Difference between revisions of "Nuclear power" - New World Encyclopedia

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[[Image:Nuclear Power Plant 2 cropped.jpg|thumb|250px|right|A nuclear power station. The nuclear reactor is contained inside the cylindrical [[containment building]]s to the right—left is a cooling tower venting non-radioactive water vapor.]]
 
[[Image:Nuclear Power Plant 2 cropped.jpg|thumb|250px|right|A nuclear power station. The nuclear reactor is contained inside the cylindrical [[containment building]]s to the right—left is a cooling tower venting non-radioactive water vapor.]]
  
'''Nuclear power''' is a type of [[nuclear technology]] involving the controlled use of [[nuclear reactions]] to release [[energy]] for [[work (thermodynamics)|work]] including [[Nuclear propulsion|propulsion]], [[heat]], and the generation of [[electricity]]. [[Nuclear energy]] is produced by a controlled [[nuclear chain reaction]] and creates heat—which is used to [[boiling|boil]] water, produce [[steam]], and drive a [[steam turbine]]. The turbine can be used for mechanical work and also to generate electricity.
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'''Nuclear power''' is a type of [[nuclear technology]] involving the controlled use of [[nuclear reactions]] to release [[energy]] for [[work (thermodynamics)|work]], including [[Nuclear propulsion|propulsion]], [[heat]], and the generation of [[electricity]]. [[Nuclear energy]] is produced by a controlled [[nuclear chain reaction]] and creates heat—which is used to [[boiling|boil]] water, produce [[steam]], and drive a [[steam turbine]]. The turbine can be used for mechanical work and also to generate electricity.
  
 
The use of nuclear power has also engendered much debate. Critics claim that nuclear power is a potentially dangerous energy source with a limited fuel supply (compared to [[renewable energy]]), and they note the problems of storing [[radioactive waste]], the potential for [[radioactive contamination]] by accident or sabotage, and the possibility of [[nuclear proliferation]]. Advocates claim that these risks are small and can be further reduced by the technology in new reactors, and the safety record is good when compared to other major types of power plants. In addition, they note that many renewable energy technologies have not solved the problem of their [[Intermittent power sources|intermittent power production]].
 
The use of nuclear power has also engendered much debate. Critics claim that nuclear power is a potentially dangerous energy source with a limited fuel supply (compared to [[renewable energy]]), and they note the problems of storing [[radioactive waste]], the potential for [[radioactive contamination]] by accident or sabotage, and the possibility of [[nuclear proliferation]]. Advocates claim that these risks are small and can be further reduced by the technology in new reactors, and the safety record is good when compared to other major types of power plants. In addition, they note that many renewable energy technologies have not solved the problem of their [[Intermittent power sources|intermittent power production]].
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{{seealso|List of nuclear reactors}}
 
{{seealso|List of nuclear reactors}}
  
As of 2004, nuclear power provided 6.5% of the world's energy and 15.7% of the world's electricity, with the [[U.S.]], [[France]], and [[Japan]] together accounting for 57% of all nuclear generated electricity.<ref name="iea_pdf">[http://www.iea.org/dbtw-wpd/Textbase/nppdf/free/2006/key2006.pdf Key World Energy Statistics] International Energy Agency. Retrieved July 20, 2007.</ref> As of 2007, the IAEA reported there are 435 nuclear power reactors in operation in the world,<ref>[http://www.iaea.org/cgi-bin/db.page.pl/pris.oprconst.htm NUCLEAR POWER PLANTS INFORMATION], by [[IAEA]], Retrieved July 20, 2007.</ref> operating in 31 different countries.<ref name="UIC">[http://www.uic.com.au/reactors.htm World NUCLEAR POWER REACTORS 2005-06]. Australian Uranium Information Centre. Retrieved July 21, 2007.</ref> These provide about 17% of the world's electricity.<ref>"The Limited Appeal of Nuclear Energy," Scientific American, July 2007</ref>
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As of 2004, nuclear power provided 6.5 percent of the world's energy and 15.7 percent of the world's electricity, with the [[U.S.]], [[France]], and [[Japan]] together accounting for 57 percent of all nuclear generated electricity.<ref>International Energy Agency, [http://www.iea.org/dbtw-wpd/Textbase/nppdf/free/2006/key2006.pdf Key World Energy Statistics]. Retrieved July 20, 2007.</ref> As of 2007, the IAEA reported there are 435 nuclear power reactors in operation in the world,<ref>IAEA, [http://www.iaea.org/cgi-bin/db.page.pl/pris.oprconst.htm Nuclear Power Plants Information.] Retrieved July 20, 2007.</ref> operating in 31 different countries.<ref>Australian Uranium Information Centre, [http://www.uic.com.au/reactors.htm World Nuclear Power Reactors 2005-06]. Retrieved July 21, 2007.</ref> These provide about 17 percent of the world's electricity.<ref>"The Limited Appeal of Nuclear Energy," ''Scientific American,'' July 2007.</ref>
  
The [[United States]] produces the most nuclear energy, with nuclear power providing 20% of the [[electricity]] it consumes, while [[France]] produces the highest percentage of its electrical energy from nuclear reactors—80% as of 2006.<ref name="eia_s.1766">[http://www.eia.doe.gov/oiaf/servicerpt/erd/nuclear.html Impacts of Energy Research and Development With Analysis of Price-Anderson Act and Hydroelectric Relicensing] Energy Information Administration. Retrieved July 20, 2007.</ref><ref name="npr20060501">Beardsley, Eleanor. 2006. [http://www.npr.org/templates/story/story.php?storyId=5369610 France Presses Ahead with Nuclear Power] NPR. Retrieved July 20, 2007.</ref> In the [[European Union]] as a whole, nuclear energy provides 30% of the electricity.<ref>[http://epp.eurostat.ec.europa.eu/portal/page?_pageid=1996,39140985&_dad=portal&_schema=PORTAL&screen=detailref&language=en&product=sdi_cc&root=sdi_cc/sdi_cc/sdi_cc_ene/sdi_cc2300  Gross electricity generation, by fuel used in power-stations.] Eurostat. Retrieved July 20, 2007.</ref> [[Nuclear energy policy]] differs between European Union countries, and some, such as Austria and Ireland, have no active nuclear power stations. In comparison France has a large number of these plants, with 16 currently in use throughout the country.
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The [[United States]] produces the most nuclear energy, with nuclear power providing 20 percent of the [[electricity]] it consumes, while [[France]] produces the highest percentage of its electrical energy from nuclear reactors—80 percent as of 2006.<ref>Energy Information Administration, [http://www.eia.doe.gov/oiaf/servicerpt/erd/nuclear.html Impacts of Energy Research and Development With Analysis of Price-Anderson Act and Hydroelectric Relicensing]. Retrieved July 20, 2007.</ref> In the [[European Union]] as a whole, nuclear energy provides 30 percent of the electricity.<ref>Eurostat, [http://epp.eurostat.ec.europa.eu/portal/page?_pageid=1996,39140985&_dad=portal&_schema=PORTAL&screen=detailref&language=en&product=sdi_cc&root=sdi_cc/sdi_cc/sdi_cc_ene/sdi_cc2300  Gross electricity generation, by fuel used in power-stations.] Retrieved July 20, 2007.</ref> [[Nuclear energy policy]] differs between European Union countries, and some, such as Austria and Ireland, have no active nuclear power stations. In comparison, France has a large number of these plants, with 16 currently in use throughout the country.
  
 
Many military and some civilian (such as some [[icebreakers]]) ships use [[nuclear marine propulsion]], a form of [[nuclear propulsion]].
 
Many military and some civilian (such as some [[icebreakers]]) ships use [[nuclear marine propulsion]], a form of [[nuclear propulsion]].
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==History==
 
==History==
 
===Origins===
 
===Origins===
The first successful experiment with [[nuclear fission]] was conducted in 1938 in [[Berlin]] by the German physicists [[Otto Hahn]], [[Lise Meitner]] and [[Fritz Strassmann]].
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The first successful experiment with [[nuclear fission]] was conducted in 1938, in [[Berlin]], by the German physicists [[Otto Hahn]], [[Lise Meitner]], and [[Fritz Strassmann]].
  
The first man-made reactor, [[Chicago Pile-1]], achieved criticality on December 2, 1942 as part of the [[Manhattan Project]].
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The first man-made reactor, [[Chicago Pile-1]], achieved criticality on December 2, 1942, as part of the [[Manhattan Project]].
  
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 kW. The Arco Reactor was also the first to partially melt down (in 1955).
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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 kW. The Arco Reactor was also the first to partially melt down (in 1955).
  
In 1952, a report by the Paley Commission (''The President's Materials Policy Commission'') for President [[Harry Truman]] made a "relatively pessimistic" assessment of nuclear power, and called for "aggressive research in the whole field of solar energy".<ref name="ieer">Makhijani, Arjun and Saleska, Scott 1996. [http://www.ieer.org/reports/npd.html The Nuclear Power Deception] Institute for Energy and Environmental Research. Retrieved July 20, 2007.</ref> A December 1953 speech by President [[Dwight Eisenhower]], "[[Atoms for Peace]]," set the U.S. on a course of strong government support for the international use of nuclear power.
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In 1952, a report by the Paley Commission ''(The President's Materials Policy Commission)'' for President [[Harry Truman]] made a "relatively pessimistic" assessment of nuclear power, and called for "aggressive research in the whole field of solar energy."<ref>Arjun Makhijani and Scott Saleska, 1996, [http://www.ieer.org/reports/npd.html The Nuclear Power Deception] Institute for Energy and Environmental Research. Retrieved July 20, 2007.</ref> A December 1953 speech by President [[Dwight Eisenhower]], "[[Atoms for Peace]]," set the U.S. on a course of strong government support for the international use of nuclear power.
  
 
===Early years===
 
===Early years===
 
[[Image:Shippingport Reactor.jpg|thumb|250px|The [[Shippingport Atomic Power Station]] in [[Shippingport, Pennsylvania]] was the first commercial reactor in the [[United States of America|USA]] and was opened in 1957.]]
 
[[Image:Shippingport Reactor.jpg|thumb|250px|The [[Shippingport Atomic Power Station]] in [[Shippingport, Pennsylvania]] was the first commercial reactor in the [[United States of America|USA]] and was opened in 1957.]]
In 1954, [[Lewis Strauss]], then chairman of the [[United States Atomic Energy Commission]] (forerunner of the U.S. [[Nuclear Regulatory Commission]]) famously spoke of electricity in the future being "too cheap to meter." <ref name="cns-snc">[http://www.cns-snc.ca/media/toocheap/toocheap.html Too Cheap to Meter?] Canadian Nuclear Society. Retrieved July 20, 2007. </ref> While few doubt he was thinking of atomic energy when he made the statement, he may have been referring to hydrogen fusion, rather than uranium fission.  Actually, the consensus of government and business at the time was that nuclear (fission) power might eventually become merely economically competitive with conventional power sources.
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In 1954, [[Lewis Strauss]], then chairman of the [[United States Atomic Energy Commission]] (forerunner of the U.S. [[Nuclear Regulatory Commission]]) famously spoke of electricity in the future being "too cheap to meter." <ref>Canadian Nuclear Society, [http://www.cns-snc.ca/media/toocheap/toocheap.html Too Cheap to Meter?] Retrieved July 20, 2007.</ref> While few doubt he was thinking of atomic energy when he made the statement, he may have been referring to hydrogen fusion, rather than uranium fission.  Actually, the consensus of government and business at the time was that nuclear (fission) power might eventually become merely economically competitive with conventional power sources.
  
On June 27 1954, the world's first nuclear power plant to generate electricity for a [[power grid]] started operations at [[Obninsk]], [[USSR]]. The reactor produced 5 megawatts (electrical), enough to power 2,000 homes.<ref name="IAEANews">[http://www.iaea.org/NewsCenter/News/2004/obninsk.html From Obninsk Beyond: Nuclear Power Conference Looks to Future]. [[International Atomic Energy Agency]]. Retrieved July 20, 2007.</ref>  
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On June 27 1954, the world's first nuclear power plant to generate electricity for a [[power grid]] started operations at [[Obninsk]], [[USSR]]. The reactor produced 5 megawatts (electrical), enough to power 2,000 homes.<ref>International Atomic Energy Agency, [http://www.iaea.org/NewsCenter/News/2004/obninsk.html From Obninsk Beyond: Nuclear Power Conference Looks to Future.] Retrieved July 20, 2007.</ref>  
In 1955 the [[United Nations]]' "First Geneva Conference," then the world's largest gathering of scientists and engineers, met to explore the technology. In 1957 [[EURATOM]] was launched alongside the [[European Economic Community]] (the latter is now the [[European Union]]). The same year also saw the launch of the [[International Atomic Energy Agency]] (IAEA).
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In 1955 the [[United Nations]]' "First Geneva Conference," then the world's largest gathering of scientists and engineers, met to explore the technology. In 1957, [[EURATOM]] was launched alongside the [[European Economic Community]] (the latter is now the [[European Union]]). The same year also saw the launch of the [[International Atomic Energy Agency]] (IAEA).
  
The world's first commercial nuclear power station, Calder Hall in [[Sellafield]], [[England]] was opened in 1956 with an initial capacity of 50 MW (later 200 MW).<ref name="bbc17oct">[http://news.bbc.co.uk/onthisday/hi/dates/stories/october/17/newsid_3147000/3147145.stm On This Day: 17 October] BBC News. Retrieved July 20, 2007.</ref> The [[Shippingport Reactor]] ([[Pennsylvania]], 1957) was the first commercial nuclear generator to become operational in the [[United States]].
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The world's first commercial nuclear power station, Calder Hall in [[Sellafield]], [[England]] was opened in 1956, with an initial capacity of 50 MW (later 200 MW).<ref> BBC News, [http://news.bbc.co.uk/onthisday/hi/dates/stories/october/17/newsid_3147000/3147145.stm On This Day: 17 October.] Retrieved July 20, 2007.</ref> The [[Shippingport Reactor]] ([[Pennsylvania]], 1957) was the first commercial nuclear generator to become operational in the [[United States]].
  
One of the first organizations to develop utilitarian nuclear power was the [[United States Navy|U.S. Navy]], for the purpose of propelling [[submarine]]s and [[aircraft carrier]]s. It has a good record in nuclear safety, perhaps because of the stringent demands of Admiral [[Hyman G. Rickover]], who was the driving force behind [[nuclear marine propulsion]]. The U.S. Navy has operated more nuclear reactors than any other entity, including the [[Soviet Navy]], with no publicly known major incidents. The first nuclear-powered submarine, [[USS Nautilus (SSN-571)|USS ''Nautilus'' (SSN-571)]], put to sea in 1955. Two U.S. nuclear submarines, [[USS Scorpion (SSN-589)|USS ''Scorpion'']] and [[USS Thresher (SSN-593)|''Thresher'']], have been lost at sea, though for reasons not related to their reactors, and their wrecks are situated such that the risk of nuclear pollution is considered low.
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One of the first organizations to develop utilitarian nuclear power was the [[United States Navy|U.S. Navy]], for the purpose of propelling [[submarine]]s and [[aircraft carrier]]s. It has a good record in nuclear safety, perhaps because of the stringent demands of Admiral [[Hyman G. Rickover]], who was the driving force behind [[nuclear marine propulsion]]. The U.S. Navy has operated more nuclear reactors than any other entity, including the [[Soviet Navy]], with no publicly known major incidents. The first nuclear-powered submarine, [[USS Nautilus (SSN-571)|USS ''Nautilus'' (SSN-571)]], put to sea in 1955. Two U.S. nuclear submarines, [[USS Scorpion (SSN-589)|USS ''Scorpion'']] and [[USS Thresher (SSN-593)|''Thresher,'']] have been lost at sea, though for reasons not related to their reactors, and their wrecks are situated such that the risk of nuclear pollution is considered low.
  
[[Enrico Fermi]] and [[Leó Szilárd]] in 1955 shared {{US patent|2708656}} for the nuclear reactor.
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[[Enrico Fermi]] and [[Leó Szilárd]], in 1955, shared {{US patent|2708656}} for the nuclear reactor.
  
 
===Development===
 
===Development===
 
[[Image:Nuclear Power Plant Cattenom a.png|right|thumb|Nuclear power plant.]]
 
