Nuclear power plant

Nuclear power plant

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A nuclear power plant is a thermal power station
Thermal power station
A thermal power station is a power plant in which the prime mover is steam driven. Water is heated, turns into steam and spins a steam turbine which drives an electrical generator. After it passes through the turbine, the steam is condensed in a condenser and recycled to where it was heated; this...

 in which the heat source is one or more nuclear reactor
Nuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...

s. As in a conventional thermal power station the heat is used to generate steam which drives a steam turbine
Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....

 connected to a generator which produces electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

.

Nuclear power plants are usually considered to be base load
Base load power plant
Baseload is the minimum amount of power that a utility or distribution company must make available to its customers, or the amount of power required to meet minimum demands based on reasonable expectations of customer requirements...

 stations, which are best suited to constant power output.

History


For more history, see nuclear reactor, nuclear power and nuclear fission.

Electricity was generated for the first time ever by a nuclear reactor on December 20, 1951 at the EBR-I experimental station near Arco, Idaho
Arco, Idaho
Arco is a city in Butte County, Idaho, United States. The population was 995 at the 2010 census. The city is the county seat of Butte County.Craters of the Moon National Monument is located along U.S. Route 20, southwest of the city. The Idaho National Laboratory is located east of Arco...

 in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. On June 27, 1954, the world's first nuclear power plant to generate electricity for a power grid started operations at Obninsk
Obninsk
Obninsk is a city in Kaluga Oblast, Russia, located southwest of Moscow. Population: Obninsk is one of the major Russian science cities. The first nuclear power plant in the world for the large-scale production of electricity opened here on June 27, 1954, and it also doubled as a training...

, USSR. The world's first commercial scale power station, Calder Hall
Sellafield
Sellafield is a nuclear reprocessing site, close to the village of Seascale on the coast of the Irish Sea in Cumbria, England. The site is served by Sellafield railway station. Sellafield is an off-shoot from the original nuclear reactor site at Windscale which is currently undergoing...

 in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 opened in October 17, 1956.

Systems



This section has recently been translated from the German Wikipedia.

The conversion to electrical energy takes place indirectly, as in conventional thermal power plants: The heat is produced by fission in a nuclear reactor (in light water reactor
Light water reactor
The light water reactor is a type of thermal reactor that uses normal water as its coolant and neutron moderator. Thermal reactors are the most common type of nuclear reactor, and light water reactors are the most common type of thermal reactor...

). Directly or indirectly water vapor-steam is produced. The pressurized steam is then usually fed to a multi-stage steam turbine. Steam turbines in Western nuclear power plants are among the largest steam turbines ever. After the steam turbine has expanded and partially condensed the steam, the remaining vapor is condensed in a condenser. The condenser is a heat exchanger which is connected to secondary side such as a river or a cooling tower
Cooling tower
Cooling towers are heat removal devices used to transfer process waste heat to the atmosphere. Cooling towers may either use the evaporation of water to remove process heat and cool the working fluid to near the wet-bulb air temperature or in the case of closed circuit dry cooling towers rely...

. The water then pumped back into the nuclear reactor and the cycle begins again. The water-steam cycle corresponds to the Rankine cycle
Rankine cycle
The Rankine cycle is a cycle that converts heat into work. The heat is supplied externally to a closed loop, which usually uses water. This cycle generates about 90% of all electric power used throughout the world, including virtually all solar thermal, biomass, coal and nuclear power plants. It is...

.

Nuclear reactors



A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction
Nuclear chain reaction
A nuclear chain reaction occurs when one nuclear reaction causes an average of one or more nuclear reactions, thus leading to a self-propagating number of these reactions. The specific nuclear reaction may be the fission of heavy isotopes or the fusion of light isotopes...

. The most common use of nuclear reactors is for the generation of electric energy
Nuclear power
Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...

 and for the propulsion of ships
Nuclear marine propulsion
Nuclear marine propulsion is propulsion of a ship by a nuclear reactor. Naval nuclear propulsion is propulsion that specifically refers to naval warships...

