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Nuclear power is the use of
nuclear reaction In nuclear physics Nuclear physics is the field of physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, space and t ...
s to produce
electricity Electricity is the set of physical Physical may refer to: *Physical examination, a regular overall check-up with a doctor *Physical (album), ''Physical'' (album), a 1981 album by Olivia Newton-John **Physical (Olivia Newton-John song), "Physi ...

electricity
. Nuclear power can be obtained from
nuclear fission Nuclear fission is a in which the of an splits into two or more smaller . The fission process often produces s, and releases a very large amount of even by the energetic standards of . Nuclear fission of heavy elements was discovered on ...

nuclear fission
,
nuclear decay Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration or nuclear disintegration) is the process by which an unstable atomic nucleus The atomic nucleus is the small, dense region consisting of proton A ...
and
nuclear fusion 400 px, The nuclear binding energy curve. The formation of nuclei with masses up to iron-56 releases energy, as illustrated above. Nuclear fusion is a nuclear reaction, reaction in which two or more atomic nuclei are combined to form one or m ...

nuclear fusion
reactions. Presently, the vast majority of electricity from nuclear power is produced by
nuclear fission Nuclear fission is a in which the of an splits into two or more smaller . The fission process often produces s, and releases a very large amount of even by the energetic standards of . Nuclear fission of heavy elements was discovered on ...

nuclear fission
of
uranium Uranium is a chemical element upright=1.0, 500px, The chemical elements ordered by link=Periodic table In chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science tha ...

uranium
and
plutonium Plutonium is a radioactive decay, radioactive chemical element with the Symbol (chemistry), symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating plutoni ...

plutonium
in
nuclear power plant A nuclear power plant (sometimes abbreviated as NPP) is a thermal power station A thermal power station is a power station in which heat energy is converted to electricity. Typically, fuel is used to boil water in a large pressure vessel to ...

nuclear power plant
s. Nuclear decay processes are used in niche applications such as
radioisotope thermoelectric generator A radioisotope thermoelectric generator (RTG, RITEG) is a type of nuclear battery that uses an array of thermocouples to convert the heat released by the decay of a suitable radioactive Radioactive decay (also known as nuclear decay, radi ...
s in some space probes such as
Voyager 2 ''Voyager 2'' is a space probe launched by NASA on August 20, 1977, to study the outer planets and interstellar space beyond the Sun's heliosphere. A part of the Voyager program, it was launched 16 days before its twin, ''Voyager 1'', on a traje ...
. Generating electricity from
fusion power Fusion power is a proposed form of that would generate by using heat from . In a fusion process, two lighter combine to form a heavier nucleus, while releasing energy. Devices designed to harness this energy are known as fusion reactors. Fusi ...
remains the focus of international research. Civilian nuclear power supplied 2,586
terawatt hour The kilowatt-hour ( SI symbol: kW⋅h or kW h; commonly written as kWh) is a unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, ...
s (TWh) of electricity in 2019, equivalent to about 10% of
global electricity generation World energy consumption is the total energy In physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , is the natural science that studies mat ...
, and was the second-largest
low-carbon power Low-carbon power is electricity Electricity is the set of physical phenomena associated with the presence and motion Image:Leaving Yongsan Station.jpg, 300px, Motion involves a change in position In physics, motion is the phenomenon in ...
source after
hydroelectricity Hydroelectricity, or hydroelectric power, is electricity produced from hydropower Hydropower (from el, ὕδωρ, "water"), also known as water power, is the use of falling or fast-running water to produce electricity or to power machin ...
. there are 444 civilian fission reactors in the world, with a combined electrical capacity of 396
gigawatt The watt (symbol: W) is a unit of power Power typically refers to: * Power (physics) In physics, power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal ...
(GW). There are also 53 nuclear power reactors under construction and 98 reactors planned, with a combined capacity of 60 GW and 103 GW, respectively. The
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

United States
has the largest fleet of nuclear reactors, generating over 800 TWh zero-emissions electricity per year with an average
capacity factor The net capacity factor is the unitless ratio of an actual electrical energy output over a given period of time to the maximum possible electrical energy output over that period. The capacity factor is defined for any electricity producing install ...
of 92%. Most reactors under construction are
generation III reactor Generation III reactors (Gen III reactors) are a class of nuclear reactor A nuclear reactor, formerly known as an atomic pile, is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactor ...
s in Asia. Nuclear power has one of the lowest levels of fatalities per unit of energy generated compared to other energy sources.
Coal Coal is a combustible black or brownish-black sedimentary rock, formed as stratum, rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen ...

Coal
,
petroleum Petroleum, also known as crude oil and oil, is a naturally occurring, yellowish-black liquid A liquid is a nearly incompressible In fluid mechanics or more generally continuum mechanics, incompressible flow (isochoric process, isoc ...

petroleum
,
natural gas Natural gas (also called fossil gas; sometimes just gas) is a naturally occurring hydrocarbon In , a hydrocarbon is an consisting entirely of and . Hydrocarbons are examples of s. Hydrocarbons are generally colourless and hydrophobic wit ...

natural gas
and hydroelectricity each have caused more fatalities per unit of energy due to
air pollution Air pollution is the presence of substances in the atmosphere An atmosphere (from the greek words ἀτμός ''(atmos)'', meaning 'vapour', and σφαῖρα ''(sphaira)'', meaning 'ball' or 'sphere') is a layer or a set of layers of gas ...

air pollution
and
accidents An accident is an unplanned event that sometimes has inconvenient or undesirable consequences, other times being inconsequential. The occurrence of such an event may or may not have unrecognized or unaddressed risks contributing to its cause. Mo ...
. Accidents in nuclear power plants include the
Chernobyl disaster The Chernobyl disaster was a that occurred on 26 April 1986 at the No. 4 in the , near the city of in the north of the in the . It is considered the worst nuclear disaster in history both in cost and casualties. It is one of only two nucle ...
in the
Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a that spanned during its existence from 1922 to 1991. It was nominally a of multiple national ; in practice and were highly until its final years. The ...
in 1986, the
Fukushima nuclear disaster The Fukushima nuclear disaster was a 2011 nuclear accident at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. The Proximate and ultimate causation, proximate cause of the disaster was the 2011 Tōhoku earthquake and tsuna ...
in
Japan Japan ( ja, 日本, or , and formally ) is an island country An island country or an island nation is a country A country is a distinct territory, territorial body or political entity. It is often referred to as the land of an in ...

Japan
in 2011, and the more contained
Three Mile Island accident The Three Mile Island accident was a Nuclear meltdown, partial meltdown of the Three Mile Island Nuclear Generating Station, Three Mile Island, Unit 2 (TMI-2) reactor in Pennsylvania. It began at 4 a.m. on March 28, 1979. It is the most significa ...
in the United States in 1979. There is a debate about nuclear power. Proponents, such as the
World Nuclear Association World Nuclear Association is the international organization that promotes nuclear power Nuclear power is the use of nuclear reactions to produce electricity Electricity is the set of physical phenomena associated with the presence and ...
and
Environmentalists for Nuclear Energy Environmentalists for Nuclear Energy (EFN) — in French: "Association des Écologistes Pour le Nucléaire – AEPN, founded in 1996" — is a pro-nuclear power non-profit organization that aims to provide information to the public on energy and ...
, contend that nuclear power is a safe, sustainable energy source that reduces
carbon emissions Greenhouse gas emissions are emissions of greenhouse gases created from a range of human activities that cause climate change, as they have increased concentrations in the earth's atmosphere. These emissions mainly include carbon dioxide emissions ...
. Nuclear power opponents, such as
Greenpeace Greenpeace is an independent global campaigning network. The network comprises 26 independent national/regional organisations in over 55 countries across Europe, the Americas, Africa, Asia and the Pacific, as well as a co-ordinating body, Green ...

Greenpeace
, Scientists for Future and NIRS, contend that nuclear power poses many threats to people and the environment and is too expensive and slow to deploy when compared to alternative
sustainable energy Energy In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in other words, t ...
sources.


History


Origins

The discovery of nuclear fission occurred in 1938 following over four decades of work on the science of
radioactivity
radioactivity
and the elaboration of new
nuclear physics Nuclear physics is the field of physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, space and time, and the related ent ...
that described the components of
atom An atom is the smallest unit of ordinary matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of ato ...

atom
s. Soon after the discovery of the fission process, it was realized that a fissioning nucleus can induce further nucleus fissions, thus inducing a self-sustaining chain reaction. Once this was experimentally confirmed in 1939, scientists in many countries petitioned their governments for support of nuclear fission research, just on the cusp of
World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a global war A world war is "a war War is an intense armed conflict between states State may refer to: Arts, entertainment, and media Literatur ...
, for the development of a
nuclear weapon A nuclear weapon (also known as an atom bomb, atomic bomb, nuclear bomb or nuclear warhead, and colloquially as an A-bomb or nuke) is an explosive device that derives its destructive force from nuclear reaction In nuclear physics Nucl ...
. In the United States, these research efforts led to the creation of the first man-made nuclear reactor, the
Chicago Pile-1 Chicago Pile-1 (CP-1) was the world's first artificial nuclear reactor A nuclear reactor, formerly known as an atomic pile, is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reac ...
, which achieved criticality on December 2, 1942. The reactor's development was part of the
Manhattan Project The Manhattan Project was a research and development Research is " creative and systematic work undertaken to increase the stock of knowledge". It involves the collection, organization, and analysis of information to increase understa ...
, the
Allied An alliance is a relationship among people, groups, or sovereign state, states that have joined together for mutual benefit or to achieve some common purpose, whether or not explicit agreement has been worked out among them. Members of an alli ...
effort to create
atomic bombs A nuclear weapon (also called an atom bomb, nuke, atomic bomb, nuclear warhead, A-bomb, or nuclear bomb) is an explosive device that derives its destructive force from nuclear reaction In nuclear physics Nuclear physics is the field of ph ...
during World War II. It led to the building of larger single-purpose production reactors for the production of
weapons-grade plutonium Weapons-grade nuclear material is any fissionable nuclear material that is pure enough to make a nuclear weapon A nuclear weapon (also called an atom bomb, nuke, atomic bomb, nuclear warhead, A-bomb, or nuclear bomb) is an explosive device ...
for use in the first nuclear weapons. The United States tested the first nuclear weapon in July 1945, the
Trinity test Trinity was the of the first detonation of a . It was conducted by the at 5:29 a.m. on July 16, 1945, as part of the . The test was conducted in the desert about southeast of , on what was then the USAAF Alamogordo Bombing and Gunnery ...
, with the
atomic bombings of Hiroshima and Nagasaki The United States detonated two nuclear weapons A nuclear weapon (also known as an atom bomb, atomic bomb, nuclear bomb or nuclear warhead, and colloquially as an A-bomb or nuke) is an explosive device that derives its destructive fo ...
taking place one month later. Despite the military nature of the first nuclear devices, the 1940s and 1950s were characterized by strong optimism for the potential of nuclear power to provide cheap and endless energy. Electricity was generated for the first time by a nuclear reactor on December 20, 1951, at the
EBR-I Experimental Breeder Reactor I (EBR-I) is a decommissioned research reactor Research reactors are nuclear reactors that serve primarily as a neutron source. They are also called non-power reactors, in contrast to power reactors that are used f ...