[[Image:Nuclear Power Plant Cattenom a.png|right|thumb|Nuclear power plant.]]
The [[1973 oil crisis]] had a significant effect on the construction of nuclear power plants worldwide. The oil embargo led to a global economic recession, [[energy conservation]], and high inflation that both reduced the projected demand for new electric generation capacity in the United States and made financing such capital intensive projects difficult. This contributed to the cancellation of over 100 reactor orders in the USA.<ref>[http://www.homestead.com/clonemaster/files/Cancel.htm Cancelled Nuclear Units Ordered in the United States]. Retrieved July 20, 2007.</ref> Even so, the plants already under construction effectively displaced oil for the generation of electricity. In 1973, oil generated 17% of the electricity in the United States. Today, oil is a minor source of electric power (except in Hawaii), while nuclear power now generates 20% of that country's electricity. The oil crisis caused other countries, such as France and Japan, which had relied even more heavily on oil for electric generation (39% and 73% respectively) to invest heavily in nuclear power.<ref>[http://www.iea.org/textbase/stats/pdf_graphs/FRELEC.pdf  
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The [[1973 oil crisis]] had a significant effect on the construction of nuclear power plants worldwide. The oil embargo led to a global economic recession, [[energy conservation]], and high inflation that both reduced the projected demand for new electric generation capacity in the United States and made financing such capital intensive projects difficult. This contributed to the cancellation of over 100 reactor orders in the U.S.<ref>Nuclear Power Plants in the U.S., [http://www.homestead.com/clonemaster/files/Cancel.htm Canceled Nuclear Units Ordered in the United States.] Retrieved July 20, 2007.</ref> Even so, the plants already under construction effectively displaced oil for the generation of electricity. In 1973, oil generated 17 percent of the electricity in the United States. Today, oil is a minor source of electric power (except in Hawaii), while nuclear power now generates 20 percent of the country's electricity. The oil crisis caused other countries, such as France and Japan, which had relied even more heavily on oil for electric generation (39 percent and 73 percent respectively) to invest heavily in nuclear power.<ref>IEA Energy Statistics, [http://www.iea.org/textbase/stats/pdf_graphs/FRELEC.pdf Evolution of Electricity Generation by Fuel from 1971 to 2004.] Retrieved July 20, 2007.</ref> Today, nuclear power supplies about 80 percent and 30 percent of the electricity in those countries, respectively.
Evolution of Electricity Generation by Fuel from 1971 to 2004] Retrieved July 20, 2007.</ref><ref> Beder, Sharon. 2006. [http://homepage.mac.com/herinst/sbeder/japan.html Conclusion: The Japanese Situation] Retrieved July 20, 2007.</ref> Today, nuclear power supplies about 80% and 30% of the electricity in those countries, respectively.
 
  
Installed nuclear capacity initially rose relatively quickly, rising from less than 1 [[gigawatt]] (GW) in 1960 to 100 GW in the late 1970s, and 300 GW in the late 1980s. Since the late 1980s capacity has risen much more slowly, reaching 366 GW in 2005, primarily due to Chinese expansion of nuclear power. Between around 1970 and 1990, more than 50 GW of capacity was under construction (peaking at over 150 GW in the late 70s and early 80s) in 2005, around 25 GW of new capacity was planned. More than two-thirds of all nuclear plants ordered after January 1970 were eventually cancelled.<ref name="iaeapdf>[http://www.iaea.org/About/Policy/GC/GC48/Documents/gc48inf-4_ftn3.pdf 50 Years of Nuclear Energy] International Atomic Energy Agency. Retrieved July 20, 2007.</ref>
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Installed nuclear capacity initially rose relatively quickly, rising from less than 1 [[gigawatt]] (GW) in 1960, to 100 GW in the late 1970s, and 300 GW in the late 1980s. Since the late 1980s capacity has risen much more slowly, reaching 366 GW in 2005, primarily due to Chinese expansion of nuclear power. Between around 1970 and 1990, more than 50 GW of capacity was under construction (peaking at over 150 GW in the late 70s and early 80s)in 2005, around 25 GW of new capacity was planned. More than two-thirds of all nuclear plants ordered after January 1970 were eventually canceled.<ref>International Atomic Energy Agency, [http://www.iaea.org/About/Policy/GC/GC48/Documents/gc48inf-4_ftn3.pdf 50 Years of Nuclear Energy.] Retrieved July 20, 2007.</ref>
  
 
[[Image:Satsop Development Park 07780.JPG|right|thumb|250px|[[Washington Public Power Supply System]] Nuclear Power Plants 3 and 5 were never completed]]
 
[[Image:Satsop Development Park 07780.JPG|right|thumb|250px|[[Washington Public Power Supply System]] Nuclear Power Plants 3 and 5 were never completed]]
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During the 1970s and 1980s rising economic costs (related to vastly extended construction times largely due to regulatory changes and pressure-group litigation) and falling fossil fuel prices made nuclear power plants then under construction less attractive. In the 1980s (U.S.) and 1990s (Europe), flat load growth and [[electricity liberalization]] also made the addition of large new baseload capacity unattractive.
 
During the 1970s and 1980s rising economic costs (related to vastly extended construction times largely due to regulatory changes and pressure-group litigation) and falling fossil fuel prices made nuclear power plants then under construction less attractive. In the 1980s (U.S.) and 1990s (Europe), flat load growth and [[electricity liberalization]] also made the addition of large new baseload capacity unattractive.
  
A general movement against nuclear power arose during the last third of the twentieth century, based on the fear of a possible [[nuclear accident]] and on fears of [[ionizing radiation|radiation]], and on the opposition to [[nuclear waste]] production, transport and final storage. Perceived risks on the citizens' health and safety, the 1979 accident at [[Three Mile Island accident|Three Mile Island]] and the 1986 [[Chernobyl disaster]] played a part in stopping new plant construction in many countries. However, in the US new construction dropped sharply before the Three Mile Island accident, after the 1973 oil crises.<ref name="PBS">[http://www.pbs.org/wgbh/pages/frontline/shows/reaction/maps/chart2.html The Rise and Fall of Nuclear Power] Public Broadcasting Service. Retrieved July 20, 2007.</ref> and the Brookings Institution suggests that new nuclear units have not been ordered in the US primarily for economic reasons rather than fears of accidents.<ref name="tbi">[http://www.brookings.edu/comm/policybriefs/pb138.htm The Political Economy of Nuclear Energy in the United States] The Brookings Institution. Retrieved July 20, 2007.</ref>
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A general movement against nuclear power arose during the last third of the twentieth century, based on the fear of a possible [[nuclear accident]] and on fears of [[ionizing radiation|radiation]], as well as in opposition to [[nuclear waste]] production, transport, and final storage. Perceived risks on the citizens' health and safety, the 1979 accident at [[Three Mile Island accident|Three Mile Island]], and the 1986 [[Chernobyl disaster]] played a part in stopping new plant construction in many countries. However, in the U.S. new construction dropped sharply before the Three Mile Island accident, after the 1973 oil crises.<ref>PBS, [http://www.pbs.org/wgbh/pages/frontline/shows/reaction/maps/chart2.html The Rise and Fall of Nuclear Power.] Retrieved July 20, 2007.</ref> and the Brookings Institution suggests that new nuclear units have not been ordered in the U.S. primarily for economic reasons rather than fears of accidents.<ref>The Brookings Institution, [http://www.brookings.edu/comm/policybriefs/pb138.htm The Political Economy of Nuclear Energy in the United States.] Retrieved July 20, 2007.</ref>
  
Unlike the Three Mile Island accident, the much more serious Chernobyl accident did not increase regulations affecting Western reactors since the Chernobyl reactors were of the problematic [[RBMK]] design only used in the Soviet Union, for example lacking [[containment building]]s.<ref name="NRC">[http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/chernobyl-bg.html Backgrounder on Chernobyl Nuclear Power Plant Accident] [[Nuclear Regulatory Commission]]. Retrieved July 20, 2007.</ref> An international organization to promote safety awareness and professional development on operators in nuclear facilities was created: [[WANO]]; World Association of Nuclear Operators.
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Unlike the Three Mile Island accident, the much more serious Chernobyl accident did not increase regulations affecting Western reactors, since the Chernobyl reactors were of the problematic [[RBMK]] design only used in the Soviet Union, lacking, for example, [[containment building]]s.<ref>Nuclear Regulatory Commission, [http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/chernobyl-bg.html Backgrounder on Chernobyl Nuclear Power Plant Accident].   Retrieved July 20, 2007.</ref> An international organization to promote safety awareness and professional development on operators in nuclear facilities was created: [[WANO]]; World Association of Nuclear Operators.
  
[[Austria]] (1978), [[Sweden]] (1980) and [[Italy]] (1987) (influenced by Chernobyl) voted in referendums to oppose or phase out nuclear power, while opposition in [[Republic of Ireland|Ireland]] prevented a nuclear program there.
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[[Austria]] (1978), [[Sweden]] (1980), and [[Italy]] (1987) (influenced by Chernobyl) voted in referendums to oppose or phase out nuclear power, while opposition in [[Republic of Ireland|Ireland]] prevented a nuclear program there.
  
 
===The future of the industry===
 
===The future of the industry===
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{{Seealso|Mitigation of global warming}}
 
{{Seealso|Mitigation of global warming}}
 
{{Seealso|Economics of new nuclear power plants}}
 
{{Seealso|Economics of new nuclear power plants}}
As of March 1, 2007, [[Watts Bar Nuclear Generating Station|Watts Bar 1]], which came on-line in 1997, was the last U.S. commercial nuclear reactor to go on-line. This is often quoted as evidence of a successful worldwide campaign for nuclear power phase-out. However, political resistance to nuclear power has only ever been successful in parts of [[Europe]], in [[New Zealand]], in the [[Philippines]], and in the United States. Even in the US and throughout Europe, investment in research and in the [[nuclear fuel cycle]] has continued, and some experts predict that [[electricity shortage]]s, fossil fuel price increases, [[global warming]] from fossil fuel use, new technology such as [[passively safe]] plants, and national energy security will renew the demand for nuclear power plants.
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As of March 1, 2007, [[Watts Bar Nuclear Generating Station|Watts Bar 1]], which came on-line in 1997, was the last U.S. commercial nuclear reactor to go on-line. This is often quoted as evidence of a successful worldwide campaign for nuclear power phase-out. However, political resistance to nuclear power has only ever been successful in parts of [[Europe]], in [[New Zealand]], in the [[Philippines]], and in the United States. Even in the U.S. and throughout Europe, investment in research and in the [[nuclear fuel cycle]] has continued, and some experts predict that [[electricity shortage]]s, fossil fuel price increases, [[global warming]] from fossil fuel use, new technology such as [[passively safe]] plants, and national energy security will renew the demand for nuclear power plants.
  
Many countries remain active in developing nuclear power, including [[Japan]], [[China]] and [[India]], all actively developing both fast and thermal technology, [[South Korea]] and the United States, developing thermal technology only, and [[South Africa]] and China, developing versions of the [[Pebble bed reactor|Pebble Bed Modular Reactor]] (PBMR). [[Finland]] and [[France]] actively pursue nuclear programs; Finland has a new [[European Pressurized Reactor]] under construction by [[Areva]]. Japan has an active nuclear construction program with new units brought on-line in 2005. In the U.S., three consortia responded in 2004 to the [[United States Department of Energy|U.S. Department of Energy]]'s solicitation under the [[Nuclear Power 2010 Program]] and were awarded matching funds—the [[Energy Policy Act of 2005]] authorized subsidies for up to six new reactors, and authorized the Department of Energy to build a reactor based on the Generation IV [[Very-High-Temperature Reactor]] concept to produce both electricity and [[hydrogen]]. As of the early twenty first century, nuclear power is of particular interest to both China and India to serve their rapidly growing economies—both are developing [[fast breeder reactor]]s. See also [[future energy development]]. In the [[energy policy of the United Kingdom]] it is recognized that there is a likely future energy supply shortfall, which may have to be filled by either new nuclear plant construction or maintaining existing plants beyond their programmed lifetime.
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Many countries remain active in developing nuclear power, including [[Japan]], [[China]], and [[India]], all actively developing both fast and thermal technology, [[South Korea]] and the United States, developing thermal technology only, and [[South Africa]] and China, developing versions of the [[Pebble bed reactor|Pebble Bed Modular Reactor]] (PBMR). [[Finland]] and [[France]] actively pursue nuclear programs; Finland has a new [[European Pressurized Reactor]] under construction by [[Areva]]. Japan has an active nuclear construction program with new units brought on-line in 2005. In the U.S., three consortia responded in 2004 to the [[United States Department of Energy|U.S. Department of Energy]]'s solicitation under the [[Nuclear Power 2010 Program]] and were awarded matching funds—the [[Energy Policy Act of 2005]] authorized subsidies for up to six new reactors, and authorized the Department of Energy to build a reactor based on the Generation IV [[Very-High-Temperature Reactor]] concept to produce both electricity and [[hydrogen]]. As of the early twenty first century, nuclear power is of particular interest to both China and India to serve their rapidly growing economies—both are developing [[fast breeder reactor]]s. See also [[future energy development]]. In the [[energy policy of the United Kingdom]], it is recognized that there is a likely future energy supply shortfall, which may have to be filled by either new nuclear plant construction or maintaining existing plants beyond their programmed lifetime.
  
On September 22, 2005 it was announced that two sites in the U.S. had been selected to receive new power reactors (exclusive of the new power reactor scheduled for [[INL]])—see [[Nuclear Power 2010 Program]].
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On September 22, 2005, it was announced that two sites in the U.S. had been selected to receive new power reactors (exclusive of the new power reactor scheduled for [[INL]]).
  
 
== Nuclear reactor technology ==
 
== Nuclear reactor technology ==
{{main|Nuclear reactor technology}}
 
  
Conventional thermal power plants all have a fuel source to provide heat. Examples are gas, coal, or oil. For a nuclear power plant, this heat is provided by [[nuclear fission]] inside the [[nuclear reactor]]. When a relatively large [[fissile]] [[atomic nucleus]] (usually [[uranium-235]] or [[plutonium-239]]) is struck by a [[neutron]] it forms two or more smaller nuclei as [[fission products]], releasing energy and neutrons in a process called nuclear fission. The neutrons then trigger further fission. And so on. When this [[nuclear chain reaction]] is controlled, the energy released can be used to heat water, produce steam and drive a [[turbine]] that generates electricity. It should be noted that a [[nuclear explosive]] involves an uncontrolled chain reaction, and the rate of fission in a reactor is not capable of reaching sufficient levels to trigger a [[nuclear explosion]] because commercial reactor grade nuclear fuel is not enriched to a high enough level. (see [[enriched uranium]])
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Conventional thermal power plants all have a fuel source to provide heat. Examples are gas, coal, or oil. For a nuclear power plant, this heat is provided by [[nuclear fission]] inside the [[nuclear reactor]]. When a relatively large [[fissile]] [[atomic nucleus]] (usually [[uranium-235]] or [[plutonium-239]]) is struck by a [[neutron]], it forms two or more smaller nuclei as [[fission products]], releasing energy and neutrons in a process called nuclear fission. The neutrons then trigger further fission. And so on. When this [[nuclear chain reaction]] is controlled, the energy released can be used to heat water, produce steam, and drive a [[turbine]] that generates electricity. It should be noted that a [[nuclear explosive]] involves an uncontrolled chain reaction, and the rate of fission in a reactor is not capable of reaching sufficient levels to trigger a [[nuclear explosion]] because commercial reactor grade nuclear fuel is not enriched to a high enough level.  
  
 
The chain reaction is controlled through the use of materials that absorb and moderate neutrons. In uranium-fueled reactors, neutrons must be moderated (slowed down) because slow neutrons are more likely to cause fission when colliding with a uranium-235 nucleus. [[Light water reactors]] use ordinary water to moderate and cool the reactors. When at operating temperatures if the temperature of the water increases, its density drops, and fewer neutrons passing through it are slowed enough to trigger further reactions. That [[negative feedback]] stabilizes the reaction rate.
 
The chain reaction is controlled through the use of materials that absorb and moderate neutrons. In uranium-fueled reactors, neutrons must be moderated (slowed down) because slow neutrons are more likely to cause fission when colliding with a uranium-235 nucleus. [[Light water reactors]] use ordinary water to moderate and cool the reactors. When at operating temperatures if the temperature of the water increases, its density drops, and fewer neutrons passing through it are slowed enough to trigger further reactions. That [[negative feedback]] stabilizes the reaction rate.
  
The current types of plants (and their common components) are discussed in the article [[nuclear reactor technology]].
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A number of other designs for nuclear power generation, the [[Generation IV reactor]]s, are the subject of active research and may be used for practical power generation in the future. A number of the advanced nuclear reactor designs could also make critical fission reactors much cleaner, much safer, and/or much less of a risk to the proliferation of nuclear weapons.
  
A number of other designs for nuclear power generation, the [[Generation IV reactor]]s, are the subject of active research and may be used for practical power generation in the future. A number of the advanced nuclear reactor designs could also make critical fission reactors much cleaner, much safer and/or much less of a risk to the proliferation of nuclear weapons.
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Controlled [[nuclear fusion]] could in principle be used in [[fusion power]] plants to produce power without the complexities of handling actinides, but significant scientific and technical obstacles remain. Several fusion reactors have been built, but as yet none has "produced" more thermal energy than electrical energy consumed. Despite research having started in the 1950s, no commercial fusion reactor is expected before 2050. The [[ITER]] project is currently leading the effort to commercialize fusion power.
  
Controlled [[nuclear fusion]] could in principle be used in [[fusion power]] plants to produce power without the complexities of handling actinides, but significant scientific and technical obstacles remain. Several fusion reactors have been built, but as yet none has 'produced' more thermal energy than electrical energy consumed. Despite research having started in the 1950s, no commercial fusion reactor is expected before 2050. The [[ITER]] project is currently leading the effort to commercialize fusion power.
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==[[Nuclear safety|Safety]]==
 
 
==Safety==
 
{{main|Nuclear safety}}
 
{{main|Nuclear safety in the U.S.}}
 
  
 
The topic of nuclear safety covers:
 
The topic of nuclear safety covers:
*The research and testing of the possible incidents/events at a nuclear power plant,
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*The research and testing of the possible incidents/events at a nuclear power plant.
*What equipment and actions are designed to prevent those incidents/events from having serious consequences,
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*What equipment and actions are designed to prevent those incidents/events from having serious consequences.
*The calculation of the probabilities of multiple systems and/or actions failing thus allowing serious consequences,
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*The calculation of the probabilities of multiple systems and/or actions failing thus allowing serious consequences.
*The evaluation of the worst-possible timing and scope of those serious consequences (the worst-possible in extreme cases being a release of radiation),
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*The evaluation of the worst-possible timing and scope of those serious consequences (the worst-possible in extreme cases being a release of radiation).
*The actions taken to protect the public during a release of radiation,
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*The actions taken to protect the public during a release of radiation.
 