.

The nuclear reactor is the heart of the plant. In its central part, the reactor core's heat is generated by controlled nuclear fission. With this heat, a coolant is heated as it is pumped through the reactor and thereby removes the energy from the reactor. Heat from nuclear fission is used to raise steam, which runs through turbines
Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....

, which in turn powers either ship's propellers or electrical generators.

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 the environment. In addition, many reactors are equipped with a dome of concrete to protect the reactor against external impacts.

In nuclear power plants, different types of reactors, nuclear fuels, and cooling circuits and moderators are sometimes used.

Steam turbine



The object 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 to prevent debris from the destruction of a turbine in operation from flying towards the reactor.

In the case of a pressurized water reactor, the steam turbine hermetically separated from the nuclear system. To detect a leak in the steam generator and thus the passage of radioactive water at an early stage is the outlet steam of the steam generator mounted an activity meter. In contrast, boiling water reactors and the steam turbine with radioactive water applied and therefore part of the control area of ​​the nuclear power plant.

Generator



The generator converts kinetic energy supplied by the turbine into electrical energy. Low-pole AC synchronous generators of high rated power are used.

Cooling system


A cooling system removes heat from the reactor core and transports it to another area of the plant, where the thermal energy can be harnessed to produce electricity or to do other useful work. Typically the hot coolant is used as a heat source for a boiler
Boiler
A boiler is a closed vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating applications.-Materials:...

, and the pressurized steam from that boiler powers one or more steam turbine
Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....

 driven electrical generator
Electrical generator
In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...

s.

The reactor coolant pump in the case of the DWR has the task to circulate the coolant between the reactor and steam generators. In western nuclear power plants, the nuclear reactor is fed with four redundant pumps (loops), each separated by Redundancy structurally accommodated in the reactor building. The design of the pump corresponds to a Centrifugal with a one-piece forged body. The throughput is up to 10,000 l / s at a pressure of 175 bar and a maximum allowable temperature of 350 °C. There is an increase in pressure through the main coolant pump when DWR indicates pressure loss in the reactor, steam generators and piping system. Even after the failure of the main coolant pumps (RESA is the result of) the circulation and thus the heat dissipation is by so-called Natural circulation guaranteed.

In the case of boiling water reactor, the reactor pressure vessel force circulation pumps to avoid core wings attached to their interpretation is approximately equal to those in a PWR. You are responsible for the safety of the plant is not absolutely necessary.

Besides these main coolant pump of a nuclear power plant has usually still have several emergency supplies at different pressure levels, the case of disturbances (see Design basis accident) maintain the cooling of the reactor core.

Safety valves



In the event of an emergency, two independent 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 the BWR, the steam is directed into the condensate chamber and condenses there. The chambers on a heat exchanger are connected to the intermediate cooling circuit.

Feedwater pump


The water level in the steam generator and nuclear reactor is controlled using the feedwater system. The feedwater pump has the task of taking the water from the feedwater tank up to the vapor pressure in the reactor and steam generator at rates of 2200 kg/s. The power required is about 20 MW per pump.

Emergency power supply


The emergency power supplies of a nuclear power plant are built up by several layers of redundancy, such as diesel generators, gas turbine generators and battery buffers. The battery backup provides uninterrupted coupling of the diesel/gas turbine units to the power supply network. If necessary, the emergency power supply allows the safe shut down of the nuclear reactor. Less important auxiliary systems such as, for example, heat tracing of pipelines are not supplied by these back ups. The majority of the required power is used to supply the feed pumps in order cool reactor and remove the decay heat after shut down.

People in a nuclear power plant


Nuclear power plants typically employ just under a thousand people per reactor (including security guards and engineers associated with the plant but possibly working elsewhere).
  • Nuclear engineers
    Nuclear engineering
    Nuclear engineering is the branch of engineering concerned with the application of the breakdown as well as the fusion of atomic nuclei and/or the application of other sub-atomic physics, based on the principles of nuclear physics...