EBR-I
experimental station near
Arco, Idaho Arco is a city in Butte County, Idaho Idaho () is a U.S. state, state in the Pacific Northwest region of the United States. It borders the state of Montana to the east and northeast, Wyoming to the east, Nevada and Utah to the south, and W ...

Arco, Idaho
, which initially produced about 100 
kW
kW
. In 1953, American President
Dwight Eisenhower Dwight David "Ike" Eisenhower (; October 14, 1890 – March 28, 1969) was an American military officer An officer is a member of an armed forces or uniformed service who holds a position of authority. In its broadest sense, the term " ...
gave his "
Atoms for Peace "Atoms for Peace" was the title of a speech delivered by U.S. President Dwight D. Eisenhower to the UN General Assembly in New York City on December 8, 1953. The United States then launched an "Atoms for Peace" program that supplied equipment ...
" speech at the
United Nations The United Nations (UN) is an intergovernmental organization aiming to maintain international peace and international security, security, develop friendly relations among nations, achieve international cooperation, and be a centre for harm ...

United Nations
, emphasizing the need to develop "peaceful" uses of nuclear power quickly. This was followed by the
Atomic Energy Act of 1954 The Atomic Energy Act of 1954, 42 U.S.C. §§ 2011-2021, 2022-2286i, 2296a-2297h-13, is a United States federal law The law of the United States comprises many levels of codified and uncodified forms of law Law is a system A system ...
which allowed rapid declassification of U.S. reactor technology and encouraged development by the private sector.


First power generation

The first organization to develop practical nuclear power was the
U.S. Navy ), (unofficial)."''Non sibi sed patriae''" ( en, "Not for self but for country") (unofficial). , colors = Blue and gold  , colors_label = Colors , march = " Anchors Aweigh" ...
, with the
S1W reactorThe S1W reactor was the first prototype United States Naval reactor, naval reactor used by the United States Navy to prove that the technology could be used for electricity generation and Nuclear marine propulsion, propulsion on submarines. The de ...
for the purpose of propelling
submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. It is also sometimes used historically or colloquially to refer to remotely operated ...

submarine
s and
aircraft carrier An aircraft carrier is a warship A warship or combatant ship is a that is built and primarily intended for . Usually they belong to the of a state. As well as being armed, warships are designed to withstand damage and are usually faster ...
s. The first nuclear-powered submarine, , was put to sea in January 1954. The
S1W reactorThe S1W reactor was the first prototype United States Naval reactor, naval reactor used by the United States Navy to prove that the technology could be used for electricity generation and Nuclear marine propulsion, propulsion on submarines. The de ...
was a
Pressurized Water Reactor A pressurized water reactor (PWR) is a type of light-water nuclear reactor A nuclear reactor, formerly known as an atomic pile, is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear react ...

Pressurized Water Reactor
. This design was chosen because it was simpler, more compact, and easier to operate compared to alternative designs, thus more suitable to be used in submarines. This decision would result in the PWR being the reactor of choice also for power generation, thus having a lasting impact on the civilian electricity market in the years to come. On June 27, 1954, the
Obninsk Nuclear Power Plant Obninsk Nuclear Power Plant (russian: Обнинская АЭС, Obninskaja AES; ) was built in the "Science City" of Obninsk Obninsk (russian: О́бнинск) is a types of inhabited localities in Russia, city in Kaluga Oblast, Russia, loca ...
in the
USSR The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a socialist state that spanned Eurasia during its existence from 1922 to 1991. It was nominally a Federation, federal union of multiple national Republics of ...

USSR
became the world's first nuclear power plant to generate electricity for a
power grid An electrical grid is an interconnected network for electricity delivery Electricity delivery is the process that starts after generation of electricity in the power station A power station, also referred to as a power plant and someti ...

power grid
, producing around 5 megawatts of electric power. The world's first commercial nuclear power station,
Calder Hall Sellafield is a large multi-function nuclear site close to Seascale Seascale is a village and civil parish on the Irish Sea coast of Cumbria, England, historically within Cumberland. The parish had a population of 1,747 in 2001, increasing s ...
at Windscale, England was connected to the national power grid on 27 August 1956. In common with a number of other
generation I reactor A generation II reactor is a design classification for a nuclear reactor, and refers to the class of commercial reactors built until the end of the 1990s. Prototypical and older versions of PWR, CANDU The CANDU (Canada Deuterium Uranium) is a ...
s, the plant had the dual purpose of producing
electricity Electricity is the set of physical Physical may refer to: *Physical examination, a regular overall check-up with a doctor *Physical (album), ''Physical'' (album), a 1981 album by Olivia Newton-John **Physical (Olivia Newton-John song), "Physi ...

electricity
and
plutonium-239 Plutonium-239 (239Pu, Pu-239) is an isotope Isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number. All isotopes of a given element have the same number of protons but differe ...

plutonium-239
, the latter for the nascent nuclear weapons program in Britain.


Early accidents

The first major nuclear accidents were the
Kyshtym disaster The Kyshtym disaster, sometimes referred to as the Mayak disaster or Ozyorsk disaster in newer sources, was a radioactive contamination accident that occurred on 29 September 1957 at Mayak, a plutonium production site for nuclear weapons and nucl ...
in the Soviet Union and the
Windscale fire The Windscale fire of 10 October 1957 was the worst nuclear accident in the United Kingdom's history, and one of the worst in the world, ranked in severity at level 5 out of a possible 7 on the International Nuclear Event Scale. The fire took pla ...
in the United Kingdom, both in 1957. The first major accident at a nuclear reactor in the USA occurred in 1961 at the
SL-1 Stationary Low-Power Reactor Number One, also known as SL-1 or the Argonne Low Power Reactor (ALPR), was a United States Army experimental nuclear reactor located at the Idaho National Laboratory#History, National Reactor Testing Station (NRTS) ...

SL-1
, a
U.S. Army The United States Army (USA) is the land Land is the solid surface of Earth that is not permanently submerged in water. Most but not all land is situated at elevations above sea level (variable over geologic time frames) and consists ma ...
experimental nuclear power reactor at the
Idaho National Laboratory Idaho National Laboratory (INL) is one of the national laboratories of the United States Department of Energy The United States Department of Energy (DOE) is a cabinet Cabinet or The Cabinet may refer to: Furniture * Cabinetry, a box ...
. An uncontrolled chain reaction resulted in a
steam explosion upright=1.5, Littoral explosion at Waikupanaha ocean entry at the big island of Hawaii was caused by the lava entering the ocean ">ocean.html" ;"title="lava entering the ocean">lava entering the ocean A steam explosion is an explosion caused by ...
which killed the three crew members and caused a meltdown.
IDO-19313: Additional Analysis of the SL-1 Excursion
Final Report of Progress July through October 1962'', November 21, 1962, Flight Propulsion Laboratory Department, General Electric Company, Idaho Falls, Idaho, U.S. Atomic Energy Commission, Division of Technical Information.
Another serious accident happened in 1968, when one of the two liquid-metal-cooled reactors on board the underwent a fuel element failure, with the emission of gaseous
fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium Uranium is a chemical element with the Symbol (chemistry), symbol U and atomic numbe ...
s into the surrounding air, resulting in 9 crew fatalities and 83 injuries.


Expansion and first opposition

The total global installed nuclear capacity initially rose relatively quickly, rising from less than 1
gigawatt The watt (symbol: W) is a unit of power Power typically refers to: * Power (physics) In physics, power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal ...
(GW) in 1960 to 100 GW in the late 1970s. During the 1970s and 1980s rising economic costs (related to extended construction times largely due to regulatory changes and pressure-group litigation) and falling fossil fuel prices made nuclear power plants then under construction less attractive. In the 1980s in the U.S. and 1990s in Europe, the flat electric grid growth and
electricity liberalization Energy liberalisation refers to the liberalisation of energy market Energy markets are commodity markets that deal specifically with the trade and supply of Energy (society), energy. Energy market may refer to an electricity market, but can also r ...
also made the addition of large new
baseload The baseload (also base load) on a grid is the minimum level of demand on an electrical grid An electrical grid is an interconnected network for electricity delivery from producers to consumers. Electrical grids vary in size and can cover who ...
energy generators economically unattractive. The 1973 oil crisis had a significant effect on countries, such as
France France (), officially the French Republic (french: link=no, République française), is a transcontinental country This is a list of countries located on more than one continent A continent is one of several large landmasses ...

France
and
Japan Japan ( ja, 日本, or , and formally ) is an island country An island country or an island nation is a country A country is a distinct territory, territorial body or political entity. It is often referred to as the land of an in ...