*The training and rehearsals performed to ensure readiness in case an incident/event occurs.
 
*The training and rehearsals performed to ensure readiness in case an incident/event occurs.
  
== Economics ==
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== [[Economics of Nuclear power|Economics]] ==
{{Main|Economics of new nuclear power plants}}
 
 
 
This is a controversial subject, since multi-billion dollar investments ride on the choice of an energy source.
 
 
 
Which power source (generally coal, natural gas, nuclear or wind) is most cost-effective depends on the assumptions used in a particular study—several are quoted in the main article.
 
  
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Nuclear economics has become increasingly controversial, since multi-billion dollar investments ride on the choice of an energy source.
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Which power source (generally coal, natural gas, nuclear, or wind) is most cost-effective depends on given assumptions used in a particular study.
  
 
==Life cycle==
 
==Life cycle==
 
[[Image:Nuclear Fuel Cycle.png|250px|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 usage in the power plant, the spent fuel is delivered to a reprocessing plant (2) or to a final repository (3) for geological disposition. In [[nuclear reprocessing|reprocessing]] 95% of spent fuel can be recycled to be returned to usage in a power plant (4).]]
 
[[Image:Nuclear Fuel Cycle.png|250px|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 usage in the power plant, the spent fuel is delivered to a reprocessing plant (2) or to a final repository (3) for geological disposition. In [[nuclear reprocessing|reprocessing]] 95% of spent fuel can be recycled to be returned to usage in a power plant (4).]]
[[Image:Nuclear fuel pellets.jpeg|250px|thumb|Nuclear fuel — a compact, inert, insoluble solid.]]
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[[Image:Nuclear fuel pellets.jpeg|250px|thumb|Nuclear fuel—a compact, inert, insoluble solid.]]
 
{{Main|Nuclear fuel cycle}}
 
{{Main|Nuclear fuel cycle}}
  
A nuclear reactor is only part of the life-cycle for nuclear power. The process starts with mining. Generally, uranium mines are either open-pit [[surface mining#Strip Mining|strip mines]], or in-situ leach mines. In either case, the uranium ore is extracted, usually converted into a stable and compact form such as [[yellowcake]], and then transported to a processing facility. Here, the yellowcake is converted to [[uranium hexafluoride]], which is then [[uranium enrichment|enriched]] using various techniques. At this point, the enriched uranium, containing more than the natural 0.7% U-235, is used to make rods of the proper composition and geometry for the particular reactor that the fuel is destined for. The fuel rods will spend about 3 years inside the reactor, generally until about 3% of their uranium has been fissioned, then they will be moved to a [[spent fuel pool]] where the short lived isotopes generated by fission can decay away. After about 5 years in a cooling pond, the spent fuel is radioactively cool enough to handle, and it can be moved to dry storage casks or reprocessed.
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A nuclear reactor is only part of the life-cycle for nuclear power. The process starts with mining. Generally, uranium mines are either open-pit [[surface mining#Strip Mining|strip mines]], or in-situ leach mines. In either case, the uranium ore is extracted, usually converted into a stable and compact form, such as [[yellowcake]], and then transported to a processing facility. Here, the yellowcake is converted to [[uranium hexafluoride]], which is then [[uranium enrichment|enriched]] using various techniques. At this point, the enriched uranium, containing more than the natural 0.7 percent U-235, is used to make rods of the proper composition and geometry for the particular reactor that the fuel is destined for. The fuel rods will spend about 3 years inside the reactor, generally, until about 3 percent of their uranium has been fissioned, then they will be moved to a [[spent fuel pool]], where the short lived isotopes generated by fission can decay away. After about 5 years in a cooling pond, the spent fuel is radioactively cool enough to handle, and it can be moved to dry storage casks or reprocessed.
  
 
=== Fuel resources ===
 
=== Fuel resources ===
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{{Main|Future_energy_development#Nuclear_power|l1=Future energy development - Nuclear power}}
 
{{Main|Future_energy_development#Nuclear_power|l1=Future energy development - Nuclear power}}
  
[[Uranium]] is a common [[chemical element|element]], approximately as common as [[tin]] or [[zinc]], and it is a constituent of most rocks and of the sea. The world's present measured resources of uranium, economically recoverable at a price of 130 $/kg, are enough to last for some 70 years at current consumption. This represents a higher level of assured resources than is normal for most minerals. On the basis of analogies with other metal minerals, a doubling of price from present levels could be expected to create about a tenfold increase in measured resources, over time. The fuel's contribution to the overall cost of the electricity produced is relatively small, so even a large fuel price escalation will have relatively little effect on final price. For instance, typically a doubling of the uranium market price would increase the fuel cost for a light water reactor by 26% and the electricity cost about 7% (whereas doubling the gas price would typically add 70% to the price of electricity from that source). At higher prices eventually extraction from sources such as granite and seawater become economically feasible.<ref>[http://www.world-nuclear.org/info/inf75.html Supply of Uranium] Retrieved July 20, 2007.</ref><ref>[http://www.world-nuclear.org/info/inf02.html The Economics of Nuclear Power]. Retrieved July 20, 2007.</ref><ref> Jopf, James. 2004. [http://www.americanenergyindependence.com/uranium.html World Uranium Reserves] American Energy Independence. Retrieved July 20, 2007.</ref><ref> [http://www.ans.org/pubs/journals/nt/va-144-2-274-278 Aquaculture of Uranium in Seawater by a Fabric-Adsorbent Submerged System]. Retrieved July 21, 2007.</ref><ref> [http://www.nuclearinfo.net/Nuclearpower/WebHomeEnergyLifecycleOfNuclear_Power Energy Lifecycle of Nuclear Power] Retrieved July 20, 2007.</ref><ref> [http://www.uraniumworld.org Uranium in a global context] Retrieved July 20, 2007. </ref>  
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[[Uranium]] is a common [[chemical element|element]], approximately as common as [[tin]] or [[zinc]], and it is a constituent of most rocks, as well as of the sea. The world's present measured resources of uranium, economically recoverable at a price of 130 $/kg, are enough to last for some 70 years at current consumption. This represents a higher level of assured resources than is normal for most minerals. On the basis of analogies with other metal minerals, a doubling of price from present levels could be expected to create about a tenfold increase in measured resources, over time. The fuel's contribution to the overall cost of the electricity produced is relatively small, so even a large fuel price escalation will have relatively little effect on final price. For instance, typically a doubling of the uranium market price would increase the fuel cost for a light water reactor by 26 percent and the electricity cost about 7 percent (whereas doubling the gas price would typically add 70 percent to the price of electricity from that source). At higher prices, eventually extraction from sources such as granite and seawater become economically feasible.<ref>World Nuclear Association, [http://www.world-nuclear.org/info/inf75.html Supply of Uranium.] Retrieved July 20, 2007.</ref>
Current [[light water reactor]]s make relatively inefficient use of nuclear fuel, leading to energy waste. But [[nuclear reprocessing]] makes this waste reusable (except in the USA, where this is not allowed) and more efficient reactor designs would allow better use of the available resources (and reduce the amount of waste material).<ref name="wna-wmitnfc">[http://www.world-nuclear.org/info/inf04.html Waste Management in the Nuclear Fuel Cycle] World Nuclear Assosciation. Retrieved July 20, 2007.</ref>
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Current [[light water reactor]]s make relatively inefficient use of nuclear fuel, leading to energy waste. But [[nuclear reprocessing]] makes this waste reusable (except in the U.S., where this is not allowed) and more efficient reactor designs would allow better use of the available resources (and reduce the amount of waste material).<ref>World Nuclear Association, [http://www.world-nuclear.org/info/inf04.html Waste Management in the Nuclear Fuel Cycle.] Retrieved July 20, 2007.</ref>
  
As opposed to current light water reactors which use [[uranium-235]] (0.7% of all natural uranium), [[fast breeder reactor]]s use [[uranium-238]] (99.3% of all natural uranium). It has been estimated that there is up to five-billion years’ (also the estimated remaining life of the [[Sun]]) worth of uranium-238 for use in these power plants.<ref name="stanford-cohen"> McCarthy, John. [http://www-formal.stanford.edu/jmc/progress/cohen.html Facts From Choen and Others] Stanford. Retrieved July 20, 2007.</ref> Breeder technology has been used in several reactors, but requires higher uranium prices before becoming justified economically.<ref name="wna-anpr">[http://www.world-nuclear.org/info/inf08.html Advanced Nuclear Power Reactors] World Nuclear Assosciation. Retrieved July 20, 2007.</ref> As of December 2005, the only breeder reactor producing power is BN-600 in Beloyarsk, Russia. (The electricity output of BN-600 is 600 MW — Russia has planned to build another unit, BN-800, at Beloyarsk nuclear power plant.) Also, Japan's [[Monju]] reactor is planned for restart (having been shut down since 1995), and both China and India intend to build breeder reactors.
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As opposed to current light water reactors which use [[uranium-235]] (0.7 percent of all natural uranium), [[fast breeder reactor]]s use [[uranium-238]] (99.3 percent of all natural uranium). It has been estimated that there is up to five-billion years’ (also the estimated remaining life of the [[Sun]]) worth of uranium-238 for use in these power plants.<ref>John McCarthy, [http://www-formal.stanford.edu/jmc/progress/cohen.html Facts From Choen and Others.] Retrieved July 20, 2007.</ref> Breeder technology has been used in several reactors, but requires higher uranium prices before becoming justified economically.<ref>World Nuclear Association, [http://www.world-nuclear.org/info/inf08.html Advanced Nuclear Power Reactors.] Retrieved July 20, 2007.</ref> As of December 2005, the only breeder reactor producing power is BN-600 in Beloyarsk, Russia. (The electricity output of BN-600 is 600 MW——ussia has planned to build another unit, BN-800, at Beloyarsk nuclear power plant.) Also, Japan's [[Monju]] reactor is planned for restart (having been shut down since 1995), and both China and India intend to build breeder reactors.
  
Another alternative would be to use uranium-233 bred from [[thorium]] as fission fuel the [[thorium fuel cycle]]. Thorium is three times more abundant in the Earth's crust than uranium, and (theoretically) all of it can be used for breeding, making the potential thorium resource orders of magnitude larger than the uranium fuel cycle operated without breeding.<ref name="wna-thorium">[http://www.world-nuclear.org/info/inf62.html Thorium] World Nuclear Assosciation. Retrieved July 20, 2007.</ref> Unlike the breeding of U-238 into plutonium, fast breeder reactors are not necessary it can be performed satisfactorily in more conventional plants.
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Another alternative would be to use uranium-233 bred from [[thorium]] as fission fuelthe [[thorium fuel cycle]]. Thorium is three times more abundant in the Earth's crust than uranium, and (theoretically) all of it can be used for breeding, making the potential thorium resource orders of magnitude larger than the uranium fuel cycle operated without breeding.<ref>World Nuclear Association, [http://www.world-nuclear.org/info/inf62.html Thorium.] Retrieved July 20, 2007.</ref> Unlike the breeding of U-238 into plutonium, fast breeder reactors are not necessaryit can be performed satisfactorily in more conventional plants.
  
[[Fusion power]] commonly propose the use of [[deuterium]], an [[isotope]] of [[hydrogen]], as fuel and in many current designs also [[lithium]]. Assuming a fusion energy output equal to the current global output and that this does not increase in the future, then the known current lithium reserves would last 3000 years, lithium from sea water would last 60 million years, and a more complicated fusion process using only deuterium from sea water would have fuel for 150 billion years.<ref>[http://www.fusie-energie.nl/artikelen/ongena.pdf ENERGY FOR FUTURE CENTURIES, Will fusion be an inexhaustible, safe and clean energy source?] Retrieved July 20, 2007.</ref>
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[[Fusion power]] commonly proposes the use of [[deuterium]], an [[isotope]] of [[hydrogen]], as fuel and in many current designs also [[lithium]]. Assuming a fusion energy output equal to the current global output and that this does not increase in the future, then the known current lithium reserves would last 3000 years, lithium from sea water would last 60 million years, and a more complicated fusion process using only deuterium from sea water would have fuel for 150 billion years.<ref>J. Onenga and G. Van Oost, [http://www.fusie-energie.nl/artikelen/ongena.pdf Energy for Future Centuries: Will Fusion be an Inexhaustible, Safe, and Clean energy source?] Retrieved July 20, 2007.</ref>
  
 
=== Depleted uranium ===
 
=== Depleted uranium ===
 
{{Main|Depleted uranium}}
 
{{Main|Depleted uranium}}
Uranium enrichment produces many tons of [[depleted uranium]] (DU) which consists of U-238 with most of the easily fissile U-235 isotope removed. U-238 is a tough metal with several commercial uses for example, aircraft production, radiation shielding, and making bullets and armor as it has a higher density than [[lead]]. There are concerns that U-238 may lead to health problems in groups exposed to this material excessively, like tank crews and civilians living in areas where large quantities of DU ammunition have been used.
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Uranium enrichment produces many tons of [[depleted uranium]] (DU) which consists of U-238, with most of the easily fissile U-235 isotope removed. U-238 is a tough metal with several commercial usesfor example, aircraft production, radiation shielding, and making bullets and armoras it has a higher density than [[lead]]. There are concerns that U-238 may lead to health problems in groups exposed to this material excessively, like tank crews and civilians living in areas where large quantities of DU ammunition have been used.
  
 
=== Solid waste ===
 
=== Solid waste ===
{{see details|Radioactive waste}}
 
  
The safe storage and disposal of nuclear waste is a significant challenge. The most important waste stream from nuclear power plants is spent fuel. A large nuclear reactor produces 3 cubic metres (25-30 tonnes) of spent fuel each year.<ref name="uic-waste">[http://www.uic.com.au/wast.htm Radioactive Waste Management] Uranium & Nuclear Power Information Centre. Retrieved July 20, 2007.</ref> It is primarily composed of unconverted uranium as well as significant quantities of transuranic [[actinides]] ([[plutonium]] and [[curium]], mostly). In addition, about 3% of it is made of [[fission product]]s. The actinides (uranium, plutonium, and curium) are responsible for the bulk of the long term radioactivity, whereas the fission products are responsible for the bulk of the short term radioactivity.  
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The safe storage and disposal of nuclear waste is a significant challenge. The most important waste stream from nuclear power plants is spent fuel. A large nuclear reactor produces 3 cubic meters (25-30 metric tons) of spent fuel each year.<ref>Uranium & Nuclear Power Information Centre, [http://www.uic.com.au/wast.htm Radioactive Waste Management.] Retrieved July 20, 2007.</ref> It is primarily composed of unconverted uranium as well as significant quantities of transuranic [[actinides]] ([[plutonium]] and [[curium]], mostly). In addition, about 3 percent of it is made of [[fission product]]s. The actinides (uranium, plutonium, and curium) are responsible for the bulk of the long term radioactivity, whereas the fission products are responsible for the bulk of the short term radioactivity.  
  
Spent fuel is highly radioactive and needs to be handled with great care and forethought. However, spent nuclear fuel becomes less radioactive over time. After 40 years, the [[radiation flux]] is 99.9% lower than it was the moment the spent fuel was removed, although still dangerously radioactive.<ref name="wna-wmitnfc"/>
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Spent fuel is highly radioactive and needs to be handled with great care and forethought. However, spent nuclear fuel becomes less radioactive over time. After 40 years, the [[radiation flux]] is 99.9 percent lower than it was the moment the spent fuel was removed, although still dangerously radioactive.
  
 
[[Spent fuel rod]]s are stored in shielded basins of water ([[spent fuel pool]]s), usually located on-site. The water provides both cooling for the still-decaying uranium, and shielding from the continuing radioactivity. After a few decades some on-site storage involves moving the now cooler, less radioactive fuel to a dry-storage facility or [[dry cask storage]], where the fuel is stored in steel and concrete containers until its radioactivity decreases naturally ("decays") to levels safe enough for other processing. This interim stage spans years or decades, depending on the type of fuel. Most U.S. waste is currently stored in temporary storage sites requiring oversight, while suitable permanent disposal methods are discussed.  
 
[[Spent fuel rod]]s are stored in shielded basins of water ([[spent fuel pool]]s), usually located on-site. The water provides both cooling for the still-decaying uranium, and shielding from the continuing radioactivity. After a few decades some on-site storage involves moving the now cooler, less radioactive fuel to a dry-storage facility or [[dry cask storage]], where the fuel is stored in steel and concrete containers until its radioactivity decreases naturally ("decays") to levels safe enough for other processing. This interim stage spans years or decades, depending on the type of fuel. Most U.S. waste is currently stored in temporary storage sites requiring oversight, while suitable permanent disposal methods are discussed.  
  
As of 2003, the [[United States]] had accumulated about 49,000 metric tons of spent nuclear fuel from nuclear reactors. Underground storage at [[Yucca Mountain]] in U.S. has been proposed as permanent storage. After 10,000 years of radioactive decay, according to [[United States Environmental Protection Agency]] standards, the spent nuclear fuel will no longer pose a threat to public health and safety.
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As of 2003, the [[United States]] had accumulated about 49,000 metric tons of spent nuclear fuel from nuclear reactors. Underground storage at [[Yucca Mountain]] in the U.S. has been proposed as permanent storage. After 10,000 years of radioactive decay, according to [[United States Environmental Protection Agency]] standards, the spent nuclear fuel will no longer pose a threat to public health and safety.
  