  • Reactor operator
    Reactor operator
    A reactor operator is an individual at a nuclear power plant who is responsible for directly controlling a nuclear reactor from a control panel and is the only individual at a nuclear power plant who can directly alter significant amounts of reactor reactivity...

    s
  • Health physicists
    Health physics
    Health physics is a field of science concerned with radiation physics and radiation biology with the goal of providing technical information and proper techniques regarding the safe use of ionizing radiation...

  • Emergency response team personnel
    Nuclear power plant emergency response team
    A nuclear power plant emergency response team is an incident response team composed of plant personnel and civil authority personnel specifically trained to respond to the occurrence of an accident at a nuclear power plant....

  • Nuclear Regulatory Commission
    Nuclear Regulatory Commission
    The Nuclear Regulatory Commission is an independent agency of the United States government that was established by the Energy Reorganization Act of 1974 from the United States Atomic Energy Commission, and was first opened January 19, 1975...

     Resident Inspectors


In the United States and Canada, workers except for management, professional (such as engineers) and security personnel are likely to be members of either the International Brotherhood of Electrical Workers
International Brotherhood of Electrical Workers
The International Brotherhood of Electrical Workers is a labor union which represents workers in the electrical industry in the United States, Canada, Panama and several Caribbean island nations; particularly electricians, or Inside Wiremen, in the construction industry and linemen and other...

 (IBEW) or the Utility Workers Union of America
Utility Workers Union of America
The Utility Workers Union of America is a labor union in the United States. It has a membership of 50,000 and is affiliated with the AFL-CIO. The union has over 50,000 members working in the electric, gas, water, and nuclear industries across the United States. Represents Utilty Workers in...

 (UWUA).

Economics



The economics of new nuclear power plants is a controversial subject, since there are diverging views on this topic, and multi-billion dollar investments ride on the choice of an energy source. Nuclear power plants typically have high capital costs for building the plant, but low direct fuel costs (with much of the costs of fuel extraction, processing, use and long term storage externalized). Therefore, comparison with other power generation methods is strongly dependent on assumptions about construction timescales and capital financing for nuclear plants. Cost estimates also need to take into account plant decommissioning
Nuclear decommissioning
Nuclear decommissioning is the dismantling of a nuclear power plant and decontamination of the site to a state no longer requiring protection from radiation for the general public...

 and nuclear waste storage costs. On the other hand measures to mitigate
Mitigation of global warming
Climate change mitigation is action to decrease the intensity of radiative forcing in order to reduce the potential effects of global warming. Mitigation is distinguished from adaptation to global warming, which involves acting to tolerate the effects of global warming...

 global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...

, such as a carbon tax
Carbon tax
A carbon tax is an environmental tax levied on the carbon content of fuels. It is a form of carbon pricing. Carbon is present in every hydrocarbon fuel and is released as carbon dioxide when they are burnt. In contrast, non-combustion energy sources—wind, sunlight, hydropower, and nuclear—do not...

 or carbon emissions trading, may favor the economics of nuclear power.

In recent years there has been a slowdown of electricity demand growth and financing has become more difficult, which has an impact on large projects such as nuclear reactors, with very large upfront costs and long project cycles which carry a large variety of risks. In Eastern Europe, a number of long-established projects are struggling to find finance, notably Belene in Bulgaria and the additional reactors at Cernavoda 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 the risks of future uncertainties. To date all operating nuclear power plants were developed by state-owned or regulated
Regulated market
A regulated market or controlled market, is the provision of goods or services that is regulated by a government appointed body. The regulation may cover the terms and conditions of supplying the goods and services and in particular the price allowed to be charged and/or to whom they are distributed...

 utility monopolies
Electric utility
An electric utility is a company that engages in the generation, transmission, and distribution of electricity for sale generally in a regulated market. The electrical utility industry is a major provider of energy in most countries. It is indispensable to factories, commercial establishments,...

