing nuclear power technologies. Actual construction costs often exceed estimates, and spent fuel management costs are difficult to define. On 1 August 2020,

5472-402: The environment and raising the possibility of nuclear proliferation." Nuclear power plants do not produce greenhouse gases during operation. Older nuclear power plants, like ones using second-generation reactors , produce approximately the same amount of carbon dioxide during the whole life cycle of nuclear power plants for an average of about 11g/kWh, as much power generated by wind , which

5568-775: The environment, and that costs do not justify benefits. Threats include health risks and environmental damage from uranium mining , processing and transport, the risk of nuclear weapons proliferation or sabotage, and the problem of radioactive nuclear waste . Another environmental issue is discharge of hot water into the sea. The hot water modifies the environmental conditions for marine flora and fauna. They also contend that reactors themselves are enormously complex machines where many things can and do go wrong, and there have been many serious nuclear accidents . Critics do not believe that these risks can be reduced through new technology , despite rapid advancements in containment procedures and storage methods. Opponents argue that when all

5664-411: The environment. In addition, many reactors are equipped with a dome of concrete to protect the reactor against both internal casualties and external impacts. The purpose of the steam turbine is to convert the heat contained in steam into mechanical energy. The engine house with the steam turbine is usually structurally separated from the main reactor building. It is aligned so as to prevent debris from

5760-490: The especially hazardous iodine-131 (with a half life of around 8 days), into the surrounding environment. Nearly 2 million people were exposed to radiation from the accident. A review by the World Nuclear Association concluded that no deaths, injuries or adverse health effects resulted from the accident, and a report by Columbia University epidemiologist Maureen Hatch confirmed this finding. Because of

5856-525: The expected growth of nuclear power from 2005 to 2055, at least four serious nuclear accidents would be expected in that period. The MIT study does not take into account improvements in safety since 1970. Nuclear power works under an insurance framework that limits or structures accident liabilities in accordance with the Paris Convention on Third Party Liability in the Field of Nuclear Energy ,

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5952-487: The health concerns, the Pennsylvania Department of Health kept a registry of more than 30,000 people that lived within 5 miles (8.0 km) of TMI at the time of the accident. The registry was kept for nearly 20 years until 1997, when no evidence was found of unusual health effects. Further epidemiology studies have not shown any increase in cancer as a result of the accident. However, almost $ 25 million

6048-406: The hot coolant is used as a heat source for a boiler, and the pressurized steam from that drives one or more steam turbine driven electrical generators . In the event of an emergency, safety valves can be used to prevent pipes from bursting or the reactor from exploding. The valves are designed so that they can derive all of the supplied flow rates with little increase in pressure. In the case of

6144-401: The initial cleanup of the plant was completed, TMI-2 has been in a condition known as Post Defueling Monitored Storage (PDMS) and is under constant monitoring to ensure the plant's safety and stability. The remaining 1% of residual fuel that still remains at the site is planned to be removed by 2029. The cost of decommissioning a closed nuclear reactor and related structures at Three Mile Island

6240-517: The initial investments are financed. Because of this high construction cost and lower operations, maintenance, and fuel costs, nuclear plants are usually used for base load generation, because this maximizes the hours over which the fixed cost of construction can be amortized. Nuclear power plants have a carbon footprint comparable to that of renewable energy such as solar farms and wind farms , and much lower than fossil fuels such as natural gas and coal . Nuclear power plants are among

6336-460: The injury was work-related, and the contractor was outside the radiological controlled area. The Three Mile Island Unit 2 was also a pressurized water reactor constructed by B&W, similar to Unit 1. TMI-2 was slightly larger with a net generating capacity of 906 MW e , compared to TMI-1, which delivered 819 MW e . Unit 2 received its operating license on February 8, 1978, and began commercial operation on December 30, 1978. TMI Unit 2