 
The amount of waste can be reduced in several ways, particularly [[Nuclear power#Reprocessing|reprocessing]]. Even so, the remaining waste will be substantially radioactive for at least 300 years even if the actinides are removed, and for up to thousands of years if the actinides are left in. Even with separation of all actinides, and using [[fast breeder reactor]]s to destroy by [[transmutation]] some of the longer-lived non-actinides as well, the waste must be segregated from the environment for one to a few hundred years, and therefore this is properly categorized as a long-term problem. [[Subcritical reactor]]s or [[fusion reactors]] could also reduce the time the waste has to be stored. It has been argued that the best solution for the nuclear waste is above ground temporary storage since technology is rapidly changing. The current waste may well become a valuable resource in the future.
 
The amount of waste can be reduced in several ways, particularly [[Nuclear power#Reprocessing|reprocessing]]. Even so, the remaining waste will be substantially radioactive for at least 300 years even if the actinides are removed, and for up to thousands of years if the actinides are left in. Even with separation of all actinides, and using [[fast breeder reactor]]s to destroy by [[transmutation]] some of the longer-lived non-actinides as well, the waste must be segregated from the environment for one to a few hundred years, and therefore this is properly categorized as a long-term problem. [[Subcritical reactor]]s or [[fusion reactors]] could also reduce the time the waste has to be stored. It has been argued that the best solution for the nuclear waste is above ground temporary storage since technology is rapidly changing. The current waste may well become a valuable resource in the future.
  
The nuclear industry also produces a volume of low-level radioactive waste 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. In the United States, the [[Nuclear Regulatory Commission]] has repeatedly attempted to allow low-level materials to be handled as normal waste: landfilled, recycled into consumer items, and so forth. Most low-level waste releases very low levels of radioactivity and is only considered radioactive waste because of its history. For example, according to the standards of the NRC, the radiation released by coffee is enough to treat it as low level waste.  
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The nuclear industry also produces a volume of low-level radioactive waste 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. In the United States, the [[Nuclear Regulatory Commission]] has repeatedly attempted to allow low-level materials to be handled as normal waste: Landfilled, recycled into consumer items, and so forth. Most low-level waste releases very low levels of radioactivity and is only considered radioactive waste because of its history. For example, according to the standards of the NRC, the radiation released by coffee is enough to treat it as low level waste.  
  
In countries with nuclear power, radioactive wastes comprise less than 1% of total industrial toxic wastes, which remain hazardous indefinitely unless they decompose or are treated so that they are less toxic or, ideally, completely non-toxic.<ref name="wna-wmitnfc"/> Overall, nuclear power produces far less waste material than fossil-fuel based power plants. [[Coal]]-burning plants are particularly noted for producing large amounts of toxic and mildly radioactive ash due to concentrating naturally occurring metals and radioactive material from the coal. Contrary to popular belief, coal power actually results in more radioactive waste being released into the environment than nuclear power <ref>Gabbard, Alex. [http://www.ornl.gov/info/ornlreview/rev26-34/text/colmain.html Coal Combustion: Nuclear Resource or Danger]. Retrieved July 20, 2007.</ref>.
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In countries with nuclear power, radioactive wastes comprise less than 1 percent of total industrial toxic wastes, which remain hazardous indefinitely unless they decompose or are treated so that they are less toxic or, ideally, completely non-toxic. Overall, nuclear power produces far less waste material than fossil-fuel based power plants. [[Coal]]-burning plants are particularly noted for producing large amounts of toxic and mildly radioactive ash due to concentrating naturally occurring metals and radioactive material from the coal. Contrary to popular belief, coal power actually results in more radioactive waste being released into the environment than nuclear power <ref>Alex Gabbard, [http://www.ornl.gov/info/ornlreview/rev26-34/text/colmain.html Coal Combustion: Nuclear Resource or Danger.] Retrieved July 20, 2007.</ref>.
  
 
=== Reprocessing ===
 
=== Reprocessing ===
{{see details|Nuclear reprocessing}}
 
  
Reprocessing can potentially recover up to 95% of the remaining uranium and plutonium in spent nuclear fuel, putting it into new [[mixed oxide fuel]]. This would produce a reduction in long term radioactivity within the remaining waste, since this is largely short-lived fission products, and reduces its volume by over 90%. Reprocessing of civilian fuel from power reactors is currently done on large scale in Britain, France and (formerly) Russia, will be in China and perhaps India, and is being done on an expanding scale in Japan. The potential of reprocessing has not been achieved because it requires [[breeder reactor]]s, which are not yet commercially available. France is generally cited as the most successful reprocessor, but it presently only recycles 28% (by weight) of the yearly fuel use, 7% within France and another 21% in Russia.<ref name="IEEE Spectrum">[http://www.spectrum.ieee.org/feb07/4891 IEEE Spectrum: Nuclear Wasteland]. Retrieved July 21, 2007.</ref>
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Reprocessing can potentially recover up to 95 percent of the remaining uranium and plutonium in spent nuclear fuel, putting it into new [[mixed oxide fuel]]. This would produce a reduction in long term radioactivity within the remaining waste, since this is largely short-lived fission products, and reduces its volume by over 90 percent. Reprocessing of civilian fuel from power reactors is currently done on a large scale in Britain, France and (formerly) Russia, will be done in China and perhaps India, and is being done on an expanding scale in Japan. The potential of reprocessing has not been achieved because it requires [[breeder reactor]]s, which are not yet commercially available. France is generally cited as the most successful reprocessor, but it presently only recycles 28 percent (by weight) of the yearly fuel use, 7 percent within France and another 21 percent in Russia.<ref>IEEE Spectrum, [http://www.spectrum.ieee.org/feb07/4891 Nuclear Wasteland]. Retrieved July 21, 2007.</ref>
  
Unlike other countries, the US has stopped civilian reprocessing as one part of US non-proliferation policy, since reprocessed material such as plutonium can be used in nuclear weapons. Spent fuel is all currently treated as waste.<ref>[http://www.world-nuclear.org/info/inf69.html Processing of Used Nuclear Fuel for Recycle]. WNA Retrieved July 20, 2007. </ref> In February, 2006, a new U.S. initiative, the [[Global Nuclear Energy Partnership]] was announced. It would be an international effort to reprocess fuel in a manner making [[nuclear proliferation]] unfeasible, while making nuclear power available to developing countries.
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Unlike other countries, the U.S. has stopped civilian reprocessing as one part of U.S. non-proliferation policy, since reprocessed material such as plutonium can be used in nuclear weapons. Spent fuel is all currently treated as waste.<ref>World Nuclear Association, [http://www.world-nuclear.org/info/inf69.html Processing of Used Nuclear Fuel for Recycle.] Retrieved July 20, 2007. </ref> In February 2006, a new U.S. initiative, the [[Global Nuclear Energy Partnership]], was announced. It would be an international effort to reprocess fuel in a manner making [[nuclear proliferation]] unfeasible, while making nuclear power available to developing countries.
  
 
==Concerns about nuclear power==
 
==Concerns about nuclear power==
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===Accidents===
 
===Accidents===
{{Main|Nuclear and radiation accidents}}
 
  
 
The [[International Nuclear Event Scale]] (INES), developed by the [[International Atomic Energy Agency]] (IAEA), is used to communicate the severity of [[nuclear accidents]] on a scale of 0 to 7. The two most well known events are the [[Three Mile Island accident ]] and the [[Chernobyl disaster]].
 
The [[International Nuclear Event Scale]] (INES), developed by the [[International Atomic Energy Agency]] (IAEA), is used to communicate the severity of [[nuclear accidents]] on a scale of 0 to 7. The two most well known events are the [[Three Mile Island accident ]] and the [[Chernobyl disaster]].
  
The 1979 accident at Three Mile Island Unit 2 was the worst civilian nuclear accident outside the Soviet Union (INES score of 5). The reactor experienced a partial core [[nuclear meltdown|meltdown]]. However, the [[reactor vessel]] and [[containment building]] were not breached and little radiation was released to the environment (well below natural background radiation levels).<ref name="usnrc-tmi">[http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.html Fact Sheet on the Accident at Three Mile Island] U.S. Nuclear Regulatory Commission. Retrieved July 20, 2007.</ref>  
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The 1979 accident at Three Mile Island Unit 2 was the worst civilian nuclear accident outside the Soviet Union (INES score of 5). The reactor experienced a partial core [[nuclear meltdown|meltdown]]. However, the [[reactor vessel]] and [[containment building]] were not breached and little radiation was released to the environment (well below natural background radiation levels).<ref>U.S. Nuclear Regulatory Commission, [http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.html Fact Sheet on the Accident at Three Mile Island.] Retrieved July 20, 2007.</ref>  
 
The event resulted in fundamental changes in how plants in the West were to be maintained and operated. There were no immediate fatalities or injuries stemming from the event and, although debated by some groups, the mainstream view is that no member of the public was injured and no detectable increase in the incidence of cancer is expected.  
 
The event resulted in fundamental changes in how plants in the West were to be maintained and operated. There were no immediate fatalities or injuries stemming from the event and, although debated by some groups, the mainstream view is that no member of the public was injured and no detectable increase in the incidence of cancer is expected.  
  
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Design changes are being pursued to lessen the risks of fission reactors; in particular, [[passive nuclear safety|passively safe]] plants (such as the [[ESBWR]]) are available to be built and [[inherently safe]] designs are being pursued. [[Fusion power|Fusion]] reactors which may come to exist in the future theoretically have very little risk.
 
Design changes are being pursued to lessen the risks of fission reactors; in particular, [[passive nuclear safety|passively safe]] plants (such as the [[ESBWR]]) are available to be built and [[inherently safe]] designs are being pursued. [[Fusion power|Fusion]] reactors which may come to exist in the future theoretically have very little risk.
  
The [[World Nuclear Association]] provides a comparison of deaths due to major accidents among different forms of energy production. In their comparison, deaths per TWy of electricity produced are 885 for hydropower, 342 for coal, 85 for natural gas, and 8 for nuclear.<ref>[http://www.world-nuclear.org/info/inf06.html Safety of Nuclear Power Reactors] Retrieved July 20, 2007. </ref> Not included in the study are deaths due to [[Pneumoconiosis|black lung disease]] or [[air pollution]] from fossil fuels.<ref name="dirty">[http://www.catf.us/publications/view/24 Dirty Air, Dirty Power: Mortality and Health Damage Due to Air Pollution from Power Plants]. Clean Air Task Force. Retrieved July 20, 2007.</ref>
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The [[World Nuclear Association]] provides a comparison of deaths due to major accidents among different forms of energy production. In their comparison, deaths per TWy of electricity produced are 885 for hydropower, 342 for coal, 85 for natural gas, and 8 for nuclear.<ref>World Nuclear Association, [http://www.world-nuclear.org/info/inf06.html Safety of Nuclear Power Reactors.] Retrieved July 20, 2007. </ref> Not included in the study are deaths due to [[Pneumoconiosis|black lung disease]] or [[air pollution]] from fossil fuels.<ref>Clean Air Task Force, [http://www.catf.us/publications/view/24 Dirty Air, Dirty Power: Mortality and Health Damage Due to Air Pollution from Power Plants.] Retrieved July 20, 2007.</ref>
  
 
===Vulnerability of plants to attack===
 
===Vulnerability of plants to attack===
  
Nuclear power plants are generally (although not always) considered "hard" targets. In the US, 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>[http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/security-enhancements.html Backgrounder - Nuclear Security Five Years After 9/11]. Retrieved July 20, 2007.</ref> The NRC's "Design Basis Threat" criteria for plants is a secret, and so what size attacking force the plants are able to protect against is unknown. However, to [[Scram]] a plant takes less than 5 seconds while unimpeded restart takes hours, severely hampering a terrorist force in a goal to release radioactivity.
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Nuclear power plants are generally (although not always) considered "hard" targets. In the U.S., plants are surrounded by a double row of tall fences which are electronically monitored. The plant grounds are patrolled by a sizable force of armed guards.<ref>Nuclear Regulatory Commission, [http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/security-enhancements.html Backgrounder--Nuclear SecurityFive Years After 9/11]. Retrieved July 20, 2007.</ref> The NRC's "Design Basis Threat" criteria for plants is a secret, and so what size attacking force the plants are able to protect against is unknown. However, to [[Scram]] a plant takes less than 5 seconds while unimpeded restart takes hours, severely hampering a terrorist force whose goal is to release radioactivity.
  
Attack from the air is a more problematic concern. The most important barrier against the release of radioactivity in the event of an aircraft strike is the [[containment building]] and its missile shield. The NRC's Chairman has said "Nuclear power plants are inherently robust structures that our studies show provide adequate protection in a hypothetical attack by an airplane. The NRC has also taken actions that require nuclear power plant operators to be able to manage large fires or explosions—no matter what has caused them." <ref name="air attack">[http://www.nrc.gov/reading-rm/doc-collections/news/2007/07-013.html Statement From Chairman Dale Klein on Commision's Affirmation of the Final DBT Rule. Nuclear Regulatory Commission]. Retrieved July 20, 2007.</ref>
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Attack from the air is a more problematic concern. The most important barrier against the release of radioactivity in the event of an aircraft strike is the [[containment building]] and its missile shield. The NRC's Chairman has said "Nuclear power plants are inherently robust structures that our studies show provide adequate protection in a hypothetical attack by an airplane. The NRC has also taken actions that require nuclear power plant operators to be able to manage large fires or explosions—no matter what has caused them." <ref>Nuclear Regulatory Commission, [http://www.nrc.gov/reading-rm/doc-collections/news/2007/07-013.html Statement From Chairman Dale Klein on Commision's Affirmation of the Final DBT Rule.] Retrieved July 20, 2007.</ref>
  
In addition, supporters point to large studies carried out by NRC and other agencies that tested the robustness of both reactor and waste fuel storage, and found that they should be able to sustain a terrorist attack comparable to the [[September 11, 2001 attacks|September 11 terrorist attacks]] in the USA. Spent fuel is usually housed inside the plant's "protected zone"<ref name="wna-tnfc">[http://www.world-nuclear.org/info/inf03.html The Nuclear Fuel Cycle] World Nuclear Association. Retrieved July 20, 2007.</ref> or a [[spent nuclear fuel shipping cask]]; stealing it for use in a "dirty bomb" is extremely difficult. Exposure to the intense radiation would almost certainly quickly incapacitate or kill any terrorists who attempt to do so.  
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In addition, supporters point to large studies carried out by NRC and other agencies that tested the robustness of both reactor and waste fuel storage, and found that they should be able to sustain a terrorist attack comparable to the [[September 11, 2001 attacks|September 11 terrorist attacks]] in the U.S. Spent fuel is usually housed inside the plant's "protected zone"<ref>World Nuclear Association, [http://www.world-nuclear.org/info/inf03.html The Nuclear Fuel Cycle.] Retrieved July 20, 2007.</ref> or a [[spent nuclear fuel shipping cask]]; stealing it for use in a "dirty bomb" is extremely difficult. Exposure to the intense radiation would almost certainly quickly incapacitate or kill any terrorists who attempt to do so.  
Nuclear power plants are designed to withstand threats deemed credible at the time of licensing. However, as weapons evolve it cannot be said unequivocably that within the 60 year life of a plant it will not become vulnerable. In addition, the future status of storage sites may be in doubt.
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Nuclear power plants are designed to withstand threats deemed credible at the time of licensing. However, as weapons evolve it cannot be said unequivocally that within the 60 year life of a plant it will not become vulnerable. In addition, the future status of storage sites may be in doubt.
 
Other forms of energy production are also vulnerable to attack, such as [[hydroelectric dams]] and [[LNG]] tankers.
 
Other forms of energy production are also vulnerable to attack, such as [[hydroelectric dams]] and [[LNG]] tankers.
  
 
===Use of waste byproduct as a weapon ===
 
===Use of waste byproduct as a weapon ===
  
Opponents of nuclear power express concerns that nuclear waste is not well protected, and that it can be possible be used as a terrorist weapon, as a [[dirty bomb]], quoting a 1999 Russian incident where workers were caught trying to sell 5 grams of radioactive material on the open market,<ref name="nti-nwfu">Nesvizhskiy, Vadim[http://www.nti.org/db/nistraff/1999/19990670.htm Neutron Weapon from Underground] Nuclear Threat Initiative. Retrieved July 20, 2007.</ref> or the incident in 1993 where Russian workers were caught selling 4.5 kilograms of enriched uranium.<ref name="aa-ionsi">[http://www.atomicarchive.com/Almanac/Smuggling_details.shtml#4 Infomation on Nuclear Smuggling Incidents] Nuclear Threat Initiative. Retrieved July 20, 2007.</ref><ref name="gu-wgus">Gentleman, Amelia and MacAskill, Ewen. 2001. [http://www.guardian.co.uk/international/story/0,3604,526856,00.html Weapons-grade Uranium Seized] Guardian Unlimited. Retrieved July 20, 2007.</ref> The [[UN]] has since called upon world leaders to improve security in order to prevent radioactive material falling into the hands of terrorists.<ref name="bbc-acodbt">[http://news.bbc.co.uk/1/hi/world/europe/2838743.stm Action Call Over Dirty Bomb Threat] BBC. Retrieved July 20, 2007.</ref> Proponents of nuclear power argue, however, that a dirty bomb is not a very effective weapon and would cause relatively few casualties, although the psychological impact would be high.
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Opponents of nuclear power express concerns that nuclear waste is not well protected, and that it could potentially be used as a terrorist weapon, as a [[dirty bomb]], quoting a 1999 Russian incident where workers were caught trying to sell 5 grams of radioactive material on the open market,<ref>Vadim Nesvizhskiy, [http://www.nti.org/db/nistraff/1999/19990670.htm Neutron Weapon from Underground.] Retrieved July 20, 2007.</ref> or the incident in 1993, where Russian workers were caught selling 4.5 kilograms of enriched uranium.<ref>Nuclear Threat Initiative, [http://www.atomicarchive.com/Almanac/Smuggling_details.shtml#4 Information on Nuclear Smuggling Incidents.] Retrieved July 20, 2007.</ref> The [[UN]] has since called upon world leaders to improve security in order to prevent radioactive material falling into the hands of terrorists.<ref>BBC, [http://news.bbc.co.uk/1/hi/world/europe/2838743.stm Action Call Over Dirty Bomb Threat.] Retrieved July 20, 2007.</ref> Proponents of nuclear power argue, however, that a dirty bomb is not a very effective weapon and would cause relatively few casualties, although the psychological impact would be high.
  
