|Three Mile Island Nuclear Generating Station|
|Location||Londonderry Township, Dauphin County, Pennsylvania|
|Construction began||Unit 1: May 18, 1968|
Unit 2: November 1, 1969
|Commission date||Unit 1: September 2, 1974|
Unit 2: December 30, 1978
|Decommission date||Unit 1: September 20, 2019|
Unit 2: March 28, 1979
|Construction cost||$1.557 billion (2007 USD) |
($2.00 billion in 2019 dollars )
|Owner(s)||Unit 1: Exelon |
Unit 2: FirstEnergy
|Nuclear power station|
|Reactor supplier||Babcock & Wilcox|
|Cooling towers||4 × Natural Draft|
|Cooling source||Susquehanna River|
|Thermal capacity||1 × 2568 MWth|
|Units operational||1 × 819 MW|
|Make and model||B&W LLP (DRYAMB)|
|Units decommissioned||1 × 880 MW|
|Nameplate capacity||819 MW|
|Capacity factor||95.65% (2017)|
|Annual net output||6862 GWh (2017)|
|Website||Three Mile Island|
|Commons||Related media on Commons|
Three Mile Island Nuclear Generating Station (TMI) is a closed nuclear power plant on Three Mile Island in Londonderry Township, Pennsylvania, on the Susquehanna River just south of Harrisburg. It had two separate units, TMI-1 (owned by Exelon Generation) and TMI-2 (owned by FirstEnergy Corp).The plant was the site of the most significant accident in United States commercial nuclear energy when, on March 28, 1979, TMI-2 suffered a partial meltdown. According to the Nuclear Regulatory Commission (NRC) report, the accident resulted in no deaths or injuries to plant workers or in nearby communities. Follow-up epidemiology studies have linked no incidents of cancer to the accident.
The reactor core of TMI-2 has since been removed from the site, but the site has not been decommissioned.In July 1998, Amergen Energy (now Exelon Generation) agreed to purchase TMI-1 from General Public Utilities for $100 million.
It is named Three Mile Island because it is located three miles downriver from Middletown, Pennsylvania.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. During 2001, GPU Inc. merged with FirstEnergy Corporation.
Exelon was operating Unit 1 at Three Mile Island at a loss since 2015. [ further explanation needed ] it shut down in 2019.In 2017 the company said it would consider ceasing operations at Unit 1 because of high costs unless there was government action;
Unit 2, which has been dormant since the accident in 1979, is still owned by FirstEnergy, and it is estimated to close in 2037.
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 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).
The Three Mile Island Unit 1 is a pressurized water reactor designed by Babcock & Wilcox with a net generating capacity of 819 MWe. The initial construction cost for TMI-1 was US$400 million, equal to $2.10 billion in 2018 dollars. Unit 1 first came online on April 19, 1974, and began commercial operations on September 2, 1974. TMI-1 is 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 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 towers. Once-through cooling with river water is used for the service water system which cools auxiliary components and removed decay heat when the reactor was shut down. When TMI-2 suffered its accident in 1979, TMI-1 was offline for refueling. It was brought back online in October 1985, after public opposition, several federal court injunctions, and some technical and regulatory complications.
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 continue operating the reactor.TMI-1 was shut down on September 20, 2019.
In February 1993, a man drove his car past a checkpoint at 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.
On November 21, 2009, a release of radioactivity occurred inside 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 [update] , it was believed that no radiation escaped the containment building and the public was not in any danger.[ citation needed ] 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 small 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 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.
The Three Mile Island Unit 2 was also a pressurized water reactor constructed by B&W, similar to Unit 1. The only difference was that TMI-2 was slightly larger with a net generating capacity of 906 MWe, compared to TMI-1, which delivers 819 MWe. Unit 2 received its operating license on February 8, 1978, and began commercial operation on December 30, 1978. TMI Unit 2 has been permanently shut off after the Three Mile Island accident in 1979.
