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{{short description|Power generated from nuclear reactions}}
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{{For|countries with the power or ability to project nuclear weapons|List of states with nuclear weapons}}
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[[File:2011-05-10 18-57-46 Switzerland - Wil crop.jpg|thumb|The [[Leibstadt Nuclear Power Plant]] in Switzerland]]
[[File:Nuclear power generation.svg|thumb|Growth of worldwide nuclear power generation]]'''Nuclear power''' is the use of [[nuclear reaction]]s to produce [[electricity]]. Nuclear power can be obtained from [[nuclear fission]], [[nuclear decay]] and [[nuclear fusion]] reactions. Presently, the vast majority of electricity from nuclear power is produced by nuclear ''fission'' of [[uranium]] and [[plutonium]] in [[nuclear power plant]]s. Nuclear ''decay'' processes are used in niche applications such as [[radioisotope thermoelectric generator]]s in some space probes such as ''[[Voyager 2]]''. Generating electricity from [[fusion power|''fusion'' power]] remains the focus of international research.

Most nuclear power plants use [[thermal reactor]]s with [[enriched uranium]] in a [[Nuclear fuel cycle#Once-through nuclear fuel cycle|once-through fuel cycle]]. Fuel is removed when the percentage of [[neutron poison|neutron absorbing atoms]] becomes so large that a [[nuclear chain reaction|chain reaction]] can no longer be sustained, typically three years. It is then cooled for several years in on-site [[spent fuel pool]]s before being transferred to long-term storage. The spent fuel, though low in volume, is [[high-level radioactive waste]]. While its radioactivity decreases exponentially it must be isolated from the biosphere for hundreds of thousands of years, though newer technologies (like [[fast reactor]]s) have the potential to reduce this significantly. Because the spent fuel is still mostly fissionable material, some countries (e.g. [[Nuclear power in France|France]] and [[Nuclear power in Russia|Russia]]) [[Nuclear reprocessing|reprocess]] their spent fuel by extracting [[fissile]] and [[Fertile material|fertile]] elements for fabrication in new fuel, although this process is more expensive than producing new fuel from [[Uranium mining|mined uranium]]. All reactors breed some [[plutonium-239]], which is found in the spent fuel, and because Pu-239 is the preferred material for [[nuclear weapons]], reprocessing is seen as a [[Nuclear proliferation|weapon proliferation]] risk.

The [[first nuclear power plant]] was built in the 1950s. The global installed nuclear capacity grew to 100{{nbsp}}GW in the late 1970s, and then expanded rapidly during the 1980s, reaching 300{{nbsp}}GW by 1990. The 1979 [[Three Mile Island accident]] in the [[United States]] and the 1986 [[Chernobyl disaster]] in the Soviet Union resulted in increased regulation and public opposition to nuclear plants.  These factors, along with high cost of construction, resulted in the global installed capacity only increasing to 390{{nbsp}}GW by 2022. These plants supplied 2,586 [[terawatt hour]]s (TWh) of electricity in 2019, equivalent to about 10% of [[global electricity generation]], and were the second-largest [[low-carbon power]] source after [[hydroelectricity]]. {{As of|2023|8|post=,}} there are [[List of nuclear reactors|410 civilian fission reactors in the world]], with overall capacity of 369{{nbsp}}GW,<ref name=":3">{{Cite web |title=PRIS - Home |url=https://pris.iaea.org/pris/home.aspx |access-date=2023-08-22 |website=pris.iaea.org}}</ref> 57 under construction and 102 planned, with a combined capacity of 59{{nbsp}}GW and 96{{nbsp}}GW, respectively. The United States has the largest fleet of nuclear reactors, generating almost 800{{nbsp}}TWh of low-carbon electricity per year with an average [[capacity factor]] of 92%. Average global capacity factor is 89%.<ref name=":3" /> Most new reactors under construction are [[generation III reactor]]s in Asia.

Proponents contend that nuclear power is a safe, sustainable energy source that reduces [[carbon emissions]]. This is because nuclear power generation causes one of the lowest levels of fatalities per unit of energy generated compared to other energy sources. [[Coal]], [[petroleum]], [[natural gas]] and hydroelectricity each have caused more fatalities per unit of energy due to [[air pollution]] and [[Energy accidents|accidents]]. Nuclear power plants also emit no [[greenhouse gases]] and result in less life-cycle carbon emissions than common "renewables". The novel radiological hazards associated with nuclear power are the primary motivations of the [[anti-nuclear movement]], which contends that nuclear power poses many threats to people and the environment, citing the potential for [[Nuclear and radiation accidents and incidents|accidents]] like the [[Fukushima nuclear disaster]] in [[Japan]] in 2011, and is too expensive/slow to deploy when compared to alternative [[sustainable energy]] sources.{{TOC limit}}

==History==
{{main|History of nuclear power}}

===Origins===
[[File:First four nuclear lit bulbs.jpeg|thumb|The first light bulbs ever lit by electricity generated by nuclear power at [[EBR-1]] at [[Argonne National Laboratory]]-West, December 20, 1951.<ref>{{cite web |title=Reactors: Modern-Day Alchemy - Argonne's Nuclear Science and Technology Legacy |url=https://www.ne.anl.gov/About/modern-day-alchemy/ |website=www.ne.anl.gov |access-date=24 March 2021}}</ref>]]
The discovery of nuclear fission occurred in 1938 following over four decades of work on the science of [[radioactivity]] and the elaboration of new [[nuclear physics]] that described the components of [[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.<ref name="Inside the Atomic Patent Office">{{cite journal | doi = 10.2968/064002008 | volume=64 | issue=2 | title=Inside the atomic patent office | year=2008 | journal=Bulletin of the Atomic Scientists | pages=26–31 | last1 = Wellerstein | first1 = Alex| bibcode=2008BuAtS..64b..26W }}</ref>
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]], for the development of a [[nuclear weapon]].<ref>{{cite web|url=http://www.atomicarchive.com/History/mp/introduction.shtml |title=The Einstein Letter |publisher=Atomicarchive.com |access-date=2013-06-22}}</ref>

In the United States, these research efforts led to the creation of the first man-made nuclear reactor, the [[Chicago Pile-1]], which achieved [[Criticality (status)|criticality]] on December 2, 1942. The reactor's development was part of the [[Manhattan Project]], the [[Allies of World War II|Allied]] effort to create [[atomic bombs]] during World War II. It led to the building of larger single-purpose [[production reactor]]s for the production of [[weapons-grade plutonium]] for use in the first nuclear weapons. The United States tested the first nuclear weapon in July 1945, the [[Trinity test]], with the [[atomic bombings of Hiroshima and Nagasaki]] taking place one month later.

[[File:Nautiluscore.jpg|thumb| The launching ceremony of the {{USS|Nautilus|SSN-571|6}} January 1954. In 1958 it would become the first vessel to reach the [[North Pole]].<ref>{{cite web |title=Nautilus (SSN-571) |url=https://www.history.navy.mil/browse-by-topic/ships/uss-nautilus.html |publisher=US Naval History and Heritage Command (US Navy)}}</ref>]]
[[File:HD.15.019 (11823864155).jpg|thumb|The [[Calder Hall nuclear power station]] in the United Kingdom, the world's first commercial nuclear power station.]]
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.<ref>{{cite book |last1=Wendt |first1=Gerald |last2=Geddes |first2=Donald Porter |title=The Atomic Age Opens |date=1945 |publisher=Pocket Books |location=New York |url=http://alsos.wlu.edu/information.aspx?id=279 |access-date=2017-11-03 |archive-date=2016-03-28 |archive-url=https://web.archive.org/web/20160328104803/http://alsos.wlu.edu/information.aspx?id=279 }}</ref>
Electricity was generated for the first time by a nuclear reactor on December 20, 1951, at the [[EBR-I]] experimental station near [[Arco, Idaho]], which initially produced about 100{{nbsp}}[[kW]].<ref>{{cite web |url=http://www.ne.anl.gov/About/reactors/frt.shtml |title=Reactors Designed by Argonne National Laboratory: Fast Reactor Technology |publisher=U.S. Department of Energy, Argonne National Laboratory |year=2012 |access-date=2012-07-25}}</ref><ref>{{cite magazine| url=https://books.google.com/books?id=yNwDAAAAMBAJ&q=1954+Popular+Mechanics+January&pg=PA105 |title=Reactor Makes Electricity |magazine=Popular Mechanics |date= March 1952| page= 105|publisher=Hearst Magazines }}</ref>
In 1953, American President [[Dwight Eisenhower]] gave his "[[Atoms for Peace]]" speech at the [[United Nations]], emphasizing the need to develop "peaceful" uses of nuclear power quickly. This was followed by the [[Atomic Energy Act of 1954]] 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 [[United States Navy|U.S. Navy]], with the [[S1W reactor]] for the purpose of propelling [[submarine]]s and [[aircraft carrier]]s. The first nuclear-powered submarine, {{USS|Nautilus|SSN-571|6}}, was put to sea in January 1954.<ref name="iaeapdf" /><ref>{{cite web |url=http://www.ne.anl.gov/About/reactors/lwr3.shtml#fragment-2 |title=STR (Submarine Thermal Reactor) in "Reactors Designed by Argonne National Laboratory: Light Water Reactor Technology Development" |publisher=U.S. Department of Energy, Argonne National Laboratory |year=2012 |access-date=2012-07-25}}</ref>
The S1W reactor was a [[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.<ref>{{cite book|last=Rockwell|first=Theodore|title=The Rickover Effect|publisher=Naval Institute Press|year=1992|page=162|isbn=978-1-55750-702-0}}</ref>

On June 27, 1954, the [[Obninsk Nuclear Power Plant]] in the [[USSR]] became the world's first nuclear power plant to generate electricity for a [[power grid]], producing around 5 megawatts of electric power.<ref name="IAEANews">{{cite web |url= http://www.iaea.org/NewsCenter/News/2004/obninsk.html |title=From Obninsk Beyond: Nuclear Power Conference Looks to Future |website=[[International Atomic Energy Agency]] | access-date = 2006-06-27|date=2004-06-23 }}</ref>
The world's first commercial nuclear power station, [[Calder Hall nuclear power station|Calder Hall]] at Windscale, England was connected to the national power grid on 27 August 1956. In common with a number of other [[generation I reactor]]s, the plant had the dual purpose of producing [[electricity]] and [[plutonium-239]], the latter for the nascent [[Nuclear weapons and the United Kingdom|nuclear weapons program in Britain]].<ref>{{cite book |last1=Hill |first1=C. N. |title=An atomic empire: a technical history of the rise and fall of the British atomic energy programme |date=2013 |publisher=Imperial College Press |location=London |isbn=978-1-908977-43-4}}</ref>

===Expansion and first opposition===
The total global installed nuclear capacity initially rose relatively quickly, rising from less than 1 [[gigawatt]] (GW) in 1960 to 100{{nbsp}}GW in the late 1970s.<ref name="iaeapdf">{{cite web |url= http://www.iaea.org/About/Policy/GC/GC48/Documents/gc48inf-4_ftn3.pdf |title=50 Years of Nuclear Energy |access-date=2006-11-09 |publisher=International Atomic Energy Agency }}</ref>
During the 1970s and 1980s rising economic costs (related to extended construction times largely due to regulatory changes and pressure-group litigation)<ref name="Bernard L. Cohen 1990">{{cite book |author=Bernard L. Cohen |date=1990 |title=The Nuclear Energy Option: An Alternative for the 90s |url=https://archive.org/details/nuclearenergyopt0000cohe |location=New York |publisher=Plenum Press |isbn=978-0-306-43567-6 |url-access=registration }}</ref> 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]] also made the addition of large new [[baseload]] energy generators economically unattractive.

The [[1973 oil crisis]] had a significant effect on countries, such as [[France]] and [[Japan]], which had relied more heavily on oil for electric generation to invest in nuclear power.<ref>{{cite web| author=Sharon Beder| url=http://www.herinst.org/sbeder/privatisation/japan.html |title=The Japanese Situation, English version of conclusion of Sharon Beder, "Power Play: The Fight to Control the World's Electricity"|publisher= Soshisha, Japan|date= 2006}}</ref>
France would construct 25 nuclear power plants over the next 15 years,<ref name="palfreman">{{Cite news| last = Palfreman| first = Jon| title = Why the French Like Nuclear Energy| work = [[Frontline (U.S. TV series)|Frontline]]| publisher = [[Public Broadcasting Service]]| access-date = 25 August 2007| year = 1997| url = https://www.pbs.org/wgbh/pages/frontline/shows/reaction/readings/french.html}}</ref><ref name="de preneuf">{{cite web| last = Rene de Preneuf| title = Nuclear Power in France&nbsp;– Why does it Work? | access-date = 25 August 2007| url = http://www.npcil.nic.in/nupower_vol13_2/npfr_.htm |archive-url = https://web.archive.org/web/20070813233335/http://www.npcil.nic.in/nupower_vol13_2/npfr_.htm <!-- Bot retrieved archive --> |archive-date = 13 August 2007}}</ref> and as of 2019, 71% of French electricity was generated by nuclear power, the highest percentage by any nation in the world.<ref name=":0" />

Some local opposition to nuclear power emerged in the United States in the early 1960s.<ref name=well>{{cite journal | author = Garb Paula | title = Review of Critical Masses: Opposition to Nuclear Power in California, 1958-1978 | url = http://jpe.library.arizona.edu/volume_6/wellockvol6.htm | journal = Journal of Political Ecology | volume = 6 | year = 1999 | access-date = 2011-03-14 | archive-date = 2018-06-01 | archive-url = https://web.archive.org/web/20180601112114/http://jpe.library.arizona.edu/volume_6/wellockvol6.htm }}</ref> In the late 1960s some members of the scientific community began to express pointed concerns.<ref name=wolfgang /> These [[anti-nuclear]] concerns related to [[nuclear accidents]], [[nuclear proliferation]], [[nuclear terrorism]] and [[High-level radioactive waste management|radioactive waste disposal]].<ref name=bm>{{cite journal| author=[[Brian Martin (social scientist)|Brian Martin]]| url= http://www.bmartin.cc/pubs/07sa.html | title=Opposing nuclear power: past and present| journal= Social Alternatives| volume= 26| number=2| date=2007|pages= 43–47}}</ref>
In the early 1970s, there were large protests about a proposed nuclear power plant in [[Wyhl]], Germany. The project was cancelled in 1975. The anti-nuclear success at Wyhl inspired opposition to nuclear power in other parts of Europe and North America.<ref name=pub>{{cite book |author1=Stephen Mills |author2=Roger Williams |title=Public acceptance of new technologies: an international review |date=1986 |publisher=Croom Helm |location=London |isbn=978-0-7099-4319-8 |url=https://books.google.com/books?id=SeMNAAAAQAAJ&q=%22public+acceptance+of+new+technologies%22 |pages=375–376}}</ref><ref name=got>Robert Gottlieb (2005). [https://books.google.com/books?id=lR0n6oqMNPkC&dq=transofrmation+of+the+american+environmental+gottlieb+revised&pg=PP1 Forcing the Spring: The Transformation of the American Environmental Movement], Revised Edition, Island Press, p. 237.</ref>

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.<ref name=jimfalk>{{cite book |last=Falk |first=Jim |date=1982|title=Global Fission: The Battle Over Nuclear Power |url=https://archive.org/details/globalfissionbat00falk |url-access=registration |location = Melbourne |publisher=Oxford University Press |pages=[https://archive.org/details/globalfissionbat00falk/page/95 95–96] |isbn=978-0-19-554315-5}}</ref><ref name=eleven>Walker, J. Samuel (2004). ''[https://books.google.com/books?id=tf0AfoynG-EC&q=Three+Mile+Island:+A+Nuclear+Crisis+in+Historical+Perspective Three Mile Island: A Nuclear Crisis in Historical Perspective]'' (Berkeley: University of California Press), pp. 10–11.</ref>
In some countries, the [[Nuclear power debate|nuclear power conflict]] "reached an intensity unprecedented in the history of technology controversies".<ref name="marcuse.org">{{cite journal |author=Herbert P. Kitschelt |date=1986 |title=Political Opportunity and Political Protest: Anti-Nuclear Movements in Four Democracies |url=http://www.marcuse.org/harold/hmimages/seabrook/861KitscheltAntiNuclear4Democracies.pdf |journal=British Journal of Political Science |volume=16 |issue=1 |page=57 |doi=10.1017/s000712340000380x|s2cid=154479502 }}</ref><ref name=kits>{{cite journal |author=Herbert P. Kitschelt |date=1986 |title=Political Opportunity and Political Protest: Anti-Nuclear Movements in Four Democracies |url=http://www.marcuse.org/harold/hmimages/seabrook/861KitscheltAntiNuclear4Democracies.pdf |journal=British Journal of Political Science |volume=16 |issue=1 |page=71|doi=10.1017/s000712340000380x|s2cid=154479502 }}</ref> 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.<ref name="phyast.pitt.edu">{{cite web |title=Costs of Nuclear Power Plants – What Went Wrong? |url=http://www.phyast.pitt.edu/~blc/book/chapter9.html |website=www.phyast.pitt.edu}}</ref><ref>{{cite news |url=https://www.washingtonexaminer.com/nuclear-energy-may-soon-be-free-from-its-tangled-regulatory-web | author1=Vance Ginn |author2= Elliott Raia|date= August 18, 2017 |title=nuclear energy may soon be free from its tangled regulatory web |work=Washington Examiner}}</ref>
In the United States, over [[List of cancelled nuclear reactors in the United States|120 LWR reactor proposals were ultimately cancelled]]<ref>{{cite web| url=https://fas.org/sgp/crs/misc/RL33442.pdf | title=Nuclear Power: Outlook for New U.S. Reactors | page= 3}}</ref> and the construction of new reactors ground to a halt.<ref name="ReferenceA">{{cite journal |date=1985-02-11 |title=Nuclear Follies |journal=Forbes Magazine|last=Cook|first=James}}</ref>
The 1979 [[Three Mile Island accident|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.<ref name=wolfgang>{{cite book|editor1-first=Wolfgang |editor1-last=Rüdig|title=Anti-nuclear Movements: A World Survey of Opposition to Nuclear Energy|url=https://books.google.com/books?id=ZXwfAQAAIAAJ|year=1990|publisher=Longman Current Affairs|location=Detroit, MI|isbn=978-0-8103-9000-3|page=1}}</ref>

===Chernobyl and renaissance===
[[File:Центр города Припять на фоне 4 энергоблокаа ЧАЭС.jpg|thumb|The town of [[Pripyat (city)|Pripyat]] abandoned since 1986, with the Chernobyl plant and the [[Chernobyl New Safe Confinement]] arch in the distance]]
[[File:OL3.jpg|thumb|[[Olkiluoto 3]] under construction in 2009. It was the first [[EPR (nuclear reactor)|EPR]], a modernized PWR design, to start construction. ]]
During the 1980s one new nuclear reactor started up every 17&nbsp;days on average.<ref>{{cite book |last1=Thorpe |first1=Gary S. |title=AP Environmental Science, 6th ed. |date=2015 |publisher=Barrons Educational Series |isbn=978-1-4380-6728-5}} {{ISBN|1-4380-6728-3}}</ref> By the end of the decade, global installed nuclear capacity reached 300{{nbsp}}GW. Since the late 1980s, new capacity additions slowed down significantly, with the installed nuclear capacity reaching 366{{nbsp}}GW in 2005.

The 1986 [[Chernobyl disaster]] in the [[USSR]], involving an [[RBMK]] reactor, altered the development of nuclear power and led to a greater focus on meeting international safety and regulatory standards.<ref>{{cite web |url= https://www.iaea.org/newscenter/focus/chernobyl|title=Chernobyl Nuclear Accident|date=14 May 2014|website=www.iaea.org | publisher=IAEA}}</ref>
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{{nbsp}}billion{{nbsp}}[[Soviet rouble|Rbl]]s (US$68{{nbsp}}billion in 2019, adjusted for inflation).<ref name="OECD02-Ch2">{{cite web|url=https://www.oecd-nea.org/rp/reports/2003/nea3508-chernobyl.pdf|title=Chernobyl: Assessment of Radiological and Health Impact, 2002 update; Chapter II – The release, dispersion and deposition of radionuclides|year=2002|publisher=OECD-NEA|access-date=3 June 2015|archive-url=https://web.archive.org/web/20150622010856/https://www.oecd-nea.org/rp/reports/2003/nea3508-chernobyl.pdf|archive-date=22 June 2015|url-status=live}}</ref><ref name="GorbachevBoC">{{cite AV media |people=Johnson, Thomas (author/director) |date=2006 |title=The battle of Chernobyl |url=https://www.andanafilms.com/catalogueFiche.php?idFiche=255&rub=Toutes%20les%20fiches%20films |publisher=Play Film / Discovery Channel}} (see 1996 interview with Mikhail Gorbachev)</ref> The international organization to promote safety awareness and the professional development of operators in nuclear facilities, the [[World Association of Nuclear Operators]] (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.<ref name=wolfgang/> Influenced by these events, Italy voted against nuclear power in a 1987 referendum,<ref>{{Cite book |last=Sassoon |first=Donald |url=https://books.google.com/books?id=W8K3AwAAQBAJ&dq=Italy+voted+against+nuclear+power+in+a+1987+referendum&pg=PT179 |title=Contemporary Italy: Politics, Economy and Society Since 1945 |date=2014-06-03 |publisher=Routledge |isbn=978-1-317-89377-6 |language=en}}</ref> becoming the first country to completely phase out nuclear power in 1990.

