Nuclear power

This article is about power derived from nuclear reactions. For countries that possess nuclear weapons see: Nuclear powers .

Risks

Opponents of nuclear power such as Greenpeace, argue against its use due to issues like the long term problems of storing radioactive waste, the potential for severe radioactive contamination by an accident, and the possibility that its use will lead to the proliferation of nuclear weapons. They point to the chequered history of nuclear power and its continual procession of nuclear accidents, from the 1950s to the present day. According to the Supreme Court of the United States in 1978, comprehensive testing and study have failed to remove the risk of a major nuclear accident resulting in extensive damage (however, since then each US plant has undergone an Individual Plant Examination process using Probabilistic Risk Assessment to quantify the risk and identify and address high-risk areas).

Related Topics:
Greenpeace - Radioactive waste - Radioactive contamination - Proliferation - Nuclear weapons - Nuclear accidents - Probabilistic Risk Assessment

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Proponents argue that the risks are small and that fear has been the single largest obstacle to the widespread use of nuclear power. They believe that nuclear power or coal are currently the only realistic large scale energy sources that would be able to replace oil and natural gas after a peak in global oil and gas production has been reached (see peak oil). Coal currently contributes significantly to problems like global warming, acid rain, various diseases due to airborne pollution, and the storage of large amounts of ash. Renewables have not solved problems like intermittent output, high costs, and diffuse output which requires the use of large surface areas and much construction material and which increases distribution losses. For example, studies in Britain have shown that increasing windpower production contribution to 20% of all energy production would only reduce coal or nuclear power plant capacity by 6.7% (from 59 to 55 GWe) since they must remain as backup. Increasing the contribution of intermittent energy sources above that is not possible with current technology http://www.world-nuclear.org/info/inf10.htm. Future technology may both increase the efficiency and safety of alternative energy sources, including nuclear, and make them more environmentally friendly.

Related Topics:
Peak oil - Coal - Global warming - Acid rain - Ash

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Accident or attack

Opponents argue that a major disadvantage of the use of nuclear reactors is the threat of a nuclear accident or terrorist attack and the possible resulting exposure to radiation. Proponents argue that the potential for a meltdown, as in the Chernobyl accident is very small due to the care taken in designing adequate safety systems, and that the nuclear industry has much better statistics regarding humans deaths from occupational accidents than coal or hydropower http://www.world-nuclear.org/info/inf06.htm. The Chernobyl accident caused great negative health, economic, and psychological effects in a widespread area. The accident at Chernobyl was caused by a combination of the faulty RBMK reactor design, the lack of a containment building, poorly trained operators, and a non-existent safety culture. The RBMK design, unlike nearly all designs used in the Western world, featured a positive void coefficient, meaning that a malfunction could result in ever-increasing generation of heat and radiation until the reactor was breached. http://www.globalsecurity.org/wmd/world/russia/rbmk.htm Even in Three Mile Island, the most severe civilian nuclear accident in the Western world, the reactor vessel and containment building were never breached so that very little radiation was released into the environment.

Related Topics:
Nuclear accident - Chernobyl accident - RBMK - Containment building - Positive void coefficient - Three Mile Island

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Research is being done to lessen the risks by developing automated and passively safe fission reactors. Fusion reactors have little risk since the fuel contained in the reaction chamber is only enough to sustain the reaction for about a minute, whereas a fission reactor contains about a year's supply of fuel. Subcritical reactors never have a self sustained nuclear chain reaction.

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Opponents of nuclear power express concerns that nuclear waste is not well protected, and that it can be released in the event of terrorist attack. (Other energy sources, such as hydropower plants and liquified natural gas tankers, are more vulnerable to accidents and attacks.) Proponents of nuclear power contend, however, that nuclear waste is already well protected, and state their argument that there has been no accident involving any form of nuclear waste from a civilian program worldwide. In addition, they 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 http://www.world-nuclear.org/news/resistance.htm. Spent fuel is usually housed inside the reactor containment building http://www.world-nuclear.org/info/inf03.htm.

Related Topics:
Liquified natural gas - Tankers - September 11 - Containment building

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According to the Nuclear Regulatory Commission, 20 American States have requested stocks of potassium iodine which the NRC suggests should be available for those living within 10 miles of a nuclear power plant in the unlikely event of a severe accident.http://www.nrc.gov/what-we-do/emerg-preparedness/protect-public/potassium-iodide.html.

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Air and water pollution

Like renewables (except biomass), nuclear generation does not produce carbon dioxide, sulfur dioxide, nitrogen oxides, mercury and other pollutants associated with the combustion of fossil fuels (pollution from fossil fuels causes many times more deaths each year in the US alone http://www.ecomall.com/greenshopping/cleanair.htm). All power sources, including renewables, contribute to global warming at least slightly, for example when mining and refining raw materials - but most life cycle analyses show that the nuclear power contribution is about equal to that of many renewables and is much less than that from fossil fuels http://www.world-nuclear.org/info/inf11.htm.