 
=== Health effect on population near nuclear plants ===
 
=== Health effect on population near nuclear plants ===
  
 
[[Image:Trojan1.jpg|thumb|200px|A couple fishes near the Trojan Nuclear Power Plant. The reactor dome is visible on the left, and the massive cooling tower on the right.]]  
 
[[Image:Trojan1.jpg|thumb|200px|A couple fishes near the Trojan Nuclear Power Plant. The reactor dome is visible on the left, and the massive cooling tower on the right.]]  
Most of human exposure to radiation comes from natural [[background radiation]]. Most of the remaining exposure comes from medical procedures. Several large studies in the US, Canada, and Europe have found no evidence of any increase in cancer mortality among people living near nuclear facilities. For example, in 1990, the [[National Cancer Institute]] (NCI) of the [[National Institutes of Health]] announced that a large-scale study, which evaluated mortality from 16 types of cancer, found no increased incidence of cancer mortality for people living near 62 nuclear installations in the United States. The study showed no increase in the incidence of childhood leukemia mortality in the study of surrounding counties after start-up of the nuclear facilities. The NCI study, the broadest of its kind ever conducted, surveyed 900,000 cancer deaths in counties near nuclear facilities.
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Most of human exposure to radiation comes from natural [[background radiation]]. Most of the remaining exposure comes from medical procedures. Several large studies in the U.S., Canada, and Europe have found no evidence of any increase in cancer mortality among people living near nuclear facilities. For example, in 1990, the [[National Cancer Institute]] (NCI) of the [[National Institutes of Health]] announced that a large-scale study, which evaluated mortality from 16 types of cancer, found no increased incidence of cancer mortality for people living near 62 nuclear installations in the United States. The study showed no increase in the incidence of childhood leukemia mortality in the study of surrounding counties after start-up of the nuclear facilities. The NCI study, the broadest of its kind ever conducted, surveyed 900,000 cancer deaths in counties near nuclear facilities.
  
However, in Britain there are elevated childhood leukemia levels near some industrial facilities, particularly near [[Sellafield]], where children living locally are ten times more likely to contract the cancer. The reasons for these increases, or clusters, are unclear, but one study of those near Sellafield has ruled out any contribution from nuclear sources. Apart from anything else, the levels of radiation at these sites are orders of magnitude too low to account for the excess incidences reported. One explanation is viruses or other infectious agents being introduced into a local community by the mass movement of migrant workers.<ref>[[Richard Doll|Sir Richard Doll]], quoted in the [[The Independent]] 1999-08-16 [http://www.acor.org/ped-onc/diseases/kinlen.html Researcher Says Childhood Leukemia Is Caused By Infection] Retrieved July 20, 2007.</ref>
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However, in Britain there are elevated childhood leukemia levels near some industrial facilities, particularly near [[Sellafield]], where children living locally are ten times more likely to contract the cancer. The reasons for these increases, or clusters, are unclear, but one study of those near Sellafield has ruled out any contribution from nuclear sources. Apart from anything else, the levels of radiation at these sites are orders of magnitude too low to account for the excess incidences reported. One explanation is viruses or other infectious agents being introduced into a local community by the mass movement of migrant workers.<ref>Sir Richard Doll, [http://www.acor.org/ped-onc/diseases/kinlen.html Researcher Says Childhood Leukemia Is Caused By Infection.] Retrieved July 20, 2007.</ref>
Likewise, small studies have found an increased incidence of childhood leukemia near some nuclear power plants has also been found in Germany <ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9210727 A cluster of childhood leukemia near a nuclear reactor in northern Germany.]. Retrieved July 20, 2007.</ref> and France <ref>Seth, Anita. [http://www.ieer.org/ensec/no-4/lahague.html Leukemia Clusters Near La Hague and Sellafield]. Retrieved July 20, 2007.</ref>. Nonetheless, the results of larger multi-site studies in these countries invalidate the hypothesis of an increased risk of leukemia related to nuclear discharge. The methodology and very small samples in the studies finding an increased incidence has been criticized. <ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11990512&dopt=Abstract Risk of childhood leukaemia in the vicinity of nuclear installations—findings and recent controversies.]. Retrieved July 20, 2007.</ref><ref>[http://www.personalmd.com/news/n0818103222.shtml Researcher Says Childhood Leukemia Is Caused By Infection]. Retrieved July 20, 2007.</ref>. Also, one study focusing on Leukemia clusters in industrial towns in England indicated a link to high-capacity electricity lines suggesting that the production or distribution of the electricity, rather than the nuclear reaction, may be a factor.
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Likewise, small studies have been conducted in Germany and France, and have found an increased incidence of childhood leukemia near some nuclear power plants.<ref>Anita Seth, [http://www.ieer.org/ensec/no-4/lahague.html Leukemia Clusters Near La Hague and Sellafield.] Retrieved July 20, 2007.</ref> Nonetheless, the results of larger multi-site studies in these countries invalidate the hypothesis of an increased risk of leukemia related to nuclear discharge. The methodology and very small samples in the studies finding an increased incidence have been criticized.<ref>PubMed, [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11990512&dopt=Abstract Risk of childhood leukaemia in the vicinity of nuclear installations—findings and recent controversies.]. Retrieved July 20, 2007.</ref> Also, one study focusing on Leukemia clusters in industrial towns in England indicated a link to high-capacity electricity lines suggesting that the production or distribution of the electricity, rather than the nuclear reaction, may be a factor.
  
 
=== Nuclear proliferation ===
 
=== Nuclear proliferation ===
{{see details|Nuclear proliferation}}
 
  
Nuclear proliferation is the spread of [[nuclear weapon]]s and related technology to nations not recognized as "Nuclear Weapon States" by the [[Nuclear Nonproliferation Treaty]]. Opponents of civilian nuclear power point out that nuclear technology may be [[dual-use technology]], and some of the materials and knowledge used in a civilian nuclear program may be used to develop nuclear weapons.
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Nuclear proliferation is the spread of [[nuclear weapon]]s and related technology to nations not recognized as "Nuclear Weapon States" by the [[Nuclear Nonproliferation Treaty]]. Opponents of civilian nuclear power point out that nuclear technology may be a [[dual-use technology]], and some of the materials and knowledge used in a civilian nuclear program may be used to develop nuclear weapons.
  
Original impetus for development of nuclear power came from the military nuclear programs, including the early designs of power reactors that were developed for [[nuclear submarine]]s. In many countries nuclear and civilian nuclear programs are linked, at least by common research projects and through agencies such as the [[US]] [[United States Department of Energy|DOE]]. In the U.S., for example, the first goal of the Department of Energy is "to advance the national, economic, and energy security of the United States; to promote scientific and technological innovation in support of that mission; and to ensure the environmental cleanup of the national nuclear weapons complex."<ref name="doe-about">[http://www.energy.gov/about/index.htm About DOE] U.S. Department of Energy. Retrieved July 20, 2007.</ref>
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Original impetus for development of nuclear power came from the military nuclear programs, including the early designs of power reactors that were developed for [[nuclear submarine]]s. In many countries governmental and civilian nuclear programs are linked, at least by common research projects and through agencies such as the [[U.S.]] [[United States Department of Energy|DOE]]. In the U.S., for example, the first goal of the Department of Energy is "to advance the national, economic, and energy security of the United States; to promote scientific and technological innovation in support of that mission; and to ensure the environmental cleanup of the national nuclear weapons complex."<ref>U.S. Department of Energy, [http://www.energy.gov/about/index.htm About DOE.] Retrieved July 20, 2007.</ref>
  
 
To prevent weapons proliferation, safeguards on nuclear technology were published in the [[Nuclear Non-Proliferation Treaty]] (NPT) and monitored since 1968 by the [[International Atomic Energy Agency]] (IAEA). Nations signing the treaty are required to report to the IAEA what nuclear materials they hold and their location. They agree to accept visits by IAEA auditors and inspectors to verify independently their material reports and physically inspect the nuclear materials concerned to confirm physical inventories of them in exchange for access to nuclear materials and equipment on the global market.
 
To prevent weapons proliferation, safeguards on nuclear technology were published in the [[Nuclear Non-Proliferation Treaty]] (NPT) and monitored since 1968 by the [[International Atomic Energy Agency]] (IAEA). Nations signing the treaty are required to report to the IAEA what nuclear materials they hold and their location. They agree to accept visits by IAEA auditors and inspectors to verify independently their material reports and physically inspect the nuclear materials concerned to confirm physical inventories of them in exchange for access to nuclear materials and equipment on the global market.
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Several states did not sign the treaty and were able to use international nuclear technology (often procured for civilian purposes) to develop nuclear weapons ([[India]], [[Pakistan]], [[Israel]], and [[South Africa]]). Of those who have signed the treaty and received shipments of nuclear paraphernalia, many states have either claimed to, or been accused of, attempting to use supposedly civilian nuclear power plants for developing weapons. Certain types of reactors may be more conducive to producing nuclear weapons materials than others, such as possible future [[fast breeder reactor]]s, and a number of international disputes over proliferation have centered on the specific model of reactor being contracted for in a country suspected of nuclear weapon ambitions.
 
Several states did not sign the treaty and were able to use international nuclear technology (often procured for civilian purposes) to develop nuclear weapons ([[India]], [[Pakistan]], [[Israel]], and [[South Africa]]). Of those who have signed the treaty and received shipments of nuclear paraphernalia, many states have either claimed to, or been accused of, attempting to use supposedly civilian nuclear power plants for developing weapons. Certain types of reactors may be more conducive to producing nuclear weapons materials than others, such as possible future [[fast breeder reactor]]s, and a number of international disputes over proliferation have centered on the specific model of reactor being contracted for in a country suspected of nuclear weapon ambitions.
  
There is concern in some countries over [[North Korea]] and [[Nuclear program of Iran|Iran]] operating research reactors and fuel enrichment plants, since those countries refuse adequate [[IAEA]] oversight and are believed to be trying to develop nuclear weapons. [[North Korea and weapons of mass destruction|North Korea]] admits that it is developing [[nuclear weapons]], while the Iranian government vehemently denies the claims against Iran.  
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There is concern in some countries over [[North Korea]] and [[Nuclear program of Iran|Iran]] operating research reactors and fuel enrichment plants, since those countries refuse adequate [[IAEA]] oversight and are believed to be trying to develop nuclear weapons. [[North Korea and weapons of mass destruction|North Korea]] admits that it is developing [[nuclear weapons]], while the Iranian government vehemently denies such claims.  
Some proponents of nuclear power agree that the risk of nuclear proliferation may be a reason to prevent nondemocratic developing nations from gaining any nuclear technology but argue that this is no reason for democratic developed nations to abandon their nuclear power plants, especially in the light of the [[democratic peace theory]], which argues that democracies refrain from war against each other. There is, however, always the risk that information of new technologies will be stolen and made public (for example, on the Internet), making it ever easier for any country to build its own nuclear facilities. However, all power sources and technology can be used to produce and use weapons. The [[weapons of mass destruction]] used in [[chemical warfare]] and [[biological warfare]] are not dependent on nuclear power. Humans could still make war even if all technology was forbidden.
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Some proponents of nuclear power agree that the risk of nuclear proliferation may be a reason to prevent nondemocratic developing nations from gaining any nuclear technology but argue that this is no reason for democratic developed nations to abandon their nuclear power plants, especially in the light of the [[democratic peace theory]], which argues that democracies refrain from war against each other. There is, however, always the risk that information of new technologies will be stolen and made public (for example, on the internet), making it ever easier for any country to build its own nuclear facilities. However, all power sources and technology can be used to produce and use weapons. The [[weapons of mass destruction]] used in [[chemical warfare]] and [[biological warfare]] are not dependent on nuclear power. Humans could still make war even if all technology was forbidden.
  
 
Proponents also note that nuclear power, like some other power sources, provides steady energy at a consistent price without competing for energy resources from other countries, something that may contribute to wars.
 
Proponents also note that nuclear power, like some other power sources, provides steady energy at a consistent price without competing for energy resources from other countries, something that may contribute to wars.
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===Concerns about floating nuclear plants===
 
===Concerns about floating nuclear plants===
  
Russia has begun building the world’s first [[Russian floating nuclear power station|floating nuclear power plant]]. The £100 million vessel, the ''Lomonosov'', to be completed in 2010, is the first of seven plants that Moscow says will bring vital energy resources to remote Russian regions. While producing only a small fraction of the power of a standard Russian land-based plant, it can supply power to a city of 200,000, or function as a [[desalination]] plant. The Russian atomic energy agency said that at least 12 countries were also interested in buying floating nuclear plants. <ref name="Chernobyl">[http://www.timesonline.co.uk/tol/news/world/europe/article1662889.ece Floating nuclear power stations raise specter of Chernobyl at sea]. Retrieved July 21, 2007. </ref>
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Russia has begun building the world’s first [[Russian floating nuclear power station|floating nuclear power plant]]. The £100 million vessel, the ''Lomonosov,'' to be completed in 2010, is the first of seven plants that Moscow says will bring vital energy resources to remote Russian regions. While producing only a small fraction of the power of a standard Russian land-based plant, it can supply power to a city of 200,000, or function as a [[desalination]] plant. The Russian atomic energy agency said that at least 12 countries were also interested in buying floating nuclear plants. <ref>Times Onlines, [http://www.timesonline.co.uk/tol/news/world/europe/article1662889.ece Floating nuclear power stations raise specter of Chernobyl at sea.] Retrieved July 21, 2007. </ref>
  
Environmental groups and nuclear experts are concerned that floating nuclear plants will be more vulnerable to accidents and terrorism than land-based stations. They point to a history of naval and nuclear accidents in Russia and the former Soviet Union, including the [[Chernobyl disaster]] of 1986.<ref name="Chernobyl" /> Russia does have 50 years of experience operating a fleet of [[nuclear powered icebreaker]]s that are also used for scientific and Arctic tourism expeditions. The Russians have commented that a [[list of sunken nuclear submarines|nuclear reactor that sinks]], such as the similar reactor involved in the ''[[Russian submarine Kursk explosion|Kursk]]'' explosion, can be raised and probably put back into operation.<ref name="Chernobyl" /> At this time it is not known what, if any, [[containment building|containment structure]] or associated missile shield will be built on the ship. The Russians believe that an airliner striking the ship would not destroy the reactor.
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Environmental groups and nuclear experts are concerned that floating nuclear plants will be more vulnerable to accidents and terrorism than land-based stations. They point to a history of naval and nuclear accidents in Russia and the former Soviet Union, including the [[Chernobyl disaster]] of 1986. Russia does have 50 years of experience operating a fleet of [[nuclear powered icebreaker]]s that are also used for scientific and Arctic tourism expeditions. The Russians have commented that a [[list of sunken nuclear submarines|nuclear reactor that sinks]], such as the similar reactor involved in the ''[[Russian submarine Kursk explosion|Kursk]]'' explosion, can be raised and probably put back into operation. At this time it is not known what, if any, [[containment building|containment structure]] or associated missile shield will be built on the ship. The Russians believe that an airliner striking the ship would not destroy the reactor.
  
 
== Environmental effects ==
 
== Environmental effects ==
 
=== Air pollution ===
 
=== Air pollution ===
{{Further|[[Environmental concerns with electricity generation]]}}
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Nuclear generation does not directly produce sulfur dioxide, nitrogen oxides, mercury, or other pollutants associated with the combustion of fossil fuels (pollution from fossil fuels is blamed for many deaths each year in the U.S. alone). It also does not directly produce [[carbon dioxide]], which has led some environmentalists to advocate increased reliance on nuclear energy as a means to reduce [[greenhouse gas]] emissions (which contribute to [[global warming]]). Non-radioactive water vapor is the significant operating emission from nuclear power plants.<ref>The Virtual Nuclear Tourist, [http://www.nucleartourist.com/basics/environ1.htm Environmental Effects of Nuclear Power.] Retrieved July 20, 2007.</ref>  
Nuclear generation does not directly produce sulfur dioxide, nitrogen oxides, mercury or other pollutants associated with the combustion of fossil fuels (pollution from fossil fuels is blamed for many deaths each year in the U.S. alone<ref name="dirty" />). It also does not directly produce [[carbon dioxide]], which has led some environmentalists to advocate increased reliance on nuclear energy as a means to reduce [[greenhouse gas]] emissions (which contribute to [[global warming]]). Non-radioactive water vapor is the significant operating emission from nuclear power plants.<ref name="nt-eeonp">[http://www.nucleartourist.com/basics/environ1.htm Environmental Effects of Nuclear Power] The Virtual Nuclear Tourist. Retrieved July 20, 2007.</ref>  
 
  
According to a 2007 story broadcast on [[60 Minutes]],<ref>[http://www.cbsnews.com/stories/2007/04/06/60minutes/main2655782.shtml France: Vive Les Nukes] Retrieved July 20, 2007. </ref> nuclear power gives France the cleanest air of any industrialized country, and the cheapest electricity in all of Europe.
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According to a 2007 story broadcast on [[60 Minutes]],<ref>CBS, [http://www.cbsnews.com/stories/2007/04/06/60minutes/main2655782.shtml France: Vive Les Nukes.] Retrieved July 20, 2007.</ref> nuclear power gives France the cleanest air of any industrialized country, and the cheapest electricity in all of Europe.
  