6432-529: The need to spend more on redundant back up safety equipment. According to the World Nuclear Association , as of March 2020: The Russian state nuclear company Rosatom is the largest player in international nuclear power market, building nuclear plants around the world. Whereas Russian oil and gas were subject to international sanctions after the Russian full-scale invasion of Ukraine in February 2022, Rosatom

6528-483: The now decommissioned German Biblis Nuclear Power Plant was designed to modulate its output 15% per minute between 40% and 100% of its nominal power. Russia has led in the practical development of floating nuclear power stations , which can be transported to the desired location and occasionally relocated or moved for easier decommissioning. In 2022, the United States Department of Energy funded

6624-470: The owner of the Unit, announced plans to invest $ 1.6 billion to bring the facility back online. The plant is expected to resume operations in 2028. The entirety of the plant's energy output will be sold to Microsoft Corporation . Microsoft entered into a 20-year agreement to purchase as much electricity as possible from the plant, which will support the company’s growing energy needs for its expanding network of data centers. Unit 2, which has been dormant since

6720-474: The prospect that all spent nuclear fuel could potentially be recycled by using future reactors, generation IV reactors are being designed to completely close the nuclear fuel cycle . However, up to now, there has not been any actual bulk recycling of waste from a NPP, and on-site temporary storage is still being used at almost all plant sites due to construction problems for deep geological repositories . Only Finland has stable repository plans, therefore from

6816-427: The reactor by the condensate and feedwater pumps. In the main condenser, the wet vapor turbine exhaust come into contact with thousands of tubes that have much colder water flowing through them on the other side. The cooling water typically come from a natural body of water such as a river or lake. Palo Verde Nuclear Generating Station , located in the desert about 97 kilometres (60 mi) west of Phoenix, Arizona,

6912-405: The reactor. TMI-1 was shut down on September 20, 2019, but may be brought back. The CEO of Constellation Energy , the owner of Unit 1, says the reactor is in "excellent shape," and estimated that it would go online within three years of committing to a restart. As of 2024 Constellation is conducting tests for a potential decision to reopen. In February 1993, a man drove his car past a checkpoint at

7008-503: The retail electricity and natural gas business from ConEdison Solutions, a subsidiary of Consolidated Edison , Inc. In the purchase, Constellation acquired ConEdison's retail electricity and natural gas customer contracts and associated supply contracts serving approximately 15 TWh of electricity and 1 billion cubic feet per annum (28,000,000 m /a) of natural gas to more than 560,000 commercial, industrial, public sector and residential customers. In August 2018, it began constructing

7104-540: The risks of future uncertainties. To date all operating nuclear power stations were developed by state-owned or regulated utilities where many of the risks associated with construction costs, operating performance, fuel price, and other factors were borne by consumers rather than suppliers. Many countries have now liberalized the electricity market where these risks and the risk of cheaper competitors emerging before capital costs are recovered, are borne by station suppliers and operators rather than consumers, which leads to

7200-660: The safest modes of electricity generation, comparable to solar and wind power plants. The first time that heat from a nuclear reactor was used to generate electricity was on December 21, 1951, at the Experimental Breeder Reactor I , powering four light bulbs. On June 27, 1954, the world's first nuclear power station to generate electricity for a power grid , the Obninsk Nuclear Power Plant , commenced operations in Obninsk , in

7296-407: The same element. Different isotopes also have different half-lives . U-238 has a longer half-life than U-235, so it takes longer to decay over time. This also means that U-238 is less radioactive than U-235. Since nuclear fission creates radioactivity, the reactor core is surrounded by a protective shield. This containment absorbs radiation and prevents radioactive material from being released into

7392-660: The site, but the site has not been fully decommissioned. In July 1998, Amergen Energy (now Exelon Generation) agreed to purchase TMI-1 from General Public Utilities for $ 100 million. The plant was originally built by General Public Utilities Corporation , later renamed GPU Incorporated. The plant was operated by Metropolitan Edison Company (Met-Ed), a subsidiary of the GPU Energy division. In 2001, GPU Inc. merged with FirstEnergy Corporation . On December 18, 2020, FirstEnergy transferred Unit 2's license to EnergySolutions ' subsidiary, TMI-2 Solutions, after receiving approval from