Japan
, which had relied more heavily on oil for electric generation to invest in nuclear power. France would construct 25 nuclear power plants over the next 15 years, and as of 2019, 71% of French electricity was generated by nuclear power, the highest percentage by any nation in the world. Some local opposition to nuclear power emerged in the United States in the early 1960s. In the late 1960s some members of the scientific community began to express pointed concerns. These anti-nuclear concerns related to
nuclear accidents to human , a Japanese nuclear plant with seven units, the largest single nuclear power station in the world, was completely shut down for 21 months following an earthquake in 2007. Safety-critical systems were found to be undamaged by the earthqua ...
,
nuclear proliferation Nuclear proliferation is the spread of nuclear weapons A nuclear weapon (also known as an atom bomb, atomic bomb, nuclear bomb or nuclear warhead, and colloquially as an A-bomb or nuke) is an explosive device that derives its destructiv ...

nuclear proliferation
,
nuclear terrorism Nuclear terrorism refers to any person or persons who detonate a nuclear weapon A nuclear weapon (also called an atom bomb, nuke, atomic bomb, nuclear warhead, A-bomb, or nuclear bomb) is an explosive device that derives its destructive force ...
and radioactive waste disposal. In the early 1970s, there were large protests about a proposed nuclear power plant in
Wyhl Wyhl () is a municipality in the district of Emmendingen in Baden-Württemberg Baden-Württemberg (; ) is a States of Germany, state (''Land'') in southwest Germany, east of the Rhine, which forms the southern part of Germany's western border ...

Wyhl
, Germany. The project was cancelled in 1975. The anti-nuclear success at Wyhl inspired opposition to nuclear power in other parts of
Europe Europe is a continent A continent is any of several large landmass A landmass, or land mass, is a large region In geography Geography (from Greek: , ''geographia'', literally "earth description") is a field of scienc ...

Europe
and
North America North America is a continent A continent is any of several large landmasses. Generally identified by convention (norm), convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continen ...

North America
.Robert Gottlieb (2005)
Forcing the Spring: The Transformation of the American Environmental Movement
Revised Edition, Island Press, p. 237.
By the mid-1970s anti-nuclear activism gained a wider appeal and influence, and nuclear power began to become an issue of major public protest.Walker, J. Samuel (2004).
Three Mile Island: A Nuclear Crisis in Historical Perspective
' (Berkeley: University of California Press), pp. 10–11.
In some countries, the nuclear power conflict "reached an intensity unprecedented in the history of technology controversies". The increased public hostility to nuclear power led to a longer license procurement process, regulations and increased requirements for safety equipment, which made new construction much more expensive. In the United States, over 120 LWR reactor proposals were ultimately cancelled and the construction of new reactors ground to a halt. The 1979 accident at Three Mile Island with no fatalities, played a major part in the reduction in the number of new plant constructions in many countries.


Chernobyl and renaissance

During the 1980s one new nuclear reactor started up every 17 days on average. By the end of the decade, global installed nuclear capacity reached 300 GW. Since the late 1980s, new capacity additions slowed down significantly, with the installed nuclear capacity reaching 366 GW in 2005. The 1986
Chernobyl disaster The Chernobyl disaster was a that occurred on 26 April 1986 at the No. 4 in the , near the city of in the north of the in the . It is considered the worst nuclear disaster in history both in cost and casualties. It is one of only two nucle ...
in the
USSR The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a socialist state that spanned Eurasia during its existence from 1922 to 1991. It was nominally a Federation, federal union of multiple national Republics of ...

USSR
, involving an
RBMK The RBMK (russian: реактор большой мощности канальный, РБМК; ''reaktor bolshoy moshchnosti kanalnyy'', "high-power channel-type reactor") is a class of designed and built by the . The name refers to its design ...

RBMK
reactor, altered the development of nuclear power and led to a greater focus on meeting international safety and regulatory standards. It is considered the worst nuclear disaster in history both in total casualties, with 56 direct deaths, and financially, with the cleanup and the cost estimated at 18 billion
Soviet ruble The Soviet ruble (russian: link=no, рубль) was the currency of the Russian Soviet Federative Socialist Republic The Russian Soviet Federative Socialist Republic (Russian SFSR or RSFSR; rus, links=1, Росси́йская Сове́т ...
s (US$68 billion in 2019, adjusted for inflation). (see 1996 interview with Mikhail Gorbachev) The international organization to promote safety awareness and the professional development of operators in nuclear facilities, the
World Association of Nuclear Operators The World Association of Nuclear Operators (WANO) is a not for profit, international organisation ''International Organization'' is a quarterly peer-reviewed academic journal that covers the entire field of international relations, international a ...
(WANO), was created as a direct outcome of the 1986 Chernobyl accident. The Chernobyl disaster played a major part in the reduction in the number of new plant constructions in the following years. Influenced by these events, Italy voted against nuclear power in a 1987 referendum, becoming the first country to completely phase out nuclear power in 1990. In the early 2000s, nuclear energy was expecting a
nuclear renaissance Since about 2001 the term nuclear renaissance has been used to refer to a possible nuclear power Nuclear power is the use of nuclear reactions to produce electricity Electricity is the set of physical phenomena associated with the ...
, an increase in the construction of new reactors, due to concerns about carbon dioxide emissions. During this period, newer
generation III reactor Generation III reactors (Gen III reactors) are a class of nuclear reactor A nuclear reactor, formerly known as an atomic pile, is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactor ...
s, such as the EPR (nuclear reactor), EPR began construction, although encountering problems and delays, and going significantly over budget. Annual world electricity net generation.svg, Net electrical generation by source and growth from 1980. In terms of energy generated between 1980 and 2010, the contribution from fission grew the fastest. Electricity in France.svg, Electricity sector in France, Electricity production in France, showing the shift to nuclear power. Nuclear power history.svg, The rate of new reactor constructions essentially halted in the late 1980s. Increased
capacity factor The net capacity factor is the unitless ratio of an actual electrical energy output over a given period of time to the maximum possible electrical energy output over that period. The capacity factor is defined for any electricity producing install ...
in existing reactors was primarily responsible for the continuing increase in electrical energy produced during this period. Top 5 Nuclear Energy Producing Countries.png, Electricity generation trends in the top five fission-energy producing countries (US EIA data)


Fukushima and current prospects

Plans for a nuclear renaissance were ended by another nuclear accident. The 2011 Fukushima Daiichi nuclear accident was caused by a large tsunami triggered by the 2011 Tōhoku earthquake and tsunami, Tōhoku earthquake, one of the largest earthquakes ever recorded. The Fukushima Daiichi Nuclear Power Plant suffered three core meltdowns due to failure of the emergency cooling system for lack of electricity supply. This resulted in the most serious nuclear accident since the Chernobyl disaster. The accident prompted a re-examination of nuclear safety and nuclear energy policy in many countries. Germany approved plans to close all its reactors by 2022, and many other countries reviewed their nuclear power programs. Following the disaster, Japan shut down all of its nuclear power reactors, some of them permanently, and in 2015 began a gradual process to restart the remaining 40 reactors, following safety checks and based on revised criteria for operations and public approval. By 2015, the IAEA's outlook for nuclear energy had become more promising, recognizing the importance of low-carbon generation for mitigating climate change. , the global trend was for new nuclear power stations coming online to be balanced by the number of old plants being retired. In 2016, the U.S. Energy Information Administration projected for its "base case" that world nuclear power generation would increase from 2,344
terawatt hour The kilowatt-hour ( SI symbol: kW⋅h or kW h; commonly written as kWh) is a unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, ...
s (TWh) in 2012 to 4,500 TWh in 2040. Most of the predicted increase was expected to be in Asia. As of 2018, there are over 150 nuclear reactors planned including 50 under construction. In January 2019, China had 45 reactors in operation, 13 under construction, and plans to build 43 more, which would make it the world's largest generator of nuclear electricity. As of 2021, 17 reactors were reported to be under construction. China built significantly fewer reactors than originally planned, its share of electricity from nuclear power was 5% in 2019 and observers have cautioned that, along with the risks, the changing economics of energy generation may cause new nuclear energy plants to "no longer make sense in a world that is leaning toward cheaper, more reliable renewable energy".


Nuclear power plants

Nuclear power plants are thermal power stations that generate electricity by harnessing the thermal energy released from
nuclear fission Nuclear fission is a in which the of an splits into two or more smaller . The fission process often produces s, and releases a very large amount of even by the energetic standards of . Nuclear fission of heavy elements was discovered on ...

nuclear fission
. A fission nuclear power plant is generally composed of a nuclear reactor, in which the nuclear reactions generating heat take place; a cooling system, which removes the heat from inside the reactor; a steam turbine, which transforms the heat into mechanical energy; an electric generator, which transforms the mechanical energy into electrical energy. When a neutron hits the nucleus of a uranium-235 or
plutonium Plutonium is a radioactive decay, radioactive chemical element with the Symbol (chemistry), symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating plutoni ...

plutonium
atom, it can split the nucleus into two smaller nuclei. The reaction is called nuclear fission. The fission reaction releases energy and neutrons. The released neutrons can hit other uranium or plutonium nuclei, causing new fission reactions, which release more energy and more neutrons. This is called a Nuclear chain reaction, chain reaction. In most commercial reactors, the reaction rate is controlled by control rods that absorb excess neutrons. The controllability of nuclear reactors depends on the fact that a small fraction of neutrons resulting from fission are Delayed neutron, delayed. The time delay between the fission and the release of the neutrons slows down changes in reaction rates and gives time for moving the control rods to adjust the reaction rate.