In the early 2000s, nuclear energy was expecting a [[nuclear renaissance]], an increase in the construction of new reactors, due to concerns about [[carbon dioxide emissions]].<ref name=":1">{{cite news |date=2011-03-14 |title=Analysis: Nuclear renaissance could fizzle after Japan quake |work=Reuters |url=https://www.reuters.com/article/us-japan-quake-nuclear-analysis-idUSTRE72C41W20110314 |access-date=2011-03-14}}</ref>
During this period, newer [[generation III reactor]]s, such as the [[EPR (nuclear reactor)|EPR]] began construction.
{{clear}}
<gallery mode="packed" heights="100px" style="text-align:left">
Global electricity generation by energy source.png|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. {{legend|#D55E00|thermofossil}}{{legend|#0072B2|hydroelectric}}{{legend|#F0E442|nuclear}}{{legend|#009E73|Other renewables}}
Nuclear-energy-timeline.svg|The rate of new reactor constructions essentially halted in the late 1980s. Increased [[capacity factor]] in existing reactors was primarily responsible for the continuing increase in electrical energy produced during this period.
Nuclear power generation in different countries.svg|Electricity generation trends in the top producing countries (Our World in Data)
</gallery>

===Fukushima===
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 | y= 2263.79 , 2298.27 , 2378.93 , 2443.85 , 2511.09 , 2553.18 , 2504.78 , 2616.24 , 2626.34 , 2660.85 , 2608.18 , 2597.81 , 2558.06 , 2629.82 , 2517.98 , 2346.19 , 2358.86 , 2410.37 , 2441.33 , 2477.30 , 2502.82 , 2562.76 , 2586.16
 | xAxisTitle=Year
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 | yAxisTitle=Generation (TWh)
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}}{{Graph:Chart
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|caption = Nuclear power generation (TWh) and operational nuclear reactors since 1997<ref name="pris-supplied" />
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Prospects of a nuclear renaissance were delayed by another nuclear accident.<ref name=":1" /><ref name=carbonbrief_2016>{{cite news |title=Analysis: The legacy of the Fukushima nuclear disaster |url=https://www.carbonbrief.org/analysis-the-legacy-of-the-fukushima-nuclear-disaster |access-date=24 March 2021 |work=Carbon Brief |date=10 March 2016 |language=en}}</ref>
The 2011 [[Fukushima Daiichi nuclear accident]] was caused by the [[2011 Tōhoku earthquake and tsunami|Tōhoku earthquake and tsunami]], 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.<ref name="sciamer2011">{{cite journal |author1=Sylvia Westall |author2=Fredrik Dahl |name-list-style=amp |date=2011-06-24 |title=IAEA Head Sees Wide Support for Stricter Nuclear Plant Safety |url=http://www.scientificamerican.com/article.cfm?id=iaea-head-sees-wide-support |archive-url=https://archive.today/20110625042535/http://www.scientificamerican.com/article.cfm?id=iaea-head-sees-wide-support |archive-date=2011-06-25 |journal=Scientific American }}</ref>
Germany approved plans to close all its reactors by 2022, and many other countries reviewed their nuclear power programs.<ref>{{cite news |author=Jo Chandler |date=2011-03-19 |title=Is this the end of the nuclear revival? |url=https://www.smh.com.au/world/is-this-the-end-of-the-nuclear-revival-20110318-1c0i9.html |newspaper=The Sydney Morning Herald|author-link=Jo Chandler }}</ref><ref>{{cite news |author=Aubrey Belford |date=2011-03-17 |title=Indonesia to Continue Plans for Nuclear Power |url=https://www.nytimes.com/2011/03/18/business/global/18atomic.html?partner=rss&emc=rss |newspaper=The New York Times}}</ref><ref name="piersmorgan.blogs.cnn.com">{{cite news|url=http://piersmorgan.blogs.cnn.com/2011/03/17/israel-prime-minister-netanyahu-japan-situation-has-caused-me-to-reconsider-nuclear-power/|title=Israel Prime Minister Netanyahu: Japan situation has "caused me to reconsider" nuclear power|author=Piers Morgan|work=CNN|date=2011-03-17|access-date=2011-03-17|archive-date=2019-09-30|archive-url=https://web.archive.org/web/20190930221401/http://piersmorgan.blogs.cnn.com/2011/03/17/israel-prime-minister-netanyahu-japan-situation-has-caused-me-to-reconsider-nuclear-power/}}</ref><ref name="news.xinhuanet.com">{{cite news|url=http://news.xinhuanet.com/english2010/world/2011-03/18/c_13784578.htm |archive-url=https://web.archive.org/web/20110318184804/http://news.xinhuanet.com/english2010/world/2011-03/18/c_13784578.htm |archive-date=March 18, 2011 |title=Israeli PM cancels plan to build nuclear plant|work= xinhuanet.com|date=2011-03-18| access-date= 2011-03-17}}</ref>
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.<ref>{{cite web |url=http://www.kyuden.co.jp/en_information_150811.html |title=Startup of Sendai Nuclear Power Unit No.1 |date=2015-08-11 |website=Kyushu Electric Power Company Inc. |access-date=2015-08-12 |archive-url=https://web.archive.org/web/20170525170529/http://www.kyuden.co.jp/en_information_150811.html |archive-date=2017-05-25 }}</ref>

In 2022, the Japanese government, under the leadership of Prime Minister [[Fumio Kishida]], has declared that 10 more nuclear power plants be reopened since the 2011 disaster.<ref>{{cite news |url=https://www.ft.com/content/b380cb74-7b2e-493f-be99-281bd0dd478f|title=Japan turns back to nuclear power in post-Fukushima shift|newspaper=Financial Times |date=24 August 2022 |access-date=November 15, 2022}}</ref> Kishida is also pushing for research and construction of new safer nuclear plants to safeguard Japanese consumers from the fluctuating fossil fuel market and reduce Japan's greenhouse gas emissions.<ref name="auto">{{cite web |url=https://reason.com/2022/08/25/japan-is-reopening-nuclear-power-plants-and-planning-to-build-new-ones/|title=Japan Is Reopening Nuclear Power Plants and Planning To Build New Ones|date=August 25, 2022}}</ref> Kishida intends to have Japan become a significant exporter of nuclear energy and technology to developing countries around the world.<ref name="auto"/>

=== Current prospects ===
By 2015, the IAEA's outlook for nuclear energy had become more promising, recognizing the importance of low-carbon generation for mitigating [[climate change]].<ref>{{cite web|url=http://www.iea.org/newsroomandevents/news/2015/january/taking-a-fresh-look-at-the-future-of-nuclear-power.html|title=January: Taking a fresh look at the future of nuclear power|website=www.iea.org}}</ref>
{{As of|2015}}, the global trend was for new nuclear power stations coming online to be balanced by the number of old plants being retired.<ref>{{cite web|publisher=[[World Nuclear Association]] |url=http://www.world-nuclear.org/info/current-and-future-generation/plans-for-new-reactors-worldwide/ |title=Plans for New Reactors Worldwide |date=October 2015}}</ref>
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]]s (TWh) in 2012 to 4,500{{nbsp}}TWh in 2040. Most of the predicted increase was expected to be in Asia.<ref>{{cite web| url=http://www.eia.gov/forecasts/aeo/data/browser/#/?id=31-IEO2016&sourcekey=0 | title=International Energy outlook 2016 | publisher= US Energy Information Administration |access-date= 17 August 2016}}</ref> As of 2018, there are over 150 nuclear reactors planned including 50 under construction.<ref>{{Cite web|title=Plans for New Nuclear Reactors Worldwide|url=http://www.world-nuclear.org/information-library/current-and-future-generation/plans-for-new-reactors-worldwide.aspx|access-date=2018-09-29|website=www.world-nuclear.org|publisher=World Nuclear Association}}</ref> 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.<ref name=china19>{{cite magazine|title=Can China become a scientific superpower? - The great experiment|url=https://www.economist.com/science-and-technology/2019/01/12/can-china-become-a-scientific-superpower|magazine=The Economist|date=12 January 2019|access-date=25 January 2019}}</ref> 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<ref name="dwfrance">{{cite news |title=A global nuclear phaseout or renaissance? {{!}} DW {{!}} 04.02.2021 |url=https://www.dw.com/en/germany-looking-for-final-repository-for-nuclear-waste-global-outlook/a-56449115 |access-date=25 November 2021 |work=Deutsche Welle (www.dw.com)}}</ref> 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".<ref name="cnnchina">{{cite news |last1=Griffiths |first1=James |title=China's gambling on a nuclear future, but is it destined to lose? |url=https://edition.cnn.com/2019/09/13/business/china-nuclear-climate-intl-hnk/index.html |access-date=25 November 2021 |work=CNN}}</ref><ref name="francere">{{cite news |title=Building new nuclear plants in France uneconomical -environment agency |url=https://www.reuters.com/article/france-nuclearpower/building-new-nuclear-plants-in-france-uneconomical-environment-agency-idUSL8N1YF5HC |access-date=25 November 2021 |work=Reuters |date=10 December 2018 |language=en}}</ref>

In October 2021, the Japanese cabinet approved the new Plan for Electricity Generation to 2030 prepared by the Agency for Natural Resources and Energy (ANRE) and an advisory committee, following public consultation. The nuclear target for 2030 requires the restart of another ten reactors. Prime Minister [[Fumio Kishida]] in July 2022 announced that the country should consider building advanced reactors and extending operating licences beyond 60 years.<ref>{{cite web|title=Nuclear Power in Japan| url=https://world-nuclear.org/information-library/country-profiles/countries-g-n/japan-nuclear-power.aspx|author= World Nuclear Association}}</ref>

As of 2022, with world oil and gas prices on the rise, while Germany is restarting its coal plants to deal with loss of Russian gas that it needs to supplement its {{lang|de|[[Energiewende]]}},<ref>{{cite news|url= https://www.reuters.com/business/energy/germanys-uniper-bring-coal-fired-power-plant-heyden-4-back-onto-electricity-2022-08-22/| title=Germany's Uniper to restart coal-fired power plant as Gazprom halts supply to Europe| date= 22 August 2022| publisher=Reuters}}</ref> many other countries have announced ambitious plans to reinvigorate ageing nuclear generating capacity with new investments. French President [[Emmanuel Macron]] announced his intention to build six new reactors in coming decades, placing nuclear at the heart of France's drive for [[carbon neutrality]] by 2050.<ref>{{cite news|url = https://www.reuters.com/business/energy/macron-bets-nuclear-carbon-neutrality-push-announces-new-reactors-2022-02-10/ | publisher=Reuters |title=Macron bets on nuclear in carbon-neutrality push, announces new reactors |date = 10 February 2022}}</ref> Meanwhile, in the United States, the [[Department of Energy]], in collaboration with commercial entities, [[TerraPower]] and [[X-energy]], is planning on building two different advanced nuclear reactors by 2027, with further plans for nuclear implementation in its long term green energy and energy security goals.<ref>{{cite news|url = https://www.science.org/content/article/department-energy-picks-two-advanced-nuclear-reactors-demonstration-projects | publisher=Science.org |title=Department of Energy picks two advanced nuclear reactors for demonstration projects, announces new reactors |date = 16 October 2020}}</ref>

== Power plants ==
[[File:PWR nuclear power plant animation.webm|thumb|thumbtime=2|An animation of a [[pressurized water reactor]] in operation]]
{{image frame
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 | y1=277,80,15,49,15,2
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|caption=Number of electricity-generating civilian reactors by type as of 2014<ref name="IAEA_reactors_stats">{{cite web|title=Nuclear Power Reactors in the World – 2015 Edition|url=http://www-pub.iaea.org/MTCD/Publications/PDF/rds2-35web-85937611.pdf|publisher=International Atomic Energy Agency (IAEA)|access-date=26 October 2017}}</ref>
{{columns-list|colwidth=4em|{{legend inline|#1f77b4|[[Pressurized water reactor|PWR]]}} {{legend inline|#ff7f0e|[[Boiling water reactor|BWR]]}} {{legend inline|#2ca02c|[[Gas-cooled reactor|GCR]]}} {{legend inline|#d62728|[[Pressurized heavy-water reactor|PHWR]]}} {{legend inline|#9467bd|[[Light water graphite-moderated reactor|LWGR]]}} {{legend inline|#8c564b|[[Fast breeder reactor|FBR]]}}}}
}}
{{Main|Nuclear power plant|Nuclear reactor}}
{{See also|List of commercial nuclear reactors|List of nuclear power stations}}
Nuclear power plants are [[thermal power station]]s that generate electricity by harnessing the [[thermal energy]] released from [[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.<ref name=WNAnuclearreactorbasics />

When a [[neutron]] hits the nucleus of a [[uranium-235]] or [[plutonium]] atom, it can split the nucleus into two smaller nuclei, which is a nuclear fission reaction. The 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 contained by [[control rod]]s 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.<ref name=WNAnuclearreactorbasics>{{cite web |title=How does a nuclear reactor make electricity? |publisher= World Nuclear Association |url=http://www.world-nuclear.org/nuclear-basics/how-does-a-nuclear-reactor-make-electricity.aspx |website=www.world-nuclear.org |access-date=24 August 2018}}</ref><ref>{{Cite news|url=https://www.scientificamerican.com/article/atomic-age-began-75-years-ago-with-the-first-controlled-nuclear-chain-reaction/|title=Atomic age began 75 years ago with the first controlled nuclear chain reaction|last1=Spyrou|first1=Artemis|date=2017-12-03|work=Scientific American|access-date=2018-11-18|last2=Mittig|first2=Wolfgang}}</ref>

== Fuel cycle ==
[[File:Nuclear Fuel Cycle.png|thumb|The nuclear fuel cycle begins when uranium is mined, enriched, and manufactured into nuclear fuel (1), which is delivered to a [[nuclear power plant]]. After use, the spent fuel is delivered to a reprocessing plant (2) or to a final repository (3). In [[nuclear reprocessing]] 95% of spent fuel can potentially be recycled to be returned to use in a power plant (4).]]

{{Main|Nuclear fuel cycle|Integrated Nuclear Fuel Cycle Information System}}

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]] (U<sub>3</sub>O<sub>8</sub>), to facilitate transport.<ref name="nrc_fuel">{{cite web |title=Stages of the Nuclear Fuel Cycle |url=https://www.nrc.gov/materials/fuel-cycle-fac/stages-fuel-cycle.html |website=NRC Web |publisher=[[Nuclear Regulatory Commission]] |access-date=17 April 2021}}</ref>
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]].<ref name="nrc_fuel"/> In civilian light water reactors, uranium is typically enriched to 3.5{{ndash}}5% uranium-235.<ref name="wna_fuel"/>
The uranium is then generally converted into [[uranium oxide]] (UO<sub>2</sub>), a ceramic, that is then compressively [[sintered]] into fuel pellets, a stack of which forms [[fuel rod]]s of the proper composition and geometry for the particular reactor.<ref name="wna_fuel">{{cite web |title=Nuclear Fuel Cycle Overview |url=https://www.world-nuclear.org/information-library/nuclear-fuel-cycle/introduction/nuclear-fuel-cycle-overview.aspx |website=www.world-nuclear.org |publisher=World Nuclear Association |access-date=17 April 2021}}</ref>

After some time in the reactor, the fuel will have reduced fissile material and increased fission products, until its use becomes impractical.<ref name="wna_fuel"/> 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.<ref name="wna_fuel"/>

=== Uranium resources ===
{{Main|Uranium market|Uranium mining|Energy development#Nuclear}}
[[File:Uranium enrichment proportions (horizontal).svg|upright=2|thumb|Proportions of the isotopes [[uranium-238]] (blue) and uranium-235 (red) found in natural uranium and in [[enriched uranium]] for different applications. Light water reactors use 3{{ndash}}5% enriched uranium, while [[CANDU]] reactors work with natural uranium.]]
[[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]].<ref>{{cite encyclopedia|url=http://www.encyclopedia.com/topic/uranium.aspx |title=uranium Facts, information, pictures &#124; Encyclopedia.com articles about uranium |encyclopedia=Encyclopedia.com |date=2001-09-11 |access-date=2013-06-14}}</ref>
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.<ref>{{cite web|url=http://www.spp.nus.edu.sg/docs/policy-briefs/201101_RSU_PolicyBrief_1-2nd_Thought_Nuclear-Sovacool.pdf |title=Second Thoughts About Nuclear Power |website=A Policy Brief – Challenges Facing Asia |date=January 2011 |archive-url=https://web.archive.org/web/20130116084833/http://spp.nus.edu.sg/docs/policy-briefs/201101_RSU_PolicyBrief_1-2nd_Thought_Nuclear-Sovacool.pdf |archive-date=January 16, 2013 }}</ref><ref>{{cite web | url= http://www.nea.fr/html/general/press/2008/2008-02.html | title= Uranium resources sufficient to meet projected nuclear energy requirements long into the future | date= 2008-06-03 | publisher= [[Nuclear Energy Agency]] (NEA) | access-date= 2008-06-16 | archive-url= https://web.archive.org/web/20081205121250/http://www.nea.fr/html/general/press/2008/2008-02.html | archive-date= 2008-12-05 }}</ref><ref name="Red">{{cite book |year=2008 |title=Uranium 2007 – Resources, Production and Demand |url=http://www.oecdbookshop.org/oecd/display.asp?sf1=identifiers&st1=9789264047662 |publisher=[[Nuclear Energy Agency]], [[Organisation for Economic Co-operation and Development]] |isbn=978-92-64-04766-2 |archive-url=https://web.archive.org/web/20090130092151/http://www.oecdbookshop.org/oecd/display.asp?sf1=identifiers&st1=9789264047662 |archive-date=2009-01-30 }}</ref>
In 2007, the OECD estimated 670 years of economically recoverable uranium in total conventional resources and [[phosphate]] ores assuming the then-current use rate.<ref>{{cite web |url=https://www.ipcc.ch/pdf/assessment-report/ar4/wg3/ar4-wg3-chapter4.pdf |title=Energy Supply |page=271 |archive-url=https://web.archive.org/web/20071215202932/http://www.ipcc.ch/pdf/assessment-report/ar4/wg3/ar4-wg3-chapter4.pdf |archive-date=2007-12-15}} and table 4.10.</ref>

Light water reactors make relatively inefficient use of nuclear fuel, mostly using only the very rare uranium-235 isotope.<ref name="wna-wmitnfc">{{cite web |url=http://www.world-nuclear.org/info/inf04.html |title=Waste Management in the Nuclear Fuel Cycle |access-date=2006-11-09 |publisher=World Nuclear Association |year=2006 |website=Information and Issue Briefs |archive-date=2010-06-11 |archive-url=https://web.archive.org/web/20100611201409/http://www.world-nuclear.org/info/inf04.html }}</ref> [[Nuclear reprocessing]] can make this waste reusable, and newer reactors also achieve a more efficient use of the available resources than older ones.<ref name="wna-wmitnfc"/> With a pure [[fast reactor]] fuel cycle with a burn up of all the uranium and [[actinide]]s (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.<ref>{{cite web |url=https://www.ipcc.ch/pdf/assessment-report/ar4/wg3/ar4-wg3-chapter4.pdf |title=Energy Supply |page=271 |archive-url=https://web.archive.org/web/20071215202932/http://www.ipcc.ch/pdf/assessment-report/ar4/wg3/ar4-wg3-chapter4.pdf |archive-date=2007-12-15}} and figure 4.10.</ref> However, reprocessing is expensive, possibly dangerous and can be used to manufacture nuclear weapons.<ref name="repr"/><ref name="future1">{{cite web |title=Toward an Assessment of Future Proliferation Risk |url=https://cpb-us-e1.wpmucdn.com/blogs.gwu.edu/dist/3/1964/files/2021/03/Mark_Hibbs.pdf |access-date=25 November 2021}}</ref><ref name="pluto">{{cite journal |last1=Zhang |first1=Hui |title=Plutonium reprocessing, breeder reactors, and decades of debate: A Chinese response |journal=Bulletin of the Atomic Scientists |date=1 July 2015 |volume=71 |issue=4 |pages=18–22 |doi=10.1177/0096340215590790 |s2cid=145763632 |language=en |issn=0096-3402}}</ref><ref name="civlib">{{cite journal |last1=Martin |first1=Brian |title=Nuclear power and civil liberties |journal=Faculty of Law, Humanities and the Arts - Papers (Archive) |date=1 January 2015 |pages=1–6 |url=https://ro.uow.edu.au/lhapapers/2126/}}</ref><ref name="detect">{{cite journal |last1=Kemp |first1=R. Scott |title=Environmental Detection of Clandestine Nuclear Weapon Programs |journal=Annual Review of Earth and Planetary Sciences |date=29 June 2016 |volume=44 |issue=1 |pages=17–35 |doi=10.1146/annurev-earth-060115-012526 |bibcode=2016AREPS..44...17K |hdl=1721.1/105171 |url=https://www.annualreviews.org/doi/full/10.1146/annurev-earth-060115-012526 |language=en |issn=0084-6597 |quote=Although commercial reprocessing involves large, expensive facilities, some of which are identifiable in structure, a small, makeshift operation using standard industrial supplies is feasible (Ferguson 1977, US GAO 1978). Such a plant could be constructed to have no visual signatures that would reveal its location by overhead imaging, could be built in several months, and once operational could produce weapon quantities of fissile material in several days|hdl-access=free }}</ref> 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.<ref>{{cite journal |last1=Monnet |first1=Antoine |last2=Gabriel |first2=Sophie |last3=Percebois |first3=Jacques |title=Long-term availability of global uranium resources |journal=Resources Policy |date=1 September 2017 |volume=53 |pages=394–407 |doi=10.1016/j.resourpol.2017.07.008 |bibcode=2017RePol..53..394M |language=en |issn=0301-4207 |url=https://tel.archives-ouvertes.fr/tel-01530739/file/2016_MONNET_diff.pdf |quote=However, it can be seen that the simulation in scenario A3 stops in 2075 due to a shortage: the R/P ratio cancels itself out. The detailed calculations also show that even though it does not cancel itself out in scenario C2, the R/P ratio constantly deteriorates, falling from 130 years in 2013 to 10 years around 2100, which raises concerns of a shortage around that time. The exploration constraints thus affect the security of supply.}}</ref> 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".<ref>{{cite conference |last1=Haji |first1=Maha N. |last2=Drysdale |first2=Jessica |last3=Buesseler |first3=Ken |last4=Slocum |first4=Alexander H. |title=Ocean Testing of a Symbiotic Device to Harvest Uranium From Seawater Through the Use of Shell Enclosures |book-title=Proceedings of the 27th International Ocean and Polar Engineering Conference |date=25 June 2017 |url=https://onepetro.org/ISOPEIOPEC/proceedings-abstract/ISOPE17/All-ISOPE17/ISOPE-I-17-356/17896 |publisher=International Society of Offshore and Polar |via=OnePetro |language=en}}</ref> Limited uranium-235 supply may inhibit substantial expansion with the current nuclear technology.<ref name="sol1"/> While various ways to reduce dependence on such resources are being explored,<ref>{{cite journal |last1=Chen |first1=Yanxin |last2=Martin |first2=Guillaume |last3=Chabert |first3=Christine |last4=Eschbach |first4=Romain |last5=He |first5=Hui |last6=Ye |first6=Guo-an |title=Prospects in China for nuclear development up to 2050 |journal=Progress in Nuclear Energy |date=1 March 2018 |volume=103 |pages=81–90 |doi=10.1016/j.pnucene.2017.11.011 |s2cid=126267852 |language=en |issn=0149-1970|url=https://hal-cea.archives-ouvertes.fr/cea-01908268/file/Chen%20-%202018%20-%20PNE%20-%20Chinese%20scenarios%20up%20to%202050.pdf }}</ref><ref>{{cite journal |last1=Gabriel |first1=Sophie |last2=Baschwitz |first2=Anne |last3=Mathonnière |first3=Gilles |last4=Eleouet |first4=Tommy |last5=Fizaine |first5=Florian |title=A critical assessment of global uranium resources, including uranium in phosphate rocks, and the possible impact of uranium shortages on nuclear power fleets |journal=Annals of Nuclear Energy |date=1 August 2013 |volume=58 |pages=213–220 |doi=10.1016/j.anucene.2013.03.010 |bibcode=2013AnNuE..58..213G |language=en |issn=0306-4549}}</ref><ref>{{cite journal |last1=Shang |first1=Delei |last2=Geissler |first2=Bernhard |last3=Mew |first3=Michael |last4=Satalkina |first4=Liliya |last5=Zenk |first5=Lukas |last6=Tulsidas |first6=Harikrishnan |last7=Barker |first7=Lee |last8=El-Yahyaoui |first8=Adil |last9=Hussein |first9=Ahmed |last10=Taha |first10=Mohamed |last11=Zheng |first11=Yanhua |last12=Wang |first12=Menglai |last13=Yao |first13=Yuan |last14=Liu |first14=Xiaodong |last15=Deng |first15=Huidong |last16=Zhong |first16=Jun |last17=Li |first17=Ziying |last18=Steiner |first18=Gerald |last19=Bertau |first19=Martin |last20=Haneklaus |first20=Nils |title=Unconventional uranium in China's phosphate rock: Review and outlook |journal=Renewable and Sustainable Energy Reviews |date=1 April 2021 |volume=140 |page=110740 |doi=10.1016/j.rser.2021.110740 |s2cid=233577205 |language=en |issn=1364-0321}}</ref> 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.<ref name="sol1"/><ref name="10.5281/zenodo.5573718"/><ref name="mil1"/> A study found it to be uncertain whether identified resources will be developed quickly enough to provide uninterrupted fuel supply to expanded nuclear facilities<ref>{{cite web |title=USGS Scientific Investigations Report 2012–5239: Critical Analysis of World Uranium Resources |url=https://pubs.usgs.gov/sir/2012/5239/ |website=pubs.usgs.gov |access-date=28 November 2021}}</ref> and various forms of mining may be challenged by ecological barriers, costs, and land requirements.<ref>{{cite journal |first=F.H. |last=Barthel |title=Thorium and unconventional uranium resources |website=International Atomic Energy Agency |date=2007 |url=https://inis.iaea.org/search/search.aspx?orig_q=RN:39023282 |language=en}}</ref><ref>{{cite journal |last1=Dungan |first1=K. |last2=Butler |first2=G. |last3=Livens |first3=F. R. |last4=Warren |first4=L. M. |title=Uranium from seawater – Infinite resource or improbable aspiration? |journal=Progress in Nuclear Energy |date=1 August 2017 |volume=99 |pages=81–85 |doi=10.1016/j.pnucene.2017.04.016 |language=en |issn=0149-1970}}</ref> Researchers also report considerable import dependence of nuclear energy.<ref>{{cite journal |last1=Fang |first1=Jianchun |last2=Lau |first2=Chi Keung Marco |last3=Lu |first3=Zhou |last4=Wu |first4=Wanshan |title=Estimating Peak uranium production in China – Based on a Stella model |journal=Energy Policy |date=1 September 2018 |volume=120 |pages=250–258 |doi=10.1016/j.enpol.2018.05.049 |s2cid=158066671 |language=en |issn=0301-4215|url=https://pure.hud.ac.uk/en/publications/4f2be679-fb50-4267-81ef-7cb2a5fe0f1d }}</ref><ref name="10.1016/j.enpol.2018.12.024"/><ref name="10.1016/j.anucene.2017.08.019"/><ref name="10.1002/ente.201600444"/>