7488-693: The steam generator and the nuclear reactor is controlled using the feedwater system. The feedwater pump has the task of taking the water from the condensate system, increasing the pressure and forcing it into either the steam generators—in the case of a pressurized water reactor — or directly into the reactor, for boiling water reactors . Continuous power supply to the plant is critical to ensure safe operation. Most nuclear stations require at least two distinct sources of offsite power for redundancy. These are usually provided by multiple transformers that are sufficiently separated and can receive power from multiple transmission lines. In addition, in some nuclear stations,

7584-487: The steam turbine, so the turbine is kept as part of the radiologically controlled area of the nuclear power station. The electric generator converts mechanical power supplied by the turbine into electrical power. Low-pole AC synchronous generators of high rated power are used. A cooling system removes heat from the reactor core and transports it to another area of the station, where the thermal energy can be harnessed to produce electricity or to do other useful work. Typically

7680-418: The total electricity generated in Pennsylvania (83.5 TWh nuclear of 215 TWh total), with Three Mile Island Generating Station contributing approximately 4% to the statewide total generation. In 2021 electrical generating facilities in the state of Pennsylvania generated approximately 241 TWh total electricity. The Three Mile Island Unit 1 is a pressurized water reactor designed by Babcock & Wilcox with

7776-477: The turbine generator can power the station's loads while the station is online, without requiring external power. This is achieved via station service transformers which tap power from the generator output before they reach the step-up transformer. Nuclear power plants generate approximately 10% of global electricity, sourced from around 440 reactors worldwide. They are recognized as a significant provider of low-carbon electricity , accounting for about one-quarter of

7872-641: The urgent demands of our nation's nuclear facilities, power grids, and critical supply chains. Constellation owns the archives of the Baltimore Gas & Electric Company, the former Consolidated Gas Light, Electric Power Company of Baltimore City, and its ancient predecessor, the Gas Light Company of Baltimore. The Baltimore Gas & Electric Company's photographic collection consists of approximately 250,000 photographic prints and negatives, in more than 50,000 series The archives are held by

7968-443: The ventilation system to prevent future air pressure changes. Work continued on the project the following day. On January 24, 2010, TMI-1 was brought back online. On September 10, 2021, a contractor from Alabama was fatally injured while unloading equipment from a truck. Fire and emergency medical personnel from Londonderry Township were dispatched and declared the contractor dead on arrival . The Nuclear Regulatory Commission said

8064-494: The work execution of the nuclear fleet. Constellation PowerLabs is a wholly owned subsidiary of Constellation. Since 1911, PowerLabs has transformed from supporting the power industry to becoming Exelon's primary calibrations and testing laboratory. It has four individual labs strategically located from the upper Midwest to the Northeast, enabling experienced staff in engineering, metrology, and nuclear power generation to support

8160-459: The world's supply in this category. As of 2020, nuclear power stood as the second-largest source of low-carbon energy, making up 26% of the total. Nuclear power facilities are active in 32 countries or regions, and their influence extends beyond these nations through regional transmission grids, especially in Europe. In 2022, nuclear power plants generated 2545 terawatt-hours (TWh) of electricity,

8256-473: Was 1 in 25,000, according to an NRC study published in August 2010. Nuclear power plant A nuclear power plant ( NPP ), also known as a nuclear power station ( NPS ), nuclear generating station ( NGS ) or atomic power station ( APS ) is a thermal power station in which the heat source is a nuclear reactor . As is typical of thermal power stations, heat is used to generate steam that drives