 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
Electricity market
In economic terms, electricity is a commodity capable of being bought, sold and traded. An electricity market is a system for effecting purchases, through bids to buy; sales, through offers to sell; and short-term trades, generally in the form of financial or obligation swaps. Bids and offers use...

 where these risks, and the risk of cheaper competitors emerging before capital costs are recovered, are borne by plant suppliers and operators rather than consumers, which leads to a significantly different evaluation of the economics of new nuclear power plants.

Following the 2011 Fukushima I nuclear accidents, costs are likely to go up for currently operating and new nuclear power plants, due to increased requirements for on-site spent fuel management and elevated design basis threats.

Safety


There are trades to be made between safety, economic and technical properties of different reactor designs for particular applications. Historically these decisions were often made in private by scientists, regulators and engineers, but this may be considered problematic, and since Chernobyl and Three Mile Island, many involved now consider informed consent and morality should be primary considerations.

Controversy


The nuclear power debate is about the controversy which has surrounded the deployment and use of nuclear fission reactors
Nuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...

 to generate electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

 from nuclear fuel
Nuclear fuel
Nuclear fuel is a material that can be 'consumed' by fission or fusion to derive nuclear energy. Nuclear fuels are the most dense sources of energy available...

 for civilian purposes. The debate about nuclear power peaked during the 1970s and 1980s, when it "reached an intensity unprecedented in the history of technology controversies", in some countries.

Proponents argue that nuclear power
Nuclear power
Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...

 is a sustainable energy
Sustainable energy
Sustainable energy is the provision of energy that meets the needs of the present without compromising the ability of future generations to meet their needs. Sustainable energy sources include all renewable energy sources, such as hydroelectricity, solar energy, wind energy, wave power, geothermal...

 source which reduces carbon emissions and can increase energy security
Energy security
Energy security is a term for an association between national security and the availability of natural resources for energy consumption. Access to cheap energy has become essential to the functioning of modern economies. However, the uneven distribution of energy supplies among countries has led...

 if its use supplants a dependence on imported fuels. Proponents advance the notion that nuclear power produces virtually no air pollution, in contrast to 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 the environment. These threats include health risks and environmental damage from uranium mining
Uranium mining
Uranium mining is the process of extraction of uranium ore from the ground. The worldwide production of uranium in 2009 amounted to 50,572 tonnes, of which 27% was mined in Kazakhstan. Kazakhstan, Canada, and Australia are the top three producers and together account for 63% of world uranium...

, processing and transport, the risk of nuclear weapons proliferation
Nuclear proliferation
Nuclear proliferation is a term now used to describe the spread of nuclear weapons, fissile material, and weapons-applicable nuclear technology and information, to nations which are not recognized as "Nuclear Weapon States" by the Treaty on the Nonproliferation of Nuclear Weapons, also known as the...

 or sabotage, and the unsolved problem of radioactive nuclear waste. 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
Technology
Technology is the making, usage, and knowledge of tools, machines, techniques, crafts, systems or methods of organization in order to solve a problem or perform a specific function. It can also refer to the collection of such tools, machinery, and procedures. The word technology comes ;...

. They argue that when all the energy-intensive stages of the nuclear fuel chain are considered, from uranium mining to nuclear decommissioning
Nuclear decommissioning
Nuclear decommissioning is the dismantling of a nuclear power plant and decontamination of the site to a state no longer requiring protection from radiation for the general public...

, nuclear power is not a low-carbon electricity source.

Reprocessing



Nuclear reprocessing technology was developed to chemically separate and recover fissionable plutonium from irradiated nuclear fuel. Reprocessing serves multiple purposes, whose relative importance has changed over time. Originally reprocessing was used solely to extract plutonium for producing nuclear weapons. With the commercialization of nuclear power
Nuclear power
Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...

, the reprocessed plutonium was recycled back into MOX nuclear fuel for thermal reactor
Thermal reactor
A thermal reactor is a nuclear reactor that uses slow or thermal neutrons. Most power reactors are of this type. These type of reactors use a neutron moderator to slow neutrons until they approach the average kinetic energy of the surrounding particles, that is, to reduce the speed of the neutrons...

s. The reprocessed uranium
Reprocessed uranium
Reprocessed uranium is the uranium recovered from nuclear reprocessing, as done commercially in France, the UK and Japan and by nuclear weapons states' military plutonium production programs. This uranium actually makes up the bulk of the material separated during reprocessing...