Life cycle of nuclear fuel

The life cycle of nuclear fuel starts with uranium mining. The uranium ore is then converted into a compact ore concentrate form, known as yellowcake (U3O8), to facilitate transport. Fission reactors generally need uranium-235, a fissile material, fissile isotopes of uranium, isotope of uranium. The concentration of uranium-235 in natural uranium is very low (about 0.7%). Some reactors can use this natural uranium as fuel, depending on their neutron economy. These reactors generally have graphite or heavy water moderators. For light water reactors, the most common type of reactor, this concentration is too low, and it must be increased by a process called uranium enrichment. In civilian light water reactors, uranium is typically enriched to 3.5-5% uranium-235. The uranium is then generally converted into uranium oxide (UO2), a ceramic, that is then compressively sintered into fuel pellets, a stack of which forms fuel rods of the proper composition and geometry for the particular reactor. After some time in the reactor, the fuel will have reduced fissile material and increased fission products, until its use becomes impractical. At this point, the spent fuel will be moved to a spent fuel pool which provides cooling for the thermal heat and shielding for ionizing radiation. After several months or years, the spent fuel is radioactively and thermally cool enough to be moved to dry storage casks or reprocessed.


Uranium resources

Uranium is a fairly common chemical element, element in the Earth's crust: it is approximately as common as tin or germanium, and is about 40 times more common than silver. Uranium is present in trace concentrations in most rocks, dirt, and ocean water, but is generally economically extracted only where it is present in high concentrations. Uranium mining can be underground, Open-pit mining, open-pit, or in-situ leach mining. An increasing number of the highest output mines are remote underground operations, such as McArthur River uranium mine, in Canada, which by itself accounts for 13% of global production. As of 2011 the world's known resources of uranium, economically recoverable at the arbitrary price ceiling of US$130/kg, were enough to last for between 70 and 100 years. In 2007, the OECD estimated 670 years of economically recoverable uranium in total conventional resources and phosphate ores assuming the then-current use rate. Light water reactors make relatively inefficient use of nuclear fuel, mostly using only the very rare uranium-235 isotope. Nuclear reprocessing can make this waste reusable, and newer reactors also achieve a more efficient use of the available resources than older ones. With a pure fast reactor fuel cycle with a burn up of all the uranium and actinides (which presently make up the most hazardous substances in nuclear waste), there is an estimated 160,000 years worth of uranium in total conventional resources and phosphate ore at the price of 60–100 US$/kg. However, reprocessing is expensive, possibly dangerous and can be used to manufacture nuclear weapons. One analysis found that for uranium prices could increase by two orders of magnitudes between 2035 and 2100 and that there could be a shortage near the end of the century. A 2017 study by researchers from MIT and Woods Hole Oceanographic Institution, WHOI found that "at the current consumption rate, global conventional reserves of terrestrial uranium (approximately 7.6 million tonnes) could be depleted in a little over a century". Limited uranium-235 supply may inhibit substantial expansion with the current nuclear technology. While various ways to reduce dependence on such resources are being explored, new nuclear technologies are considered to not be available in time for climate change mitigation purposes or competition with alternatives of renewables in addition to being more expensive and require costly research and development. A study found it to be uncertain whether identified resources will be developed quickly enough to provide uninterrupted fuel supply to expanded nuclear facilities and various forms of mining may be challenged by ecological barriers, costs, and land requirements. Researchers also report considerable import dependence of nuclear energy. Unconventional uranium resources also exist. Uranium is naturally present in seawater at a concentration of about 3 micrograms per liter, with 4.4 billion tons of uranium considered present in seawater at any time. In 2014 it was suggested that it would be economically competitive to produce nuclear fuel from seawater if the process was implemented at large scale. Like fossil fuels, over geological timescales, uranium extracted on an industrial scale from seawater would be replenished by both river erosion of rocks and the natural process of uranium leaching (metallurgy), dissolved from the surface area of the ocean floor, both of which maintain the Solubility equilibrium, solubility equilibria of seawater concentration at a stable level. Some commentators have argued that this strengthens the case for Nuclear power proposed as renewable energy, nuclear power to be considered a renewable energy.


Nuclear waste

The normal operation of nuclear power plants and facilities produce radioactive waste, or nuclear waste. This type of waste is also produced during plant decommissioning. There are two broad categories of nuclear waste: low-level waste and high-level waste. The first has low radioactivity and includes contaminated items such as clothing, which poses limited threat. High-level waste is mainly the spent fuel from nuclear reactors, which is very radioactive and must be cooled and then safely disposed of or reprocessed.


High-level waste

The most important waste stream from nuclear power reactors is spent nuclear fuel, which is considered high-level waste. For LWRs, spent fuel is typically composed of 95% uranium, 4%
fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium Uranium is a chemical element with the Symbol (chemistry), symbol U and atomic numbe ...
s, and about 1% transuranic actinides (mostly
plutonium Plutonium is a radioactive decay, radioactive chemical element with the Symbol (chemistry), symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating plutoni ...

plutonium
, neptunium and americium). The plutonium and other transuranics are responsible for the bulk of the long-term radioactivity, whereas the fission products are responsible for the bulk of the short-term radioactivity. High-level waste requires treatment, management, and isolation from the environment. These operations present considerable challenges due to the extremely long periods these materials remain potentially hazardous to living organisms. This is due to long-lived fission products (LLFP), such as technetium-99 (half-life 220,000 years) and iodine-129 (half-life 15.7 million years). LLFP dominate the waste stream in terms of radioactivity, after the more intensely radioactive short-lived fission products (SLFPs) have decayed into stable elements, which takes approximately 300 years. Due to the exponential decrease of radioactivity with time, spent nuclear fuel activity decrease by 99.5% after 100 years. After about 100,000 years, the spent fuel becomes less radioactive than natural uranium ore. Commonly suggested methods to isolate LLFP waste from the biosphere include separation and Nuclear transmutation, transmutation, synroc treatments, or deep geological storage. Thermal-neutron reactors, which presently constitute the majority of the world fleet, cannot burn up the reactor grade plutonium that is generated during the reactor operation. This limits the life of nuclear fuel to a few years. In some countries, such as the United States, spent fuel is classified in its entirety as a nuclear waste. In other countries, such as France, it is largely reprocessed to produce a partially recycled fuel, known as mixed oxide fuel or MOX. For spent fuel that does not undergo reprocessing, the most concerning isotopes are the medium-lived transuranic elements, which are led by reactor-grade plutonium (half-life 24,000 years). Some proposed reactor designs, such as the Integral Fast Reactor and molten salt reactors, can use as fuel the plutonium and other actinides in spent fuel from light water reactors, thanks to their fast fission spectrum. This offers a potentially more attractive alternative to deep geological disposal. The thorium fuel cycle results in similar fission products, though creates a much smaller proportion of transuranic elements from neutron capture events within a reactor. Spent thorium fuel, although more difficult to handle than spent uranium fuel, may present somewhat lower proliferation risks.


Low-level waste

The nuclear industry also produces a large volume of low-level waste, with low radioactivity, in the form of contaminated items like clothing, hand tools, water purifier resins, and (upon decommissioning) the materials of which the reactor itself is built. Low-level waste can be stored on-site until radiation levels are low enough to be disposed of as ordinary waste, or it can be sent to a low-level waste disposal site.


Waste relative to other types

In countries with nuclear power, radioactive wastes account for less than 1% of total industrial toxic wastes, much of which remains hazardous for long periods. Overall, nuclear power produces far less waste material by volume than fossil-fuel based power plants. Coal-burning plants, in particular, produce large amounts of toxic and mildly radioactive ash resulting from the concentration of naturally occurring radioactive materials in coal. A 2008 report from Oak Ridge National Laboratory concluded that coal power actually results in more radioactivity being released into the environment than nuclear power operation, and that the population effective dose equivalent from radiation from coal plants is 100 times that from the operation of nuclear plants. Although coal ash is much less radioactive than spent nuclear fuel by weight, coal ash is produced in much higher quantities per unit of energy generated. It is also released directly into the environment as fly ash, whereas nuclear plants use shielding to protect the environment from radioactive materials. Nuclear waste volume is small compared to the energy produced. For example, at Yankee Rowe Nuclear Power Station, which generated 44 billion kilowatt hours of electricity when in service, its complete spent fuel inventory is contained within sixteen casks. It is estimated that to produce a lifetime supply of energy for a person at a western standard of living (approximately 3 GWh) would require on the order of the volume of a soda can of low enriched uranium, resulting in a similar volume of spent fuel generated.


Waste disposal

Following interim storage in a spent fuel pool, the bundles of used fuel rod assemblies of a typical nuclear power station are often stored on site in dry cask storage vessels. Presently, waste is mainly stored at individual reactor sites and there are over 430 locations around the world where radioactive material continues to accumulate. Disposal of nuclear waste is often considered the most politically divisive aspect in the lifecycle of a nuclear power facility.Montgomery, Scott L. (2010). ''The Powers That Be'', University of Chicago Press, p. 137. With the lack of movement of nuclear waste in the 2 billion year old natural nuclear fission reactors in Oklo, Gabon being cited as "a source of essential information today." Experts suggest that centralized underground repositories which are well-managed, guarded, and monitored, would be a vast improvement. There is an "international consensus on the advisability of storing nuclear waste in deep geological repository, deep geological repositories". With the advent of new technologies, other methods including horizontal drillhole disposal into geologically inactive areas have been proposed. There are no commercial scale purpose built underground high-level waste repositories in operation. However, in Finland the Onkalo spent nuclear fuel repository of the Olkiluoto Nuclear Power Plant is under construction as of 2015.