On March 28, 1979, there was a cooling system malfunction that caused a partial meltdown of the reactor core. This loss-of-coolant accident resulted in the release of an amount of radioactivity, estimated at 43,000 curies (1.59 PBq) of radioactive krypton-85 gas (half life 10 yrs), but less than 20 curies (740 GBq) of the especially hazardous iodine-131 (half life 8 days), into the surrounding environment.
Nearly 2 million people were exposed to a small amount of 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 the health concerns, the Pennsylvania Department of Health kept a registry of more than 30,000 people that lived within 5 miles 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 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 been 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 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 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. TMI's Unit 2 reactor has been shut down since the partial meltdown in 1979.
Exelon Corporation was created in October 2000 by the merger of PECO Energy Company and Unicom, of Philadelphia and Chicago 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 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, 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 rescues the nuclear industry, which is as of 2017 struggling to compete as newfound natural gas resources have driven down electricity prices. Exelon Generation's Senior Vice President Bryan Hanson noted that once Three Mile Island 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 dollars over the last half-decade despite it being one of Exelon's best-performing power plants.
Shut down of Unit 1 can go in two possible directions, the first being the immediate dismantlement immediately after the radioactive fuel has been moved away from the plant. The dismantlement can proceed after the spent fuel is removed from the pool, put into storage casks, and the casks are transferred to the ISFSI pad for storage until the DOE takes them away to a DOE repository. Dismantling the plant this way will take anywhere from 8 to 10 years.The second option Exelon could take is the long-term storage, which involves mothballing the plant and letting the radiation decay for up to 60 years on its own to a harmless level before completely dismantling the buildings. The advantage to the long-term storage is the lack of radiation when the dismantlement would begin but the disadvantage would be the possible lack of qualified workers at the time of dismantlement. Exelon would also have to pay for limited maintenance and security of the plant over the potential sixty years. The entirety of the spent fuel will be moved to the Londonderry Township facility, which is another process that could take decades to complete.
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.
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 was 1 in 25,000, according to an NRC study published in August 2010.
The Three Mile Island accident was a partial meltdown of reactor number 2 of Three Mile Island Nuclear Generating Station (TMI-2) in Dauphin County, Pennsylvania, near Harrisburg, and subsequent radiation leak that occurred on March 28, 1979. It is the most significant accident in U.S. commercial nuclear power plant history. On the seven-point International Nuclear Event Scale, the incident was rated a five as an "accident with wider consequences."
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The Robert Emmett Ginna Nuclear Power Plant, commonly known as Ginna, is a nuclear power plant located on the southern shore of Lake Ontario, in the town of Ontario, Wayne County, New York, approximately 20 miles (32 km) east of Rochester, New York. It is a single unit Westinghouse 2-Loop pressurized water reactor, similar to those at Point Beach, Kewaunee, and Prairie Island. Having gone into commercial operation in 1970, Ginna became the second oldest nuclear power reactor, after Nine Mile unit 1, still in operation in the United States when the Oyster Creek power plant was permanently shut down on September 17, 2018.
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The Prairie Island Nuclear Generating Plant is an electricity-generating facility located in Red Wing, Minnesota along the Mississippi River, and adjacent to the Prairie Island Indian Community reservation.
Nine Mile Point Nuclear Station is a nuclear power plant with two nuclear reactors located in the town of Scriba, approximately five miles northeast of Oswego, New York, on the shore of Lake Ontario. The 900-acre (360 ha) site is also occupied by the James A. FitzPatrick Nuclear Power Plant.
Zion Nuclear Power Station was the third dual-reactor nuclear power plant in the Commonwealth Edison (ComEd) network and served Chicago and the northern quarter of Illinois. The plant was built in 1973, and the first unit started producing power in December 1973. The second unit came online in September 1974. This power generating station is located on 257 acres (104 ha) of Lake Michigan shoreline, in the city of Zion, Lake County, Illinois. It is approximately 40 direct-line miles north of Chicago, Illinois and 42 miles (68 km) south of Milwaukee, Wisconsin.