, which constitutes the bulk of the spent fuel material, can in principle also be re-used as fuel, but that is only economic when uranium prices are high. Finally, the breeder reactor
Breeder reactor
A breeder reactor is a nuclear reactor capable of generating more fissile material than it consumes because its neutron economy is high enough to breed fissile from fertile material like uranium-238 or thorium-232. Breeders were at first considered superior because of their superior fuel economy...

 can employ not only the recycled plutonium and uranium in spent fuel, but all the actinide
Actinide
The actinide or actinoid series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium.The actinide series derives its name from the group 3 element actinium...

s, closing the nuclear fuel cycle
Nuclear fuel cycle
The nuclear fuel cycle, also called nuclear fuel chain, is the progression of nuclear fuel through a series of differing stages. It consists of steps in the front end, which are the preparation of the fuel, steps in the service period in which the fuel is used during reactor operation, and steps in...

 and potentially multiplying the energy
Energy
In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...

 extracted from natural uranium
Natural uranium
Natural uranium refers to refined uranium with the same isotopic ratio as found in nature. It contains 0.7 % uranium-235, 99.3 % uranium-238, and a trace of uranium-234 by weight. In terms of the amount of radioactivity, approximately 2.2 % comes from uranium-235, 48.6 % uranium-238, and 49.2 %...

 by more than 60 times.

Nuclear reprocessing reduces the volume of high-level waste, but by itself does not reduce radioactivity or heat generation and therefore does not eliminate the need for a geological waste repository. Reprocessing has been politically controversial because of the potential to contribute to nuclear proliferation
Nuclear proliferation
Nuclear proliferation is a term now used to describe the spread of nuclear weapons, fissile material, and weapons-applicable nuclear technology and information, to nations which are not recognized as "Nuclear Weapon States" by the Treaty on the Nonproliferation of Nuclear Weapons, also known as the...

, the potential vulnerability to nuclear terrorism
Nuclear terrorism
Nuclear terrorism denotes the use, or threat of the use, of nuclear weapons or radiological weapons in acts of terrorism, includingattacks against facilities where radioactive materials are present...

, the political challenges of repository siting (a problem that applies equally to direct disposal of spent fuel), and because of its high cost compared to the once-through fuel cycle. The Obama administration stepped back from President Bush's plans for commercial-scale reprocessing and reverted to a program focused on reprocessing-related scientific research.

Accident indemnification


The Vienna Convention on Civil Liability for Nuclear Damage
Vienna Convention on Civil Liability for Nuclear Damage
Vienna Convention on Civil Liability for Nuclear Damage-Background:In September 1997, many of the world's governments took a significant step forward in improving the liability regime for nuclear damage...

 puts in place an international framework for nuclear liability.
However states with a majority of the world's nuclear power plants, including the U.S., Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

, China
People's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...

 and Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, are not party to international nuclear liability conventions.

In the U.S., insurance for nuclear or radiological incidents is covered (for facilities licensed through 2025) by the Price-Anderson Nuclear Industries Indemnity Act
Price-Anderson Nuclear Industries Indemnity Act
The Price-Anderson Nuclear Industries Indemnity Act is a United States federal law, first passed in 1957 and since renewed several times, which governs liability-related issues for all non-military nuclear facilities constructed in the United States before 2026...

.