Unconventional uranium resources also exist. Uranium is naturally present in seawater at a concentration of about 3 [[microgram]]s per liter,<ref name="books.google.ie">{{Cite book |url=https://books.google.com/books?id=OeEUcIRsIwAC&q=Radium+and+thorium+isotopes+in+the+surface+waters+of+the+East+Pacific+and+coastal+southern+California.+Earth+Planet.+Sci.+Lett.,+39:+235249.&pg=PA598 |page=399|title=Isotopes of the Earth's Hydrosphere|isbn=978-94-007-2856-1|last1=Ferronsky|first1=V.I.|last2=Polyakov|first2=V.A.|year=2012|publisher=Springer }}</ref><ref>{{Cite web |url=http://www.atsdr.cdc.gov/toxprofiles/tp147.pdf |title=Toxicological profile for thorium |year=1990 |publisher=Agency for Toxic Substances and Disease Registry |page=76 |quote=world average concentration in seawater is 0.05 μg/L (Harmsen and De Haan 1980)}}</ref><ref>{{Cite journal |doi=10.1021/ac00288a030|title = Determination of thorium concentration in seawater by neutron activation analysis|journal = Analytical Chemistry|volume = 57|issue = 11|pages = 2138–2142|year = 2002|last1 = Huh|first1 = C.A.|last2 = Bacon|first2 = M.P.}}</ref> with 4.4 billion tons of uranium considered present in seawater at any time.<ref name="gepr.org" />
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.<ref>{{Cite journal |doi=10.3390/jmse2010081|title=Development of a Kelp-Type Structure Module in a Coastal Ocean Model to Assess the Hydrodynamic Impact of Seawater Uranium Extraction Technology|journal=Journal of Marine Science and Engineering|volume=2|pages=81–92|year=2014|last1=Wang|first1=Taiping|last2=Khangaonkar|first2=Tarang|last3=Long|first3=Wen|last4=Gill|first4=Gary|doi-access=free}}</ref>
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.<ref name="gepr.org">{{cite web |url=http://www.gepr.org/en/contents/20130729-01/ |title= The current state of promising research into extraction of uranium from seawater – Utilization of Japan's plentiful seas |first=Noriaki|last=Seko| publisher=Global Energy Policy Research |date=July 29, 2013}}</ref>
Some commentators have argued that this strengthens the case for [[Nuclear power proposed as renewable energy|nuclear power to be considered a renewable energy]].<ref>{{cite journal |vauthors=Alexandratos SD, Kung S |journal=Industrial & Engineering Chemistry Research |date=April 20, 2016 |volume=55 |issue=15 |pages=4101–4362 |title=Uranium in Seawater |doi=10.1021/acs.iecr.6b01293 |doi-access=free}}</ref>

=== Waste ===
{{main|Nuclear waste}}
[[File:Nuclear fuel composition.svg|upright=1.5|thumb|Typical composition of [[uranium dioxide]] fuel before and after approximately three years in the [[once-through nuclear fuel cycle]] of a [[LWR]]<ref name="jaif">{{cite web|url=http://www.jaif.or.jp/ja/wnu_si_intro/document/08-07-16-finck_philip.pdf | title=Current Options for the Nuclear Fuel Cycle |publisher=JAIF |author=Finck, Philip| archive-url=https://web.archive.org/web/20120412130546/http://www.jaif.or.jp/ja/wnu_si_intro/document/08-07-16-finck_philip.pdf | archive-date=2012-04-12 }}</ref>]]
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.<ref name=nrc_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.<ref name=nrc_waste>{{cite web |title=Backgrounder on Radioactive Waste |url=https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/radwaste.html |website=NRC |publisher=[[Nuclear Regulatory Commission]] |access-date=20 April 2021}}</ref>

==== High-level waste ====
{{main|High-level waste|Spent nuclear fuel}}
[[File:Spent nuclear fuel decay sievert.jpg|thumb|Activity of spent UOx fuel in comparison to the activity of natural [[uranium ore]] over time<ref name="m.phys.org">{{Cite web | url=https://m.phys.org/news/2017-11-fast-reactor-shorten-lifetime-long-lived.html |title = A fast reactor system to shorten the lifetime of long-lived fission products}}</ref><ref name="jaif"/>]]
[[File:Nuclear dry storage.jpg|thumb|[[Dry cask storage]] vessels storing spent nuclear fuel assemblies]]

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]]s, and about 1% [[transuranic]] [[actinides]] (mostly [[plutonium]], [[neptunium]] and [[americium]]).<ref>{{cite web |title=Radioactivity: Minor Actinides |url=http://www.radioactivity.eu.com/site/pages/Minor_Actinides.htm |website=www.radioactivity.eu.com |access-date=2018-12-23 |archive-date=2018-12-11 |archive-url=https://web.archive.org/web/20181211042617/http://www.radioactivity.eu.com/site/pages/Minor_Actinides.htm }}</ref> The fission products are responsible for the bulk of the short-term radioactivity, whereas the plutonium and other transuranics are responsible for the bulk of the long-term radioactivity.<ref>{{cite book |last1=Ojovan |first1=Michael I. |title=An introduction to nuclear waste immobilisation, second edition |date=2014 |publisher=Elsevier |location=Kidlington, Oxford, U.K. |isbn=978-0-08-099392-8 |edition=2nd}}</ref>

High-level waste (HLW) must be stored isolated from the [[biosphere]] with sufficient shielding so as to limit radiation exposure.  After being removed from the reactors, used fuel bundles are stored for six to ten years in [[spent fuel pool]]s, which provide cooling and shielding against radiation. After that, the fuel is cool enough that it can be safely transferred to [[dry cask storage]].<ref>{{Cite web|url=http://nuclearsafety.gc.ca/eng/waste/high-level-waste/index.cfm|title=High-level radioactive waste|publisher=Canadian Nuclear Safety Commission|date=February 3, 2014|website=nuclearsafety.gc.ca|access-date=April 19, 2022|archive-date=April 14, 2022|archive-url=https://web.archive.org/web/20220414190417/http://nuclearsafety.gc.ca/eng/waste/high-level-waste/index.cfm|url-status=dead}}</ref> The radioactivity decreases exponentially with time, such that it will have decreased by 99.5% after 100 years.<ref>{{cite tech report |last1=Hedin |first1=A. |title=Spent nuclear fuel - how dangerous is it? A report from the project 'Description of risk' |date=1997 |url=https://www.osti.gov/etdeweb/biblio/587853 |publisher=Energy Technology Data Exchange}}</ref> The more intensely radioactive short-lived [[fission products]] (SLFPs) decay into stable elements in approximately 300 years, and after about 100,000 years, the spent fuel becomes less radioactive than natural uranium ore.<ref name="jaif"/><ref>{{cite book |last1=Bruno |first1=Jordi |last2=Duro |first2=Laura |last3=Diaz-Maurin |first3=François |date=2020 |title=Advances in Nuclear Fuel Chemistry |chapter=Chapter 13 – Spent nuclear fuel and disposal |series=Woodhead Publishing Series in Energy |pages=527–553 |chapter-url=https://www.sciencedirect.com/science/article/pii/B9780081025710000148 |publisher=Woodhead Publishing|doi=10.1016/B978-0-08-102571-0.00014-8 |isbn=978-0-08-102571-0 |s2cid=216544356 }}</ref>

Commonly suggested methods to isolate LLFP waste from the biosphere include separation and [[Nuclear transmutation|transmutation]],<ref name="jaif"/> [[synroc]] treatments, or deep geological storage.<ref>{{cite book|author1=Ojovan, M.I. |author2=Lee, W.E. |title=An Introduction to Nuclear Waste Immobilisation|publisher=Elsevier Science Publishers|location=Amsterdam|page=315|year=2005|isbn=978-0-08-044462-8}}</ref><ref>{{cite book |title=Technical Bases for Yucca Mountain Standards |author=National Research Council |year=1995 |publisher=National Academy Press |location=Washington, DC |isbn=978-0-309-05289-4|url=https://books.google.com/books?id=1DLyAtgVPy0C&pg=PA91|page=91}}</ref><ref>{{cite web |url=http://www.aps.org/units/fps/newsletters/2006/january/article1.html |title=The Status of Nuclear Waste Disposal |date=January 2006 |publisher=The American Physical Society |access-date=2008-06-06}}</ref><ref>{{cite web |url=http://www.epa.gov/radiation/docs/yucca/70fr49013.pdf |title=Public Health and Environmental Radiation Protection Standards for Yucca Mountain, Nevada; Proposed Rule |date=2005-08-22| publisher=United States Environmental Protection Agency |access-date=2008-06-06}}</ref>

[[Thermal-neutron reactor]]s, 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.<ref>{{cite web|url=https://fas.org/sgp/crs/misc/RL32163.pdf |title=CRS Report for Congress. Radioactive Waste Streams: Waste Classification for Disposal |quote=The Nuclear Waste Policy Act of 1982 (NWPA) defined irradiated fuel as spent nuclear fuel, and the byproducts as high-level waste.}}</ref>
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 element]]s, which are led by reactor-grade plutonium (half-life 24,000 years).<ref>{{harvnb|Vandenbosch|2007|p=21.|Ref=none}}</ref>
Some proposed reactor designs, such as the [[integral fast reactor]] and [[molten salt reactor]]s, 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.<ref>{{cite news|author=Duncan Clark |url=https://www.theguardian.com/environment/2012/jul/09/nuclear-waste-burning-reactor |title=Nuclear waste-burning reactor moves a step closer to reality &#124; Environment &#124; guardian.co.uk |newspaper=Guardian |date=2012-07-09 |access-date=2013-06-14 |location=London}}</ref><ref>{{cite web|url=http://www.monbiot.com/2011/12/05/a-waste-of-waste/ |author=George Monbiot |title= A Waste of Waste |date=5 December 2011 |publisher=Monbiot.com |access-date=2013-06-14}}</ref><ref>{{cite web|url=https://www.youtube.com/watch?v=AZR0UKxNPh8  |archive-url=https://ghostarchive.org/varchive/youtube/20211211/AZR0UKxNPh8| archive-date=2021-12-11 |url-status=live|title=Energy From Thorium: A Nuclear Waste Burning Liquid Salt Thorium Reactor |publisher=YouTube |date=2009-07-23 |access-date=2013-06-14}}{{cbignore}}</ref>

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.<ref>{{cite web |title=Role of Thorium to Supplement Fuel Cycles of Future Nuclear Energy Systems |url=https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1540_web.pdf |publisher=IAEA |access-date=7 April 2021 |date=2012 |quote=Once irradiated in a reactor, the fuel of a thorium–uranium cycle contains an admixture of 232U (half-life 68.9 years) whose radioactive decay chain includes emitters (particularly 208Tl) of high energy gamma radiation (2.6{{nbsp}}MeV). This makes spent thorium fuel treatment more difficult, requires remote handling/control during reprocessing and during further fuel fabrication, but on the other hand, may be considered as an additional non-proliferation barrier.}}</ref>

==== Low-level waste ====
{{main|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.<ref>{{cite web |title=NRC: Low-Level Waste |url=https://www.nrc.gov/waste/low-level-waste.html |website=www.nrc.gov |access-date=28 August 2018 |language=en}}</ref>

==== Waste relative to other types ====
{{See also|Radioactive waste#Naturally occurring radioactive material}}
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.<ref name="wna-wmitnfc" /> Overall, nuclear power produces far less waste material by volume than fossil-fuel based power plants.<ref>{{cite web|url=http://nuclearinfo.net/Nuclearpower/TheRisksOfNuclearPower|title=The Challenges of Nuclear Power|access-date=2013-01-04|archive-date=2017-05-10|archive-url=https://web.archive.org/web/20170510092527/http://nuclearinfo.net/Nuclearpower/TheRisksOfNuclearPower}}</ref> Coal-burning plants, in particular, produce large amounts of toxic and mildly radioactive ash resulting from the concentration of [[naturally occurring radioactive material]]s in coal.<ref>{{cite journal |date=2007-12-13 |title=Coal Ash Is More Radioactive than Nuclear Waste |url=http://www.scientificamerican.com/article.cfm?id=coal-ash-is-more-radioactive-than-nuclear-waste |journal=Scientific American}}</ref>
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.<ref name="colmain">{{cite web|url=http://www.ornl.gov/info/ornlreview/rev26-34/text/colmain.html |title=Coal Combustion: Nuclear Resource or Danger |author=Alex Gabbard |date=2008-02-05 |publisher=Oak Ridge National Laboratory |access-date=2008-01-31 |archive-url=https://web.archive.org/web/20070205103749/http://www.ornl.gov/info/ornlreview/rev26-34/text/colmain.html |archive-date=February 5, 2007 }}</ref>
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.<ref name="cejournal">{{cite journal |date=2008-12-31 |title=Coal ash is ''not'' more radioactive than nuclear waste |url= http://www.cejournal.net/?p=410 |journal=CE Journal |archive-url=https://web.archive.org/web/20090827045039/http://www.cejournal.net/?p=410 |archive-date=2009-08-27 }}</ref>

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.<ref>{{cite web|url=http://www.yankeerowe.com/ |title=Yankee Nuclear Power Plant |publisher=Yankeerowe.com |access-date=2013-06-22}}</ref> It is estimated that to produce a lifetime supply of energy for a person at a western [[standard of living]] (approximately 3{{nbsp}}[[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.<ref name="Generation Atomic">{{cite web|url=https://www.generationatomic.org/why-nuclear |title=Why nuclear energy|work=Generation Atomic|date=26 January 2021}}</ref><ref name="npr.org">{{cite news| url=https://www.npr.org/templates/story/story.php?storyId=125740818 |title=NPR Nuclear Waste May Get A Second Life| work=NPR}}</ref><ref>{{Cite web|url=https://hypertextbook.com/facts/1998/TommyZhou.shtml|title=Energy Consumption of the United States - The Physics Factbook|website=hypertextbook.com}}</ref>

==== Waste disposal ====
{{See also|List of radioactive waste treatment technologies}}
[[File:WIPP-04.jpeg|alt=Storage of radioactive waste at WIPP|thumb|[[nuclear flask|Nuclear waste flasks]] generated by the United States during the Cold War are stored underground at the [[Waste Isolation Pilot Plant]] (WIPP) in [[New Mexico]]. The facility is seen as a potential demonstration for storing spent fuel from civilian reactors.]]
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.<ref>{{cite web|url=https://www.nrc.gov/waste/spent-fuel-storage/dry-cask-storage.html |title=NRC: Dry Cask Storage |publisher=Nrc.gov |date=2013-03-26 |access-date=2013-06-22}}</ref>
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.<ref name=mont2011>Montgomery, Scott L. (2010). ''The Powers That Be'', University of Chicago Press, p. 137.</ref>
With the lack of movement of nuclear waste in the 2 billion year old [[natural nuclear fission reactor]]s in [[Oklo]], [[Gabon]] being cited as "a source of essential information today."<ref>{{cite web |url= http://www.efn.org.au/NucWaste-Comby.pdf |title= international Journal of Environmental Studies, The Solutions for Nuclear waste, December 2005 |access-date= 2013-06-22 |archive-date= 2013-04-26 |archive-url= https://web.archive.org/web/20130426083758/http://www.efn.org.au/NucWaste-Comby.pdf |url-status= dead }}</ref><ref>{{cite web |url= http://www.ocrwm.doe.gov/factsheets/doeymp0010.shtml |title=Oklo: Natural Nuclear Reactors |publisher=U.S. Department of Energy Office of Civilian Radioactive Waste Management, Yucca Mountain Project, DOE/YMP-0010|date=November 2004 |access-date=2009-09-15 |archive-url=https://web.archive.org/web/20090825013752/http://www.ocrwm.doe.gov/factsheets/doeymp0010.shtml |archive-date=2009-08-25 }}</ref>
Experts suggest that centralized underground repositories which are well-managed, guarded, and monitored, would be a vast improvement.<ref name=mont2011 />
There is an "international consensus on the advisability of storing nuclear waste in [[deep geological repository|deep geological repositories]]".<ref name=go /> With the advent of new technologies, other methods including [[horizontal drillhole disposal]] into geologically inactive areas have been proposed.<ref>{{Cite journal|title=Disposal of High-Level Nuclear Waste in Deep Horizontal Drillholes|date=May 29, 2019|journal=Energies|doi=10.3390/en12112052|last1=Muller|first1=Richard A.|last2=Finsterle|first2=Stefan|last3=Grimsich|first3=John|last4=Baltzer|first4=Rod|last5=Muller|first5=Elizabeth A.|last6=Rector|first6=James W.|last7=Payer|first7=Joe|last8=Apps|first8=John|volume=12|issue=11|page=2052|doi-access=free}}</ref><ref>{{Cite journal|title=The State of the Science and Technology in Deep Borehole Disposal of Nuclear Waste|date=February 14, 2020|journal=Energies|doi=10.3390/en13040833|last1=Mallants|first1=Dirk|last2=Travis|first2=Karl|last3=Chapman|first3=Neil|last4=Brady|first4=Patrick V.|last5=Griffiths|first5=Hefin|volume=13|issue=4|page=833|doi-access=free}}</ref>

[[File:Alpha-Gamma Hot Cell Facility 001.jpg|thumb|Most waste packaging, small-scale experimental fuel recycling chemistry and [[radiopharmaceutical]] refinement is conducted within remote-handled [[hot cell]]s.]]
There are no commercial scale purpose built underground high-level waste repositories in operation.<ref name=go>{{cite book |last=Gore |first=Al |date=2009 |title=Our Choice: A Plan to Solve the Climate Crisis |publisher=Rodale |location=Emmaus, PA |pages=[https://archive.org/details/ourchoiceplantos00gore/page/165 165–166] |isbn=978-1-59486-734-7 |url-access=registration |url=https://archive.org/details/ourchoiceplantos00gore/page/165 }}</ref><ref>{{cite magazine| url= http://www.sciam.com/article.cfm?id=a-nuclear-renaissance&print=true| archive-url= https://wayback.archive-it.org/all/20170525170540/https://www.scientificamerican.com/article/a-nuclear-renaissance/| archive-date= 2017-05-25| title= A Nuclear Power Renaissance?| date= 2008-04-28| magazine= [[Scientific American]]| access-date= 2008-05-15}}</ref><ref>{{cite magazine| url= http://www.sciam.com/article.cfm?id=rethinking-nuclear-fuel-recycling| title= Nuclear Fuel Recycling: More Trouble Than It's Worth
| last= von Hippel | first= Frank N. | author-link= Frank N. von Hippel| date= April 2008 |magazine= Scientific American| access-date= 2008-05-15 }}</ref> However, in Finland the [[Onkalo spent nuclear fuel repository]] of the [[Olkiluoto Nuclear Power Plant]] is under construction as of 2015.<ref>{{Cite web|url=http://www.world-nuclear-news.org/WR-Licence-granted-for-Finnish-used-fuel-repository-1211155.html|title=Licence granted for Finnish used fuel repository|date=2015-11-12|website=World Nuclear News|access-date=2018-11-18}}</ref>

=== Reprocessing ===
{{main|Nuclear reprocessing}}
{{see also|Plutonium Management and Disposition Agreement}}

Most [[thermal-neutron reactor]]s 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.<ref>{{Cite journal|doi=10.1016/j.energy.2014.02.069|title=Assessment of the environmental footprint of nuclear energy systems. Comparison between closed and open fuel cycles|journal=Energy|volume=69|pages=199–211|date=May 2014|last1=Poinssot|first1=Ch.|last2=Bourg|first2=S.|last3=Ouvrier|first3=N.|last4=Combernoux|first4=N.|last5=Rostaing|first5=C.|last6=Vargas-Gonzalez|first6=M.|last7=Bruno|first7=J.|doi-access=free}}</ref>
Spent MOX fuel cannot generally be recycled for use in thermal-neutron reactors. This issue does not affect [[fast-neutron reactor]]s, which are therefore preferred in order to achieve the full energy potential of the original uranium.<ref name="berrytoll" /><ref name="IEEE Spectrum">{{cite news|last1=Fairley|first1=Peter|title=Nuclear Wasteland|url=https://spectrum.ieee.org/feb07/4891|work=IEEE Spectrum|date=February 2007}}</ref>

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.<ref name="WNA3">{{cite web |url=http://www.world-nuclear.org/information-library/nuclear-fuel-cycle/fuel-recycling/processing-of-used-nuclear-fuel.aspx |title=Processing of Used Nuclear Fuel |date=2018 |publisher=World Nuclear Association |access-date=2018-12-26}}</ref>
Reprocessed uranium is also safer in terms of nuclear proliferation potential.<ref>{{cite tech report |url=https://www.osti.gov/biblio/6743129-proliferation-resistant-nuclear-fuel-cycles-spiking-plutonium-sup-pu |title=Proliferation-resistant nuclear fuel cycles. [Spiking of plutonium with /sup 238/Pu] |publisher=Oak Ridge National Laboratory |year=1978|doi=10.2172/6743129|osti=6743129|last1=Campbell|first1=D.O.|last2=Gift|first2=E.H. |via=Office of Scientific and Technical Information}}</ref><ref>{{cite journal|title= Formation of proliferation-resistant nuclear fuel supplies based on reprocessed uranium for Russian nuclear technologies recipient countries|journal= Nuclear Energy and Technology|volume= 1|issue= 2|pages= 111–116|doi= 10.1016/j.nucet.2015.11.023|year= 2015|last1= Fedorov|first1= M.I.|last2= Dyachenko|first2= A.I.|last3= Balagurov|first3= N.A.|last4= Artisyuk|first4= V.V.|doi-access= free}}</ref><ref>{{cite journal|title=Proliferation resistant plutonium: An updated analysis|journal=Nuclear Engineering and Design|volume=330|pages=297–302|doi=10.1016/j.nucengdes.2018.02.012|year=2018|last1=Lloyd|first1=Cody|last2=Goddard|first2=Braden}}</ref>