The Clinton Power Station is a nuclear power plant located near Clinton, Illinois, USA. The power station began commercial operation on November 24, 1987 and has a nominal net electric output of 1062 MWe. Due to inflation and cost overruns, Clinton's final construction cost was $4.25 billion, nearly 1,000% over the original budget of $430 million and seven years behind schedule.
LaSalle County Nuclear Generating Station, located in Brookfield Township, LaSalle County, Illinois, near Marseilles, 11 miles (18 km) southeast of Ottawa, serves Chicago and Northern Illinois with electricity. The plant is owned and operated by the Exelon Corporation. Its Units 1 and 2 began commercial operation in October 1982, and October 1984, respectively.
Quad Cities Generating Station is a two-unit nuclear power plant located near Cordova, Illinois, United States, on the Mississippi River. The two General Electric boiling water reactors give the plant a total gross electric capacity of approximately 1,880 MW. It was named for the nearby cities of Moline, Illinois, Rock Island, Illinois, Davenport, Iowa, East Moline, Illinois, and Bettendorf, Iowa — known as the Quad Cities.
Nuclear power in the United States is provided by 93 commercial reactors with a net capacity of 95.5 gigawatts (GW), with 62 pressurized water reactors and 31 boiling water reactors. In 2019, they produced a total of 809.41 terawatt-hours of electricity, which accounted for 20% of the nation's total electric energy generation. In 2018, nuclear comprised nearly 50 percent of U.S. emission-free energy generation.
Nuclear decommissioning is the process whereby a nuclear facility is dismantled to the point that it no longer requires measures for radiation protection. The presence of radioactive material necessitates processes that are potentially occupationally hazardous, expensive, time-intensive, and present environmental risks that must be addressed to ensure radioactive materials are either transported elsewhere for storage or stored on-site in a safe manner. The challenge in nuclear decommissioning is not just technical, but also economical and social.
The United States Government Accountability Office reported more than 150 incidents from 2001 to 2006 of nuclear plants not performing within acceptable safety guidelines. According to a 2010 survey of energy accidents, there have been at least 56 accidents at nuclear reactors in the United States. The most serious of these was the Three Mile Island accident in 1979. Davis-Besse Nuclear Power Plant has been the source of two of the top five most dangerous nuclear incidents in the United States since 1979. Relatively few accidents have involved fatalities.
Nuclear power plants pose high risk if chemicals are exposed to those in surrounding communities and areas. This nuclear emergency level classificationresponse system was firstly developed by the US Nuclear Regulatory Commission to allow effective and urgent responses to ultimately control and minimise any detrimental effects that nuclear chemicals can have. These classifications come in four different categories – Unusual Event, Alert, Site Area Emergency (SAE), as well as General Emergency. Thus, each classification has differing characteristics and purposes, depending on the situation at hand. Every nuclear power plant has a different emergency response action plan, also depending on its structure, location and nature. They were developed by thorough discussion and planning with numerous authoritative parties such as local, state, federal agencies as well as other private and non-profit groups that are in association with emergency services. Today, nuclear emergency plans are continuously being developed over time to be improved for future serious events to keep communities and nuclear power plant working members safe. There is a high emphasis for the need of these emergency responses in case of future events. Thus, nuclear plants can, and have paid up to approximately $78 million to ensure that are required measurements are readily available, and that equipment is sufficient and safe. This is applicable for all nuclear power plants in the United States of America.
Nuclear power has been widely established in Pennsylvania since the 1950s, and has grown to provide almost 25% of the energy produced in PA. This is achieved through the four active reactors currently operating. There are five inactive reactors in PA, including Three Mile Island, which had a partial meltdown and caused a reevaluation of nuclear reactor safety practices.
Thyroid cancer incidence has not increased in Dauphin County, the county in which TMI is located. York County demonstrated a trend toward increasing thyroid cancer incidence beginning in 1995, approximately 15 years after the TMI accident. Lancaster County showed a significant increase in thyroid cancer incidence beginning in 1990. These findings, however, do not provide a causal link to the TMI accident.
unless the government intervenes to keep the plant running, the notorious facility's "long-term future past 2019" is in doubt.
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