Reprocessing

Most thermal-neutron reactors run on a once-through nuclear fuel cycle, mainly due to the low price of fresh uranium. However, many reactors are also fueled with recycled fissionable materials that remain in spent nuclear fuel. The most common fissionable material that is recycled is the reactor-grade plutonium (RGPu) that is extracted from spent fuel, it is mixed with uranium oxide and fabricated into mixed-oxide or MOX fuel. Because thermal LWRs remain the most common reactor worldwide, this type of recycling is the most common. It is considered to increase the sustainability of the nuclear fuel cycle, reduce the attractiveness of spent fuel to theft, and lower the volume of high level nuclear waste. Spent MOX fuel cannot generally be recycled for use in thermal-neutron reactors. This issue does not affect fast-neutron reactors, which are therefore preferred in order to achieve the full energy potential of the original uranium. The main constituent of spent fuel from LWRs is slightly enriched uranium. This can be recycled into reprocessed uranium (RepU), which can be used in a fast reactor, used directly as fuel in CANDU reactors, or re-enriched for another cycle through an LWR. Re-enriching of reprocessed uranium is common in France and Russia. Reprocessed uranium is also safer in terms of nuclear proliferation potential. Reprocessing has the potential to recover up to 95% of the uranium and plutonium fuel in spent nuclear fuel, as well as reduce long-term radioactivity within the remaining waste. However, reprocessing has been politically controversial because of the potential for
nuclear proliferation Nuclear proliferation is the spread of nuclear weapons A nuclear weapon (also known as an atom bomb, atomic bomb, nuclear bomb or nuclear warhead, and colloquially as an A-bomb or nuke) is an explosive device that derives its destructiv ...

nuclear proliferation
and varied perceptions of increasing the vulnerability to
nuclear terrorism Nuclear terrorism refers to any person or persons who detonate a nuclear weapon A nuclear weapon (also called an atom bomb, nuke, atomic bomb, nuclear warhead, A-bomb, or nuclear bomb) is an explosive device that derives its destructive force ...
. Reprocessing also leads to higher fuel cost compared to the once-through fuel cycle.R. Stephen Berry and George S. Tolley
Nuclear Fuel Reprocessing
The University of Chicago, 2013.
While reprocessing reduces the volume of high-level waste, it does not reduce the
fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium Uranium is a chemical element with the Symbol (chemistry), symbol U and atomic numbe ...
s that are the primary causes of residual heat generation and radioactivity for the first few centuries outside the reactor. Thus, reprocessed waste still requires an almost identical treatment for the initial first few hundred years. Reprocessing of civilian fuel from power reactors is currently done in France, the United Kingdom, Russia, Japan, and India. In the United States, spent nuclear fuel is currently not reprocessed. The La Hague site, La Hague reprocessing facility in France has operated commercially since 1976 and is responsible for half the world's reprocessing as of 2010. It produces MOX fuel from spent fuel derived from several countries. More than 32,000 tonnes of spent fuel had been reprocessed as of 2015, with the majority from France, 17% from Germany, and 9% from Japan.


Breeding

Breeding is the process of converting non-fissile material into fissile material that can be used as nuclear fuel. The non-fissile material that can be used for this process is called fertile material, and constitute the vast majority of current nuclear waste. This breeding process occurs naturally in breeder reactors. As opposed to light water thermal-neutron reactors, which use uranium-235 (0.7% of all natural uranium), fast-neutron breeder reactors use uranium-238 (99.3% of all natural uranium) or thorium. A number of fuel cycles and breeder reactor combinations are considered to be sustainable or renewable sources of energy. In 2006 it was estimated that with seawater extraction, there was likely five billion years' worth of uranium resources for use in breeder reactors. Citing: Breeder technology has been used in several reactors, but as of 2006, the high cost of reprocessing fuel safely requires uranium prices of more than US$200/kg before becoming justified economically. Breeder reactors are however being developed for their potential to burn up all of the actinides (the most active and dangerous components) in the present inventory of nuclear waste, while also producing power and creating additional quantities of fuel for more reactors via the breeding process. As of 2017, there are two breeders producing commercial power, BN-600 reactor and the BN-800 reactor, both in Russia. The Phénix breeder reactor in France was powered down in 2009 after 36 years of operation. Both China and India are building breeder reactors. The Indian 500 MWe Prototype Fast Breeder Reactor is in the commissioning phase, with plans to build more. Another alternative to fast-neutron breeders are thermal-neutron breeder reactors that use uranium-233 bred from thorium as fission fuel in the thorium fuel cycle. Thorium is about 3.5 times more common than uranium in the Earth's crust, and has different geographic characteristics. India's three-stage nuclear power programme features the use of a thorium fuel cycle in the third stage, as it has abundant thorium reserves but little uranium.


Nuclear decommissioning

Nuclear decommissioning is the process of dismantling a nuclear facility to the point that it no longer requires measures for radiation protection, returning the facility and its parts to a safe enough level to be entrusted for other uses. Due to the presence of radioactive materials, nuclear decommissioning presents technical and economic challenges. The costs of decommissioning are generally spread over the lifetime of a facility and saved in a decommissioning fund.


Installed capacity and electricity production

Civilian nuclear power supplied 2,586
terawatt hour The kilowatt-hour ( SI symbol: kW⋅h or kW h; commonly written as kWh) is a unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, ...
s (TWh) of electricity in 2019, equivalent to about 10% of
global electricity generation World energy consumption is the total energy In physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , is the natural science that studies mat ...
, and was the second largest
low-carbon power Low-carbon power is electricity Electricity is the set of physical phenomena associated with the presence and motion Image:Leaving Yongsan Station.jpg, 300px, Motion involves a change in position In physics, motion is the phenomenon in ...
source after
hydroelectricity Hydroelectricity, or hydroelectric power, is electricity produced from hydropower Hydropower (from el, ὕδωρ, "water"), also known as water power, is the use of falling or fast-running water to produce electricity or to power machin ...
. Since electricity accounts for about 25% of world energy consumption, nuclear power's contribution to global energy was about 2.5% in 2011. This is a little more than the combined global electricity production from wind, solar, biomass and geothermal power, which together provided 2% of global final energy consumption in 2014. Nuclear power's share of global electricity production has fallen from 16.5% in 1997, in large part because the economics of nuclear power have become more difficult. there are List of nuclear reactors, 442 civilian fission reactors in the world, with a combined electrical capacity of 392
gigawatt The watt (symbol: W) is a unit of power Power typically refers to: * Power (physics) In physics, power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal ...
(GW). There are also 53 nuclear power reactors under construction and 98 reactors planned, with a combined capacity of 60 GW and 103 GW, respectively. The United States has the largest fleet of nuclear reactors, generating over 800 TWh per year with an average
capacity factor The net capacity factor is the unitless ratio of an actual electrical energy output over a given period of time to the maximum possible electrical energy output over that period. The capacity factor is defined for any electricity producing install ...
of 92%. Most reactors under construction are
generation III reactor Generation III reactors (Gen III reactors) are a class of nuclear reactor A nuclear reactor, formerly known as an atomic pile, is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactor ...
s in Asia. Regional differences in the use of nuclear power are large. The United States produces the most nuclear energy in the world, with nuclear power providing 20% of the electricity it consumes, while France produces the highest percentage of its electrical energy from nuclear reactors – 71% in 2019. In the European Union, nuclear power provides 26% of the electricity as of 2018. Nuclear power is the single largest low-carbon electricity source in the United States, and accounts for two-thirds of the European Union's low-carbon electricity. Nuclear energy policy differs among European Union countries, and some, such as Austria, Estonia, Ireland and Nuclear power in Italy, Italy, have no active nuclear power stations. In addition, there were approximately 140 naval vessels using nuclear propulsion in operation, powered by about 180 reactors. These include military and some civilian ships, such as nuclear-powered icebreakers. International research is continuing into additional uses of process heat such as hydrogen production (in support of a hydrogen economy), for desalination, desalinating sea water, and for use in district heating systems.


Economics

The economics of new nuclear power plants is a controversial subject and multibillion-dollar investments depend on the choice of energy sources. Nuclear power plants typically have high capital costs for building the plant. For this reason, comparison with other power generation methods is strongly dependent on assumptions about construction timescales and capital financing for nuclear plants. Fuel costs account for about 30 percent of the operating costs, while prices are subject to the market.''What's behind the red-hot uranium boom.''
CNN, 19 April 2007
The high cost of construction is one of the biggest challenges for nuclear power plants. A new 1,100 MW plant is estimated to cost between $6 billion to $9 billion. Nuclear power cost trends show large disparity by nation, design, build rate and the establishment of familiarity in expertise. The only two nations for which data is available that saw cost decreases in the 2000s were India and South Korea. Analysis of the economics of nuclear power must also take into account who bears the risks of future uncertainties. As of 2010, all operating nuclear power plants have been developed by state-owned or Regulated market, regulated electric utility monopolies. Many countries have since liberalized the electricity market 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. The levelized cost of electricity (LCOE) from a new nuclear power plant is estimated to be 69 USD/MWh, according to an analysis by the International Energy Agency and the OECD Nuclear Energy Agency. This represents the median cost estimate for an nth-of-a-kind nuclear power plant to be completed in 2025, at a Discounting, discount rate of 7%. Nuclear power was found to be the least-cost option among Dispatchable generation, dispatchable technologies. Variable renewable energy, Variable renewables can generate cheaper electricity: the median cost of onshore wind power was estimated to be 50 USD/MWh, and utility-scale solar power 56 USD/MWh. At the assumed CO2 emission cost of USD 30 per ton, power from coal (88 USD/MWh) and gas (71 USD/MWh) is more expensive than low-carbon technologies. Electricity from long-term operation of nuclear power plants by lifetime extension was found the be the least-cost option, at 32 USD/MWh. Measures to Mitigation of global warming, mitigate global warming, such as a carbon tax or carbon emissions trading, may favor the economics of nuclear power. New small modular reactors, such as those developed by NuScale Power, are aimed at reducing the investment costs for new construction by making the reactors smaller and modular, so that they can be built in a factory. Certain designs had considerable early positive economics, such as the CANDU, which realized much higher
capacity factor The net capacity factor is the unitless ratio of an actual electrical energy output over a given period of time to the maximum possible electrical energy output over that period. The capacity factor is defined for any electricity producing install ...
and reliability when compared to generation II light water reactors up to the 1990s. Nuclear power plants, though capable of some grid-load following, are typically run as much as possible to keep the cost of the generated electrical energy as low as possible, supplying mostly base-load electricity. Due to the on-line refueling reactor design, PHWRs (of which the CANDU design is a part) continue to hold many world record positions for longest continual electricity generation, often over 800 days. The specific record as of 2019 is held by a PHWR at Kaiga Atomic Power Station, generating electricity continuously for 962 days. Costs not considered in LCOE calculations include funds for research and development, and disasters (the Fukushima disaster is estimated to cost taxpayers ~$187 billion). Governments were found to in some cases force "consumers to pay upfront for potential cost overruns" or subsidize uneconomic nuclear energy or be required to do so. Nuclear operators are liable to pay for the waste management in the EU. In the U.S. the Congress reportedly decided 40 years ago that the nation, and not private companies, would be responsible for storing radioactive waste with taxpayers paying for the costs. The World Nuclear Waste Report 2019 found that "even in countries in which the polluter-pays-principle is a legal requirement, it is applied incompletely" and notes the case of the German Asse II mine, Asse II deep geological disposal facility, where the retrieval of large amounts of waste has to be paid for by taxpayers. Similarly, other forms of energy, including fossil fuels and renewables, have a portion of their costs covered by governments.