 
Like any power source (including renewables like wind and solar energy), the facilities to produce and distribute the electricity require energy to build and subsequently decommission. Mineral ores must be collected and processed to produce nuclear fuel. These processes are either directly powered by diesel and gasoline engines, or draw electricity from the power grid, which may be generated from fossil fuels. [[Life cycle analysis|Life cycle analyses]] assess the amount of energy consumed by these processes (given today's mix of energy resources) and calculate, over the lifetime of a nuclear power plant, the amount of carbon dioxide saved (related to the amount of electricity produced by the plant) vs. the amount of carbon dioxide used (related to construction and fuel acquisition).
 
Like any power source (including renewables like wind and solar energy), the facilities to produce and distribute the electricity require energy to build and subsequently decommission. Mineral ores must be collected and processed to produce nuclear fuel. These processes are either directly powered by diesel and gasoline engines, or draw electricity from the power grid, which may be generated from fossil fuels. [[Life cycle analysis|Life cycle analyses]] assess the amount of energy consumed by these processes (given today's mix of energy resources) and calculate, over the lifetime of a nuclear power plant, the amount of carbon dioxide saved (related to the amount of electricity produced by the plant) vs. the amount of carbon dioxide used (related to construction and fuel acquisition).
  
 
In a study conducted in 2006 by the UK's Parliamentary Office of Science and Technology (POST), nuclear power's lifecycle was evaluated to emit the least amount of carbon dioxide (very close to wind power's lifecycle emissions) when compared to the other alternatives (fossil oil, coal, and some renewable energy including biomass and PV solar panels).
 
In a study conducted in 2006 by the UK's Parliamentary Office of Science and Technology (POST), nuclear power's lifecycle was evaluated to emit the least amount of carbon dioxide (very close to wind power's lifecycle emissions) when compared to the other alternatives (fossil oil, coal, and some renewable energy including biomass and PV solar panels).
<ref name="POST">[http://www.parliament.uk/documents/upload/postpn268.pdf Carbon Footprint of Electricity Generation] Parliamentary Office of Science and Technology. Retrieved July 20, 2007.</ref> In 2006, a UK government advisory panel, The Sustainable Development Commission, concluded that if the UK's existing nuclear capacity were doubled, it would provide an 8% decrease in total UK CO<sub>2</sub> emissions by 2035. This can be compared to the country's goal to reduce greenhouse gas emissions by 60&nbsp;% by 2050. As of 2006, the UK government was to publish its official findings later in the year.<ref name="bbc-nqffnp">[http://news.bbc.co.uk/1/hi/sci/tech/4778344.stm 'No Quick Fix' From Nuclear Power] BBC News. Retrieved July 20, 2007.</ref><ref>[http://www.sd-commission.org.uk/pages/060306.html|title=Is nuclear the answer?] Sustainable Development Commission. Retrieved July 20, 2007. </ref> On 21 September 2005 the Oxford Research Group published a report, in the form of a memorandum to a committee of the [[British House of Commons]], which argued that, while nuclear plants do not generate [[carbon dioxide]] while they operate, the other steps necessary to produce nuclear power, including the mining of [[uranium]] and the storing of waste, result in substantial amounts of carbon dioxide pollution.
+
<ref>Parliamentary Office of Science and Technology, [http://www.parliament.uk/documents/upload/postpn268.pdf Carbon Footprint of Electricity Generation.] Retrieved July 20, 2007.</ref> In 2006, a UK government advisory panel, The Sustainable Development Commission, concluded that if the UK's existing nuclear capacity were doubled, it would provide an 8 percent decrease in total UK CO<sub>2</sub> emissions by 2035. This can be compared to the country's goal to reduce greenhouse gas emissions by 60 percent by 2050. On September 21, 2005, the Oxford Research Group published a report, in the form of a memorandum to a committee of the [[British House of Commons]], which argued that, while nuclear plants do not generate [[carbon dioxide]] while they operate, the other steps necessary to produce nuclear power, including the mining of [[uranium]] and the storing of waste, result in substantial amounts of carbon dioxide pollution.
  
According to one life cycle study from 2001–2005, carbon dioxide emissions from nuclear power per kilowatt hour could range from 20% to 120% of those for [[natural gas]]-fired power stations depending on the availability of high grade ores.<ref name="stormsmith">Willem Storm van Leeuwen, Jan and Smith, Philip [http://www.stormsmith.nl/ Nuclear Power — The Energy Balance]. Retrieved July 20, 2007.</ref> The study was strongly criticized by the [[World Nuclear Association]] (WNA), rebutted in 2003, then dismissed by the WNA in 2006 based on its own life-cycle-energy calculation (with comparisons). The WNA also listed several other independent life cycle analyses which show similar emissions per [[watt-hour|kilowatt-hour]] from nuclear power and from renewables such as wind power.<ref>[http://www.world-nuclear.org/info/inf100.html Energy Balances and CO2 Implications] Retrieved July 20, 2007.</ref><ref> [http://www.world-nuclear.org/info/inf11.html Energy Analysis of Power Systems] Retrieved July 20, 2007. </ref>
+
According to one life cycle study from 2001–2005, carbon dioxide emissions from nuclear power per kilowatt hour could range from 20 percent to 120 percent of those for [[natural gas]]-fired power stations depending on the availability of high grade ores.<ref>Jan Willem Storm van Leeuwen, and Philip Smith, [http://www.stormsmith.nl/ Nuclear Power—The Energy Balance]. Retrieved July 20, 2007.</ref> The study was strongly criticized by the [[World Nuclear Association]] (WNA), rebutted in 2003, then dismissed by the WNA in 2006, based on its own life-cycle-energy calculation (with comparisons). The WNA also listed several other independent life cycle analyses which show similar emissions per [[watt-hour|kilowatt-hour]] from nuclear power and from renewables such as wind power.<ref>World Nuclear Association, [http://www.world-nuclear.org/info/inf100.html Energy Balances and CO2 Implications.] Retrieved July 20, 2007.</ref>
  
==See also==
 
  
*[[Electricity]]
 
* [[Geothermal power]]
 
* [[Hydroelectricity]]
 
*[[Nuclear physics]]
 
*[[Nuclear reaction]]
 
* [[Plutonium]]
 
* [[Radioactivity]]
 
*[[Renewable energy]]
 
* [[Uranium]]
 
  
 
== Notes ==
 
== Notes ==
Line 243: Line 219:
  
 
==References==
 
==References==
 
+
* ALSOS. 2007. [http://alsos.wlu.edu/default.aspx Nuclear power information archives from ALSOS, the National Digital Science Library at Washington & Lee University.] ''Alsos Digital Library for Nuclear Issues''. Retrieved on July 20, 2007.
 +
* Bodansky, David. 2004. ''Nuclear Energy: Principles, Practices, and Prospects''. 2nd ed. New York: Springer. ISBN 0387207783
 +
* Cohen, Bernard L. 1990. [http://www.phyast.pitt.edu/~blc/book/BOOK.html The Nuclear Energy Option, online book by Bernard L. Cohen. Pro nuclear power. Emphasis on risk estimates of nuclear.] ''The Nuclear Energy Option''. Retrieved on July 20, 2007.
 +
* Kaku, Michio. 1989. ''Nuclear Power: Both Sides.'' New York: W. W. Norton & Company. ISBN 0393301281
 
* Kennesaw State University. 2005. [http://www.chemcases.com/2003version/nuclear/nc-10.htm An entry to nuclear power through an educational discussion of reactors.] ''Nuclear Chemistry - Nuclear Reactors''. Retrieved on July 20, 2007.
 
* Kennesaw State University. 2005. [http://www.chemcases.com/2003version/nuclear/nc-10.htm An entry to nuclear power through an educational discussion of reactors.] ''Nuclear Chemistry - Nuclear Reactors''. Retrieved on July 20, 2007.
* Cohen, Bernard L. 1990. [http://www.phyast.pitt.edu/~blc/book/BOOK.html The Nuclear Energy Option, online book by Bernard L. Cohen. Pro nuclear power. Emphasis on risk estimates of nuclear.] ''The Nuclear Energy Option''. Retrieved on July 20, 2007.
+
* Murray, Raymond. 2001. ''Nuclear Energy: An Introduction to the Concepts, Systems, and Applications of Nuclear Processes.'' 5th ed. Oxford: Butterworth-Heinemann. ISBN 075067136X
* Thomas, Steve. 2005. [http://www.psiru.org/reports/2005-09-E-Nuclear.pdf "The Economics of Nuclear Power: analysis of recent studies", PSIRU, University of Greenwich, UK.] '' The Nuclear Energy Option''. Retrieved on July 20, 2007.
+
* Thomas, Steve. 2005. [http://www.psiru.org/reports/2005-09-E-Nuclear.pdf "The Economics of Nuclear Power: analysis of recent studies," PSIRU, University of Greenwich, UK.] '' The Nuclear Energy Option''. Retrieved on July 20, 2007.
* Alsos. 2007. [http://alsos.wlu.edu/default.aspx Nuclear power information archives from ALSOS, the National Digital Science Library at Washington & Lee University.] ''Alsos Digital Library for Nuclear Issues''. Retrieved on July 20, 2007.
 
* Bodansky, David. 2004. ''Nuclear Energy: Principles, Practices, and Prospects''. 2nd ed. New York, NY: Springer. ISBN 0387207783.
 
* Kaku, Michio. 1989. ''Nuclear Power: Both Sides''. New York, NY: W. W. Norton & Company. ISBN 0393301281.
 
* Murray, Raymond. 2001. ''Nuclear Energy: An Introduction to the Concepts, Systems, and Applications of Nuclear Processes''. 5th ed. Oxford, UK: Butterworth-Heinemann. ISBN 075067136X.
 
  
 
==External links==
 
==External links==
 
* [http://www.iaea.org/ The International Atomic Energy Agency.] Retrieved on July 20, 2007.
 
* [http://www.iaea.org/ The International Atomic Energy Agency.] Retrieved on July 20, 2007.
 
* [http://eia.doe.gov Energy Information Administration] provides lots of statistics and information. Retrieved on July 20, 2007.
 
* [http://eia.doe.gov Energy Information Administration] provides lots of statistics and information. Retrieved on July 20, 2007.
* [http://www.insc.anl.gov/pwrmaps/ Argonne National Laboratory — Maps of Nuclear Power Reactors.] Retrieved on July 20, 2007.
+
* [http://www.insc.anl.gov/pwrmaps/ Argonne National Laboratory—Maps of Nuclear Power Reactors.] Retrieved on July 20, 2007.
 
* [[http://usinfo.state.gov/usa/infousa/tech/energy/nuclear.pdf Congressional Research Service report on Nuclear Energy Policy.] Retrieved on July 20, 2007.
 
* [[http://usinfo.state.gov/usa/infousa/tech/energy/nuclear.pdf Congressional Research Service report on Nuclear Energy Policy.] Retrieved on July 20, 2007.
* [http://www.newscientist.com/channel/mech-tech/nuclear New Scientist — Nuclear Power Articles.] Retrieved on July 20, 2007.
+
* [http://www.newscientist.com/channel/mech-tech/nuclear New Scientist—Nuclear Power Articles.] Retrieved on July 20, 2007.
 
* [http://nuclearinfo.net Nuclear Power Education.] Retrieved on July 20, 2007.
 
* [http://nuclearinfo.net Nuclear Power Education.] Retrieved on July 20, 2007.
* [http://www.wilsoncenter.org/index.cfm?fuseaction=wq.essay&essay_id=203041 Wilson Quarterly — Nuclear Power: Both Sides.] Retrieved on July 20, 2007.
+
* [http://www.wilsoncenter.org/index.cfm?fuseaction=wq.essay&essay_id=203041 Wilson Quarterly—Nuclear Power: Both Sides.] Retrieved on July 20, 2007.
 
* [http://energyscience.org.au/ Briefing Papers from the Australian EnergyScience Coaltion.] Retrieved on July 20, 2007.
 
* [http://energyscience.org.au/ Briefing Papers from the Australian EnergyScience Coaltion.] Retrieved on July 20, 2007.
 
* [http://www.world-nuclear-news.com Nuclear News from around the world.] Retrieved on July 20, 2007.
 
* [http://www.world-nuclear-news.com Nuclear News from around the world.] Retrieved on July 20, 2007.

Revision as of 15:31, 5 July 2008

A nuclear power station. The nuclear reactor is contained inside the cylindrical containment buildings to the right—left is a cooling tower venting non-radioactive water vapor.

Nuclear power is a type of nuclear technology involving the controlled use of nuclear reactions to release energy for work, including propulsion, heat, and the generation of electricity. Nuclear energy is produced by a controlled nuclear chain reaction and creates heat—which is used to boil water, produce steam, and drive a steam turbine. The turbine can be used for mechanical work and also to generate electricity.

The use of nuclear power has also engendered much debate. Critics claim that nuclear power is a potentially dangerous energy source with a limited fuel supply (compared to renewable energy), and they note the problems of storing radioactive waste, the potential for radioactive contamination by accident or sabotage, and the possibility of nuclear proliferation. Advocates claim that these risks are small and can be further reduced by the technology in new reactors, and the safety record is good when compared to other major types of power plants. In addition, they note that many renewable energy technologies have not solved the problem of their intermittent power production.

Use

Historical and projected world energy use by energy source, 1980-2030, Source: International Energy Outlook 2007, EIA.
File:Nuclear power stations.png
The status of nuclear power globally. Nations in dark green have reactors and are constructing new reactors, those in light green are constructing their first reactor, those in dark yellow are considering new reactors, those in light yellow are considering their first reactor, those in blue have reactors but are not constructing or decommissioning, those in light blue are considering decommissioning and those in red have decommissioned all their commercial reactors.


As of 2004, nuclear power provided 6.5 percent of the world's energy and 15.7 percent of the world's electricity, with the U.S., France, and Japan together accounting for 57 percent of all nuclear generated electricity.[1] As of 2007, the IAEA reported there are 435 nuclear power reactors in operation in the world,[2] operating in 31 different countries.[3] These provide about 17 percent of the world's electricity.[4]

The United States produces the most nuclear energy, with nuclear power providing 20 percent of the electricity it consumes, while France produces the highest percentage of its electrical energy from nuclear reactors—80 percent as of 2006.[5] In the European Union as a whole, nuclear energy provides 30 percent of the electricity.[6] Nuclear energy policy differs between European Union countries, and some, such as Austria and Ireland, have no active nuclear power stations. In comparison, France has a large number of these plants, with 16 currently in use throughout the country.

Many military and some civilian (such as some icebreakers) ships use nuclear marine propulsion, a form of nuclear propulsion.

International research is ongoing into different safety improvements such as passively safe plants, the use of nuclear fusion, and additional uses of produced heat such as the hydrogen production (in support of a hydrogen economy), for desalinating sea water, and for use in district heating systems.

History

Origins

The first successful experiment with nuclear fission was conducted in 1938, in Berlin, by the German physicists Otto Hahn, Lise Meitner, and Fritz Strassmann.

The first man-made reactor, Chicago Pile-1, achieved criticality on December 2, 1942, as part of the Manhattan Project.

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 kW. The Arco Reactor was also the first to partially melt down (in 1955).

In 1952, a report by the Paley Commission (The President's Materials Policy Commission) for President Harry Truman made a "relatively pessimistic" assessment of nuclear power, and called for "aggressive research in the whole field of solar energy."[7] A December 1953 speech by President Dwight Eisenhower, "Atoms for Peace," set the U.S. on a course of strong government support for the international use of nuclear power.

Early years

The Shippingport Atomic Power Station in Shippingport, Pennsylvania was the first commercial reactor in the USA and was opened in 1957.

In 1954, Lewis Strauss, then chairman of the United States Atomic Energy Commission (forerunner of the U.S. Nuclear Regulatory Commission) famously spoke of electricity in the future being "too cheap to meter." [8] While few doubt he was thinking of atomic energy when he made the statement, he may have been referring to hydrogen fusion, rather than uranium fission. Actually, the consensus of government and business at the time was that nuclear (fission) power might eventually become merely economically competitive with conventional power sources.

On June 27 1954, the world's first nuclear power plant to generate electricity for a power grid started operations at Obninsk, USSR. The reactor produced 5 megawatts (electrical), enough to power 2,000 homes.[9] In 1955 the United Nations' "First Geneva Conference," then the world's largest gathering of scientists and engineers, met to explore the technology. In 1957, EURATOM was launched alongside the European Economic Community (the latter is now the European Union). The same year also saw the launch of the International Atomic Energy Agency (IAEA).