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Fission reactors do produce gases such as iodine-131 or krypton-85 which have to be stored on-site for several half-lives until they have decayed to levels officially regarded as safe. However, according to several independent organizations, a person receives more radioactivity from household appliances than from nuclear power http://www.world-nuclear.org/education/ne/ne6.htm.

Related Topics:
Iodine - Krypton

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Nuclear reactors require water to keep the reactor cool. The process of extracting energy from a heat source, called the Rankine cycle, requires the steam to be cooled down. In practice, this means that on extremely hot days, which is when demand can be at its highest, the capacity of a nuclear plant may go down because the incoming water - usually a river - has been warmed so that the maximum allowed temperature for the exhaust water (which is lower than the fishkill temperature) is closer to the inlet temperature. This was a significant factor in the European heat wave of 2003. Engineers consider this in making better power plant designs because increased cooling capacity will increase costs.

Related Topics:
Rankine cycle - European heat wave of 2003

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Health effect on population near nuclear plants

Most of the 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.

Related Topics:
Background radiation - National Cancer Institute - National Institutes of Health

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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. Likewise, small studies have found an increased incidence of childhood leukemia near some nuclear power plants has also been found in Germany http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9210727 and France http://www.ieer.org/ensec/no-4/lahague.html. Nonetheless, the results of larger multi-site studies in these countries invalidate the hypothesis of an increased risk of leukaemia related to nuclear discharge. The methodology and very small samples in the studies finding an increased incidence has been criticized. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11990512&dopt=Abstract

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http://www.nei.org/doc.asp?catnum=3&catid=1112&docid=&format=print

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http://www.world-nuclear.org/info/inf05.htm

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http://www.personalmd.com/news/n0818103222.shtml.

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Aside from the immediate effects of the Chernobyl accident (see above), there is continuing impact from soils containing radioactivity in Ukraine and Belarus (since there is no level of radiological exposure which does not cause cancers in some portion of the exposed population http://www.ieer.org/comments/beir/beir7presentation.ppt). For this reason a Zone of alienation was established around the Chernobyl plant.

Related Topics:
Ukraine - Belarus - Zone of alienation

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Nuclear proliferation

Opponents of nuclear power point out that nuclear technology is often dual-use, and much of the same materials and knowledge used in a civilian nuclear program can be used to develop nuclear weapons. This concern is known as nuclear proliferation and is a major reactor design criterion.

Related Topics:
Dual-use - Nuclear weapons

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The military and civil purposes for nuclear energy are intertwined in most countries with nuclear capabilities. In the US for example the first goal of the Department of Energy is "To protect our national security by applying advanced science and nuclear technology to the Nation?s defense." http://www.doe.gov/engine/content.do?BT_CODE=ABOUTDOE

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While the enriched uranium used in most nuclear reactors is not concentrated enough to build a bomb (most nuclear reactors run on 4% enriched uranium, while a bomb requires an estimated 90% enrichment), the technology used to enrich uranium could be used to make the highly enriched uranium needed to build a bomb. In addition, designs such as CANDU can be more easily misused to generate plutonium suitable for bomb making. It is believed that the nuclear programs of India and Pakistan used CANDU reactors to produce fissionable materials for their weapons, however, this is a myth. India used a research reactor named CIRUS, based on the Canadian NRX design, which was donated by Canada under the condition that it not be used for weapons productionhttp://archives.cbc.ca/IDC-1-75-104-898/science_technology/candu/clip4. Pakistan is believed to have produced the material for its weapons from an indigenious enrichment program http://www.fas.org/nuke/guide/pakistan/nuke/chron.htm.

Related Topics:
CANDU - Plutonium

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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.

Related Topics:
Nuclear Non-Proliferation Treaty - 1968 - International Atomic Energy Agency

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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). South Africa has since signed the NPT, and now holds the distinction of being the only known state to have indigenously produced nuclear weapons, and then verifiably dismantled themhttp://www.fas.org/nuke/guide/rsa/nuke/. 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, including Iran and North Korea. Certain types of reactors are more conducive to producing nuclear weapons materials than others, 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.

Related Topics:
India - Pakistan - Israel - South Africa - Iran - North Korea

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New technology, like SSTAR, may lessen the risk of nuclear proliferation by providing sealed reactors with a limited self-contained fuel supply and with restrictions against tampering.

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One possible obstacle for expanding the use of nuclear power might be a limitated supply of uranium ore, without which it would become necessary to build and operate breeder reactors. However, at current usage there is sufficient uranium for an extended period - "In summary, the actual recoverable uranium supply is likely to be enough to last several hundred (up to 1000) years, even using standard reactors." http://www.americanenergyindependence.com/uranium.html (see Fuel resources above). Breeder reactors have been banned in the US since President Carter's administration prohibited reprocessing because of what it regarded as the unacceptable risk of proliferation of weapon grade materials.

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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 since it seems that democracies never make war against each other (See the democratic peace theory).

Related Topics:
Democratic peace theory - Weapons of mass destruction - Chemical warfare - Biological warfare

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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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