Use in space

The most common use of nuclear power in space is the use of
radioisotope thermoelectric generator A radioisotope thermoelectric generator (RTG, RITEG) is a type of nuclear battery that uses an array of thermocouples to convert the heat released by the decay of a suitable radioactive Radioactive decay (also known as nuclear decay, radi ...
s, which use radioactive decay to generate power. These power generators are relatively small scale (few kW), and they are mostly used to power space missions and experiments for long periods where solar power is not available in sufficient quantity, such as in the
Voyager 2 ''Voyager 2'' is a space probe launched by NASA on August 20, 1977, to study the outer planets and interstellar space beyond the Sun's heliosphere. A part of the Voyager program, it was launched 16 days before its twin, ''Voyager 1'', on a traje ...
space probe. A few space vehicles have been launched using nuclear reactors: 34 reactors belong to the Soviet RORSAT series and one was the American SNAP-10A. Both Nuclear fission, fission and fusion appear promising for Spacecraft propulsion, space propulsion applications, generating higher mission velocities with less reaction mass.


Safety

Nuclear power plants have three unique characteristics that affect their safety, as compared to other power plants. Firstly, intensely radioactive materials are present in a nuclear reactor. Their release to the environment could be hazardous. Secondly, the
fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium Uranium is a chemical element with the Symbol (chemistry), symbol U and atomic numbe ...
s, which make up most of the intensely radioactive substances in the reactor, continue to generate a significant amount of decay heat even after the fission Nuclear chain reaction, chain reaction has stopped. If the heat cannot be removed from the reactor, the fuel rods may overheat and release radioactive materials. Thirdly, a criticality accident (a rapid increase of the reactor power) is possible in certain reactor designs if the chain reaction cannot be controlled. These three characteristics have to be taken into account when designing nuclear reactors. All modern reactors are designed so that an uncontrolled increase of the reactor power is prevented by natural feedback mechanisms, a concept known as negative void coefficient of reactivity. If the temperature or the amount of steam in the reactor increases, the fission rate inherently decreases. The chain reaction can also be manually stopped by inserting control rods into the reactor core. Emergency core cooling systems (ECCS) can remove the decay heat from the reactor if normal cooling systems fail. If the ECCS fails, multiple physical barriers limit the release of radioactive materials to the environment even in the case of an accident. The last physical barrier is the large containment building. With a death rate of 0.07 per TWh, nuclear power is the safest energy source per unit of energy generated in terms of mortality when the historical track-record is considered. Energy produced by coal, petroleum, natural gas and hydropower has caused more deaths per unit of energy generated due to
air pollution Air pollution is the presence of substances in the atmosphere An atmosphere (from the greek words ἀτμός ''(atmos)'', meaning 'vapour', and σφαῖρα ''(sphaira)'', meaning 'ball' or 'sphere') is a layer or a set of layers of gas ...

air pollution
and energy accidents. This is found when comparing the immediate deaths from other energy sources to both the immediate and the latent, or predicted, indirect cancer deaths from nuclear energy accidents. When the direct and indirect fatalities (including fatalities resulting from the mining and air pollution) from nuclear power and fossil fuels are compared, the use of nuclear power has been calculated to have prevented about 1.8 million deaths between 1971 and 2009, by reducing the proportion of energy that would otherwise have been generated by fossil fuels. Following the 2011 Fukushima nuclear disaster, it has been estimated that if Japan had never adopted nuclear power, accidents and pollution from coal or gas plants would have caused more lost years of life. Serious impacts of nuclear accidents are often not directly attributable to radiation exposure, but rather social and psychological effects. Evacuation and long-term displacement of affected populations created problems for many people, especially the elderly and hospital patients. Forced evacuation from a nuclear accident may lead to social isolation, anxiety, depression, psychosomatic medical problems, reckless behavior, and suicide. A comprehensive 2005 study on the aftermath of the Chernobyl disaster concluded that the mental health impact is the largest public health problem caused by the accident. Frank N. von Hippel, an American scientist, commented that a disproportionate fear of ionizing radiation (radiophobia) could have long-term psychological effects on the population of contaminated areas following the Fukushima disaster. In January 2015, the number of Fukushima evacuees was around 119,000, compared with a peak of around 164,000 in June 2012.


Accidents and attacks


Accidents

Some serious nuclear and radiation accidents by death toll, nuclear and radiation accidents have occurred. The severity of nuclear accidents is generally classified using the International Nuclear Event Scale (INES) introduced by the International Atomic Energy Agency (IAEA). The scale ranks anomalous events or accidents on a scale from 0 (a deviation from normal operation that poses no safety risk) to 7 (a major accident with widespread effects). There have been 3 accidents of level 5 or higher in the civilian nuclear power industry, two of which, the Chernobyl accident and the Fukushima accident, are ranked at level 7. The Fukushima Daiichi nuclear accident was caused by the 2011 Tohoku earthquake and tsunami. The accident has not caused any radiation-related deaths but resulted in radioactive contamination of surrounding areas. The difficult Fukushima disaster cleanup, cleanup operation is expected to cost tens of billions of dollars over 40 or more years. The
Three Mile Island accident The Three Mile Island accident was a Nuclear meltdown, partial meltdown of the Three Mile Island Nuclear Generating Station, Three Mile Island, Unit 2 (TMI-2) reactor in Pennsylvania. It began at 4 a.m. on March 28, 1979. It is the most significa ...
in 1979 was a smaller scale accident, rated at INES level 5. There were no direct or indirect deaths caused by the accident. The impact of nuclear accidents is controversial. According to Benjamin K. Sovacool, fission energy accidents ranked first among energy sources in terms of their total economic cost, accounting for 41 percent of all property damage attributed to energy accidents. Another analysis found that coal, oil, liquid petroleum gas and hydroelectric accidents (primarily due to the Banqiao Dam disaster) have resulted in greater economic impacts than nuclear power accidents. The study compares latent cancer deaths attributable to nuclear with immediate deaths from other energy sources per unit of energy generated, and does not include fossil fuel related cancer and other indirect deaths created by the use of fossil fuel consumption in its "severe accident" (an accident with more than 5 fatalities) classification. The Chernobyl accident in 1986 caused approximately 50 deaths from direct and indirect effects, and some temporary serious injuries from acute radiation syndrome. The future predicted mortality from increases in cancer rates is estimated at about 4000 in the decades to come. However, the costs have been large and are increasing. Extreme weather events, including events made more severe by climate change, decrease the reliability of nuclear energy. Novel reactor types and weakening of safety standards to increase competitiveness of nuclear energy may increase risks or have new risks of accidents. Nuclear power works under an insurance framework that limits or structures accident liabilities in accordance with national and international conventions. It is often argued that this potential shortfall in liability represents an external cost not included in the cost of nuclear electricity. This cost is small, amounting to about 0.1% of the levelized cost of electricity, according to a study by the Congressional Budget Office in the United States. These beyond-regular insurance costs for worst-case scenarios are not unique to nuclear power. Hydroelectric power plants are similarly not fully insured against a catastrophic event such as dam failures. For example, the failure of the Banqiao Dam caused the death of an estimated 30,000 to 200,000 people, and 11 million people lost their homes. As private insurers base dam insurance premiums on limited scenarios, major disaster insurance in this sector is likewise provided by the state.


Attacks and sabotage

Terrorists could target
nuclear power plant A nuclear power plant (sometimes abbreviated as NPP) is a thermal power station A thermal power station is a power station in which heat energy is converted to electricity. Typically, fuel is used to boil water in a large pressure vessel to ...

nuclear power plant
s in an attempt to release radioactive contamination into the community. The United States 9/11 Commission has said that nuclear power plants were potential targets originally considered for the September 11, 2001 attacks. An attack on a reactor's spent fuel pool could also be serious, as these pools are less protected than the reactor core. The release of radioactivity could lead to thousands of near-term deaths and greater numbers of long-term fatalities. In the United States, the NRC carries out "Force on Force" (FOF) exercises at all nuclear power plant sites at least once every three years. In the United States, plants are surrounded by a double row of tall fences which are electronically monitored. The plant grounds are patrolled by a sizeable force of armed guards. Insider sabotage is also a threat because insiders can observe and work around security measures. Successful insider crimes depended on the perpetrators' observation and knowledge of security vulnerabilities. A fire caused 5–10 million dollars worth of damage to New York's Indian Point Energy Center in 1971. The arsonist turned out to be a plant maintenance worker.