8352-534: Was 211,261, an increase of 10.9 percent in a decade, according to an analysis of U.S. Census data. The 2010 U.S. population within 50 miles (80 km) was 2,803,322, an increase of 10.3 percent since 2000. Cities within 50 miles include Harrisburg (12 miles to city center), York (13 miles to city center), and Lancaster (24 miles to city center). During its last full year of operation in 2018, Three Mile Island generated 7,355 GWh of electricity. In that same year, electricity from nuclear power produced approximately 39% of

8448-544: Was believed that no radiation escaped the containment building and the public was not in any danger. The inside airborne contamination was caused by a change in air pressure inside the containment building that dislodged small irradiated particles in the reactor piping system. Some of the particles became airborne inside the building and were detected by an array of monitors in place to detect such material. The air pressure change occurred when inside building ventilation fans were started to support outage activities. The site modified

8544-410: Was brought back online on October 9, 1985, after public opposition, several federal court injunctions, and some technical and regulatory complications – more than six years after it initially went offline. Unit 1 was scheduled to be shut down by September 2019 after Exelon announced they did not receive any commitments for subsidies from the state, rendering Exelon unable to financially continue operating

8640-563: Was closed, it could never be reopened for use again. Hanson explicitly stated the reason for the shutdown is because of the unprofitability of Unit 1. Unit 1 has lost the company over $ 300 million over the last half-decade despite it being one of Exelon's best-performing power plants. About 70 state legislators signed the industry-inspired Nuclear Caucus but made no financial commitments. In April 2019, Exelon stated it would cost $ 1.2 billion over nearly 60 years to completely decommission Unit 1. Unit 1 closed on September 20, 2019. In 2022, Unit 1

8736-437: Was founded in 2022 after splitting off from Exelon . Before merging with Exelon, Constellation Energy Group operated more than 35 power plants in 11 states (mainly Maryland, Pennsylvania, New York, West Virginia, and California). Baltimore Gas and Electric created Constellation as a holding company in 1999. On September 15, 2005, Constellation Energy announced a joint venture, UniStar Nuclear, with Areva to market

8832-477: Was not targeted by sanctions. However, some countries, especially in Europe, scaled back or cancelled planned nuclear power plants that were to be built by Rosatom. Modern nuclear reactor designs have had numerous safety improvements since the first-generation nuclear reactors. A nuclear power plant cannot explode like a nuclear weapon because the fuel for uranium reactors is not enriched enough, and nuclear weapons require precision explosives to force fuel into

8928-562: Was paid in insurance settlements to people who then agreed not to discuss their injuries in ongoing litigation. Unit 2 has not been operational since the accident occurred. The New York Times reported on August 14, 1993, 14 years after the accident, that the cleanup had finished. According to the United States NRC, 2.3 million gallons of waste water had been removed. The incident was widely publicized internationally, and had far-reaching effects on public opinion, particularly in

9024-468: Was permanently shut off after the Three Mile Island accident in 1979. On March 28, 1979, a cooling system malfunction caused a partial meltdown of the reactor core . This loss-of-coolant accident resulted in the release of an estimated 43,000 curies (1.59  PBq ) of radioactive krypton-85 gas (with an approximate half life of 11 years), and less than 20 curies (740 GBq) of

9120-560: Was transferred to Constellation Energy following separation from Exelon. Unit 2 was also transferred to TriArtisan ES Partners, LLC – following their acquisition of EnergySolutions . Following the TMI-2 accident in 1979, approximately 99% of the fuel and damaged core debris was removed from the reactor vessel and associated systems and shipped to the Idaho National Laboratory near Idaho Falls, Idaho . Since 1993, when

9216-683: Was transported in two parts, weighing a combined 670 tons. It was refurbished and installed during a refueling outage at Shearon Harris NPP in November 2010. Exelon Corporation was created in October 2000 by the merger of PECO Energy Company and Unicom, of Philadelphia , Pennsylvania and Chicago, Illinois respectively. Unicom owned Commonwealth Edison . The PECO share in AmerGen was acquired by Exelon during late 2000. Exelon acquired British Energy's share in AmerGen in 2003, and transferred Unit 1 under

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