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]] and varied perceptions of increasing the vulnerability to [[nuclear terrorism]].<ref name=berrytoll/><ref name=bas2011/> Reprocessing also leads to higher fuel cost compared to the once-through fuel cycle.<ref name=berrytoll>R. Stephen Berry and George S. Tolley, [http://franke.uchicago.edu/energy2013/group6.pdf Nuclear Fuel Reprocessing] {{Webarchive|url=https://web.archive.org/web/20170525170152/http://franke.uchicago.edu/energy2013/group6.pdf |date=2017-05-25 }}, The University of Chicago, 2013.</ref><ref name=bas2011>{{cite web|url=http://www.thebulletin.org/web-edition/features/managing-nuclear-spent-fuel-policy-lessons-10-country-study|title=Managing nuclear spent fuel: Policy lessons from a 10-country study|author=Harold Feiveson|year=2011|website=Bulletin of the Atomic Scientists|display-authors=etal|access-date=2016-07-18|archive-date=2012-04-26|archive-url=https://web.archive.org/web/20120426011518/http://www.thebulletin.org/web-edition/features/managing-nuclear-spent-fuel-policy-lessons-10-country-study}}</ref>
While reprocessing reduces the volume of high-level waste, it does not reduce the [[fission product]]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.<ref name="WNA3" />
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.<ref>{{cite book|last=Kok|first=Kenneth D.|title=Nuclear Engineering Handbook|year=2010|publisher=CRC Press|page=332|isbn=978-1-4200-5391-3|url=https://books.google.com/books?id=EMy2OyUrqbUC&pg=PA332}}</ref> 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.<ref>{{cite news|url=http://www.mineweb.com/news/energy/crisis-for-arevas-plant-as-clients-shun-nuclear/|archive-url=https://web.archive.org/web/20150723193237/http://www.mineweb.com/news/energy/crisis-for-arevas-plant-as-clients-shun-nuclear/|archive-date=23 July 2015|title=Crisis for Areva's plant as clients shun nuclear|author=Emmanuel Jarry|newspaper=Moneyweb|agency=Reuters|date=6 May 2015|access-date=6 May 2015}}</ref>

=== Breeding ===
[[File:Nuclear-Fuel.jpg|thumb|upright|[[Nuclear fuel]] assemblies being inspected before entering a [[pressurized water reactor]] in the United States]]
{{Main|Breeder reactor|Nuclear power proposed as renewable energy}}
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 reactor]]s. 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.<ref>{{cite journal|title=Future Scenarios for Fission Based Reactors|journal=Nuclear Physics A|volume=751|pages=429–441|bibcode=2005NuPhA.751..429D|last1=David|first1=S.|year=2005|doi=10.1016/j.nuclphysa.2005.02.014}}</ref><ref name="Brundtland">{{cite web|title=Chapter 7: Energy: Choices for Environment and Development|url=http://www.un-documents.net/ocf-07.htm|work=Our Common Future: Report of the World Commission on Environment and Development|first=Gro Harlem|last=Brundtland|location=Oslo|date=20 March 1987|access-date=27 March 2013|quote=Today's primary sources of energy are mainly non-renewable: natural gas, oil, coal, peat, and conventional nuclear power. There are also renewable sources, including wood, plants, dung, falling water, geothermal sources, solar, tidal, wind, and wave energy, as well as human and animal muscle-power. Nuclear reactors that produce their own fuel ('breeders') and eventually fusion reactors are also in this category}}</ref> In 2006 it was estimated that with seawater extraction, there was likely five billion years' worth of uranium resources for use in breeder reactors.<ref name="stanford-cohen">{{cite web |url=http://www-formal.stanford.edu/jmc/progress/cohen.html |title=Facts From Cohen and Others |access-date=2006-11-09 |publisher=Stanford |year=2006 |author=John McCarthy |author-link=John McCarthy (computer scientist) |website=Progress and its Sustainability |archive-url=https://web.archive.org/web/20070410165316/http://www-formal.stanford.edu/jmc/progress/cohen.html |archive-date=2007-04-10 }} Citing: {{cite journal |last1=Cohen |first1=Bernard L. |s2cid=119587950 |title=Breeder reactors: A renewable energy source |journal=American Journal of Physics |date=January 1983 |volume=51 |issue=1 |pages=75–76 |doi=10.1119/1.13440 |bibcode=1983AmJPh..51...75C }}</ref>

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.<ref name="wna-anpr">{{cite web |url=http://www.world-nuclear.org/info/inf08.html |title=Advanced Nuclear Power Reactors |access-date=2006-11-09 |publisher=World Nuclear Association |year=2006 |website=Information and Issue Briefs |archive-date=2010-06-15 |archive-url=https://web.archive.org/web/20100615004046/http://www.world-nuclear.org/info/inf08.html }}</ref>
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.<ref>{{cite web |url=http://www.worldenergy.org/documents/p001515.pdf |title=Synergy between Fast Reactors and Thermal Breeders for Safe, Clean, and Sustainable Nuclear Power |website=World Energy Council |archive-url=https://web.archive.org/web/20110110121245/http://worldenergy.org/documents/p001515.pdf |archive-date=2011-01-10}}</ref><ref>{{cite web |url=http://e360.yale.edu/feature/are_fast-breeder_reactors_a_nuclear_power_panacea/2557/ |title=Are Fast-Breeder Reactors A Nuclear Power Panacea? by Fred Pearce: Yale Environment 360 |author=Rebecca Kessler |publisher=E360.yale.edu |access-date=2013-06-14}}</ref>
As of 2017, there are two breeders producing commercial power, [[BN-600 reactor]] and the [[BN-800 reactor]], both in Russia.<ref name=WNAfast>{{cite web |title=Fast Neutron Reactors {{!}} FBR – World Nuclear Association |url=http://www.world-nuclear.org/information-library/current-and-future-generation/fast-neutron-reactors.aspx |website=www.world-nuclear.org |access-date=7 October 2018}}</ref>
The [[Phénix]] breeder reactor in France was powered down in 2009 after 36 years of operation.<ref name=WNAfast />
Both China and India are building breeder reactors. The Indian 500 MWe [[Prototype Fast Breeder Reactor]] is in the commissioning phase,<ref>{{cite news |title=Prototype fast breeder reactor to be commissioned in two months: IGCAR director |url=https://timesofindia.indiatimes.com/city/chennai/prototype-fast-breeder-reactor-to-be-commissioned-in-two-months-igcar-director/articleshow/61968967.cms |access-date=28 August 2018 |work=The Times of India}}</ref> with plans to build more.<ref>{{cite news |url=http://www.hindustantimes.com/India-news/NewDelhi/India-s-breeder-reactor-to-be-commissioned-in-2013/Article1-814183.aspx |title=India's breeder reactor to be commissioned in 2013 |newspaper=Hindustan Times |access-date=2013-06-14 |archive-url=https://web.archive.org/web/20130426141852/http://www.hindustantimes.com/India-news/NewDelhi/India-s-breeder-reactor-to-be-commissioned-in-2013/Article1-814183.aspx |archive-date=2013-04-26 }}</ref>

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]].<ref name="wna-thorium" /> Thorium is about 3.5 times more common than uranium in the Earth's crust, and has different geographic characteristics.<ref name="wna-thorium">{{cite web |url=http://www.world-nuclear.org/info/inf62.html |title=Thorium |access-date=2006-11-09 |publisher=World Nuclear Association |year=2006 |website=Information and Issue Briefs |archive-date=2013-02-16 |archive-url=https://web.archive.org/web/20130216102005/http://www.world-nuclear.org/info/inf62.html }}</ref> [[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.<ref name="wna-thorium" />

== Decommissioning ==
{{Main|Nuclear decommissioning}}
Nuclear decommissioning is the process of dismantling a [[nuclear facility]] to the point that it no longer requires measures for radiation protection,<ref>{{Cite journal|date=2020-09-01|title=Developing policies for the end-of-life of energy infrastructure: Coming to terms with the challenges of decommissioning|journal=Energy Policy|language=en|volume=144|page=111677|doi=10.1016/j.enpol.2020.111677|issn=0301-4215|doi-access=free|last1=Invernizzi|first1=Diletta Colette|last2=Locatelli|first2=Giorgio|last3=Velenturf|first3=Anne|last4=Love|first4=Peter ED.|last5=Purnell|first5=Phil|last6=Brookes|first6=Naomi J.|hdl=11311/1204791|hdl-access=free}}</ref> returning the facility and its parts to a safe enough level to be entrusted for other uses.<ref name="iaea_decommissioning">{{cite web |title=Decommissioning of nuclear installations |url=https://www.iaea.org/topics/decommissioning |website=www.iaea.org |access-date=19 April 2021 |language=en |date=17 October 2016}}</ref>
Due to the presence of radioactive materials, nuclear decommissioning presents technical and economic challenges.<ref>{{Cite journal|last1=Invernizzi|first1=Diletta Colette|last2=Locatelli|first2=Giorgio|last3=Brookes|first3=Naomi J.|date=2017-08-01|title=How benchmarking can support the selection, planning and delivery of nuclear decommissioning projects|journal=Progress in Nuclear Energy|volume=99|pages=155–164 |doi=10.1016/j.pnucene.2017.05.002 |url=http://eprints.whiterose.ac.uk/117185/1/Copy%20to%20deposit.pdf}}</ref>
The costs of decommissioning are generally spread over the lifetime of a facility and saved in a decommissioning fund.<ref>{{cite web |url=https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/decommissioning.html |title=Backgrounder on Decommissioning Nuclear Power Plants |publisher=United States Nuclear Regulatory Commission |access-date=27 August 2021 |quote=Before a nuclear power plant begins operations, the licensee must establish or obtain a financial mechanism – such as a trust fund or a guarantee from its parent company – to ensure there will be sufficient money to pay for the ultimate decommissioning of the facility}}</ref>

== Production ==
{{Further|Nuclear power by country|List of nuclear reactors}}
[[File:Nuclear-energy-electricity-production.png|thumb|right|330px|Share of electricity production from nuclear, 2022<ref>{{cite web |title=Share of electricity production from nuclear |url=https://ourworldindata.org/grapher/share-electricity-nuclear |website=Our World in Data |access-date=15 August 2023}}</ref>]]
[[File:Nuclear power station.svg|thumb|right|330px|The status of nuclear power globally (click for legend)]]
{{Latest pie chart of world power by source}}
Civilian nuclear power supplied 2,586 [[terawatt hour]]s (TWh) of electricity in 2019, equivalent to about 10% of [[global electricity generation]], and was the second largest [[low-carbon power]] source after [[hydroelectricity]].<ref name="pris-supplied">{{cite web|url=https://pris.iaea.org/PRIS/WorldStatistics/WorldTrendinElectricalProduction.aspx |title=Trend in Electricity Supplied |publisher=International Atomic Energy Agency |access-date=2021-01-09}}</ref><ref name="IEA2019">{{Cite web|url=https://www.iea.org/newsroom/news/2019/may/steep-decline-in-nuclear-power-would-threaten-energy-security-and-climate-goals.html|title=Steep decline in nuclear power would threaten energy security and climate goals|publisher=International Energy Agency|date=2019-05-28|access-date=2019-07-08}}</ref>
Since electricity accounts for about 25% of [[world energy consumption]], nuclear power's contribution to global energy was about 2.5% in 2011.<ref>{{cite journal | last1 = Armaroli | first1 = Nicola | author-link = Nicola Armaroli | author-link2 = Vincenzo Balzani | last2 = Balzani | first2 = Vincenzo | s2cid = 1752800 | year = 2011 | title = Towards an electricity-powered world | journal = [[Energy and Environmental Science]] | volume = 4 | issue = 9| pages = 3193–3222 [3200] | doi = 10.1039/c1ee01249e }}</ref>
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.<ref>{{Cite web|url=http://www.ren21.net/Portals/0/documents/Resources/GSR/2014/GSR2014_KeyFindings_low%20res.pdf|title=REN 21. Renewables 2014 Global Status Report}}</ref>
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.<ref name=ft-20180903>{{cite news |url=https://www.ft.com/content/fa6ca7ac-ab9a-11e8-89a1-e5de165fa619 |archive-url=https://ghostarchive.org/archive/20221210/https://www.ft.com/content/fa6ca7ac-ab9a-11e8-89a1-e5de165fa619 |archive-date=2022-12-10 |url-access=subscription |url-status=live |title=The challenge for nuclear is to recover its competitive edge |last=Butler |first=Nick |newspaper=Financial Times |date=3 September 2018 |access-date=9 September 2018}}</ref>

{{As of|2022|3|post=,}} there are [[List of nuclear reactors|439 civilian fission reactors in the world]], with a combined electrical capacity of 392 [[gigawatt]] (GW). There are also 56 nuclear power reactors under construction and 96 reactors planned, with a combined capacity of 62{{nbsp}}GW and 96{{nbsp}}GW, respectively.<ref name="WNA">{{cite web|title=World Nuclear Power Reactors & Uranium Requirements |publisher= World Nuclear Association|url=https://www.world-nuclear.org/information-library/facts-and-figures/world-nuclear-power-reactors-and-uranium-requireme.aspx|access-date=2022-04-18}}</ref>
The United States has the largest fleet of nuclear reactors, generating over 800{{nbsp}}TWh per year with an average [[capacity factor]] of 92%.<ref name=":2">{{Cite web|title=What's the Lifespan for a Nuclear Reactor? Much Longer Than You Might Think|url=https://www.energy.gov/ne/articles/whats-lifespan-nuclear-reactor-much-longer-you-might-think|access-date=2020-06-09|website=Energy.gov|language=en}}</ref> Most reactors under construction are [[generation III reactor]]s in Asia.<ref>{{cite web|url=https://pris.iaea.org/PRIS/WorldStatistics/UnderConstructionReactorsByCountry.aspx |title=Under Construction Reactors |publisher=International Atomic Energy Agency |access-date=2019-12-15}}</ref>

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{{mdash}}71% in 2019.<ref name=":0">{{Cite web |url=https://pris.iaea.org/PRIS/WorldStatistics/NuclearShareofElectricityGeneration.aspx|title=Nuclear Share of Electricity Generation in 2019|website=Power Reactor Information System|publisher=International Atomic Energy Agency|access-date=2021-01-09}}</ref>
In the [[European Union]], nuclear power provides 26% of the electricity as of 2018.<ref>{{cite book | url=https://op.europa.eu/en/publication-detail/-/publication/87b16988-f740-11ea-991b-01aa75ed71a1 | title=EU energy in figures | access-date=2021-01-09 | publisher=European Commission | year=2020 | page=94 | isbn=978-92-76-19443-9 }}</ref>
Nuclear power is the single largest low-carbon electricity source in the United States,<ref name=issues>{{Cite web|url=https://issues.org/apt-3/|archive-url=https://web.archive.org/web/20130927013232/http://www.issues.org/23.3/apt.html  |title=Promoting Low-Carbon Electricity Production|first1=Jay|last1=Apt|first2=David W.|last2=Keith|first3=M. Granger|last3=Morgan|date=January 1, 1970|archive-date=September 27, 2013}}</ref> and accounts for two-thirds of the [[European Union]]'s low-carbon electricity.<ref>{{cite web | url=http://ec.europa.eu/energy/publications/doc/2010_setplan_brochure.pdf | title=The European Strategic Energy Technology Plan SET-Plan Towards a low-carbon future 2010 | page=6 | access-date=2015-08-17 | archive-date=2014-02-11 | archive-url=https://web.archive.org/web/20140211100220/http://ec.europa.eu/energy/publications/doc/2010_setplan_brochure.pdf }}</ref>
[[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.<ref>{{cite web |url=http://www.engineersgarage.com/articles/nuclear-power-plants?page=2 |title=What is Nuclear Power Plant – How Nuclear Power Plants work &#124; What is Nuclear Power Reactor – Types of Nuclear Power Reactors |publisher=EngineersGarage |access-date=2013-06-14 |archive-url=https://web.archive.org/web/20131004215527/http://www.engineersgarage.com/articles/nuclear-power-plants?page=2 |archive-date=2013-10-04 }}</ref><ref>{{cite web |url=http://www.ewp.rpi.edu/hartford/~ernesto/F2010/EP2/Materials4Students/Misiaszek/NuclearMarinePropulsion.pdf |title=Naval Nuclear Propulsion |access-date=2015-06-04 |archive-url=https://web.archive.org/web/20150226055625/http://www.ewp.rpi.edu/hartford/~ernesto/F2010/EP2/Materials4Students/Misiaszek/NuclearMarinePropulsion.pdf |archive-date=2015-02-26 |author= Magdi Ragheb| quote=As of 2001, about 235 naval reactors had been built}}</ref>
These include military and some civilian ships, such as [[nuclear-powered icebreaker]]s.<ref>{{Cite news | url=http://www.bellona.org/english_import_area/international/russia/civilian_nuclear_vessels/icebreakers/30131 |title=Nuclear Icebreaker Lenin |publisher=Bellona |date=2003-06-20 |access-date=2007-11-01 |archive-url= https://web.archive.org/web/20071015031630/http://www.bellona.org/english_import_area/international/russia/civilian_nuclear_vessels/icebreakers/30131 |archive-date=October 15, 2007 }}</ref>

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.<ref>{{cite book |title=Non-electric Applications of Nuclear Power: Seawater Desalination, Hydrogen Production and other Industrial Applications |date=2007 |publisher=International Atomic Energy Agency |isbn=978-92-0-108808-6 |url=https://www.iaea.org/publications/7979/non-electric-applications-of-nuclear-power-seawater-desalination-hydrogen-production-and-other-industrial-applications |access-date=21 August 2018}}</ref>

== Economics ==
{{Main|Economics of nuclear power plants|List of companies in the nuclear sector|cost of electricity by source}}
The economics of new nuclear power plants is a controversial subject and multi-billion-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.<ref name=cnnmoney>[https://money.cnn.com/2007/04/19/markets/uranium/index.htm ''What's behind the red-hot uranium boom.''] CNN, 19 April 2007</ref>

The high cost of construction is one of the biggest challenges for nuclear power plants. A new 1,100{{nbsp}}MW plant is estimated to cost between $6 billion to $9 billion.<ref>{{Cite web|title=Synapse Energy {{!}}|url=https://www.synapse-energy.com/|access-date=2020-12-29|website=www.synapse-energy.com}}</ref> 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.<ref name=Lovering2016>{{cite journal |doi=10.1016/j.enpol.2016.01.011 |title=Historical construction costs of global nuclear power reactors |journal=Energy Policy |volume=91 |pages=371–382 |year=2016 |last1=Lovering |first1=Jessica R. |last2=Yip |first2=Arthur |last3=Nordhaus |first3=Ted |doi-access=free }}</ref>

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.<ref name=ft-20100912>{{cite news |author=Ed Crooks |date=2010-09-12 |title=Nuclear: New dawn now seems limited to the east |url=http://www.ft.com/cms/s/0/ad15fcfe-bc71-11df-a42b-00144feab49a.html |archive-url=https://ghostarchive.org/archive/20221210/http://www.ft.com/cms/s/0/ad15fcfe-bc71-11df-a42b-00144feab49a.html |archive-date=2022-12-10 |url-access=subscription |newspaper=Financial Times |access-date=2010-09-12}}</ref>
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.<ref name=MIT-2003>{{Cite book |url=http://web.mit.edu/nuclearpower/ |title=The Future of Nuclear Power |publisher=[[Massachusetts Institute of Technology]] |year=2003 |isbn=978-0-615-12420-9 |access-date=2006-11-10 }}</ref>

The [[levelized cost of electricity]] (LCOE) from a new nuclear power plant is estimated to be 69{{nbsp}}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]].<ref name="IEA_LCOE_2020"/> [[Variable renewable energy|Variable renewables]] can generate cheaper electricity: the median cost of onshore wind power was estimated to be 50{{nbsp}}USD/MWh, and utility-scale solar power 56{{nbsp}}USD/MWh.<ref name="IEA_LCOE_2020"/>
At the assumed CO<sub>2</sub> emission cost of 30{{nbsp}}USD/ton, power from coal (88{{nbsp}}USD/MWh) and gas (71{{nbsp}}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{{nbsp}}USD/MWh.<ref name="IEA_LCOE_2020">{{cite web |title=Projected Costs of Generating Electricity 2020 |url=https://www.iea.org/reports/projected-costs-of-generating-electricity-2020 |publisher=International Energy Agency & OECD Nuclear Energy Agency |access-date=12 December 2020}}</ref> 
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.<ref>{{cite book |title=Update of the MIT 2003 Future of Nuclear Power |date=2009 |publisher=Massachusetts Institute of Technology |url=http://web.mit.edu/nuclearpower/pdf/nuclearpower-update2009.pdf |access-date=21 August 2018}}</ref><ref>{{cite news |title=Splitting the cost |url=https://www.economist.com/britain/2009/11/12/splitting-the-cost |access-date=21 August 2018 |newspaper=The Economist |date=12 November 2009 |language=en}}</ref> Extreme weather events, including events made more severe by climate change, are decreasing all energy source reliability including nuclear energy by a small degree, depending on location siting.<ref>{{cite news |title=Nuclear power's reliability is dropping as extreme weather increases |url=https://arstechnica.com/science/2021/07/climate-events-are-the-leading-cause-of-nuclear-power-outages/ |access-date=24 November 2021 |work=Ars Technica |date=24 July 2021 |language=en-us}}</ref><ref>{{cite journal |last1=Ahmad |first1=Ali |title=Increase in frequency of nuclear power outages due to changing climate |journal=Nature Energy |date=July 2021 |volume=6 |issue=7 |pages=755–762 |doi=10.1038/s41560-021-00849-y |bibcode=2021NatEn...6..755A |s2cid=237818619 |language=en |issn=2058-7546}}</ref>

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]] and reliability when compared to generation II light water reactors up to the 1990s.<ref>{{Cite web | url=http://www.nuclearfaq.ca/cnf_sectionA.htm | title=The Canadian Nuclear FAQ - Section A: CANDU Technology | access-date=2019-08-05 | archive-url=https://web.archive.org/web/20131101054647/http://nuclearfaq.ca/cnf_sectionA.htm | archive-date=2013-11-01 }}</ref>

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.<ref>{{cite web|url=https://www.oecd-nea.org/nea-news/2011/29-2/nea-news-29-2-load-following-e.pdf |title=Load-following with nuclear power plants |author= A. Lokhov}}</ref>
Due to the on-line refueling reactor design, [[PHWR]]s (of which the CANDU design is a part) continue to hold many world record positions for longest continual electricity generation, often over 800 days.<ref>{{Cite web | url=https://www.world-nuclear-news.org/Articles/Indian-reactor-breaks-operating-record |title = Indian reactor breaks operating record | work=World Nuclear News | date=25 October 2018}}</ref>
The specific record as of 2019 is held by a PHWR at [[Kaiga Atomic Power Station]], generating electricity continuously for 962 days.<ref>{{cite web |title=Indian-Designed Nuclear Reactor Breaks Record for Continuous Operation |url=https://www.powermag.com/indian-designed-nuclear-reactor-breaks-record-for-continuous-operation/ |website=POWER Magazine |access-date=28 March 2019 |date=1 February 2019}}</ref>