Nuclear proliferation

Nuclear proliferation is the spread of
nuclear weapon A nuclear weapon (also known as an atom bomb, atomic bomb, nuclear bomb or nuclear warhead, and colloquially as an A-bomb or nuke) is an explosive device that derives its destructive force from nuclear reaction In nuclear physics Nucl ...
s, fissionable material, and weapons-related nuclear technology to states that do not already possess nuclear weapons. Many technologies and materials associated with the creation of a nuclear power program have a dual-use capability, in that they can also be used to make nuclear weapons. For this reason, nuclear power presents proliferation risks. Nuclear power program can become a route leading to a nuclear weapon. An example of this is the concern over Nuclear program of Iran, Iran's nuclear program. The re-purposing of civilian nuclear industries for military purposes would be a breach of the Non-proliferation treaty, to which 190 countries adhere. As of April 2012, there are Nuclear power by country, thirty one countries that have civil nuclear power plants, of which List of states with nuclear weapons, nine have nuclear weapons. The vast majority of these nuclear weapons states have produced weapons before commercial nuclear power stations. A fundamental goal for global security is to minimize the nuclear proliferation risks associated with the expansion of nuclear power. The Global Nuclear Energy Partnership was an international effort to create a distribution network in which developing countries in need of energy would receive nuclear fuel at a discounted rate, in exchange for that nation agreeing to forgo their own indigenous development of a uranium enrichment program. The France-based Eurodif/''European Gaseous Diffusion Uranium Enrichment Consortium'' is a program that successfully implemented this concept, with Nuclear power in Spain, Spain and other countries without enrichment facilities buying a share of the fuel produced at the French-controlled enrichment facility, but without a transfer of technology. Iran was an early participant from 1974 and remains a shareholder of Eurodif via Sofidif. A 2009 United Nations report said that:
the revival of interest in nuclear power could result in the worldwide dissemination of uranium enrichment and spent fuel reprocessing technologies, which present obvious risks of proliferation as these technologies can produce fissile materials that are directly usable in nuclear weapons.
On the other hand, power reactors can also reduce nuclear weapons arsenals when military-grade nuclear materials are reprocessed to be used as fuel in nuclear power plants. The Megatons to Megawatts Program is considered the single most successful non-proliferation program to date. Up to 2005, the program had processed $8 billion of high enriched, weapons-grade uranium into low enriched uranium suitable as nuclear fuel for commercial fission reactors by diluting it with natural uranium. This corresponds to the elimination of 10,000 nuclear weapons. For approximately two decades, this material generated nearly 10 percent of all the electricity consumed in the United States, or about half of all U.S. nuclear electricity, with a total of around 7,000 TWh of electricity produced. In total it is estimated to have cost $17 billion, a "bargain for US ratepayers", with Russia profiting $12 billion from the deal. Much needed profit for the Russian nuclear oversight industry, which after the collapse of the Soviet economy, had difficulties paying for the maintenance and security of the Russian Federations highly enriched uranium and warheads. The Megatons to Megawatts Program was hailed as a major success by anti-nuclear weapon advocates as it has largely been the driving force behind the sharp reduction in the number of nuclear weapons worldwide since the cold war ended. However, without an increase in nuclear reactors and greater demand for fissile fuel, the cost of dismantling and down blending has dissuaded Russia from continuing their disarmament. As of 2013 Russia appears to not be interested in extending the program.


Environmental impact

Being a low-carbon energy source with relatively little land-use requirements, nuclear energy can have a positive environmental impact. It also requires a constant supply of significant amounts of water and affects the environment through mining and milling. Its largest potential negative impacts on the environment may arise from its transgenerational risks for nuclear weapons proliferation that may increase risks of their use in the future, risks for problems associated with the management of the radioactive waste such as groundwater contamination, risks for accidents and for risks for various forms of attacks on waste storage sites or reprocessing- and power-plants. However, these remain mostly only risks as historically there have only been few disasters at nuclear power plants with known relatively substantial environmental impacts.


Carbon emissions

Nuclear power is one of the leading low carbon power generation methods of producing
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electricity
, and in terms of Life-cycle greenhouse-gas emissions of energy sources, total life-cycle greenhouse gas emissions per unit of energy generated, has emission values comparable to or lower than renewable energy. A 2014 analysis of the carbon footprint literature by the Intergovernmental Panel on Climate Change (IPCC) reported that the embodied Life cycle assessment, total life-cycle emission intensity of nuclear power has a median value of 12 g carbon dioxide equivalent, eq/kilowatt-hour, kWh, which is the lowest among all commercial
baseload The baseload (also base load) on a grid is the minimum level of demand on an electrical grid An electrical grid is an interconnected network for electricity delivery from producers to consumers. Electrical grids vary in size and can cover who ...
energy sources. This is contrasted with coal and
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natural gas
at 820 and 490 g eq/kWh. From the beginning of its commercialization in the 1970s, nuclear power has prevented the emission of about 64 billion tonnes of carbon dioxide equivalent that would have otherwise resulted from the burning of fossil fuels in thermal power stations.


Radiation

The average dose from natural background radiation is 2.4 millisievert per year (mSv/a) globally. It varies between 1 mSv/a and 13 mSv/a, depending mostly on the geology of the location. According to the United Nations (UNSCEAR), regular nuclear power plant operations, including the nuclear fuel cycle, increases this amount by 0.0002 mSv/a of public exposure as a global average. The average dose from operating nuclear power plants to the local populations around them is less than 0.0001 mSv/a. For comparison, the average dose to those living within 50 miles of a coal power plant is over three times this dose, at 0.0003 mSv/a. Chernobyl resulted in the most affected surrounding populations and male recovery personnel receiving an average initial 50 to 100 mSv over a few hours to weeks, while the remaining global legacy of the worst nuclear power plant accident in average exposure is 0.002 mSv/a and is continually dropping at the decaying rate, from the initial high of 0.04 mSv per person averaged over the entire populace of the Northern Hemisphere in the year of the accident in 1986.


Debate on nuclear power

The nuclear power debate concerns the controversy which has surrounded the deployment and use of nuclear fission reactors to generate electricity from nuclear fuel for civilian purposes. Proponents of nuclear energy regard it as a
sustainable energy Energy In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in other words, t ...
source that reduces
carbon emissions Greenhouse gas emissions are emissions of greenhouse gases created from a range of human activities that cause climate change, as they have increased concentrations in the earth's atmosphere. These emissions mainly include carbon dioxide emissions ...
and increases energy security by decreasing dependence on other energy sources that are also often dependent on imports.. M. King Hubbert, who popularized the concept of peak oil, saw oil as a resource that would run out and considered nuclear energy its replacement. Proponents also claim that the present quantity of nuclear waste is small and can be reduced through the latest technology of newer reactors and that the operational safety record of fission-electricity in terms of deaths is so far "unparalleled". Kharecha and James Hansen, Hansen estimated that "global nuclear power has prevented an average of 1.84 million air pollution-related deaths and 64 gigatonnes of CO2-equivalent (GtCO2-eq) greenhouse gas (GHG) emissions that would have resulted from fossil fuel burning" and, if continued, it could prevent up to 7 million deaths and 240 GtCO2-eq emissions by 2050. Opponents find that nuclear power poses many threats to people's health and environment such as the risk of nuclear weapons proliferation, long-term safe waste management and terrorism in the future. They also contend that nuclear power plants are complex systems where many things can and have gone wrong. Costs of the
Chernobyl disaster The Chernobyl disaster was a that occurred on 26 April 1986 at the No. 4 in the , near the city of in the north of the in the . It is considered the worst nuclear disaster in history both in cost and casualties. It is one of only two nucle ...
amount to ~$68 billion as of 2019 and are increasing, the Fukushima Daiichi nuclear disaster, Fukushima disaster is estimated to cost taxpayers ~$187 billion, and radioactive waste management is estimated to cost the EU nuclear operators ~$250 billion by 2050. However, in countries that already use nuclear energy, when not considering reprocessing, intermediate nuclear waste disposal costs could be relatively fixed to certain but unknown degrees "as the main part of these costs stems from the operation of the intermediate storage facility". Critics find that one of the largest drawbacks to building new nuclear fission power plants are the large construction and operating costs when compared to alternatives of sustainable energy sources. Further costs include costs for ongoing research and development, expensive Nuclear reprocessing, reprocessing in cases where such is practiced and decommissioning. Overall, many opponents find that nuclear energy cannot meaningfully contribute to climate change mitigation as they find it to be, in overall summary, too dangerous, too expensive, to take too long for deployment and to be an obstacle to achieving a transition towards sustainability and carbon-neutrality, effectively being a distracting competition for resources (i.e. human, financial, time, infrastructure and expertise) for the deployment and development of alternative, sustainable, energy system technologies (such as for wind, ocean and solar–including e.g. floating solar–as well as ways to manage Variable renewable energy, their intermittency other than nuclear baseload generation such as dispatchable generation, renewables-diversification, super grids, flexible energy demand and supply regulating smart grids and energy storage technologies). Nevertheless, there is ongoing research and debate over costs of new nuclear, especially in regions where i.a. seasonal energy storage is difficult to provide and which aim to fossil fuel phase-out, phase out fossil fuels in favor of low carbon power faster than the global average. Some find that financial transition costs for a 100% renewables-based European energy system that has completely phased out nuclear energy could be more costly by 2050 based on current technologies (i.e. not considering potential advances in e.g. green hydrogen, transmission- and flexibility capacities, ways to reduce energy-needs, geothermal energy and fusion energy) when the grid only extends across Europe. Arguments of economics and safety are used by both sides of the debate.