Under the Energy policy of the United Kingdom
Energy policy of the United Kingdom
The current energy policy of the United Kingdom is set out in the Energy White Paper of May 2007 and Low Carbon Transition Plan of July 2009, building on previous work including the 2003 Energy White Paper and the Energy Review Report in 2006...

 through its Nuclear Installations Act of 1965, liability is governed for nuclear damage for which a UK nuclear licensee is responsible. The Act requires compensation to be paid for damage up to a limit of £150 million by the liable operator for ten years after the incident. Between ten and thirty years afterwards, the Government meets this obligation. The Government is also liable for additional limited cross-border liability (about £300 million) under international conventions (Paris Convention on Third Party Liability in the Field of Nuclear Energy
Paris Convention on Third Party Liability in the Field of Nuclear Energy
The Paris Convention on Third Party Liability in the Field of Nuclear Energy is an OECD Convention on liability and compensation for damage caused by accidents occurring while producing nuclear energy.The convention:...

 and Brussels Convention supplementary to the Paris Convention).

Decommissioning



Nuclear decommissioning is the dismantling of a nuclear power plant and decontamination of the site to a state no longer requiring protection from radiation for the general public. The main difference from the dismantling of other power plants is the presence of radioactive material that requires special precautions.

Generally speaking, nuclear plants were designed for a life of about 30 years. Newer plants are designed for a 40 to 60-year operating life.

Decommissioning involves many administrative and technical actions. It includes all clean-up of radioactivity and progressive demolition of the plant. Once a facility is decommissioned, there should no longer be any danger of a radioactive accident or to any persons visiting it. After a facility has been completely decommissioned it is released from regulatory control, and the licensee of the plant no longer has responsibility for its nuclear safety.

Historic accidents


The nuclear industry says that new technology and oversight have made nuclear plants much safer, but 57 accidents have occurred since the Chernobyl disaster
Chernobyl disaster
The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in Ukraine , which was under the direct jurisdiction of the central authorities in Moscow...

 in 1986. Two thirds of these mishaps occurred in the US. The French Atomic Energy Agency (CEA) has concluded that technical innovation cannot eliminate the risk of human errors in nuclear plant operation.

An interdisciplinary team from MIT have estimated that given the expected growth of nuclear power from 2005–2055, at least four serious nuclear power accidents would be expected in that period.

Flexibility of nuclear power plants


It is often claimed that nuclear stations are inflexible in their output, implying that other forms of energy would be required to meet peak demand. While that is true for the vast majority of reactors, this is no longer true of at least some modern designs.

Nuclear plants are routinely used in load following mode on a large scale in France. Unit A at the German Biblis Nuclear Power Plant
Biblis Nuclear Power Plant
The Biblis Nuclear Power Plant is in the South Hessian municipality of Biblis and consists of two units: unit A with a gross output of 1200 megawatts and unit B with a gross output of 1300 megawatts. Both units are pressurized water reactors...

 is designed to in- and decrease his output 15 % per minute between 40 and 100 % of its nominal power.
Boiling water reactors normally have load-following capability, implemented by varying the recirculation water flow.

Future power plants


A number of new designs for nuclear power generation, collectively known as the Generation IV reactor
Generation IV reactor
Generation IV reactors are a set of theoretical nuclear reactor designs currently being researched. Most of these designs are generally not expected to be available for commercial construction before 2030...

s, are the subject of active research and may be used for practical power generation in the future. Many of these new designs specifically attempt to make fission reactors cleaner, safer and/or less of a risk to the proliferation of nuclear weapons. Passively safe
Passive nuclear safety
Passive nuclear safety is a safety feature of a nuclear reactor that does not require operator actions or electronic feedback in order to shut down safely in the event of a particular type of emergency...

 plants (such as the ESBWR
Economic Simplified Boiling Water Reactor
The type of nuclear reactor formally known as the Economic Simplified Boiling Water Reactor is a passively safe generation III+ reactor derived from the predecessor Simplified Boiling Water Reactor and the Advanced Boiling Water Reactor...

) are available to be built and other designs that are believed to be nearly fool-proof are being pursued. Fusion reactors
Fusion power
Fusion power is the power generated by nuclear fusion processes. In fusion reactions two light atomic nuclei fuse together to form a heavier nucleus . In doing so they release a comparatively large amount of energy arising from the binding energy due to the strong nuclear force which is manifested...