Costs not considered in LCOE calculations include funds for research and development, and disasters (the Fukushima disaster is estimated to cost taxpayers ≈$187 billion<ref name=guardian-20170130/>). Governments were found to in some cases force "consumers to pay upfront for potential cost overruns"<ref name="mil1"/> or subsidize uneconomic nuclear energy<ref>{{cite news |last1=Gardner |first1=Timothy |title=Illinois approves $700 million in subsidies to Exelon, prevents nuclear plant closures |url=https://www.reuters.com/world/us/illinois-senate-close-providing-lifeline-3-nuclear-power-plants-2021-09-13/ |access-date=28 November 2021 |work=Reuters |date=13 September 2021 |language=en}}</ref> or be required to do so.<ref name="francere"/> Nuclear operators are liable to pay for the waste management in the EU.<ref name="euwastecosts"/> 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.<ref>{{cite news |last1=Wade |first1=Will |title=Americans are paying more than ever to store deadly nuclear waste |url=https://www.latimes.com/business/la-fi-radioactive-nuclear-waste-storage-20190614-story.html |access-date=28 November 2021 |work=Los Angeles Times |date=14 June 2019}}</ref> 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.<ref>{{cite web |title=The World Nuclear Waste Report 2019 |url=https://www.boell.de/sites/default/files/2019-11/World_Nuclear_Waste_Report_2019_summary.pdf |access-date=28 November 2021}}</ref> Similarly, other forms of energy, including fossil fuels and renewables, have a portion of their costs covered by governments.<ref>[https://world-nuclear.org/information-library/economic-aspects/energy-subsidies.aspx Energy Subsidies], World Nuclear Association, 2018.</ref>

== Use in space ==
[[File:Msl-MMRTG.jpg|thumb|The [[multi-mission radioisotope thermoelectric generator]] (MMRTG), used in several space missions such as the [[Curiosity (rover)|''Curiosity'' Mars rover]] ]]
{{Main|Nuclear power in space}}
The most common use of nuclear power in space is the use of [[radioisotope thermoelectric generator]]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 mission]]s and experiments for long periods where solar power is not available in sufficient quantity, such as in the ''[[Voyager 2]]'' space probe.<ref name=WNA_space/>
A few space vehicles have been launched using [[nuclear reactor]]s: 34 reactors belong to the Soviet [[RORSAT]] series and one was the American [[SNAP-10A]].<ref name=WNA_space>{{cite web |title=Nuclear Reactors for Space - World Nuclear Association |url=https://world-nuclear.org/information-library/non-power-nuclear-applications/transport/nuclear-reactors-for-space.aspx |website=world-nuclear.org |access-date=17 April 2021}}</ref>

Both [[Nuclear fission|fission]] and fusion appear promising for [[Spacecraft propulsion|space propulsion]] applications, generating higher mission velocities with less [[reaction mass]].<ref name=WNA_space/><ref>{{cite news |last1=Patel |first1=Prachi |title=Nuclear-Powered Rockets Get a Second Look for Travel to Mars |url=https://spectrum.ieee.org/aerospace/space-flight/nuclear-powered-rockets-get-a-second-look-for-travel-to-mars |access-date=17 April 2021 |work=IEEE Spectrum |language=en}}</ref>

== Safety ==
{{See also|Nuclear safety and security|Nuclear reactor safety system}}
[[File:Death rates from energy production per TWh (including solar).svg|thumb|Death rates from air pollution and accidents related to energy production, measured in deaths in the past per terawatt hours (TWh)]]
Nuclear power plants have three unique characteristics that affect their safety, as compared to other power plants.
Firstly, intensely [[radioactive material]]s are present in a nuclear reactor. Their release to the environment could be hazardous.
Secondly, the [[fission product]]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.<ref name=IAEAsafety>{{Cite web|url=https://ansn.iaea.org/ansn.org/Common/Documents/apmd/asia251p4.pdf|title=Basic principles of nuclear safety|last=Deitrich|first=L.W.|publisher=International Atomic Energy Agency|access-date=2018-11-18}}</ref>

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 rod]]s into the reactor core. [[Emergency core cooling system]]s (ECCS) can remove the decay heat from the reactor if normal cooling systems fail.<ref>{{Cite web|url=https://www.nrc.gov/reading-rm/basic-ref/glossary/emergency-core-cooling-systems-eccs.html|title=Emergency core cooling systems (ECCS)|date=2018-07-06|publisher=United States Nuclear Regulatory Commission|access-date=2018-12-10}}</ref> 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]].<ref name="IAEAsafety" />

With a death rate of 0.03 per [[TWh]], nuclear power is the second safest energy source per unit of energy generated, after solar power, in terms of mortality when the historical track-record is considered.<ref>{{Cite web|title=What are the safest and cleanest sources of energy?|url=https://ourworldindata.org/safest-sources-of-energy|website=Our World in Data|access-date=2023-11-15}}</ref>
Energy produced by coal, petroleum, natural gas and [[hydropower]] has caused more deaths per unit of energy generated due to [[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.<ref name="without the hot air">{{cite web |url= http://www.inference.phy.cam.ac.uk/withouthotair/c24/page_168.shtml |title=Dr. MacKay ''Sustainable Energy without the hot air'' |website= Data from studies by the [[Paul Scherrer Institute]] including non EU data |page= 168 |access-date=2012-09-15}}</ref><ref name="theage2006">{{cite news | url= http://www.theage.com.au/news/national/nuclear-power-cheaper-safer-than-coal-and-gas/2006/06/04/1149359609052.html | title= Nuclear power 'cheaper, safer' than coal and gas |author= Brendan Nicholson |date= 2006-06-05 |newspaper= [[The Age]] | access-date= 2008-01-18 | location=Melbourne}}</ref>
When the direct and indirect fatalities (including fatalities resulting from the mining and air pollution) from nuclear power and fossil fuels are compared,<ref name="MarkandyaWilkinson2007">{{cite journal | doi = 10.1016/S0140-6736(07)61253-7 | last1 = Markandya | first1 = A. | last2 = Wilkinson | first2 = P. | title = Electricity generation and health | journal = Lancet | volume = 370 | issue = 9591 | pages = 979–990 | year = 2007 | pmid = 17876910| s2cid = 25504602 |quote=Nuclear power has lower electricity related health risks than Coal, Oil, & gas. ...the health burdens are appreciably smaller for generation from natural gas, and lower still for nuclear power. This study includes the latent or indirect fatalities, for example those caused by the inhalation of fossil fuel created particulate matter, smog induced cardiopulmonary events, black lung etc. in its comparison.}}</ref> the use of nuclear power has been calculated to have prevented about 1.84 million deaths from air pollution between 1971 and 2009, by reducing the proportion of energy that would otherwise have been generated by fossil fuels.<ref name="autogenerated1">{{cite web|url=http://cen.acs.org/articles/91/web/2013/04/Nuclear-Power-Prevents-Deaths-Causes.html |title=Nuclear Power Prevents More Deaths Than It Causes &#124; Chemical & Engineering News |publisher=Cen.acs.org |access-date=2014-01-24}}</ref><ref name="Kharecha Pushker A 2013 4889–4895">{{cite journal | last1=Kharecha | first1=Pushker A. | last2=Hansen | first2=James E. |title=Prevented Mortality and Greenhouse Gas Emissions from Historical and Projected Nuclear Power |doi=10.1021/es3051197 |pmid=23495839 |bibcode = 2013EnST...47.4889K |volume=47 |issue=9 |journal=Environmental Science & Technology |pages=4889–4895 |year=2013 |doi-access=free |hdl=2060/20140017100 |hdl-access=free }}</ref>
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.<ref>{{cite journal|author=Dennis Normile |date=2012-07-27 |title=Is Nuclear Power Good for You? |url=http://news.sciencemag.org/scienceinsider/2012/07/is-nuclear-power-good-for-you.html |journal=Science |page=395 |volume=337 |issue=6093 |doi=10.1126/science.337.6093.395-b |archive-url=https://web.archive.org/web/20130301082701/http://news.sciencemag.org/scienceinsider/2012/07/is-nuclear-power-good-for-you.html |archive-date=2013-03-01 }}</ref>

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.<ref>{{cite journal |last1=Hasegawa |first1=Arifumi |last2=Tanigawa |first2=Koichi |last3=Ohtsuru |first3=Akira |last4=Yabe |first4=Hirooki |last5=Maeda |first5=Masaharu |last6=Shigemura |first6=Jun |last7=Ohira |first7=Tetsuya |last8=Tominaga |first8=Takako |last9=Akashi |first9=Makoto |last10=Hirohashi |first10=Nobuyuki |last11=Ishikawa |first11=Tetsuo |last12=Kamiya |first12=Kenji |last13=Shibuya |first13=Kenji |last14=Yamashita |first14=Shunichi |last15=Chhem |first15=Rethy K |title=Health effects of radiation and other health problems in the aftermath of nuclear accidents, with an emphasis on Fukushima |journal=The Lancet |date=August 2015 |volume=386 |issue=9992 |pages=479–488 |doi=10.1016/S0140-6736(15)61106-0 |pmid=26251393 |s2cid=19289052 |url=http://ir.fmu.ac.jp/dspace/bitstream/123456789/1575/1/Lancet_386_p479.pdf }}</ref>
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.<ref name=riv12>{{cite news |author=Andrew C. Revkin |author-link=Andrew C. Revkin |date=2012-03-10 |title=Nuclear Risk and Fear, from Hiroshima to Fukushima |url=http://dotearth.blogs.nytimes.com/2012/03/10/nuclear-risk-and-fear-from-hiroshima-to-fukushima/ |newspaper=The New York Times}}</ref>
[[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.<ref name="Frank N. von Hippel 27–36">{{cite journal |url=http://bos.sagepub.com/content/67/5/27.full |title=The radiological and psychological consequences of the Fukushima Daiichi accident |author= Frank N. von Hippel |date= September–October 2011 |volume= 67 |issue= 5 |journal= Bulletin of the Atomic Scientists |pages= 27–36 |doi=10.1177/0096340211421588 |bibcode=2011BuAtS..67e..27V |s2cid=218769799 }}</ref>

=== Accidents ===
[[File:Fukushima I by Digital Globe crop.jpg|thumb|Following the 2011 [[Fukushima Daiichi nuclear disaster]], the world's worst [[nuclear accident]] since 1986, 50,000 households were displaced after [[radiation]] leaked into the air, soil and sea.<ref>{{cite news |author1=Tomoko Yamazaki |author2=Shunichi Ozasa |name-list-style=amp |date=2011-06-27 |title=Fukushima Retiree Leads Anti-Nuclear Shareholders at Tepco Annual Meeting |url=https://www.bloomberg.com/news/2011-06-26/fukushima-retiree-to-lead-anti-nuclear-motion.html |work=Bloomberg }}</ref> Radiation checks led to bans of some shipments of vegetables and fish.<ref>{{cite news |author=Mari Saito |date=2011-05-07 |title=Japan anti-nuclear protesters rally after PM call to close plant |url=https://www.reuters.com/article/us-japan-nuclear-idUSTRE74610J20110507 |work=Reuters}}</ref>]]
[[File:Decay heat illustration2.PNG|thumb|Reactor [[decay heat]] as a fraction of full power after the reactor shutdown, using two different correlations. To remove the decay heat, reactors need cooling after the shutdown of the fission reactions. A loss of the ability to remove decay heat caused the [[Fukushima accident]].]]
{{See also|Energy accidents|Nuclear and radiation accidents and incidents|Lists of nuclear disasters and radioactive incidents}}

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 three 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 first major nuclear accidents were the [[Kyshtym disaster]] in the Soviet Union and the [[Windscale fire]] 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]], a [[U.S. Army]] experimental nuclear power reactor at the [[Idaho National Laboratory]]. An uncontrolled chain reaction resulted in a [[steam explosion]] which killed the three crew members and caused a [[nuclear meltdown|meltdown]].<ref name=ido19313>''[http://www.id.doe.gov/foia/PDF/IDO-19313.pdf IDO-19313: Additional Analysis of the SL-1 Excursion]'' {{webarchive|url=https://web.archive.org/web/20110927065809/http://www.id.doe.gov/foia/PDF/IDO-19313.pdf |date=2011-09-27 }} ''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.</ref><ref>{{cite book |last=McKeown |first=William |title=Idaho Falls: The Untold Story of America's First Nuclear Accident |isbn=978-1-55022-562-4 |year=2003 |publisher=ECW Press |location=Toronto}}</ref>
Another serious accident happened in 1968, when one of the two [[liquid-metal-cooled reactor]]s on board the {{ship|Soviet submarine|K-27}} underwent a [[fuel element failure]], with the emission of gaseous [[fission product]]s into the surrounding air, resulting in 9 crew fatalities and 83 injuries.<ref name=johnston2007>{{cite web |url=http://www.johnstonsarchive.net/nuclear/radevents/radevents1.html |title=Deadliest radiation accidents and other events causing radiation casualties |author=Johnston, Robert |date=2007-09-23 |publisher=Database of Radiological Incidents and Related Events }}</ref>

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.<ref name="Richard Schiffman">{{cite news |author=Richard Schiffman |date=2013-03-12 |title=Two years on, America hasn't learned lessons of Fukushima nuclear disaster |url=https://www.theguardian.com/commentisfree/2013/mar/12/fukushima-nuclear-accident-lessons-for-us |work=The Guardian |location=London}}</ref><ref name="Martin Fackler">{{cite news |author=Martin Fackler |date=2011-06-01 |title=Report Finds Japan Underestimated Tsunami Danger |url=https://www.nytimes.com/2011/06/02/world/asia/02japan.html?_r=1&ref=world |newspaper=The New York Times }}</ref>
The [[Three Mile Island accident]] in 1979 was a smaller scale accident, rated at INES level 5.
There were no direct or indirect deaths caused by the accident.<ref name="timenuke">{{cite magazine|url=http://www.time.com/time/photogallery/0,29307,1887705,00.html|archive-url=https://web.archive.org/web/20090328130544/http://www.time.com/time/photogallery/0,29307,1887705,00.html|archive-date=March 28, 2009|title=The Worst Nuclear Disasters|date=2009-03-25|access-date=2013-06-22|magazine=Time.com}}</ref>

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.<ref>{{Cite journal | last1 = Sovacool | first1 = B.K. | title = The costs of failure: A preliminary assessment of major energy accidents, 1907–2007 | doi = 10.1016/j.enpol.2008.01.040 | journal = Energy Policy | volume = 36 | issue = 5 | pages = 1802–1820 | year = 2008 }}</ref> 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.<ref>{{cite journal |last1=Burgherr |first1=Peter |last2=Hirschberg |first2=Stefan |title=A Comparative Analysis of Accident Risks in Fossil, Hydro, and Nuclear Energy Chains |journal=Human and Ecological Risk Assessment |date=10 October 2008 |volume=14 |issue=5 |pages=947–973 |doi=10.1080/10807030802387556 |bibcode=2008HERA...14..947B |s2cid=110522982 }}</ref> 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 five 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]].<ref name=WHO2012>{{cite web|date=23 April 2011|title=Chernobyl at 25th anniversary – Frequently Asked Questions |publisher=World Health Organisation|access-date=14 April 2012|url=https://www.who.int/ionizing_radiation/chernobyl/20110423_FAQs_Chernobyl.pdf}}</ref> The future predicted mortality from increases in cancer rates is estimated at 4000 in the decades to come.<ref>{{cite web |url=http://www.iaea.org/Publications/Magazines/Bulletin/Bull383/boxp6.html |title=Assessing the Chernobyl Consequences |website=International Atomic Energy Agency |archive-url=https://web.archive.org/web/20130830073635/http://www.iaea.org/Publications/Magazines/Bulletin/Bull383/boxp6.html |archive-date=30 August 2013 |df=dmy-all}}</ref><ref name=UNSCEAR_2008_D>{{cite web |url=http://www.unscear.org/docs/reports/2008/11-80076_Report_2008_Annex_D.pdf |title=UNSCEAR 2008 Report to the General Assembly, Annex D |website=United Nations Scientific Committee on the Effects of Atomic Radiation |year=2008}}</ref><ref>{{cite web |url=http://www.unscear.org/docs/reports/2008/09-86753_Report_2008_GA_Report_corr2.pdf |title=UNSCEAR 2008 Report to the General Assembly |website=United Nations Scientific Committee on the Effects of Atomic Radiation |year=2008}}</ref> However, the costs have been large and are increasing.

Nuclear power works under an [[insurance]] framework that limits or structures accident liabilities in accordance with national and international conventions.<ref>{{cite web| url=http://www.iaea.org/Publications/Documents/Conventions/liability.html |title=Publications: Vienna Convention on Civil Liability for Nuclear Damage|date=27 August 2014 |publisher= [[International Atomic Energy Agency]]}}</ref>
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.<ref>{{cite web|url=http://www.cbo.gov/sites/default/files/05-02-nuclear.pdf |title=Nuclear Power's Role in Generating Electricity|publisher= [[Congressional Budget Office]]|date= May 2008}}</ref>
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 failure]]s. 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.<ref>{{cite web | url=http://www.damsafety.org/media/Documents/FEMA/AvailabilityOfDamInsurance.pdf | title=Availability of Dam Insurance | date=1999 | access-date=2016-09-08 | archive-date=2016-01-08 | archive-url=https://web.archive.org/web/20160108185336/http://www.damsafety.org/media/documents/fema/availabilityofdaminsurance.pdf }}</ref>

=== Attacks and sabotage ===
{{Main|Vulnerability of nuclear plants to attack|Nuclear terrorism|Nuclear safety in the United States}}
Terrorists could target [[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.<ref name=fas12>{{cite web |url=https://fas.org/pubs/_docs/Nuclear_Energy_Report-lowres.pdf |title=The Future of Nuclear Power in the United States |author1=Charles D. Ferguson |author2=Frank A. Settle |name-list-style=amp |year=2012 |website=Federation of American Scientists }}</ref>

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.<ref name=fas12 />
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.<ref>{{cite web|url=https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/security-enhancements.html| title=Nuclear Security – Five Years After 9/11 | publisher=U.S. NRC |access-date=23 July 2007}}</ref>

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.<ref>{{cite web |url=https://www.amacad.org/content/publications/pubContent.aspx?d=1427 |title=A Worst Practices Guide to Insider Threats: Lessons from Past Mistakes |author=Matthew Bunn |author-link=Matthew Bunn |author2=Scott Sagan|author2-link=Scott Sagan |name-list-style=amp |date=2014 |publisher=The American Academy of Arts & Sciences}}</ref>
A fire caused 5–10 million dollars worth of damage to New York's [[Indian Point Energy Center]] in 1971.<ref>{{Cite news|url=https://www.nytimes.com/1971/11/14/archives/damage-is-put-at-millions-in-blaze-at-con-ed-plant-con-ed-damage.html|title=Damage Is Put at Millions In Blaze at Con Ed Plant|last=McFadden|first=Robert D.|date=1971-11-14|work=The New York Times|access-date=2020-01-15|language=en-US|issn=0362-4331}}</ref>
The arsonist was a plant maintenance worker.<ref>{{Cite news|url=https://www.nytimes.com/1972/01/30/archives/mechanic-seized-in-indian-pt-fire-con-ed-employe-accused-of-arson.html|title=Mechanic Seized in Indian Pt. Fire|last=Knight|first=Michael|date=1972-01-30|work=The New York Times|access-date=2020-01-15|language=en-US|issn=0362-4331}}</ref>

== Proliferation ==
{{further|Nuclear proliferation}}
{{see also|Plutonium Management and Disposition Agreement}}
[[File:US and USSR nuclear stockpiles.svg|thumb|United States and [[USSR]]/Russian [[nuclear weapons]] stockpiles, 1945–2006. The [[Megatons to Megawatts Program]] was the main driving force behind the sharp reduction in the quantity of nuclear weapons worldwide since the cold war ended.<ref name="thebulletin.org" /><ref name="usec.com">{{cite web|url=http://www.usec.com/ |title=home |publisher=usec.com |date=2013-05-24 |access-date=2013-06-14 |archive-url=https://web.archive.org/web/20130621223711/http://www.usec.com/ |archive-date=2013-06-21 }}</ref>]]
[[File:US Navy 060420-N-9621S-004 The guided-missile cruiser USS Monterey (CG 61) conducts a fueling at sea (FAS) with the Nimitz-class aircraft carrier USS George Washington (CVN 73).jpg|thumb|The guided-missile cruiser USS Monterey (CG 61) receives fuel at sea (FAS) from the Nimitz-class aircraft carrier USS George Washington (CVN 73).]]
Nuclear proliferation is the spread of [[nuclear weapon]]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]].<ref name=dfall2009>{{cite journal |title=Nuclear power without nuclear proliferation? |author1=Steven E. Miller |author2=Scott D. Sagan |name-list-style=amp |date=Fall 2009 |journal=Dædalus |doi=10.1162/daed.2009.138.4.7 |volume=138 |issue=4 |page=7 |s2cid=57568427 |doi-access=free }}</ref>
The re-purposing of civilian nuclear industries for military purposes would be a breach of the [[Non-proliferation treaty|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,<ref>{{cite web|url=http://www.world-nuclear.org/info/inf01.html |title=Nuclear Power in the World Today |publisher=World-nuclear.org |access-date=2013-06-22}}</ref> of which [[List of states with nuclear weapons|nine have nuclear weapons]]. The vast majority of these [[nuclear weapons state]]s 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.<ref name=dfall2009 />
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.<ref>{{cite web|url=http://www.world-nuclear.org/info/Nuclear-Fuel-Cycle/Conversion-Enrichment-and-Fabrication/Uranium-Enrichment/|title=Uranium Enrichment|publisher=World Nuclear Association|website=www.world-nuclear.org|access-date=2015-08-12|archive-date=2013-07-01|archive-url=https://web.archive.org/web/20130701071520/http://www.world-nuclear.org/info/Nuclear-Fuel-Cycle/Conversion-Enrichment-and-Fabrication/Uranium-Enrichment/}}</ref>
Iran was an early participant from 1974 and remains a shareholder of Eurodif via [[Sofidif]].