Comparison with renewable energy

Slowing global warming requires a transition to a low-carbon economy, mainly by burning far less fossil fuel. Limiting global warming to 1.5 °C is technically possible if no new fossil fuel power plants are built from 2019. This has generated considerable interest and dispute in determining the best path forward to rapidly replace fossil-based fuels in the global energy consumption, global energy mix, with intense academic debate. Sometimes the IEA says that countries without nuclear should develop it as well as their renewable power. Several studies suggest that it might be theoretically possible to cover a majority of world energy generation with new renewable sources. The Intergovernmental Panel on Climate Change (IPCC) has said that if governments were supportive, renewable energy supply could account for close to 80% of the world's energy use by 2050. While in developed nations the economically feasible geography for new hydropower is lacking, with every geographically suitable area largely already exploited, some proponents of wind and solar energy claim these resources alone could eliminate the need for nuclear power. Nuclear power is comparable to, and in some cases lower, than many renewable energy sources in terms of lives lost in the past per unit of electricity delivered. Depending on recycling of renewable energy technologies, nuclear reactors may produce a much smaller volume of waste, although much more toxic, expensive to manage and longer-lived. A nuclear plant also needs to be disassembled and removed and much of the disassembled nuclear plant needs to be stored as low-level nuclear waste for a few decades. The disposal and management of the wide variety of radioactive waste, of which there are over one quarter of a million tons as of 2018, can cause future damage and costs across the world radioactive waste#Fuel composition and long term radioactivity, for over or during hundreds of thousands of years–possibly over a million years, due to issues such as leakage, malign retrieval, vulnerability to attacks (including of reprocessing- and Vulnerability of nuclear plants to attack, power plants), groundwater contamination, radiation and leakage to above ground, brine leakage or bacterial corrosion. The European Commission Joint Research Centre found that as of 2021 the necessary technologies for geological disposal of nuclear waste are now available and can be deployed. Corrosion experts noted in 2020 that putting the problem of storage off any longer "isn't good for anyone". Separated
plutonium Plutonium is a radioactive decay, radioactive chemical element with the Symbol (chemistry), symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating plutoni ...

plutonium
and enriched uranium could be used for
nuclear weapon A nuclear weapon (also known as an atom bomb, atomic bomb, nuclear bomb or nuclear warhead, and colloquially as an A-bomb or nuke) is an explosive device that derives its destructive force from nuclear reaction In nuclear physics Nucl ...
s, which – even with the current centralized control (e.g. state-level) and level of prevalence – are considered to be a difficult and Global catastrophic risk#Warfare and mass destruction, substantial global risk for substantial future impacts on human health, lives, civilization and the environment.


Speed of transition and investment needed

Analysis in 2015 by professor Barry Brook (scientist), Barry W. Brook and colleagues found that nuclear energy could displace or remove fossil fuels from the electric grid completely within 10 years. This finding was based on the historically modest and proven rate at which nuclear energy was added in France and Sweden during their building programs in the 1980s. In a similar analysis, Brook had earlier determined that 50% of all world energy consumption, global energy, including transportation synthetic fuels etc., could be generated within approximately 30 years if the global nuclear fission build rate was identical to historical proven installation rates calculated in Gigawatt, GW per year per unit of global GDP (GW/year/$). This is in contrast to the conceptual studies for 100% renewable energy systems, which would require an orders of magnitude more costly global investment per year, which has no historical precedent. These renewable scenarios would also need far greater land devoted to onshore wind and onshore solar projects. Brook notes that the "principal limitations on nuclear fission are not technical, economic or fuel-related, but are instead linked to complex issues of societal acceptance, fiscal and political inertia, and inadequate critical evaluation of the real-world constraints facing [the other] low-carbon alternatives." Contrary to his views, the construction and operating costs of nuclear are very large when compared to alternatives of sustainable energy sources whose costs are decreasing and which are the fastest-growing source of electricity generation with there being ongoing research and development into options to move beyond current constraints in a highly decarbonized energy system without reliance on new nuclear. The costs and the increasing competition from sustainable energy technologies may be main drivers of an apparent decline of nuclear. Some have argued that recent publicity of nuclear energy – including for novel reactor designs like "small modular reactors" – is driven in part or mostly by a "declining industry's desperation for capital and its related lobby depicting it as a solution for climate change". Scientific data indicates that–assuming 2021 emissions levels–humanity only has a carbon budget equivalent to 11 years of emissions left for limiting warming to 1.5 °C while the construction of new nuclear reactors took a median of 7.2–10.9 years in 2018–2020, substantially longer than, alongside other measures, scaling up the deployment of wind and solar – especially for novel reactor types – as well as being more risky, often delayed and more dependent on state-support. Researchers have cautioned that novel nuclear technologies – which have been in development since decades, are less tested, have higher Radioactive waste#Proliferation concerns, proliferation risks, have more new safety problems, are often far from commercialization and are more expensive – are not available in time. Critics of nuclear energy often only oppose nuclear fission energy but not nuclear fusion – however, fusion energy is unlikely to be commercially widespread before 2050.


Land use

Nuclear power stations require approximately one square kilometer of land per typical reactor. Environmentalists and Conservation movement, conservationists have begun to question the global renewable energy expansion proposals, as they are opposed to the frequently controversial use of once forested land to situate renewable energy systems. Seventy five academic conservationists signed a letter, suggesting a more effective policy to mitigate climate change involving the reforestation of this land proposed for renewable energy production, to its prior natural landscape, by means of the native trees that previously inhabited it, in tandem with the lower land use footprint of nuclear energy, as the path to assure both the commitment to carbon emission reductions and to succeed with landscape Rewilding (conservation biology), rewilding programs that are part of the global native species protection and re-introduction initiatives. These scientists argue that government commitments to increase renewable energy usage while simultaneously making commitments to expand areas of biological conservation are two competing land-use outcomes, in opposition to one another, that are increasingly coming into conflict. With the existing protected areas for conservation at present regarded as insufficient to safeguard biodiversity "the conflict for space between energy production and habitat will remain one of the key future conservation issues to resolve."


Research


Advanced fission reactor designs

Current fission reactors in operation around the world are generation II reactor, second or generation III reactor, third generation systems, with most of the first-generation systems having been already retired. Research into advanced generation IV reactor types was officially started by the Generation IV International Forum (GIF) based on eight technology goals, including to improve economics, safety, proliferation resistance, natural resource utilization and the ability to consume existing nuclear waste in the production of electricity. Most of these reactors differ significantly from current operating light water reactors, and are expected to be available for commercial construction after 2030.


Hybrid nuclear fusion-fission

Hybrid nuclear power is a proposed means of generating power by the use of a combination of nuclear fusion and fission processes. The concept dates to the 1950s and was briefly advocated by Hans Bethe during the 1970s, but largely remained unexplored until a revival of interest in 2009, due to delays in the realization of pure fusion. When a sustained nuclear fusion power plant is built, it has the potential to be capable of extracting all the fission energy that remains in spent fission fuel, reducing the volume of nuclear waste by orders of magnitude, and more importantly, eliminating all actinides present in the spent fuel, substances which cause security concerns.


Nuclear fusion

Fusion power, Nuclear fusion reactions have the potential to be safer and generate less radioactive waste than fission. These reactions appear potentially viable, though technically quite difficult and have yet to be created on a scale that could be used in a functional power plant. Fusion power has been under theoretical and experimental investigation since the 1950s. Several experimental nuclear fusion reactors and facilities exist. The largest and most ambitious international nuclear fusion project currently in progress is ITER, a large tokamak under construction in France. ITER is planned to pave the way for commercial fusion power by demonstrating self-sustained nuclear fusion reactions with positive energy gain. Construction of the ITER facility began in 2007, but the project has run into many delays and budget overruns. The facility is now not expected to begin operations until the year 2027–11 years after initially anticipated. A follow on commercial nuclear fusion power station, DEMOnstration Power Station, DEMO, has been proposed. – Projected fusion power timeline There are also suggestions for a power plant based upon a different fusion approach, that of an inertial fusion power plant. Fusion-powered electricity generation was initially believed to be readily achievable, as fission-electric power had been. However, the extreme requirements for continuous reactions and plasma containment led to projections being extended by several decades. In 2020, more than 80 years after Timeline of nuclear fusion#1930s, the first attempts, commercialization of fusion power production was thought to be unlikely before 2050.


See also

* Atomic battery * Nuclear power by country * Nuclear weapons debate * Thorium-based nuclear power * Uranium mining debate * World energy consumption


References


Further reading

* AEC Atom Information Booklets
Both series, "Understanding the Atom" and "The World of the Atom"
A total of 75 booklets published by the U.S. Atomic Energy Commission (AEC) in the 1960s and 1970s, Authored by scientists and taken together, the booklets comprise the history of nuclear science and its applications at the time. * Armstrong, Robert C., Catherine Wolfram, Robert Gross, Nathan S. Lewis, and M.V. Ramana et al
The Frontiers of Energy
''Nature Energy'', Vol 1, 11 January 2016. * Brown, Kate (2013). Plutopia, ''Plutopia: Nuclear Families, Atomic Cities, and the Great Soviet and American Plutonium Disasters'', Oxford University Press. * Clarfield, Gerald H. and William M. Wiecek (1984). ''Nuclear America: Military and Civilian Nuclear Power in the United States 1940–1980'', Harper & Row. * Stephanie Cooke, Cooke, Stephanie (2009). ''In Mortal Hands: A Cautionary History of the Nuclear Age'', Black Inc. * * David Elliott (professor), Elliott, David (2007). ''Nuclear or Not?, Nuclear or Not? Does Nuclear Power Have a Place in a Sustainable Energy Future?'', Palgrave. * Ferguson, Charles D., (2007). ''Nuclear Energy: Balancing Benefits and Risks'' Council on Foreign Relations. * Garwin, Richard L. and Charpak, Georges (2001) Megawatts and Megatons A Turning Point in the Nuclear Age?, Knopf. * Herbst, Alan M. and George W. Hopley (2007). ''Nuclear Energy Now: Why the Time has come for the World's Most Misunderstood Energy Source'', Wiley. * * Mycle Schneider, Schneider, Mycle, Stephen Thomas (professor), Steve Thomas, Antony Froggatt, Doug Koplow (2016). ''The World Nuclear Industry Status Report: World Nuclear Industry Status as of 1 January 2016''. * Walker, J. Samuel (1992). ''Containing the Atom: Nuclear Regulation in a Changing Environment, 1993–1971'', Berkeley: University of California Press. * Spencer Weart, Weart, Spencer R. ''The Rise of Nuclear Fear''. Cambridge, MA: Harvard University Press, 2012.


External links


U.S. Energy Information Administration

Nuclear Fuel Cycle Cost Calculator
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