The world's first commercial nuclear power station, Calder Hall in Sellafield, England was opened in 1956, with an initial capacity of 50 MW (later 200 MW).[10] The Shippingport Reactor (Pennsylvania, 1957) was the first commercial nuclear generator to become operational in the United States.

One of the first organizations to develop utilitarian nuclear power was the U.S. Navy, for the purpose of propelling submarines and aircraft carriers. It has a good record in nuclear safety, perhaps because of the stringent demands of Admiral Hyman G. Rickover, who was the driving force behind nuclear marine propulsion. The U.S. Navy has operated more nuclear reactors than any other entity, including the Soviet Navy, with no publicly known major incidents. The first nuclear-powered submarine, USS Nautilus (SSN-571), put to sea in 1955. Two U.S. nuclear submarines, USS Scorpion and Thresher, have been lost at sea, though for reasons not related to their reactors, and their wrecks are situated such that the risk of nuclear pollution is considered low.

Enrico Fermi and Leó Szilárd, in 1955, shared U.S. Patent 2708656 (PDF) for the nuclear reactor.

Development

Nuclear power plant.

The 1973 oil crisis had a significant effect on the construction of nuclear power plants worldwide. The oil embargo led to a global economic recession, energy conservation, and high inflation that both reduced the projected demand for new electric generation capacity in the United States and made financing such capital intensive projects difficult. This contributed to the cancellation of over 100 reactor orders in the U.S.[11] Even so, the plants already under construction effectively displaced oil for the generation of electricity. In 1973, oil generated 17 percent of the electricity in the United States. Today, oil is a minor source of electric power (except in Hawaii), while nuclear power now generates 20 percent of the country's electricity. The oil crisis caused other countries, such as France and Japan, which had relied even more heavily on oil for electric generation (39 percent and 73 percent respectively) to invest heavily in nuclear power.[12] Today, nuclear power supplies about 80 percent and 30 percent of the electricity in those countries, respectively.

Installed nuclear capacity initially rose relatively quickly, rising from less than 1 gigawatt (GW) in 1960, to 100 GW in the late 1970s, and 300 GW in the late 1980s. Since the late 1980s capacity has risen much more slowly, reaching 366 GW in 2005, primarily due to Chinese expansion of nuclear power. Between around 1970 and 1990, more than 50 GW of capacity was under construction (peaking at over 150 GW in the late 70s and early 80s)—in 2005, around 25 GW of new capacity was planned. More than two-thirds of all nuclear plants ordered after January 1970 were eventually canceled.[13]

Washington Public Power Supply System Nuclear Power Plants 3 and 5 were never completed

During the 1970s and 1980s rising economic costs (related to vastly extended construction times largely due to regulatory changes and pressure-group litigation) and falling fossil fuel prices made nuclear power plants then under construction less attractive. In the 1980s (U.S.) and 1990s (Europe), flat load growth and electricity liberalization also made the addition of large new baseload capacity unattractive.

A general movement against nuclear power arose during the last third of the twentieth century, based on the fear of a possible nuclear accident and on fears of radiation, as well as in opposition to nuclear waste production, transport, and final storage. Perceived risks on the citizens' health and safety, the 1979 accident at Three Mile Island, and the 1986 Chernobyl disaster played a part in stopping new plant construction in many countries. However, in the U.S. new construction dropped sharply before the Three Mile Island accident, after the 1973 oil crises.[14] and the Brookings Institution suggests that new nuclear units have not been ordered in the U.S. primarily for economic reasons rather than fears of accidents.[15]

Unlike the Three Mile Island accident, the much more serious Chernobyl accident did not increase regulations affecting Western reactors, since the Chernobyl reactors were of the problematic RBMK design only used in the Soviet Union, lacking, for example, containment buildings.[16] An international organization to promote safety awareness and professional development on operators in nuclear facilities was created: WANO; World Association of Nuclear Operators.

Austria (1978), Sweden (1980), and Italy (1987) (influenced by Chernobyl) voted in referendums to oppose or phase out nuclear power, while opposition in Ireland prevented a nuclear program there.

The future of the industry

As of March 1, 2007, Watts Bar 1, which came on-line in 1997, was the last U.S. commercial nuclear reactor to go on-line. This is often quoted as evidence of a successful worldwide campaign for nuclear power phase-out. However, political resistance to nuclear power has only ever been successful in parts of Europe, in New Zealand, in the Philippines, and in the United States. Even in the U.S. and throughout Europe, investment in research and in the nuclear fuel cycle has continued, and some experts predict that electricity shortages, fossil fuel price increases, global warming from fossil fuel use, new technology such as passively safe plants, and national energy security will renew the demand for nuclear power plants.

Many countries remain active in developing nuclear power, including Japan, China, and India, all actively developing both fast and thermal technology, South Korea and the United States, developing thermal technology only, and South Africa and China, developing versions of the Pebble Bed Modular Reactor (PBMR). Finland and France actively pursue nuclear programs; Finland has a new European Pressurized Reactor under construction by Areva. Japan has an active nuclear construction program with new units brought on-line in 2005. In the U.S., three consortia responded in 2004 to the U.S. Department of Energy's solicitation under the Nuclear Power 2010 Program and were awarded matching funds—the Energy Policy Act of 2005 authorized subsidies for up to six new reactors, and authorized the Department of Energy to build a reactor based on the Generation IV Very-High-Temperature Reactor concept to produce both electricity and hydrogen. As of the early twenty first century, nuclear power is of particular interest to both China and India to serve their rapidly growing economies—both are developing fast breeder reactors. See also future energy development. In the energy policy of the United Kingdom, it is recognized that there is a likely future energy supply shortfall, which may have to be filled by either new nuclear plant construction or maintaining existing plants beyond their programmed lifetime.

On September 22, 2005, it was announced that two sites in the U.S. had been selected to receive new power reactors (exclusive of the new power reactor scheduled for INL).

Nuclear reactor technology

Conventional thermal power plants all have a fuel source to provide heat. Examples are gas, coal, or oil. For a nuclear power plant, this heat is provided by nuclear fission inside the nuclear reactor. When a relatively large fissile atomic nucleus (usually uranium-235 or plutonium-239) is struck by a neutron, it forms two or more smaller nuclei as fission products, releasing energy and neutrons in a process called nuclear fission. The neutrons then trigger further fission. And so on. When this nuclear chain reaction is controlled, the energy released can be used to heat water, produce steam, and drive a turbine that generates electricity. It should be noted that a nuclear explosive involves an uncontrolled chain reaction, and the rate of fission in a reactor is not capable of reaching sufficient levels to trigger a nuclear explosion because commercial reactor grade nuclear fuel is not enriched to a high enough level.

The chain reaction is controlled through the use of materials that absorb and moderate neutrons. In uranium-fueled reactors, neutrons must be moderated (slowed down) because slow neutrons are more likely to cause fission when colliding with a uranium-235 nucleus. Light water reactors use ordinary water to moderate and cool the reactors. When at operating temperatures if the temperature of the water increases, its density drops, and fewer neutrons passing through it are slowed enough to trigger further reactions. That negative feedback stabilizes the reaction rate.

A number of other designs for nuclear power generation, the Generation IV reactors, are the subject of active research and may be used for practical power generation in the future. A number of the advanced nuclear reactor designs could also make critical fission reactors much cleaner, much safer, and/or much less of a risk to the proliferation of nuclear weapons.

Controlled nuclear fusion could in principle be used in fusion power plants to produce power without the complexities of handling actinides, but significant scientific and technical obstacles remain. Several fusion reactors have been built, but as yet none has "produced" more thermal energy than electrical energy consumed. Despite research having started in the 1950s, no commercial fusion reactor is expected before 2050. The ITER project is currently leading the effort to commercialize fusion power.

Safety

The topic of nuclear safety covers:

  • The research and testing of the possible incidents/events at a nuclear power plant.
  • What equipment and actions are designed to prevent those incidents/events from having serious consequences.
  • The calculation of the probabilities of multiple systems and/or actions failing thus allowing serious consequences.
  • The evaluation of the worst-possible timing and scope of those serious consequences (the worst-possible in extreme cases being a release of radiation).
  • The actions taken to protect the public during a release of radiation.
  • The training and rehearsals performed to ensure readiness in case an incident/event occurs.

Economics

Nuclear economics has become increasingly controversial, since multi-billion dollar investments ride on the choice of an energy source. Which power source (generally coal, natural gas, nuclear, or wind) is most cost-effective depends on given assumptions used in a particular study.

Life cycle

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 usage in the power plant, the spent fuel is delivered to a reprocessing plant (2) or to a final repository (3) for geological disposition. In reprocessing 95% of spent fuel can be recycled to be returned to usage in a power plant (4).
Nuclear fuel—a compact, inert, insoluble solid.


A nuclear reactor is only part of the life-cycle for nuclear power. The process starts with mining. Generally, uranium mines are either open-pit strip mines, or in-situ leach mines. In either case, the uranium ore is extracted, usually converted into a stable and compact form, such as yellowcake, and then transported to a processing facility. Here, the yellowcake is converted to uranium hexafluoride, which is then enriched using various techniques. At this point, the enriched uranium, containing more than the natural 0.7 percent U-235, is used to make rods of the proper composition and geometry for the particular reactor that the fuel is destined for. The fuel rods will spend about 3 years inside the reactor, generally, until about 3 percent of their uranium has been fissioned, then they will be moved to a spent fuel pool, where the short lived isotopes generated by fission can decay away. After about 5 years in a cooling pond, the spent fuel is radioactively cool enough to handle, and it can be moved to dry storage casks or reprocessed.

Fuel resources

Uranium is a common element, approximately as common as tin or zinc, and it is a constituent of most rocks, as well as of the sea. The world's present measured resources of uranium, economically recoverable at a price of 130 $/kg, are enough to last for some 70 years at current consumption. This represents a higher level of assured resources than is normal for most minerals. On the basis of analogies with other metal minerals, a doubling of price from present levels could be expected to create about a tenfold increase in measured resources, over time. The fuel's contribution to the overall cost of the electricity produced is relatively small, so even a large fuel price escalation will have relatively little effect on final price. For instance, typically a doubling of the uranium market price would increase the fuel cost for a light water reactor by 26 percent and the electricity cost about 7 percent (whereas doubling the gas price would typically add 70 percent to the price of electricity from that source). At higher prices, eventually extraction from sources such as granite and seawater become economically feasible.[17] Current light water reactors make relatively inefficient use of nuclear fuel, leading to energy waste. But nuclear reprocessing makes this waste reusable (except in the U.S., where this is not allowed) and more efficient reactor designs would allow better use of the available resources (and reduce the amount of waste material).[18]

As opposed to current light water reactors which use uranium-235 (0.7 percent of all natural uranium), fast breeder reactors use uranium-238 (99.3 percent of all natural uranium). It has been estimated that there is up to five-billion years’ (also the estimated remaining life of the Sun) worth of uranium-238 for use in these power plants.[19] Breeder technology has been used in several reactors, but requires higher uranium prices before becoming justified economically.[20] As of December 2005, the only breeder reactor producing power is BN-600 in Beloyarsk, Russia. (The electricity output of BN-600 is 600 MW——ussia has planned to build another unit, BN-800, at Beloyarsk nuclear power plant.) Also, Japan's Monju reactor is planned for restart (having been shut down since 1995), and both China and India intend to build breeder reactors.

Another alternative would be to use uranium-233 bred from thorium as fission fuel—the thorium fuel cycle. Thorium is three times more abundant in the Earth's crust than uranium, and (theoretically) all of it can be used for breeding, making the potential thorium resource orders of magnitude larger than the uranium fuel cycle operated without breeding.[21] Unlike the breeding of U-238 into plutonium, fast breeder reactors are not necessary—it can be performed satisfactorily in more conventional plants.

Fusion power commonly proposes the use of deuterium, an isotope of hydrogen, as fuel and in many current designs also lithium. Assuming a fusion energy output equal to the current global output and that this does not increase in the future, then the known current lithium reserves would last 3000 years, lithium from sea water would last 60 million years, and a more complicated fusion process using only deuterium from sea water would have fuel for 150 billion years.[22]

Depleted uranium

Uranium enrichment produces many tons of depleted uranium (DU) which consists of U-238, with most of the easily fissile U-235 isotope removed. U-238 is a tough metal with several commercial uses—for example, aircraft production, radiation shielding, and making bullets and armor—as it has a higher density than lead. There are concerns that U-238 may lead to health problems in groups exposed to this material excessively, like tank crews and civilians living in areas where large quantities of DU ammunition have been used.

Solid waste

The safe storage and disposal of nuclear waste is a significant challenge. The most important waste stream from nuclear power plants is spent fuel. A large nuclear reactor produces 3 cubic meters (25-30 metric tons) of spent fuel each year.[23] It is primarily composed of unconverted uranium as well as significant quantities of transuranic actinides (plutonium and curium, mostly). In addition, about 3 percent of it is made of fission products. The actinides (uranium, plutonium, and curium) are responsible for the bulk of the long term radioactivity, whereas the fission products are responsible for the bulk of the short term radioactivity.

Spent fuel is highly radioactive and needs to be handled with great care and forethought. However, spent nuclear fuel becomes less radioactive over time. After 40 years, the radiation flux is 99.9 percent lower than it was the moment the spent fuel was removed, although still dangerously radioactive.

Spent fuel rods are stored in shielded basins of water (spent fuel pools), usually located on-site. The water provides both cooling for the still-decaying uranium, and shielding from the continuing radioactivity. After a few decades some on-site storage involves moving the now cooler, less radioactive fuel to a dry-storage facility or dry cask storage, where the fuel is stored in steel and concrete containers until its radioactivity decreases naturally ("decays") to levels safe enough for other processing. This interim stage spans years or decades, depending on the type of fuel. Most U.S. waste is currently stored in temporary storage sites requiring oversight, while suitable permanent disposal methods are discussed.

As of 2003, the United States had accumulated about 49,000 metric tons of spent nuclear fuel from nuclear reactors. Underground storage at Yucca Mountain in the U.S. has been proposed as permanent storage. After 10,000 years of radioactive decay, according to United States Environmental Protection Agency standards, the spent nuclear fuel will no longer pose a threat to public health and safety.

The amount of waste can be reduced in several ways, particularly reprocessing. Even so, the remaining waste will be substantially radioactive for at least 300 years even if the actinides are removed, and for up to thousands of years if the actinides are left in. Even with separation of all actinides, and using fast breeder reactors to destroy by transmutation some of the longer-lived non-actinides as well, the waste must be segregated from the environment for one to a few hundred years, and therefore this is properly categorized as a long-term problem. Subcritical reactors or fusion reactors could also reduce the time the waste has to be stored. It has been argued that the best solution for the nuclear waste is above ground temporary storage since technology is rapidly changing. The current waste may well become a valuable resource in the future.

The nuclear industry also produces a volume of low-level radioactive waste 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. In the United States, the Nuclear Regulatory Commission has repeatedly attempted to allow low-level materials to be handled as normal waste: Landfilled, recycled into consumer items, and so forth. Most low-level waste releases very low levels of radioactivity and is only considered radioactive waste because of its history. For example, according to the standards of the NRC, the radiation released by coffee is enough to treat it as low level waste.

In countries with nuclear power, radioactive wastes comprise less than 1 percent of total industrial toxic wastes, which remain hazardous indefinitely unless they decompose or are treated so that they are less toxic or, ideally, completely non-toxic. Overall, nuclear power produces far less waste material than fossil-fuel based power plants. Coal-burning plants are particularly noted for producing large amounts of toxic and mildly radioactive ash due to concentrating naturally occurring metals and radioactive material from the coal. Contrary to popular belief, coal power actually results in more radioactive waste being released into the environment than nuclear power [24].

Reprocessing

Reprocessing can potentially recover up to 95 percent of the remaining uranium and plutonium in spent nuclear fuel, putting it into new mixed oxide fuel. This would produce a reduction in long term radioactivity within the remaining waste, since this is largely short-lived fission products, and reduces its volume by over 90 percent. Reprocessing of civilian fuel from power reactors is currently done on a large scale in Britain, France and (formerly) Russia, will be done in China and perhaps India, and is being done on an expanding scale in Japan. The potential of reprocessing has not been achieved because it requires breeder reactors, which are not yet commercially available. France is generally cited as the most successful reprocessor, but it presently only recycles 28 percent (by weight) of the yearly fuel use, 7 percent within France and another 21 percent in Russia.[25]

Unlike other countries, the U.S. has stopped civilian reprocessing as one part of U.S. non-proliferation policy, since reprocessed material such as plutonium can be used in nuclear weapons. Spent fuel is all currently treated as waste.[26] In February 2006, a new U.S. initiative, the Global Nuclear Energy Partnership, was announced. It would be an international effort to reprocess fuel in a manner making nuclear proliferation unfeasible, while making nuclear power available to developing countries.

Concerns about nuclear power

Critics, including most major environmental groups, claim that nuclear power is an uneconomic and potentially dangerous energy source with a limited fuel supply, especially compared to renewable energy, and dispute whether the costs and risks can be reduced through new technology. They also point to the problem of storing radioactive waste, the potential for possibly severe radioactive contamination by accident or sabotage, and the possibility of nuclear proliferation. Proponents claim that these risks are small and can be further reduced by the technology in the new reactors. They further claim that the safety record is already good when compared to the other major kinds of power plants, that many renewables have not solved the problem with their intermittent power production, in effect limiting them to a minority share of power production, and that nuclear power is a sustainable energy source.