, which may be viable in the future, diminish or eliminate many of the risks associated with nuclear fission.

The 1600 MWe
MWE
MWE may refer to:*Manufacturer's Weight Empty*McDermott Will & Emery*Midwest Express, an airline*Merowe Airport - IATA code*Multiword expressionMWe may refer to:*Megawatt electrical...

 European Pressurized Reactor
European Pressurized Reactor
The EPR is a third generation pressurized water reactor design. It has been designed and developed mainly by Framatome , Electricité de France in France, and Siemens AG in Germany...

 reactor is being built in Olkiluoto
Olkiluoto
The Olkiluoto Nuclear Power Plant is on Olkiluoto Island, which is on the shore of the Gulf of Bothnia in the municipality of Eurajoki in western Finland. It is one of Finland's two nuclear power plants, the other being the two-unit VVER Loviisa Nuclear Power Plant...

, Finland
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

. A joint effort of French AREVA
Areva
AREVA is a French public multinational industrial conglomerate headquartered in the Tour Areva in Courbevoie, Paris. AREVA is mainly known for nuclear power; it also has interests in other energy projects. It was created on 3 September 2001, by the merger of Framatome , Cogema and...

 and German Siemens AG
Siemens AG
Siemens AG is a German multinational conglomerate company headquartered in Munich, Germany. It is the largest Europe-based electronics and electrical engineering company....

, it will be the largest reactor in the world. In December 2006 construction was about 18 months behind schedule so completion was expected 2010-2011.

As of March, 2007, there are seven nuclear power plants under construction in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

, and five in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

.

In November 2011 Gulf Power stated that by the end of 2012 it hopes to finish buying off 4000 acres of land north of Pensacola, Florida in order to build a posable nuclear power plant.

Russia has begun building the world’s first
floating nuclear power plant
Russian floating nuclear power station
Floating nuclear power stations are vessels projected by Rosatom that present self-contained, low-capacity, floating nuclear power plants...

. The £100 million vessel, the Lomonosov, is the first of seven plants that Moscow says will bring vital energy resources to remote Russian regions.

By 2025, Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...

 nations would have a total of 29 nuclear power plants, Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

 will have 4 nuclear power plants, Malaysia 4, Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

 5 and Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...

 16 from nothing at all in 2011.

In popular culture

  • On the fourth season of the television show 24
    24 (TV series)
    24 is an American television series produced for the Fox Network and syndicated worldwide, starring Kiefer Sutherland as Counter Terrorist Unit agent Jack Bauer. Each 24-episode season covers 24 hours in the life of Bauer, using the real time method of narration...

    , Habib Marwan (and his associates) attempt to hijack
    Robbery
    Robbery is the crime of taking or attempting to take something of value by force or threat of force or by putting the victim in fear. At common law, robbery is defined as taking the property of another, with the intent to permanently deprive the person of that property, by means of force or fear....

     and melt down every nuclear reactor in the United States
    United States
    The United States of America is a federal constitutional republic comprising fifty states and a federal district...

    , but all remain stable except one.
  • The 1979 film
    Film
    A film, also called a movie or motion picture, is a series of still or moving images. It is produced by recording photographic images with cameras, or by creating images using animation techniques or visual effects...

     The China Syndrome
    The China Syndrome
    The China Syndrome is a 1979 American thriller film that tells the story of a reporter and cameraman who discover safety coverups at a nuclear power plant. It stars Jane Fonda, Jack Lemmon, Michael Douglas, Scott Brady, James Hampton, Peter Donat, Richard Herd, and Wilford Brimley.The film was...

    features an accident and implied core meltdown at a nuclear power plant.
  • In the 2006 film, 10.5: Apocalypse
    10.5: Apocalypse
    10.5: Apocalypse is a 2006 television miniseries written and directed by John Lafia. A sequel to 2004's 10.5, the film follows a series of catastrophic seismic disasters .-Plot:...

    , a moving trench heads toward the 2 largest nuclear reactors in the United States
    United States
    The United States of America is a federal constitutional republic comprising fifty states and a federal district...