A 2009 United Nations report said that:
<blockquote>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.<ref name=bks2011>{{cite book |last=Sovacool |first=Benjamin |author-link=Benjamin K. Sovacool |date=2011 |title=Contesting the Future of Nuclear Power: A Critical Global Assessment of Atomic Energy |publisher=[[World Scientific]] |location=Hackensack, NJ |page=190 |isbn=978-981-4322-75-1|title-link=Contesting the Future of Nuclear Power }}</ref></blockquote>

On the other hand, power reactors can also reduce nuclear weapon 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.<ref name="thebulletin.org">{{cite web |url=http://www.thebulletin.org/web-edition/op-eds/support-of-the-megatons-to-megawatts-program |title=The Bulletin of atomic scientists support the megatons to megawatts program |archive-url=https://web.archive.org/web/20110708162741/http://www.thebulletin.org/web-edition/op-eds/support-of-the-megatons-to-megawatts-program |archive-date=2011-07-08 |access-date=2012-09-15|date=2008-10-23 }}</ref>
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.<ref>{{cite web |url=http://www.usec.com/news/megatons-megawatts-eliminates-equivalent-10000-nuclear-warheads |title=Megatons to Megawatts Eliminates Equivalent of 10,000 Nuclear Warheads |publisher=Usec.com |date=2005-09-21 |access-date=2013-06-22 |archive-url=https://web.archive.org/web/20130426130245/http://www.usec.com/news/megatons-megawatts-eliminates-equivalent-10000-nuclear-warheads |archive-date=2013-04-26 }}</ref>
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{{nbsp}}[[TWh]] of electricity produced.<ref name="ReferenceB">{{cite journal |author=Dawn Stover |date=2014-02-21 |title=More megatons to megawatts |url=http://thebulletin.org/more-megatons-megawatts |journal=The Bulletin |access-date=2015-08-11 |archive-date=2017-05-04 |archive-url=https://web.archive.org/web/20170504175156/http://thebulletin.org/more-megatons-megawatts }}</ref>
In total it is estimated to have cost $17 billion, a "bargain for US ratepayers", with Russia profiting $12 billion from the deal.<ref name="ReferenceB" /> 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.<ref name="A Farewell to Arms, 2014">{{cite web|url=http://www.technologyreview.com/article/529861/a-farewell-to-arms/|title=Against Long Odds, MIT's Thomas Neff Hatched a Plan to Turn Russian Warheads into American Electricity|first=Anne-Marie|last=Corley}}</ref>
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.<ref name="thebulletin.org" />
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.<ref>{{cite news |date=2009-12-05 |title=Future Unclear For 'Megatons To Megawatts' Program |url=https://www.npr.org/templates/story/story.php?storyId=121125743 |work=All Things Considered |publisher=NPR |access-date=2013-06-22}}</ref>

== Environmental impact{{anchor|Environmental_issues}} ==
{{Main|Environmental impact of nuclear power}}
[[File:Ikata Nuclear Powerplant.JPG|thumb|The [[Ikata Nuclear Power Plant]], a [[pressurized water reactor]] that cools by utilizing a secondary coolant [[heat exchanger]] with a large body of water, an alternative cooling approach to large [[cooling towers]]]]
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.<ref>{{cite web |title=Life Cycle Assessment of Electricity Generation Options |url=https://unece.org/sites/default/files/2021-10/LCA-2.pdf |access-date=24 November 2021}}</ref><ref>{{cite web |title=Nuclear energy and water use in the columbia river basin |url=https://www.umt.edu/bridges/resources/Documents/Blog-Items/C1-Nuclear-Energy-Water.pdf |access-date=24 November 2021}}</ref><ref name="10.1016/j.enpol.2016.03.012"/><ref name="10.3390/ijerph13070700">{{cite journal |last1=Kyne |first1=Dean |last2=Bolin |first2=Bob |title=Emerging Environmental Justice Issues in Nuclear Power and Radioactive Contamination |journal=International Journal of Environmental Research and Public Health |date=July 2016 |volume=13 |issue=7 |page=700 |doi=10.3390/ijerph13070700 |pmid=27420080 |pmc=4962241 |language=en|doi-access=free }}</ref> 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.<ref name="repr"/><ref name="wi1"/><ref name="worldnuclearwastereport"/><ref name="risks"/><ref name="plane1"/><ref name="10.3390/ijerph13070700"/><ref>{{cite journal |last1=Ahearne |first1=John F. |title=Intergenerational Issues Regarding Nuclear Power, Nuclear Waste, and Nuclear Weapons |journal=Risk Analysis |date=2000 |volume=20 |issue=6 |pages=763–770 |doi=10.1111/0272-4332.206070 |pmid=11314726 |bibcode=2000RiskA..20..763A |s2cid=23395683 |language=en |issn=1539-6924}}</ref><ref name="dont"/> 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 ===
{{See also|Life-cycle greenhouse gas emissions of energy sources}}
{{Further|#Historic effect on carbon emissions}}
{{climate change mitigation|Energy}}

[[File:CO2 Emissions from Electricity Production IPCC.png|thumb|Life-cycle greenhouse gas emissions of electricity supply technologies, median values calculated by [[IPCC]]<ref name="IPCC 2014 Annex III" />]]
Nuclear power is one of the leading [[low carbon power generation]] methods of producing [[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]].<ref name="Nrel.gov">{{cite web |url=http://www.nrel.gov/analysis/sustain_lca_nuclear.html | title=Nuclear Power Results – Life Cycle Assessment Harmonization| quote=Collectively, life cycle assessment literature shows that nuclear power is similar to other renewable and much lower than fossil fuel in total life cycle GHG emissions. |publisher=nrel.gov |author= [[National Renewable Energy Laboratory]] (NREL) |date=2013-01-24 |access-date=2013-06-22 |archive-url=https://web.archive.org/web/20130702205635/http://www.nrel.gov/analysis/sustain_lca_nuclear.html |archive-date=2013-07-02 }}</ref><ref>{{cite web | url=http://www.nrel.gov/analysis/sustain_lca_results.html | title=Life Cycle Assessment Harmonization Results and Findings. Figure 1 | publisher=NREL | access-date=2016-09-08 | archive-date=2017-05-06 | archive-url=https://web.archive.org/web/20170506114117/http://www.nrel.gov/analysis/sustain_lca_results.html }}</ref>
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{{nbsp}}g {{CO2}}[[carbon dioxide equivalent|eq]]/[[kilowatt-hour|kWh]], which is the lowest among all commercial [[baseload]] energy sources.<ref name="IPCC 2014 Annex III">{{cite web|url=https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-iii.pdf |title=IPCC Working Group III – Mitigation of Climate Change, Annex III: Technology–specific cost and performance parameters |year=2014 |publisher=IPCC |at=table A.III.2 |access-date=2019-01-19 }}</ref><ref name="report.mitigation2014.org">{{cite web|url=https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-ii.pdf |title=IPCC Working Group III – Mitigation of Climate Change, Annex II Metrics & Methodology. |year=2014 |publisher=IPCC |at=section A.II.9.3 |access-date=2019-01-19 }}</ref>
This is contrasted with [[coal]] and [[natural gas]] at 820 and 490&nbsp;g {{CO2}} eq/kWh.<ref name="IPCC 2014 Annex III" /><ref name="report.mitigation2014.org" />
As of 2021, nuclear reactors worldwide have helped avoid the emission of 72 billion tonnes of carbon dioxide since 1970, compared to coal-fired electricity generation, according to a report.<ref name="Kharecha Pushker A 2013 4889–4895" /><ref>{{cite web|url=https://world-nuclear.org/getmedia/264c91d4-d443-4edb-bc08-f5175c0ac6ba/performance-report-2021-cop26.pdf.aspx |title=World nuclear performance report 2021 |publisher=World Nuclear Association}}</ref>

=== Radiation ===
The average dose from natural [[background radiation]] is 2.4 [[millisievert]] per year (mSv/a) globally. It varies between 1{{nbsp}}mSv/a and 13{{nbsp}}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{{nbsp}}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{{nbsp}}mSv/a.<ref name=UNSCEAR_GA>{{cite web |url= http://www.unscear.org/docs/reports/2008/09-86753_Report_2008_GA_Report_corr2.pdf |title=UNSCEAR 2008 Report to the General Assembly |publisher=United Nations Scientific Committee on the Effects of Atomic Radiation |year=2008}}</ref>
For comparison, the average dose to those living within {{convert|50|miles}} of a [[coal power plant]] is over three times this dose, at 0.0003{{nbsp}}mSv/a.<ref>{{cite web |url=http://www.nsc.org/resources/issues/rad/exposure.aspx |title=National Safety Council |publisher=Nsc.org |access-date=18 June 2013 |url-status=live |archive-url= https://web.archive.org/web/20091012025401/http://www.nsc.org/resources/issues/rad/exposure.aspx |archive-date=12 October 2009 }}</ref>

Chernobyl resulted in the most affected surrounding populations and male recovery personnel receiving an average initial 50 to 100{{nbsp}}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{{nbsp}}mSv/a and is continuously dropping at the decaying rate, from the initial high of 0.04{{nbsp}}mSv per person averaged over the entire populace of the Northern Hemisphere in the year of the accident in 1986.<ref name=UNSCEAR_GA />

== Debate ==
{{Main|Nuclear power debate}}
{{See also|Nuclear energy policy|Pro-nuclear movement|Anti-nuclear movement}}
[[File:3-Learning-curves-for-electricity-prices.png|thumb|upright=2|A comparison of prices over time for energy from nuclear fission and from other sources. Over the presented time, thousands of wind turbines and similar were built on assembly lines in mass production resulting in an economy of scale. While nuclear remains bespoke, many first of their kind facilities added in the timeframe indicated and none are in serial production. 
''Our World in Data'' notes that this cost is the global ''average'', while the 2 projects that drove nuclear pricing upwards were in the US. The organization recognises that the [[median]] cost of the most exported and produced nuclear energy facility in the 2010s the South Korean [[APR1400]], remained "constant", including in export.<ref>{{cite web | url=https://ourworldindata.org/cheap-renewables-growth | title=Why did renewables become so cheap so fast? | website=Our World in Data | date=1 December 2020 | last1=Roser | first1=Max }}</ref><br /><small>[[Levelized cost of energy|LCOE]] is a measure of the average net present cost of electricity generation for a generating plant over its lifetime. As a metric, it remains controversial as the lifespan of units are not independent but manufacturer projections, not a demonstrated longevity.</small>]]
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.<ref name=eleven /><ref name="jstor.org">{{cite journal| author=James J. MacKenzie |jstor=2823429 |title=Review of The Nuclear Power Controversy by Arthur W. Murphy |journal=The Quarterly Review of Biology|volume= 52|number= 4 |date=December 1977|pages= 467–468|doi=10.1086/410301 }}</ref><ref name="marcuse.org" />

Proponents of nuclear energy regard it as a [[sustainable energy]] source that reduces [[carbon emissions]] and increases [[energy security]] by decreasing dependence on other energy sources that are also<ref name="10.1016/j.enpol.2018.12.024">{{cite journal |last1=Jewell |first1=Jessica |last2=Vetier |first2=Marta |last3=Garcia-Cabrera |first3=Daniel |title=The international technological nuclear cooperation landscape: A new dataset and network analysis |journal=Energy Policy |date=1 May 2019 |volume=128 |pages=838–852 |doi=10.1016/j.enpol.2018.12.024 |s2cid=159233075 |language=en |issn=0301-4215|url=http://pure.iiasa.ac.at/id/eprint/15756/1/IR_nuclear_draft_180712.pdf }}</ref><ref name="10.1016/j.anucene.2017.08.019">{{cite journal |last1=Xing |first1=Wanli |last2=Wang |first2=Anjian |last3=Yan |first3=Qiang |last4=Chen |first4=Shan |title=A study of China's uranium resources security issues: Based on analysis of China's nuclear power development trend |journal=Annals of Nuclear Energy |date=1 December 2017 |volume=110 |pages=1156–1164 |doi=10.1016/j.anucene.2017.08.019 |bibcode=2017AnNuE.110.1156X |language=en |issn=0306-4549}}</ref><ref name="10.1002/ente.201600444">{{cite journal |last1=Yue |first1=Qiang |last2=He |first2=Jingke |last3=Stamford |first3=Laurence |last4=Azapagic |first4=Adisa |title=Nuclear Power in China: An Analysis of the Current and Near-Future Uranium Flows |journal=Energy Technology |date=2017 |volume=5 |issue=5 |pages=681–691 |doi=10.1002/ente.201600444 |language=en |issn=2194-4296|doi-access=free }}</ref> often dependent on imports.<ref name="bloomberg.com">{{cite news |url=https://www.bloomberg.com/apps/news?pid=10000103&sid=aXb5iuqdZoD4&refer=us |title=U.S. Energy Legislation May Be 'Renaissance' for Nuclear Power |work=Bloomberg |access-date=2017-03-10 |archive-date=2009-06-26 |archive-url=https://web.archive.org/web/20090626182130/http://www.bloomberg.com/apps/news?pid=10000103 }}.</ref><ref>{{cite news |last=Patterson |first=Thom |date=2013-11-03 |title=Climate change warriors: It's time to go nuclear |url=http://www.cnn.com/2013/11/03/world/nuclear-energy-climate-change-scientists/index.html |newspaper=CNN}}</ref><ref>{{cite web| url= http://www.world-nuclear.org/info/inf10.html| title= Renewable Energy and Electricity| date= June 2010| publisher= World Nuclear Association| access-date= 2010-07-04| archive-date= 2010-06-19| archive-url= https://web.archive.org/web/20100619061729/http://world-nuclear.org/info/inf10.html}}</ref> For example, proponents note that annually, nuclear-generated electricity reduces 470 million metric tons of carbon dioxide emissions that would otherwise come from fossil fuels.<ref>{{cite web |title=Climate |url=https://www.nei.org/advantages/climate |access-date=18 February 2022}}</ref> Additionally, the amount of comparatively low waste that nuclear energy does create is safely disposed of by the large scale nuclear energy production facilities or it is repurposed/recycled for other energy uses.<ref>{{cite web |title=Radioactive Waste Management |url=https://www.world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-wastes/radioactive-waste-management.aspx  |date= February 2022}}</ref> [[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.<ref>{{cite web |url=http://www.hubbertpeak.com/hubbert/1956/1956.pdf |title=Nuclear Energy and the Fossil Fuels 'Drilling and Production Practice' |author=M. King Hubbert |publisher=[[American Petroleum Institute|API]] |page=36 |date=June 1956 |access-date=2008-04-18 |archive-url=https://web.archive.org/web/20080527233843/http://www.hubbertpeak.com/hubbert/1956/1956.pdf |archive-date=2008-05-27 }}</ref>
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".<ref name="Bernard L. Cohen 1990"/> 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 CO<sub>2</sub>-equivalent (Gt{{CO2}}-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{{nbsp}}Gt{{CO2}}-eq emissions by 2050.<ref name="Kharecha Pushker A 2013 4889–4895" />

Proponents also bring to attention the opportunity cost of utilizing other forms of electricity. For example, the Environmental Protection Agency estimates that coal kills 30,000 people a year,<ref>{{cite journal |title=Particulate matter air pollution and national and county life expectancy loss in the USA: A spatiotemporal analysis |date=23 July 2019| doi=10.1371/journal.pmed.1002856 | last1=Bennett | first1=James E. | last2=Tamura-Wicks | first2=Helen | last3=Parks | first3=Robbie M. | last4=Burnett | first4=Richard T. | last5=Pope | first5=C. Arden | last6=Bechle | first6=Matthew J. | last7=Marshall | first7=Julian D. | last8=Danaei | first8=Goodarz | last9=Ezzati | first9=Majid | journal=PLOS Medicine | volume=16 | issue=7 | pages=e1002856 | pmid=31335874 | pmc=6650052 |doi-access=free }}</ref> as a result of its environmental impact, while 60 people died in the Chernobyl disaster.<ref>{{cite web |title=Nuclear Power and Energy Independence |url=https://reason.com/2008/10/22/nuclear-power-and-energy-indep/ |date=22 October 2008}}</ref> A real world example of impact provided by proponents is the 650,000 ton increase in carbon emissions in the two months following the closure of the Vermont Yankee nuclear plant.<ref>{{cite web |title=Climate |url=https://www.nuclearmatters.com/climate |access-date=18 February 2022}}</ref>

Opponents believe that nuclear power poses many threats to people's health and environment<ref>{{cite book|author=Spencer R. Weart|title=The Rise of Nuclear Fear|date=2012|publisher=Harvard University Press|author-link=Spencer R. Weart}}</ref><ref name="Sturgis">{{cite web|url=http://www.southernstudies.org/2009/04/post-4.html |title=Investigation: Revelations about Three Mile Island disaster raise doubts over nuclear plant safety |last=Sturgis |first=Sue |publisher=[[Institute for Southern Studies]]|access-date=2010-08-24 |archive-url=https://web.archive.org/web/20100418063024/http://www.southernstudies.org/2009/04/post-4.html |archive-date=2010-04-18 }}</ref> such as the risk of nuclear weapons proliferation, long-term safe waste management and terrorism in the future.<ref name=gierec>{{cite web |publisher= Greenpeace International and European Renewable Energy Council |date= January 2007 |url= http://www.energyblueprint.info/fileadmin/media/documents/energy_revolution.pdf |title= Energy Revolution: A Sustainable World Energy Outlook |page= 7 |access-date= 2010-02-28 |archive-date= 2009-08-06 |archive-url= https://web.archive.org/web/20090806121526/http://www.energyblueprint.info/fileadmin/media/documents/energy_revolution.pdf }}</ref><ref name=protest>{{cite book |last1=Giugni |first1=Marco |title=Social protest and policy change: ecology, antinuclear, and peace movements in comparative perspective |date=2004 |publisher=Rowman & Littlefield |location=Lanham |isbn=978-0-7425-1826-1|url=https://books.google.com/books?id=Kn6YhNtyVigC&pg=PA44 |page=44}}</ref> They also contend that nuclear power plants are complex systems where many things can and have gone wrong.<ref name=bksenpol>{{cite journal | author = Sovacool Benjamin K. | author-link = Benjamin K. Sovacool | year = 2008 | title = The costs of failure: A preliminary assessment of major energy accidents, 1907–2007 | journal = [[Energy Policy (journal)|Energy Policy]] | volume = 36 | issue = 5| pages = 1802–1820 | doi=10.1016/j.enpol.2008.01.040}}</ref><ref>{{cite book |last1=Cooke |first1=Stephanie |title=[[In Mortal Hands: A Cautionary History of the Nuclear Age]] |date=2009 |publisher=Bloomsbury |location=New York |isbn=978-1-59691-617-3 |page=280 }}</ref> Costs of the [[Chernobyl disaster]] amount to ≈$68 billion as of 2019 and are increasing,<ref name="OECD02-Ch2"/> the [[Fukushima Daiichi nuclear disaster|Fukushima disaster]] is estimated to cost taxpayers ~$187 billion,<ref name=guardian-20170130>{{cite news |url=https://www.theguardian.com/environment/2017/jan/31/possible-nuclear-fuel-find-fukushima-plant |title=Possible nuclear fuel find raises hopes of Fukushima plant breakthrough |author=Justin McCurry |newspaper=The Guardian |date=30 January 2017 |access-date=3 February 2017}}</ref> and radioactive waste management is estimated to cost the EU nuclear operators ~$250 billion by 2050.<ref name="euwastecosts">{{cite news |title=Europe faces €253bn nuclear waste bill |url=https://www.theguardian.com/environment/2016/apr/04/europe-faces-253bn-nuclear-waste-bill |access-date=24 November 2021 |work=The Guardian |date=4 April 2016 |language=en}}</ref> 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<ref>{{cite journal |last1=Rodriguez |first1=C. |last2=Baxter |first2=A. |last3=McEachern |first3=D. |last4=Fikani |first4=M. |last5=Venneri |first5=F. |title=Deep-Burn: making nuclear waste transmutation practical |journal=Nuclear Engineering and Design |date=1 June 2003 |volume=222 |issue=2 |pages=299–317 |doi=10.1016/S0029-5493(03)00034-7 |language=en |issn=0029-5493}}</ref> "as the main part of these costs stems from the operation of the intermediate storage facility".<ref>{{cite journal |last1=Geissmann |first1=Thomas |last2=Ponta |first2=Oriana |title=A probabilistic approach to the computation of the levelized cost of electricity |journal=Energy |date=1 April 2017 |volume=124 |pages=372–381 |doi=10.1016/j.energy.2017.02.078 |language=en |issn=0360-5442}}</ref>