Accidents

The International Nuclear Event Scale (INES), developed by the International Atomic Energy Agency (IAEA), is used to communicate the severity of nuclear accidents on a scale of 0 to 7. The two most well known events are the Three Mile Island accident and the Chernobyl disaster.

The 1979 accident at Three Mile Island Unit 2 was the worst civilian nuclear accident outside the Soviet Union (INES score of 5). The reactor experienced a partial core meltdown. However, the reactor vessel and containment building were not breached and little radiation was released to the environment (well below natural background radiation levels).[27] The event resulted in fundamental changes in how plants in the West were to be maintained and operated. There were no immediate fatalities or injuries stemming from the event and, although debated by some groups, the mainstream view is that no member of the public was injured and no detectable increase in the incidence of cancer is expected.

The Chernobyl disaster in 1986 at the Chernobyl Nuclear Power Plant in the Ukrainian Soviet Socialist Republic (now Ukraine) was the worst nuclear accident in history and is the only event to receive an INES score of 7. The power excursion and resulting steam explosion and fire spread radioactive contamination across large portions of Europe. Eight workers were fatally irradiated, and the death toll among civilians may be as high as 4000. Operator error and plant design were cited as causes for the explosion.

Design changes are being pursued to lessen the risks of fission reactors; in particular, passively safe plants (such as the ESBWR) are available to be built and inherently safe designs are being pursued. Fusion reactors which may come to exist in the future theoretically have very little risk.

The World Nuclear Association provides a comparison of deaths due to major accidents among different forms of energy production. In their comparison, deaths per TWy of electricity produced are 885 for hydropower, 342 for coal, 85 for natural gas, and 8 for nuclear.[28] Not included in the study are deaths due to black lung disease or air pollution from fossil fuels.[29]

Vulnerability of plants to attack

Nuclear power plants are generally (although not always) considered "hard" targets. In the U.S., plants are surrounded by a double row of tall fences which are electronically monitored. The plant grounds are patrolled by a sizable force of armed guards.[30] The NRC's "Design Basis Threat" criteria for plants is a secret, and so what size attacking force the plants are able to protect against is unknown. However, to Scram a plant takes less than 5 seconds while unimpeded restart takes hours, severely hampering a terrorist force whose goal is to release radioactivity.

Attack from the air is a more problematic concern. The most important barrier against the release of radioactivity in the event of an aircraft strike is the containment building and its missile shield. The NRC's Chairman has said "Nuclear power plants are inherently robust structures that our studies show provide adequate protection in a hypothetical attack by an airplane. The NRC has also taken actions that require nuclear power plant operators to be able to manage large fires or explosions—no matter what has caused them." [31]

In addition, supporters point to large studies carried out by NRC and other agencies that tested the robustness of both reactor and waste fuel storage, and found that they should be able to sustain a terrorist attack comparable to the September 11 terrorist attacks in the U.S. Spent fuel is usually housed inside the plant's "protected zone"[32] or a spent nuclear fuel shipping cask; stealing it for use in a "dirty bomb" is extremely difficult. Exposure to the intense radiation would almost certainly quickly incapacitate or kill any terrorists who attempt to do so. Nuclear power plants are designed to withstand threats deemed credible at the time of licensing. However, as weapons evolve it cannot be said unequivocally that within the 60 year life of a plant it will not become vulnerable. In addition, the future status of storage sites may be in doubt. Other forms of energy production are also vulnerable to attack, such as hydroelectric dams and LNG tankers.

Use of waste byproduct as a weapon

Opponents of nuclear power express concerns that nuclear waste is not well protected, and that it could potentially be used as a terrorist weapon, as a dirty bomb, quoting a 1999 Russian incident where workers were caught trying to sell 5 grams of radioactive material on the open market,[33] or the incident in 1993, where Russian workers were caught selling 4.5 kilograms of enriched uranium.[34] The UN has since called upon world leaders to improve security in order to prevent radioactive material falling into the hands of terrorists.[35] Proponents of nuclear power argue, however, that a dirty bomb is not a very effective weapon and would cause relatively few casualties, although the psychological impact would be high.

Health effect on population near nuclear plants

A couple fishes near the Trojan Nuclear Power Plant. The reactor dome is visible on the left, and the massive cooling tower on the right.

Most of human exposure to radiation comes from natural background radiation. Most of the remaining exposure comes from medical procedures. Several large studies in the U.S., Canada, and Europe have found no evidence of any increase in cancer mortality among people living near nuclear facilities. For example, in 1990, the National Cancer Institute (NCI) of the National Institutes of Health announced that a large-scale study, which evaluated mortality from 16 types of cancer, found no increased incidence of cancer mortality for people living near 62 nuclear installations in the United States. The study showed no increase in the incidence of childhood leukemia mortality in the study of surrounding counties after start-up of the nuclear facilities. The NCI study, the broadest of its kind ever conducted, surveyed 900,000 cancer deaths in counties near nuclear facilities.

However, in Britain there are elevated childhood leukemia levels near some industrial facilities, particularly near Sellafield, where children living locally are ten times more likely to contract the cancer. The reasons for these increases, or clusters, are unclear, but one study of those near Sellafield has ruled out any contribution from nuclear sources. Apart from anything else, the levels of radiation at these sites are orders of magnitude too low to account for the excess incidences reported. One explanation is viruses or other infectious agents being introduced into a local community by the mass movement of migrant workers.[36] Likewise, small studies have been conducted in Germany and France, and have found an increased incidence of childhood leukemia near some nuclear power plants.[37] Nonetheless, the results of larger multi-site studies in these countries invalidate the hypothesis of an increased risk of leukemia related to nuclear discharge. The methodology and very small samples in the studies finding an increased incidence have been criticized.[38] Also, one study focusing on Leukemia clusters in industrial towns in England indicated a link to high-capacity electricity lines suggesting that the production or distribution of the electricity, rather than the nuclear reaction, may be a factor.

Nuclear proliferation

Nuclear proliferation is the spread of nuclear weapons and related technology to nations not recognized as "Nuclear Weapon States" by the Nuclear Nonproliferation Treaty. Opponents of civilian nuclear power point out that nuclear technology may be a dual-use technology, and some of the materials and knowledge used in a civilian nuclear program may be used to develop nuclear weapons.

Original impetus for development of nuclear power came from the military nuclear programs, including the early designs of power reactors that were developed for nuclear submarines. In many countries governmental and civilian nuclear programs are linked, at least by common research projects and through agencies such as the U.S. DOE. In the U.S., for example, the first goal of the Department of Energy is "to advance the national, economic, and energy security of the United States; to promote scientific and technological innovation in support of that mission; and to ensure the environmental cleanup of the national nuclear weapons complex."[39]

To prevent weapons proliferation, safeguards on nuclear technology were published in the Nuclear Non-Proliferation Treaty (NPT) and monitored since 1968 by the International Atomic Energy Agency (IAEA). Nations signing the treaty are required to report to the IAEA what nuclear materials they hold and their location. They agree to accept visits by IAEA auditors and inspectors to verify independently their material reports and physically inspect the nuclear materials concerned to confirm physical inventories of them in exchange for access to nuclear materials and equipment on the global market.

Several states did not sign the treaty and were able to use international nuclear technology (often procured for civilian purposes) to develop nuclear weapons (India, Pakistan, Israel, and South Africa). Of those who have signed the treaty and received shipments of nuclear paraphernalia, many states have either claimed to, or been accused of, attempting to use supposedly civilian nuclear power plants for developing weapons. Certain types of reactors may be more conducive to producing nuclear weapons materials than others, such as possible future fast breeder reactors, and a number of international disputes over proliferation have centered on the specific model of reactor being contracted for in a country suspected of nuclear weapon ambitions.

There is concern in some countries over North Korea and Iran operating research reactors and fuel enrichment plants, since those countries refuse adequate IAEA oversight and are believed to be trying to develop nuclear weapons. North Korea admits that it is developing nuclear weapons, while the Iranian government vehemently denies such claims. Some proponents of nuclear power agree that the risk of nuclear proliferation may be a reason to prevent nondemocratic developing nations from gaining any nuclear technology but argue that this is no reason for democratic developed nations to abandon their nuclear power plants, especially in the light of the democratic peace theory, which argues that democracies refrain from war against each other. There is, however, always the risk that information of new technologies will be stolen and made public (for example, on the internet), making it ever easier for any country to build its own nuclear facilities. However, all power sources and technology can be used to produce and use weapons. The weapons of mass destruction used in chemical warfare and biological warfare are not dependent on nuclear power. Humans could still make war even if all technology was forbidden.

Proponents also note that nuclear power, like some other power sources, provides steady energy at a consistent price without competing for energy resources from other countries, something that may contribute to wars.

Concerns about floating nuclear plants

Russia has begun building the world’s first floating nuclear power plant. The £100 million vessel, the Lomonosov, to be completed in 2010, is the first of seven plants that Moscow says will bring vital energy resources to remote Russian regions. While producing only a small fraction of the power of a standard Russian land-based plant, it can supply power to a city of 200,000, or function as a desalination plant. The Russian atomic energy agency said that at least 12 countries were also interested in buying floating nuclear plants. [40]

Environmental groups and nuclear experts are concerned that floating nuclear plants will be more vulnerable to accidents and terrorism than land-based stations. They point to a history of naval and nuclear accidents in Russia and the former Soviet Union, including the Chernobyl disaster of 1986. Russia does have 50 years of experience operating a fleet of nuclear powered icebreakers that are also used for scientific and Arctic tourism expeditions. The Russians have commented that a nuclear reactor that sinks, such as the similar reactor involved in the Kursk explosion, can be raised and probably put back into operation. At this time it is not known what, if any, containment structure or associated missile shield will be built on the ship. The Russians believe that an airliner striking the ship would not destroy the reactor.

Environmental effects

Air pollution

Nuclear generation does not directly produce sulfur dioxide, nitrogen oxides, mercury, or other pollutants associated with the combustion of fossil fuels (pollution from fossil fuels is blamed for many deaths each year in the U.S. alone). It also does not directly produce carbon dioxide, which has led some environmentalists to advocate increased reliance on nuclear energy as a means to reduce greenhouse gas emissions (which contribute to global warming). Non-radioactive water vapor is the significant operating emission from nuclear power plants.[41]

According to a 2007 story broadcast on 60 Minutes,[42] nuclear power gives France the cleanest air of any industrialized country, and the cheapest electricity in all of Europe.

Like any power source (including renewables like wind and solar energy), the facilities to produce and distribute the electricity require energy to build and subsequently decommission. Mineral ores must be collected and processed to produce nuclear fuel. These processes are either directly powered by diesel and gasoline engines, or draw electricity from the power grid, which may be generated from fossil fuels. Life cycle analyses assess the amount of energy consumed by these processes (given today's mix of energy resources) and calculate, over the lifetime of a nuclear power plant, the amount of carbon dioxide saved (related to the amount of electricity produced by the plant) vs. the amount of carbon dioxide used (related to construction and fuel acquisition).

In a study conducted in 2006 by the UK's Parliamentary Office of Science and Technology (POST), nuclear power's lifecycle was evaluated to emit the least amount of carbon dioxide (very close to wind power's lifecycle emissions) when compared to the other alternatives (fossil oil, coal, and some renewable energy including biomass and PV solar panels). [43] In 2006, a UK government advisory panel, The Sustainable Development Commission, concluded that if the UK's existing nuclear capacity were doubled, it would provide an 8 percent decrease in total UK CO2 emissions by 2035. This can be compared to the country's goal to reduce greenhouse gas emissions by 60 percent by 2050. On September 21, 2005, the Oxford Research Group published a report, in the form of a memorandum to a committee of the British House of Commons, which argued that, while nuclear plants do not generate carbon dioxide while they operate, the other steps necessary to produce nuclear power, including the mining of uranium and the storing of waste, result in substantial amounts of carbon dioxide pollution.

According to one life cycle study from 2001–2005, carbon dioxide emissions from nuclear power per kilowatt hour could range from 20 percent to 120 percent of those for natural gas-fired power stations depending on the availability of high grade ores.[44] The study was strongly criticized by the World Nuclear Association (WNA), rebutted in 2003, then dismissed by the WNA in 2006, based on its own life-cycle-energy calculation (with comparisons). The WNA also listed several other independent life cycle analyses which show similar emissions per kilowatt-hour from nuclear power and from renewables such as wind power.[45]


Notes

  1. International Energy Agency, Key World Energy Statistics. Retrieved July 20, 2007.
  2. IAEA, Nuclear Power Plants Information. Retrieved July 20, 2007.
  3. Australian Uranium Information Centre, World Nuclear Power Reactors 2005-06. Retrieved July 21, 2007.
  4. "The Limited Appeal of Nuclear Energy," Scientific American, July 2007.
  5. Energy Information Administration, Impacts of Energy Research and Development With Analysis of Price-Anderson Act and Hydroelectric Relicensing. Retrieved July 20, 2007.
  6. Eurostat, Gross electricity generation, by fuel used in power-stations. Retrieved July 20, 2007.
  7. Arjun Makhijani and Scott Saleska, 1996, The Nuclear Power Deception Institute for Energy and Environmental Research. Retrieved July 20, 2007.
  8. Canadian Nuclear Society, Too Cheap to Meter? Retrieved July 20, 2007.
  9. International Atomic Energy Agency, From Obninsk Beyond: Nuclear Power Conference Looks to Future. Retrieved July 20, 2007.
  10. BBC News, On This Day: 17 October. Retrieved July 20, 2007.
  11. Nuclear Power Plants in the U.S., Canceled Nuclear Units Ordered in the United States. Retrieved July 20, 2007.
  12. IEA Energy Statistics, Evolution of Electricity Generation by Fuel from 1971 to 2004. Retrieved July 20, 2007.
  13. International Atomic Energy Agency, 50 Years of Nuclear Energy. Retrieved July 20, 2007.
  14. PBS, The Rise and Fall of Nuclear Power. Retrieved July 20, 2007.
  15. The Brookings Institution, The Political Economy of Nuclear Energy in the United States. Retrieved July 20, 2007.
  16. Nuclear Regulatory Commission, Backgrounder on Chernobyl Nuclear Power Plant Accident. Retrieved July 20, 2007.
  17. World Nuclear Association, Supply of Uranium. Retrieved July 20, 2007.
  18. World Nuclear Association, Waste Management in the Nuclear Fuel Cycle. Retrieved July 20, 2007.
  19. John McCarthy, Facts From Choen and Others. Retrieved July 20, 2007.
  20. World Nuclear Association, Advanced Nuclear Power Reactors. Retrieved July 20, 2007.
  21. World Nuclear Association, Thorium. Retrieved July 20, 2007.
  22. J. Onenga and G. Van Oost, Energy for Future Centuries: Will Fusion be an Inexhaustible, Safe, and Clean energy source? Retrieved July 20, 2007.
  23. Uranium & Nuclear Power Information Centre, Radioactive Waste Management. Retrieved July 20, 2007.
  24. Alex Gabbard, Coal Combustion: Nuclear Resource or Danger. Retrieved July 20, 2007.
  25. IEEE Spectrum, Nuclear Wasteland. Retrieved July 21, 2007.
  26. World Nuclear Association, Processing of Used Nuclear Fuel for Recycle. Retrieved July 20, 2007.
  27. U.S. Nuclear Regulatory Commission, Fact Sheet on the Accident at Three Mile Island. Retrieved July 20, 2007.
  28. World Nuclear Association, Safety of Nuclear Power Reactors. Retrieved July 20, 2007.
  29. Clean Air Task Force, Dirty Air, Dirty Power: Mortality and Health Damage Due to Air Pollution from Power Plants. Retrieved July 20, 2007.
  30. Nuclear Regulatory Commission, Backgrounder—Nuclear Security—Five Years After 9/11. Retrieved July 20, 2007.
  31. Nuclear Regulatory Commission, Statement From Chairman Dale Klein on Commision's Affirmation of the Final DBT Rule. Retrieved July 20, 2007.
  32. World Nuclear Association, The Nuclear Fuel Cycle. Retrieved July 20, 2007.
  33. Vadim Nesvizhskiy, Neutron Weapon from Underground. Retrieved July 20, 2007.
  34. Nuclear Threat Initiative, Information on Nuclear Smuggling Incidents. Retrieved July 20, 2007.
  35. BBC, Action Call Over Dirty Bomb Threat. Retrieved July 20, 2007.
  36. Sir Richard Doll, Researcher Says Childhood Leukemia Is Caused By Infection. Retrieved July 20, 2007.
  37. Anita Seth, Leukemia Clusters Near La Hague and Sellafield. Retrieved July 20, 2007.
  38. PubMed, Risk of childhood leukaemia in the vicinity of nuclear installations—findings and recent controversies.. Retrieved July 20, 2007.
  39. U.S. Department of Energy, About DOE. Retrieved July 20, 2007.
  40. Times Onlines, Floating nuclear power stations raise specter of Chernobyl at sea. Retrieved July 21, 2007.
  41. The Virtual Nuclear Tourist, Environmental Effects of Nuclear Power. Retrieved July 20, 2007.
  42. CBS, France: Vive Les Nukes. Retrieved July 20, 2007.
  43. Parliamentary Office of Science and Technology, Carbon Footprint of Electricity Generation. Retrieved July 20, 2007.
  44. Jan Willem Storm van Leeuwen, and Philip Smith, Nuclear Power—The Energy Balance. Retrieved July 20, 2007.
  45. World Nuclear Association, Energy Balances and CO2 Implications. Retrieved July 20, 2007.

References
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