    , located in Texas
    Texas
    Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

    .
  • Homer Simpson
    Homer Simpson
    Homer Jay Simpson is a fictional character in the animated television series The Simpsons and the patriarch of the eponymous family. He is voiced by Dan Castellaneta and first appeared on television, along with the rest of his family, in The Tracey Ullman Show short "Good Night" on April 19, 1987...

     from the Simpsons works mainly at a nuclear power plant.

See also



  • List of nuclear reactors
  • Nuclear power by country
    Nuclear power by country
    Thirty countries operate nuclear power stations, and there are a considerable number of new reactors being built in China, South Korea, India, Pakistan, and Russia...

  • Nuclear Information and Resource Service
    Nuclear Information and Resource Service
    The Nuclear Information and Resource Service is an anti-nuclear group founded in 1978 to be the information and networking center for citizens and organizations concerned about nuclear power, radioactive waste, radiation and sustainable energy issues...

  • Gerald W. Brown
    Gerald W. Brown
    Gerald W. "Jerry" Brown is an American whistleblower who concerned himself with deficiencies in passive fire protection systems in US and Canadian nuclear power plants.-Thermo-Lag scandal:...

    , American
    United States
    The United States of America is a federal constitutional republic comprising fifty states and a federal district...

     whistleblower
    Whistleblower
    A whistleblower is a person who tells the public or someone in authority about alleged dishonest or illegal activities occurring in a government department, a public or private organization, or a company...

     on passive fire protection
    Passive fire protection
    Passive fire protection is an integral component of the three components of structural fire protection and fire safety in a building. PFP attempts to contain fires or slow the spread, through use of fire-resistant walls, floors, and doors...

    /circuit integrity
    Circuit integrity
    Circuit integrity refers to the operability of electrical circuits during a fire. It is a form of fire-resistance rating. Circuit integrity is achieved via passive fire protection means, which are subject to stringent listing and approval use and compliance.-Fireproofing:Providing fireproofing for...

     deficiencies
    Deficiency
    A deficiency is generally a lack of something. It may also refer to:*A deficient number, in mathematics, a number n for which σ A deficiency is generally a lack of something. It may also refer to:...

     in US and Canadian
    Canada
    Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

     plants
  • Nuclear fuel cycle
    Nuclear fuel cycle
    The nuclear fuel cycle, also called nuclear fuel chain, is the progression of nuclear fuel through a series of differing stages. It consists of steps in the front end, which are the preparation of the fuel, steps in the service period in which the fuel is used during reactor operation, and steps in...

  • Containment building
    Containment building
    A containment building, in its most common usage, is a steel or reinforced concrete structure enclosing a nuclear reactor. It is designed, in any emergency, to contain the escape of radiation to a maximum pressure in the range of 60 to 200 psi...

  • Safety engineering
    Safety engineering
    Safety engineering is an applied science strongly related to systems engineering / industrial engineering and the subset System Safety Engineering...

  • SCRAM
    Scram
    A scram or SCRAM is an emergency shutdown of a nuclear reactor – though the term has been extended to cover shutdowns of other complex operations, such as server farms and even large model railroads...

  • FEMA
  • Nuclear Regulatory Commission
    Nuclear Regulatory Commission
    The Nuclear Regulatory Commission is an independent agency of the United States government that was established by the Energy Reorganization Act of 1974 from the United States Atomic Energy Commission, and was first opened January 19, 1975...

     of the USA
  • Auxiliary feedwater
    Auxiliary feedwater
    Auxiliary feedwater is a backup water supply system found in pressurized water reactor nuclear power plants. This system, sometimes known as Emergency feedwater, can be used during shutdowns, including accident conditions, and sometimes during startup. It works by pumping water to the steam...

  • Uranium market
    Uranium market
    The uranium market, like all commodity markets, has a history of volatility, moving not only with the standard forces of supply and demand, but also to whims of geopolitics. It has also evolved particularities of its own in response to the unique nature and use of this material.The only significant...


External links