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.<ref name="cnnchina"/><ref name="10.1016/j.erss.2014.04.015">{{cite journal |last1=Ramana |first1=M. V. |last2=Mian |first2=Zia |title=One size doesn't fit all: Social priorities and technical conflicts for small modular reactors |journal=Energy Research & Social Science |date=1 June 2014 |volume=2 |pages=115–124 |doi=10.1016/j.erss.2014.04.015 |language=en |issn=2214-6296}}</ref><ref name="10.5281/zenodo.5573718">{{cite periodical |title=Kernenergie und Klima |periodical=Diskussionsbeiträge der Scientists for Future |date=16 October 2021 |doi=10.5281/zenodo.5573718 |doi-access=free |language=de |last1=Wealer |first1=Ben |last2=Breyer |first2=Christian |last3=Hennicke |first3=Peter |last4=Hirsch |first4=Helmut |last5=von Hirschhausen |first5=Christian |last6=Klafka |first6=Peter |last7=Kromp-Kolb |first7=Helga |last8=Präger |first8=Fabian |last9=Steigerwald |first9=Björn |last10=Traber |first10=Thure |last11=Baumann |first11=Franz |last12=Herold |first12=Anke |last13=Kemfert |first13=Claudia |last14=Kromp |first14=Wolfgang |last15=Liebert |first15=Wolfgang |last16=Müschen |first16=Klaus }}</ref><ref name="10.1016/j.enpol.2016.03.012">{{cite journal |last1=Ramana |first1=M. V. |last2=Ahmad |first2=Ali |title=Wishful thinking and real problems: Small modular reactors, planning constraints, and nuclear power in Jordan |journal=Energy Policy |date=1 June 2016 |volume=93 |pages=236–245 |doi=10.1016/j.enpol.2016.03.012 |language=en |issn=0301-4215}}</ref><ref name="10.1177/2399654418777765">{{cite journal |last1=Meckling |first1=Jonas |title=Governing renewables: Policy feedback in a global energy transition |journal=Environment and Planning C: Politics and Space |date=1 March 2019 |volume=37 |issue=2 |pages=317–338 |doi=10.1177/2399654418777765 |s2cid=169975439 |language=en |issn=2399-6544}}</ref>
Further costs include costs for ongoing research and development, expensive [[Nuclear reprocessing|reprocessing]] in cases where such is practiced<ref name="repr"/><ref name="future1"/><ref name="pluto"/><ref name="detect"/> and decommissioning.<ref>[https://www.nrc.gov/reading-rm/basic-ref/students/decommissioning.html Decommissioning a Nuclear Power Plant], 2007-4-20, [http://www.nrc.gov/ U.S. Nuclear Regulatory Commission], Retrieved 2007-6-12</ref><ref>{{cite web |url=http://www.world-nuclear-news.org/newsarticle.aspx?id=13304&LangType=2057 |title=Decommissioning at Chernobyl |publisher=World-nuclear-news.org |date=2007-04-26 |access-date=2015-11-01 |archive-date=2010-08-23 |archive-url=https://web.archive.org/web/20100823095416/http://www.world-nuclear-news.org/newsarticle.aspx?id=13304&LangType=2057 }}</ref><ref name="10.1016/j.rser.2021.110836">{{cite journal |last1=Wealer |first1=B. |last2=Bauer |first2=S. |last3=Hirschhausen |first3=C. v. |last4=Kemfert |first4=C. |last5=Göke |first5=L. |title=Investing into third generation nuclear power plants - Review of recent trends and analysis of future investments using Monte Carlo Simulation |journal=Renewable and Sustainable Energy Reviews |date=1 June 2021 |volume=143 |page=110836 |doi=10.1016/j.rser.2021.110836 |s2cid=233564525 |language=en |issn=1364-0321 |quote=We conclude that our numerical exercise confirms the literature review, i.e. the economics of nuclear power plants are not favorable to future investments, even though additional costs (decommissioning, long-term storage) and the social costs of accidents are not even considered.}}</ref> Proponents note that focussing on the [[Levelized Cost of Energy]] (LCOE), however, ignores the value premium associated with 24/7 dispatchable electricity and the cost of storage and backup systems necessary to integrate variable energy sources into a reliable electrical grid.<ref>{{Cite web|url=https://www.reutersevents.com/nuclear/new-nuclear-lto-among-cheapest-low-carbon-options-report-shows|title=New nuclear, LTO among cheapest low carbon options, report shows |website=Reuters Events}}</ref> "Nuclear thus remains the dispatchable low-carbon technology with the lowest expected costs in 2025. Only large hydro reservoirs can provide a similar contribution at comparable costs but remain highly dependent on the natural endowments of individual countries."<ref>{{Cite web|url=https://www.iea.org/reports/projected-costs-of-generating-electricity-2020|title=Projected Costs of Generating Electricity 2020 – Analysis|website=IEA}}</ref>
[[File:Grüne protests against nuclear energy.jpg|right|thumb|Anti-nuclear protest near [[Deep geological repository|nuclear waste disposal centre]] at [[Gorleben]] in northern Germany]]
Overall, many opponents find that nuclear energy cannot meaningfully contribute to climate change mitigation. In general, they find it to be, too dangerous, too expensive, to take too long for deployment, to be an obstacle to achieving a transition towards sustainability and carbon-neutrality,<ref name="10.5281/zenodo.5573718"/><ref>{{cite web |title=Empirically grounded technology forecasts and the energy transition |website=University of Oxford |url=https://www.inet.ox.ac.uk/files/energy_transition_paper-INET-working-paper.pdf |archive-url=https://web.archive.org/web/20211018072825/https://www.inet.ox.ac.uk/files/energy_transition_paper-INET-working-paper.pdf |archive-date=2021-10-18 |language=en}}</ref><ref name="slowexpensive">{{cite news |title=Nuclear energy too slow, too expensive to save climate: report |url=https://www.reuters.com/article/us-energy-nuclearpower-idUSKBN1W909J |access-date=24 November 2021 |work=Reuters |date=24 September 2019 |language=en}}</ref><ref>{{cite web |last1=Farmer |first1=J. Doyne |last2=Way |first2=Rupert |last3=Mealy |first3=Penny |title=Estimating the costs of energy transition scenarios using probabilistic forecasting methods |website=University of Oxford |date=December 2020 |url=https://www.inet.ox.ac.uk/files/energy_transition_paper-INET-working-paper.pdf |archive-url=https://web.archive.org/web/20211018072825/https://www.inet.ox.ac.uk/files/energy_transition_paper-INET-working-paper.pdf |archive-date=2021-10-18 |language=en}}</ref> effectively being a distracting<ref name="gates2">{{cite news |title=Scientists pour cold water on Bill Gates' nuclear plans {{!}} DW {{!}} 08.11.2021 |url=https://www.dw.com/en/scientists-pour-cold-water-on-bill-gates-nuclear-plans/a-59751405 |access-date=24 November 2021 |work=Deutsche Welle (www.dw.com)}}</ref><ref name="cd1">{{cite web |title=Scientists Warn Experimental Nuclear Plant Backed by Bill Gates Is 'Outright Dangerous' |url=https://www.commondreams.org/news/2021/11/17/scientists-warn-experimental-nuclear-plant-backed-bill-gates-outright-dangerous |website=Common Dreams |access-date=24 November 2021 |language=en}}</ref> competition for resources (i.e. human, financial, time, infrastructure and expertise) for the deployment and development of alternative, sustainable, [[energy system]] technologies<ref name="mil1">{{cite web |title=Hidden military implications of 'building back' with new nuclear in the UK |url=https://www.sgr.org.uk/sites/default/files/2021-09/SGR_RS03_2021_Johnstone%2BStirling.pdf |access-date=24 November 2021}}</ref><ref name="cd1"/><ref name="10.5281/zenodo.5573718"/><ref>{{cite journal |last1=Szyszczak |first1=Erika |title=State aid for energy infrastructure and nuclear power projects |journal=ERA Forum |date=1 July 2015 |volume=16 |issue=1 |pages=25–38 |doi=10.1007/s12027-015-0371-6 |s2cid=154617833 |language=en |issn=1863-9038}}</ref> (such as for wind, ocean and solar<ref name="10.5281/zenodo.5573718"/> – including e.g. [[floating solar]]&nbsp;– as well as ways to manage [[Variable renewable energy|their intermittency]] other than nuclear baseload<ref name=MIT2018>{{cite web|url=http://energy.mit.edu/wp-content/uploads/2018/09/The-Future-of-Nuclear-Energy-in-a-Carbon-Constrained-World.pdf|title=The Future of Nuclear Energy in a Carbon-Constrained World|date=2018|publisher=[[Massachusetts Institute of Technology]]}}</ref> generation such as [[dispatchable generation]], renewables-diversification,<ref>{{cite journal |last1=Crespo |first1=Diego |title=STE can replace coal, nuclear and early gas as demonstrated in an hourly simulation over 4 years in the Spanish electricity mix |journal=AIP Conference Proceedings |series=SOLARPACES 2018: International Conference on Concentrating Solar Power and Chemical Energy Systems |date=25 July 2019 |volume=2126 |issue=1 |page=130003 |doi=10.1063/1.5117645 |bibcode=2019AIPC.2126m0003C |s2cid=201317957 |issn=0094-243X|doi-access=free }}</ref><ref name="10.1016/j.esr.2019.01.007">{{cite journal |last1=Benasla |first1=Mokhtar |last2=Hess |first2=Denis |last3=Allaoui |first3=Tayeb |last4=Brahami |first4=Mostefa |last5=Denaï |first5=Mouloud |title=The transition towards a sustainable energy system in Europe: What role can North Africa's solar resources play? |journal=Energy Strategy Reviews |date=1 April 2019 |volume=24 |pages=1–13 |doi=10.1016/j.esr.2019.01.007 |s2cid=169342098 |language=en |issn=2211-467X|doi-access=free |hdl=2299/21546 |hdl-access=free }}</ref> [[super grid]]s, flexible energy demand and supply regulating [[smart grid]]s and energy storage<ref>{{cite journal |last1=Haller |first1=Markus |last2=Ludig |first2=Sylvie |last3=Bauer |first3=Nico |title=Decarbonization scenarios for the EU and MENA power system: Considering spatial distribution and short term dynamics of renewable generation |journal=Energy Policy |date=1 August 2012 |volume=47 |pages=282–290 |doi=10.1016/j.enpol.2012.04.069 |language=en |issn=0301-4215}}</ref><ref>{{cite journal |last1=Arbabzadeh |first1=Maryam |last2=Sioshansi |first2=Ramteen |last3=Johnson |first3=Jeremiah X. |last4=Keoleian |first4=Gregory A. |title=The role of energy storage in deep decarbonization of electricity production |journal=Nature Communications |date=30 July 2019 |volume=10 |issue=1 |page=3413 |doi=10.1038/s41467-019-11161-5 |pmid=31363084 |pmc=6667472 |bibcode=2019NatCo..10.3413A |language=en |issn=2041-1723}}</ref><ref>{{cite book |last1=Liu |first1=Jianing |last2=Zhang |first2=Weiqi |last3=Zhou |first3=Rui |last4=Zhong |first4=Jin |title=2012 IEEE Power and Energy Society General Meeting |chapter=Impacts of distributed renewable energy generations on smart grid operation and dispatch |date=July 2012 |pages=1–5 |doi=10.1109/PESGM.2012.6344997|isbn=978-1-4673-2729-9 |s2cid=25157226 }}</ref><ref>{{cite journal |last1=Ayodele |first1=T. R. |last2=Ogunjuyigbe |first2=A. S. O. |title=Mitigation of wind power intermittency: Storage technology approach |journal=Renewable and Sustainable Energy Reviews |date=1 April 2015 |volume=44 |pages=447–456 |doi=10.1016/j.rser.2014.12.034 |language=en |issn=1364-0321}}</ref><ref name="natgeo"/> technologies).<ref name="10.1016/j.enpol.2016.04.013">{{cite journal |last1=Khatib |first1=Hisham |last2=Difiglio |first2=Carmine |title=Economics of nuclear and renewables |journal=Energy Policy |date=1 September 2016 |volume=96 |pages=740–750 |doi=10.1016/j.enpol.2016.04.013 |language=en |issn=0301-4215}}</ref><ref>{{cite periodical |title=Klimaverträgliche Energieversorgung für Deutschland – 16 Orientierungspunkte |trans-title=Climate-friendly energy supply for Germany—16 points of orientation |periodical=Diskussionsbeiträge der Scientists for Future |date=22 April 2021 |doi=10.5281/zenodo.4409334 |doi-access=free |language=de |last1=Gerhards |first1=Christoph |last2=Weber |first2=Urban |last3=Klafka |first3=Peter |last4=Golla |first4=Stefan |last5=Hagedorn |first5=Gregor |last6=Baumann |first6=Franz |last7=Brendel |first7=Heiko |last8=Breyer |first8=Christian |last9=Clausen |first9=Jens |last10=Creutzig |first10=Felix |last11=Daub |first11=Claus-Heinrich |last12=Helgenberger |first12=Sebastian |last13=Hentschel |first13=Karl-Martin |last14=Hirschhausen |first14=Christian von |last15=Jordan |first15=Ulrike |last16=Kemfert |first16=Claudia |last17=Krause |first17=Harald |last18=Linow |first18=Sven |last19=Oei |first19=Pao-Yu |last20=Pehnt |first20=Martin |last21=Pfennig |first21=Andreas |last22=Präger |first22=Fabian |last23=Quaschning |first23=Volker |last24=Schneider |first24=Jens |last25=Spindler |first25=Uli |last26=Stelzer |first26=Volker |last27=Sterner |first27=Michael |last28=Wagener-Lohse |first28=Georg |last29=Weinsziehr |first29=Theresa }}</ref><ref>{{cite journal |last1=Lap |first1=Tjerk |last2=Benders |first2=René |last3=van der Hilst |first3=Floor |last4=Faaij |first4=André |title=How does the interplay between resource availability, intersectoral competition and reliability affect a low-carbon power generation mix in Brazil for 2050? |journal=Energy |date=15 March 2020 |volume=195 |page=116948 |doi=10.1016/j.energy.2020.116948 |s2cid=214336333 |language=en |issn=0360-5442|doi-access=free }}</ref><ref>{{cite journal |last1=Bustreo |first1=C. |last2=Giuliani |first2=U. |last3=Maggio |first3=D. |last4=Zollino |first4=G. |title=How fusion power can contribute to a fully decarbonized European power mix after 2050 |journal=Fusion Engineering and Design |date=1 September 2019 |volume=146 |pages=2189–2193 |doi=10.1016/j.fusengdes.2019.03.150 |s2cid=133216477 |language=en |issn=0920-3796}}</ref><ref>{{cite journal |last1=McPherson |first1=Madeleine |last2=Tahseen |first2=Samiha |title=Deploying storage assets to facilitate variable renewable energy integration: The impacts of grid flexibility, renewable penetration, and market structure |journal=Energy |date=15 February 2018 |volume=145 |pages=856–870 |doi=10.1016/j.energy.2018.01.002 |language=en |issn=0360-5442}}</ref><ref>{{cite journal |last1=Kan |first1=Xiaoming |last2=Hedenus |first2=Fredrik |last3=Reichenberg |first3=Lina |title=The cost of a future low-carbon electricity system without nuclear power – the case of Sweden |journal=Energy |date=15 March 2020 |volume=195 |page=117015 |doi=10.1016/j.energy.2020.117015| arxiv=2001.03679  |s2cid=213083726 |language=en |issn=0360-5442 |quote=There is little economic rationale for Sweden to reinvest in nuclear power. Abundant hydropower allows for a low-cost renewable power system without nuclear.}}</ref><ref>{{cite journal |last1=McPherson |first1=Madeleine |last2=Karney |first2=Bryan |title=A scenario based approach to designing electricity grids with high variable renewable energy penetrations in Ontario, Canada: Development and application of the SILVER model |journal=Energy |date=1 November 2017 |volume=138 |pages=185–196 |doi=10.1016/j.energy.2017.07.027 |language=en |issn=0360-5442 |quote=Several flexibility options have been proposed to facilitate VRE integration, including interconnecting geographically dispersed resources, interconnecting different VRE types, building flexible and dispatchable generation assets, shifting flexible loads through demand response, shifting electricity generation through storage, curtailing excess generation, interconnections to the transport or heating energy sectors, and improving VRE forecasting methodologies (Delucchi and Jacobson 2011). Previous VRE integration studies have considered different combinations of balancing options, but few have considered all flexibility options simultaneously.}}</ref><ref>{{cite web |title=Barriers to Renewable Energy Technologies {{!}} Union of Concerned Scientists |url=https://ucsusa.org/resources/barriers-renewable-energy-technologies |website=ucsusa.org |access-date=25 October 2021 |language=en |quote=Renewable energy opponents love to highlight the variability of the sun and wind as a way of bolstering support for coal, gas, and nuclear plants, which can more easily operate on-demand or provide "baseload" (continuous) power. The argument is used to undermine large investments in renewable energy, presenting a rhetorical barrier to higher rates of wind and solar adoption. But reality is much more favorable for clean energy.}}</ref><ref name="dont">{{cite web |title=CoP 26 Statement {{!}} Don't nuke the Climate! |url=https://dont-nuke-the-climate.org/cop-26-statement |access-date=24 November 2021 |archive-date=25 November 2021 |archive-url=https://web.archive.org/web/20211125033418/https://www.dont-nuke-the-climate.org/cop-26-statement }}</ref>

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.<ref>{{cite news |title=Does Hitachi decision mean the end of UK's nuclear ambitions? |url=https://www.theguardian.com/business/2019/jan/17/does-the-hitachi-decision-mean-the-end-of-the-uks-nuclear-dream |work=The Guardian |date=17 January 2019}}</ref> 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.<ref>{{cite journal |last1=Zappa |first1=William |last2=Junginger |first2=Martin |last3=van den Broek |first3=Machteld |title=Is a 100% renewable European power system feasible by 2050? |journal=Applied Energy |date=1 January 2019 |volume=233-234 |pages=1027–1050 |doi=10.1016/j.apenergy.2018.08.109 |s2cid=116855350 |language=en |issn=0306-2619|doi-access=free |bibcode=2019ApEn..233.1027Z }}</ref> Arguments of economics and safety are used by both sides of the debate.

=== Comparison with renewable energy ===
{{See also|Renewable energy debate}}

Slowing [[global warming]] requires a transition to a [[low-carbon economy]], mainly by burning far less [[fossil fuel]]. Limiting global warming to 1.5{{nbsp}}°C is technically possible if no new fossil fuel power plants are built from 2019.<ref>{{cite journal |author=Smith|display-authors=etal|date=15 January 2019 |title=Current fossil fuel infrastructure does not yet commit us to 1.5 °C warming |journal=Nature |volume=10|issue=1|page=101|bibcode=2019NatCo..10..101S|doi=10.1038/s41467-018-07999-w|pmid=30647408|pmc=6333788}}</ref> 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]],<ref>{{cite magazine |url=https://spectrum.ieee.org/energy/renewables/what-it-would-really-take-to-reverse-climate-change|title= What It Would Really Take to Reverse Climate Change|magazine=IEEE Spectrum|author1=Ross Koningstein |author2=David Fork|date=18 November 2014}}</ref><ref>{{cite web|url=https://grist.org/article/most-paths-to-a-clean-energy-future-start-the-same-way/ |title=Agree to Agree Fights over renewable standards and nuclear power can be vicious. Here's a list of things that climate hawks agree on. |author=Nathanael Johnson | work=[[Grist (magazine)|Grist]] |date=2018}}</ref> with intense academic debate.<ref>{{cite news|url=https://www.utilitydive.com/news/whats-missing-from-the-100-renewable-energy-debate/447658/ |title=What's missing from the 100% renewable energy debate| work=Utility Dive}}</ref><ref name="GTM-NewFront">{{cite web |last1=Deign |first1=Jason |title=Renewables or Nuclear? A New Front in the Academic War Over Decarbonization |url=https://www.greentechmedia.com/articles/read/the-war-over-renewables-versus-nuclear |website=gtm |publisher=Greentech Media |date=March 30, 2018}}</ref> Sometimes the IEA says that countries without nuclear should develop it as well as their renewable power.<ref>{{Cite web|url=https://www.dailysabah.com/energy/2019/07/06/turkey-may-benefit-from-nuclear-power-in-its-bid-for-clean-energy|title=Turkey may benefit from nuclear power in its bid for clean energy|website=DailySabah|date=6 July 2019|access-date=2019-07-14}}</ref>
{{Pie chart
| thumb = right
| caption = World total primary energy supply of 162,494 [[Kilowatt hour#Watt-hour multiples|TWh]] (or 13,792 [[tonne of oil equivalent|Mtoe]]) by fuels in 2017 (IEA, 2019)<ref name="IEA-Report-keyworld-2019">{{cite web |title = 2019 Key World Energy Statistics |date = 2019 |publisher = IEA |url = https://webstore.iea.org/download/direct/2831?fileName=Key_World_Energy_Statistics_2019.pdf }}{{Dead link|date=August 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>{{rp|6,8}}
| other =
| label1 = Oil
| value1 = 32
| color1 = #7C6250
| label2 = Coal/Peat/Shale
| value2 = 27.1
| color2 = #313c42
| label3 = Natural Gas
| value3 = 22.2
| color3 = #ef8e39
| label4 = Biofuels and waste
| value4 = 9.5
| color4 = #ABFF57
| label5 = Nuclear
| value5 = 4.9
| color5 = #de2821
| label6 = Hydro
| value6 = 2.5
| color6 = #005CE6
| label7 = Others ([[Renewable energy|Renewables]])
| value7 = 1.8
| color7 = #00CC4B
}}

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.<ref name=ipccccc>{{cite news|author=Fiona Harvey|date=2011-05-09|title=Renewable energy can power the world, says landmark IPCC study|url=https://www.theguardian.com/environment/2011/may/09/ipcc-renewable-energy-power-world|newspaper=The Guardian|location=London}}</ref>
While in developed nations the economically feasible geography for new hydropower is lacking, with every geographically suitable area largely already exploited,<ref>{{cite web|url=https://water.usgs.gov/edu/wuhy.html| publisher=[[USGS]]|title= Hydroelectric power water use}}</ref> some proponents of wind and solar energy claim these resources alone could eliminate the need for nuclear power.<ref name="GTM-NewFront" /><ref>{{cite web|url=https://thebulletin.org/2014/01/nuclear-vs-renewables-divided-they-fall/ |title=Nuclear vs. renewables: Divided they fall|author= Dawn Stover| work=Bulletin of the Atomic Scientists|date= January 30, 2014}}</ref>

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.<ref name="MarkandyaWilkinson2007" /><ref name="without the hot air" /><ref name="Starfelt">{{cite web|url=http://manhaz.cyf.gov.pl/manhaz/strona_konferencja_EAE-2001/15%20-%20Polenp~1.pdf|archive-url=https://web.archive.org/web/20070927230434/http://manhaz.cyf.gov.pl/manhaz/strona_konferencja_EAE-2001/15%20-%20Polenp~1.pdf|archive-date=2007-09-27|title=Economic Analysis of Various Options of Electricity Generation – Taking into Account Health and Environmental Effects|author1=Nils Starfelt|author2=Carl-Erik Wikdahl|access-date=2012-09-08}}</ref> 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.<ref>{{cite journal|author=David Biello|date=2009-01-28|title=Spent Nuclear Fuel: A Trash Heap Deadly for 250,000 Years or a Renewable Energy Source?|url=http://www.scientificamerican.com/article.cfm?id=nuclear-waste-lethal-trash-or-renewable-energy-source|journal=Scientific American|access-date=2014-01-24}}</ref><ref name="worldnuclearwastereport"/> 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.<ref>{{cite web|url=http://www.unep.org/yearbook/2012/pdfs/UYB_2012_CH_3.pdf|title=Closing and Decommissioning Nuclear Power Plants|date=2012-03-07|website=United Nations Environment Programme|archive-url=http://arquivo.pt/wayback/20160518164428/http://www.unep.org/yearbook/2012/pdfs/UYB_2012_CH_3.pdf|archive-date=2016-05-18}}</ref> The disposal and management of the wide variety<ref>{{cite journal |last1=Ewing |first1=Rodney C. |last2=Whittleston |first2=Robert A. |last3=Yardley |first3=Bruce W.D. |title=Geological Disposal of Nuclear Waste: a Primer |journal=Elements |date=1 August 2016 |volume=12 |issue=4 |pages=233–237 |doi=10.2113/gselements.12.4.233 |bibcode=2016Eleme..12..233E |issn=1811-5209|url=http://eprints.whiterose.ac.uk/104498/3/YardleyGeological%20Disposal%20of%20Nuclear%20Waste.pdf }}</ref> 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]]<ref>{{cite web |last1=Stothard |first1=Michael |title=Nuclear waste: keep out for 100,000 years |url=https://www.ft.com/content/db87c16c-4947-11e6-b387-64ab0a67014c |archive-url=https://ghostarchive.org/archive/20221210/https://www.ft.com/content/db87c16c-4947-11e6-b387-64ab0a67014c |archive-date=2022-12-10 |url-access=subscription |url-status=live |website=Financial Times |access-date=28 November 2021 |date=14 July 2016}}</ref><ref>{{cite web |title=High-Level Waste |url=https://www.nrc.gov/waste/high-level-waste.html |website=NRC Web |access-date=28 November 2021}}</ref><ref>{{cite journal |last1=Grambow |first1=Bernd |title=Mobile fission and activation products in nuclear waste disposal |journal=Journal of Contaminant Hydrology |date=12 December 2008 |volume=102 |issue=3 |pages=180–186 |doi=10.1016/j.jconhyd.2008.10.006 |pmid=19008015 |bibcode=2008JCHyd.102..180G |language=en |issn=0169-7722}}</ref> – possibly over a million years,<ref name="spektr">{{cite web |title=Kernkraft: 6 Fakten über unseren Atommüll und dessen Entsorgung |url=https://www.spektrum.de/wissen/6-fakten-ueber-unseren-atommuell-und-dessen-entsorgung/1342930 |website=www.spektrum.de |access-date=28 November 2021 |language=de}}</ref><ref>{{cite journal |last1=Rosborg |first1=B. |last2=Werme |first2=L. |title=The Swedish nuclear waste program and the long-term corrosion behaviour of copper |journal=Journal of Nuclear Materials |date=30 September 2008 |volume=379 |issue=1 |pages=142–153 |doi=10.1016/j.jnucmat.2008.06.025 |bibcode=2008JNuM..379..142R |language=en |issn=0022-3115}}</ref><ref>{{cite journal |last1=Shrader-Frechette |first1=Kristin |title=Mortgaging the future: Dumping ethics with nuclear waste |journal=Science and Engineering Ethics |date=1 December 2005 |volume=11 |issue=4 |pages=518–520 |doi=10.1007/s11948-005-0023-2 |pmid=16279752 |s2cid=43721467 |language=en |issn=1471-5546}}</ref><ref>{{cite journal |last1=Shrader-Frechette |first1=Kristin |title=Ethical Dilemmas and Radioactive Waste: A Survey of the Issues |journal=Environmental Ethics |date=1 November 1991 |volume=13 |issue=4 |pages=327–343 |doi=10.5840/enviroethics199113438 |language=en}}</ref> due to issues such as leakage,<ref>{{cite web |title=Radioactive waste leaking at German storage site: report {{!}} DW {{!}} 16.04.2018 |url=https://www.dw.com/en/radioactive-waste-leaking-at-german-storage-site-report/a-43399896 |website=DW.COM |publisher=Deutsche Welle (www.dw.com) |access-date=24 November 2021}}</ref> malign retrieval, vulnerability to attacks (including of reprocessing<ref name="civlib"/><ref name="repr"/> and [[Vulnerability of nuclear plants to attack|power plants]]), groundwater contamination, radiation and leakage to above ground, brine leakage or bacterial corrosion.<ref>{{cite journal |last1=Libert |first1=Marie |last2=Schütz |first2=Marta Kerber |last3=Esnault |first3=Loïc |last4=Féron |first4=Damien |last5=Bildstein |first5=Olivier |title=Impact of microbial activity on the radioactive waste disposal: long term prediction of biocorrosion processes |journal=Bioelectrochemistry |date=June 2014 |volume=97 |pages=162–168 |doi=10.1016/j.bioelechem.2013.10.001 |pmid=24177136 |issn=1878-562X}}</ref><ref name="spektr"/><ref>{{cite journal |last1=Butler |first1=Declan |title=Nuclear-waste facility on high alert over risk of new explosions |journal=Nature |date=27 May 2014 |doi=10.1038/nature.2014.15290 |s2cid=130354940 |language=en |issn=1476-4687}}</ref><ref name="statusreport">{{cite web |title=World Nuclear Industry Status Report 2021 |url=https://www.worldnuclearreport.org/IMG/pdf/wnisr2021-lr.pdf |access-date=24 November 2021}}</ref> 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.<ref>{{Cite web|url=https://ec.europa.eu/info/sites/default/files/business_economy_euro/banking_and_finance/documents/210329-jrc-report-nuclear-energy-assessment_en.pdf|title=Technical assessment of nuclear energy with respect to the 'do no significant harm' criteria of Regulation (EU) 2020/852 ('Taxonomy Regulation')|date=2021|access-date=2021-11-27|publisher=European Commission Joint Research Centre|page=8}}</ref> Corrosion experts noted in 2020 that putting the problem of storage off any longer "isn't good for anyone".<ref>{{cite web |title=As nuclear waste piles up, scientists seek the best long-term storage solutions |url=https://cen.acs.org/environment/pollution/nuclear-waste-pilesscientists-seek-best/98/i12 |website=cen.acs.org |access-date=28 November 2021}}</ref> Separated [[plutonium]] and [[enriched uranium]] could be used for [[nuclear weapon]]s, which&nbsp;– 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.<ref name="repr">{{cite web|title=Nuclear Reprocessing: Dangerous, Dirty, and Expensive|url=https://www.ucsusa.org/resources/nuclear-reprocessing-dangerous-dirty-and-expensive|publisher=Union of Concerned Scientists|access-date=26 January 2020}}</ref><ref name="wi1">{{cite web|title=Is nuclear power the answer to climate change?|url=https://wiseinternational.org/nuclear-energy/nuclear-power-answer-climate-change|publisher=World Information Service on Energy|access-date=1 February 2020}}</ref><ref name="worldnuclearwastereport">{{cite web |title=World Nuclear Waste Report |url=https://worldnuclearwastereport.org/ |access-date=25 October 2021}}</ref><ref name="risks">{{cite web |last1=Smith |first1=Brice |title=Insurmountable Risks: The Dangers of Using Nuclear Power to Combat Global Climate Change - Institute for Energy and Environmental Research |url=https://ieer.org/resource/books/insurmountable-risks-dangers-nuclear/ |access-date=24 November 2021 |language=en}}</ref><ref name="plane1">{{cite journal |last1=Prăvălie |first1=Remus |last2=Bandoc |first2=Georgeta |title=Nuclear energy: Between global electricity demand, worldwide decarbonisation imperativeness, and planetary environmental implications |journal=Journal of Environmental Management |date=1 March 2018 |volume=209 |pages=81–92 |doi=10.1016/j.jenvman.2017.12.043 |pmid=29287177 |issn=1095-8630}}</ref>

====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.<ref name="journals.plos.org">{{cite journal|title=Potential for Worldwide Displacement of Fossil-Fuel Electricity by Nuclear Energy in Three Decades Based on Extrapolation of Regional Deployment Data|first1=Staffan A.|last1=Qvist|first2=Barry W.|last2=Brook|date=13 May 2015|journal=PLOS ONE|volume=10|issue=5|pages=e0124074|doi=10.1371/journal.pone.0124074|pmid=25970621|pmc=4429979|bibcode=2015PLoSO..1024074Q|doi-access=free}}</ref><ref>{{cite web|url=https://www.discovery.com/dscovrd/tech/report-world-can-rid-itself-of-fossil-fuel-dependence-in-as-little-as-10-years/ |title=Report: World can Rid Itself of Fossil Fuel Dependence in as little as 10 years| work= Discovery}}</ref> 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/$).<ref name="brook_could_2012">{{cite journal|doi=10.1016/j.enpol.2011.11.041|volume=42|title=Could nuclear fission energy, etc., solve the greenhouse problem? The affirmative case|year=2012|journal=Energy Policy|pages=4–8|author=Brook Barry W}}</ref>
This is in contrast to the conceptual studies for [[100% renewable energy]] systems, which would require an order of magnitude more costly global investment per year, which has no historical precedent.<ref name="loftus_critical_2015">{{cite journal|last1=Loftus|first1=Peter J.|last2=Cohen|first2=Armond M.|last3=Long|first3=Jane C.S.|last4=Jenkins|first4=Jesse D.|title=A critical review of global decarbonization scenarios: what do they tell us about feasibility?|journal=WIREs Climate Change|date=January 2015|volume=6|issue=1|pages=93–112|doi=10.1002/wcc.324|bibcode=2015WIRCC...6...93L |s2cid=4835733|url=https://www.qualenergia.it/sites/default/files/articolo-doc/wcc324-1.pdf|access-date=2019-12-01|archive-date=2019-08-06|archive-url=https://web.archive.org/web/20190806203759/https://www.qualenergia.it/sites/default/files/articolo-doc/wcc324-1.pdf|url-status=dead}}</ref> These renewable scenarios would also need far greater land devoted to onshore wind and onshore solar projects.<ref name="brook_could_2012" /><ref name="loftus_critical_2015" /> 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."<ref name="brook_could_2012" />

Scientific data indicates that&nbsp;– assuming 2021 emissions levels&nbsp;– humanity only has a [[carbon budget]] equivalent to 11 years of emissions left for limiting warming to 1.5{{nbsp}}°C<ref>{{cite news |last1=Neuman |first1=Scott |title=Earth has 11 years to cut emissions to avoid dire climate scenarios, a report says |url=https://www.npr.org/2021/11/04/1052267118/climate-change-carbon-dioxide-emissions-global-carbon-budget |access-date=9 November 2021 |work=NPR |date=4 November 2021 |language=en}}</ref><ref>{{cite journal |author=Pierre Friedlingstein |author2=Matthew W. Jones |display-authors=etal |title=Global Carbon Budget 2021 |journal=Earth System Science Data Discussions |date=4 November 2021 |pages=1–191 |doi=10.5194/essd-2021-386 |s2cid=240490309 |url=http://pure.iiasa.ac.at/id/eprint/17620/1/essd-2021-386.pdf |access-date=26 November 2021 |archive-date=24 November 2021 |archive-url=https://web.archive.org/web/20211124190932/http://pure.iiasa.ac.at/id/eprint/17620/1/essd-2021-386.pdf |doi-access=free }}</ref> while the construction of new nuclear reactors took a median of 7.2–10.9 years in 2018–2020<!--average time between the start of construction and grid connection was 10 years in the past decade-->,<ref name="statusreport"/> substantially longer than, alongside other measures, scaling up the deployment of wind and solar&nbsp;– especially for novel reactor types&nbsp;– as well as being more risky, often delayed and more dependent on state-support.<ref>{{cite journal |last1=Tromans |first1=Stephen |title=State support for nuclear new build |journal=The Journal of World Energy Law & Business |date=1 March 2019 |volume=12 |issue=1 |pages=36–51 |doi=10.1093/jwelb/jwy035}}</ref><ref>{{cite web |title=Nuclear power is too costly, too slow, so it's zero use to Australia's emissions plan |website=[[TheGuardian.com]] |date=18 October 2021 |url=https://www.theguardian.com/business/grogonomics/2021/oct/19/nuclear-power-too-costly-too-slow-so-its-zero-use-to-australias-emissions-plan |access-date=24 November 2021}}</ref><ref name="slowexpensive"/><ref name="gates2"/><ref name="10.5281/zenodo.5573718"/><ref name="worldnuclearreport">{{cite web |title=Renewables vs. Nuclear: 256-0 |url=https://www.worldnuclearreport.org/Renewables-vs-Nuclear-256-0.html |website=World Nuclear Industry Status Report |access-date=24 November 2021 |language=en |date=12 October 2021}}</ref><ref name="10.1016/j.enpol.2016.04.013"/> Researchers have cautioned that novel nuclear technologies&nbsp;– which have been in development since decades,<ref>{{cite news |title=UK poised to confirm funding for mini nuclear reactors for carbon-free energy |url=https://www.theguardian.com/business/2021/oct/15/uk-poised-to-confirm-funding-for-mini-nuclear-reactors-for-green-energy |access-date=24 November 2021 |work=The Guardian |date=15 October 2021 |language=en|quote=Small modular reactors were first developed in the 1950s for use in nuclear-powered submarines. Since then Rolls-Royce has designed reactors for seven classes of submarine and two separate land-based prototype reactors.}}</ref><ref name="10.5281/zenodo.5573718"/><ref name="10.1016/j.erss.2014.04.015"/> 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<ref name="10.1016/j.erss.2014.04.015"/><ref name="10.5281/zenodo.5573718"/><ref name="10.1016/j.enpol.2016.03.012"/><ref name="adva1">{{cite web |title="Advanced" Isn't Always Better {{!}} Union of Concerned Scientists |url=https://ucsusa.org/resources/advanced-isnt-always-better |website=ucsusa.org |access-date=25 November 2021 |language=en}}</ref> – are not available in time.<ref name="sol1">{{cite journal |last1=Muellner |first1=Nikolaus |last2=Arnold |first2=Nikolaus |last3=Gufler |first3=Klaus |last4=Kromp |first4=Wolfgang |last5=Renneberg |first5=Wolfgang |last6=Liebert |first6=Wolfgang |title=Nuclear energy - The solution to climate change? |journal=Energy Policy |date=1 August 2021 |volume=155 |page=112363 |doi=10.1016/j.enpol.2021.112363 |s2cid=236254316 |language=en |issn=0301-4215|doi-access=free }}</ref><ref name="mil1"/><ref>{{cite web |title=Small Modular Reactors - Was ist von den neuen Reaktorkonzepten zu erwarten? |url=https://www.base.bund.de/DE/themen/kt/kta-deutschland/neue_reaktoren/neue-reaktoren_node.html |website=BASE |access-date=24 November 2021 |language=de}}</ref><ref name="gates2"/><ref name="10.1080/00963402.2021.1941600">{{cite journal |last1=Makhijani |first1=Arjun |last2=Ramana |first2=M. V. |title=Can small modular reactors help mitigate climate change? |journal=Bulletin of the Atomic Scientists |date=4 July 2021 |volume=77 |issue=4 |pages=207–214 |doi=10.1080/00963402.2021.1941600 |bibcode=2021BuAtS..77d.207M |s2cid=236163222 |issn=0096-3402}}</ref><ref name="natgeo">{{cite news |title=The controversial future of nuclear power in the U.S. |url=https://www.nationalgeographic.com/environment/article/nuclear-plants-are-closing-in-the-us-should-we-build-more |archive-url=https://web.archive.org/web/20210504162222/https://www.nationalgeographic.com/environment/article/nuclear-plants-are-closing-in-the-us-should-we-build-more |url-status=dead |archive-date=May 4, 2021 |access-date=25 November 2021 |date=4 May 2021 |language=en}}</ref><ref>{{cite news |title=Can Sodium Save Nuclear Power? |url=https://www.scientificamerican.com/article/can-sodium-save-nuclear-power/ |access-date=24 November 2021 |work=Scientific American |language=en}}</ref> 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.<ref name="ITERorg"/><ref name="fusion2">{{cite news |title=A lightbulb moment for nuclear fusion? |url=https://www.theguardian.com/environment/2019/oct/27/nuclear-fusion-research-power-generation-iter-jet-step-carbon-neutral-2050-boris-johnson |access-date=25 November 2021 |work=The Guardian |date=27 October 2019 |language=en}}</ref><ref name="fusiongua">{{cite news |last1=Turrell |first1=Arthur |title=The race to give nuclear fusion a role in the climate emergency |url=https://www.theguardian.com/environment/2021/aug/28/the-race-to-give-nuclear-fusion-a-role-in-the-climate-emergency |access-date=26 November 2021 |work=The Guardian |date=28 August 2021 |language=en}}</ref><ref name="fusion3">{{cite journal |last1=Entler |first1=Slavomir |last2=Horacek |first2=Jan |last3=Dlouhy |first3=Tomas |last4=Dostal |first4=Vaclav |title=Approximation of the economy of fusion energy |journal=Energy |date=1 June 2018 |volume=152 |pages=489–497 |doi=10.1016/j.energy.2018.03.130 |s2cid=115968344 |language=en |issn=0360-5442|doi-access=free }}</ref><ref name="fusion4">{{cite journal |last1=Nam |first1=Hoseok |last2=Nam |first2=Hyungseok |last3=Konishi |first3=Satoshi |title=Techno-economic analysis of hydrogen production from the nuclear fusion-biomass hybrid system |journal=International Journal of Energy Research |date=2021 |volume=45 |issue=8 |pages=11992–12012 |doi=10.1002/er.5994 |s2cid=228937388 |language=en |issn=1099-114X|doi-access=free }}</ref>

====Land use====
The median land area used by US nuclear power stations per 1{{nbsp}}GW installed capacity is {{convert|1.3|sqmi|km2|lk=on}}.<ref name=NEI_news_2015>{{cite web |title=Land Needs for Wind, Solar Dwarf Nuclear Plant's Footprint |url=https://www.nei.org/news/2015/land-needs-for-wind-solar-dwarf-nuclear-plants |website=nei.org |publisher=NEI |date=July 9, 2015}}</ref><ref name=Energy_gov_Fast_Facts >{{ cite web | url=https://www.energy.gov/sites/prod/files/2019/01/f58/Ultimate%20Fast%20Facts%20Guide-PRINT.pdf | title=THE ULTIMATE FAST FACTS GUIDE TO NUCLEAR ENERGY | last= | first= | work=[[United States Department of Energy]] | date=2019-01-01  }}</ref> To generate the same amount of electricity annually (taking into account [[capacity factor]]s) from [[solar PV]] would require about {{convert|60|sqmi|km2}}, and from a wind farm about {{convert|310|sqmi|km2}}.{{ r | NEI_news_2015 | Energy_gov_Fast_Facts }} Not included in this, is land required for the associated transmission lines, water supply, rail lines, mining and processing of nuclear fuel, and for waste disposal.<ref>{{cite web |url=https://www.energy.gov/sites/prod/files/2017/03/f34/qtr-2015-chapter10.pdf |title=Quadrennial technology review concepts in integrated analysis|date= September 2015 |page=388}}</ref>

==Research==
===Advanced fission reactor designs===
{{Main|Generation IV reactor}}
 
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.<ref>{{cite web |url=http://ossfoundation.us/projects/energy/nuclear |title=4th Generation Nuclear Power – OSS Foundation |publisher=Ossfoundation.us |access-date=2014-01-24 |archive-date=2014-02-01 |archive-url=https://web.archive.org/web/20140201171808/http://ossfoundation.us/projects/energy/nuclear }}</ref>

=== Hybrid fusion-fission ===
{{Main|Nuclear fusion–fission hybrid}}
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.<ref name="hybrid">{{cite journal | author = Gerstner, E. | title = Nuclear energy: The hybrid returns | year = 2009 | journal = [[Nature (journal)|Nature]] | volume = 460 | issue = 7251| pages = 25–28 | pmid = 19571861|doi=10.1038/460025a| s2cid = 205047403 |url=http://www.nature.com/news/2009/090701/pdf/460025a.pdf | doi-access = free }}</ref>

=== Fusion ===
[[File:U.S. Department of Energy - Science - 425 003 001 (9786811206).jpg|thumb|Schematic of the [[ITER]] [[tokamak]] under construction in France]]
{{Main|Nuclear fusion|Fusion power}}
[[Fusion power|Nuclear fusion]] reactions have the potential to be safer and generate less radioactive waste than fission.<ref>{{cite book |last1=Roth |first1=J. Reece |title=Introduction to fusion energy |date=1986 |publisher=Ibis Pub |location=Charlottesville, Va. |isbn=978-0-935005-07-3}}</ref><ref name="WorldEnergyCouncil">{{cite web |url=http://www.worldenergy.org/wec-geis/publications/default/tech_papers/18th_Congress/downloads/ds/ds6/ds6_5.pdf |title=Fusion as a Future Power Source: Recent Achievements and Prospects |author1=T. Hamacher |author2=A.M. Bradshaw |name-list-style=amp |publisher=World Energy Council |date=October 2001 |archive-url=https://web.archive.org/web/20040506065141/http://www.worldenergy.org/wec-geis/publications/default/tech_papers/18th_Congress/downloads/ds/ds6/ds6_5.pdf |archive-date=2004-05-06 }}</ref>
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. [[Nuclear fusion]] research is underway but fusion energy is not likely to be commercially widespread before 2050.<ref>{{cite news |date=27 October 2019 |title=A lightbulb moment for nuclear fusion? |language=en |work=The Guardian |url=https://www.theguardian.com/environment/2019/oct/27/nuclear-fusion-research-power-generation-iter-jet-step-carbon-neutral-2050-boris-johnson |access-date=25 November 2021}}</ref><ref>{{cite journal |last1=Entler |first1=Slavomir |last2=Horacek |first2=Jan |last3=Dlouhy |first3=Tomas |last4=Dostal |first4=Vaclav |date=1 June 2018 |title=Approximation of the economy of fusion energy |journal=Energy |language=en |volume=152 |pages=489–497 |doi=10.1016/j.energy.2018.03.130 |s2cid=115968344 |issn=0360-5442|doi-access=free }}</ref><ref>{{cite journal |last1=Nam |first1=Hoseok |last2=Nam |first2=Hyungseok |last3=Konishi |first3=Satoshi |date=2021 |title=Techno-economic analysis of hydrogen production from the nuclear fusion-biomass hybrid system |journal=International Journal of Energy Research |language=en |volume=45 |issue=8 |pages=11992–12012 |doi=10.1002/er.5994 |issn=1099-114X |s2cid=228937388|doi-access=free }}</ref>

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.<ref>{{cite journal |author=W Wayt Gibbs |date=2013-12-30 |title=Triple-threat method sparks hope for fusion |journal=Nature|volume=505 |issue=7481 |pages=9–10 |bibcode=2014Natur.505....9G |doi=10.1038/505009a |pmid=24380935 |doi-access=free }}</ref> A follow on commercial nuclear fusion power station, [[DEMOnstration Power Station|DEMO]], has been proposed.<ref name="ITERorg">{{cite web|url=http://www.iter.org/Future-beyond.htm |title=Beyond ITER |publisher=Information Services, Princeton Plasma Physics Laboratory |website=The ITER Project |archive-url=https://web.archive.org/web/20061107220145/http://www.iter.org/Future-beyond.htm |archive-date=2006-11-07 |access-date=2011-02-05 }} – Projected fusion power timeline</ref><ref name="EFDA_Activities">{{cite web|url=http://www.efda.org/about_efda/downloads/EFDAoverview.ppt |title=Overview of EFDA Activities |website=www.efda.org |publisher=[[European Fusion Development Agreement]] |archive-url=https://web.archive.org/web/20061001123645/http://www.efda.org/about_efda/downloads/EFDAoverview.ppt |archive-date=2006-10-01 |access-date=2006-11-11 }}</ref> 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.<ref name="ITERorg" /><ref name="fusion2"/><ref name="fusiongua"/><ref name="fusion3"/><ref name="fusion4"/>

To enhance and accelerate the development of fusion energy, the [[United States Department of Energy]] (DOE) granted $46 million to eight firms, including [[Commonwealth Fusion Systems]] and [[Tokamak Energy]] Inc, in 2023. This ambitious initiative aims to introduce pilot-scale fusion within a decade.<ref>{{cite press release|url=https://www.reuters.com/business/energy/us-announces-46-million-funds-eight-nuclear-fusion-companies-2023-05-31/ |title=US announces $46 million in funds to eight nuclear fusion companies |date=31 May 2023 |access-date= 13 June 2023 }}</ref>

== See also ==
{{Portal|Nuclear technology|Energy}}
{{div col|colwidth=20em}}
* [[Atomic battery]]
* [[Nuclear power by country]]
* [[Nuclear weapons debate]]
* [[Pro-nuclear movement]]
* [[Thorium-based nuclear power]]
* [[Uranium mining debate]]
* [[World energy consumption]]
{{div col end}}
{{clear}}

== References ==
{{reflist}}

== Further reading ==
{{sister project|project=Wikiversity
|text=[[v:How things work college course/Nuclear power quizzes|Wikiversity quizzes on nuclear power]]}}
{{See also|List of books about nuclear issues|List of films about nuclear issues}}
* AEC Atom Information Booklets, [https://www.osti.gov/opennet/aec_atom 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. [http://www.nature.com/articles/nenergy201520 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.
* {{Cite book | last = Cravens | first = Gwyneth | title = Power to Save the World: the Truth about Nuclear Energy | publisher = Knopf | year = 2007 | location = New York | url = https://archive.org/details/powertosaveworld00gwyn_0 | isbn = 978-0-307-26656-9 | url-access = registration }}
* [[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.
* {{cite book |last1=Mahaffey |first1=James |title=Atomic accidents: a history of nuclear meltdowns and disasters: from the Ozark Mountains to Fukushima |date=2015 |publisher=Pegasus Books |isbn=978-1-60598-680-7 }}
* [[Naomi Oreskes|Oreskes, Naomi]], "Breaking the Techno-Promise: We do not have enough time for nuclear power to save us from the [[climate crisis]]", ''[[Scientific American]]'', vol. 326, no. 2 (February 2022), p.&nbsp;74.
* [[Mycle Schneider|Schneider, Mycle]], [[Stephen Thomas (economist)|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. {{ISBN|0-674-05233-1}}

== External links ==
{{Sister project links|Nuclear power}}
* [https://www.eia.gov/ U.S. Energy Information Administration]
* [https://thebulletin.org/2015/05/introducing-the-nuclear-fuel-cycle-cost-calculator/ Nuclear Fuel Cycle Cost Calculator]

{{Nuclear power by country}}
{{Nuclear technology}}
{{Electricity generation}}
{{Natural resources}}

{{Authority control}}

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