Nuclear power is the use of nuclear reactions that release nuclear energy to generate heat, which most frequently is then used in steam turbines to produce electricity in a nuclear power plant. As a nuclear technology, nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of uranium and plutonium. Nuclear decay processes are used in niche applications such as radioisotope thermoelectric generators. Generating electricity from fusion power remains at the focus of international research. This article mostly deals with nuclear fission power for electricity generation.
Civilian nuclear power supplied 2,488 terawatt hours (TWh) of electricity in 2017, equivalent to about 10% of global electricity generation. As of April 2018, there are 449 civilian fission reactors in the world, with a combined electrical capacity of 394 gigawatt (GW). As of 2018, there are 58 power reactors under construction and 154 reactors planned, with a combined capacity of 63 GW and 157 GW, respectively. As of January 2019, 337 more reactors were proposed. Most reactors under construction are generation III reactors in Asia.
Nuclear power is classified as a low greenhouse gas energy supply technology, along with renewable energy, by the Intergovernmental Panel on Climate Change. Since its commercialization in the 1970s, nuclear power has prevented about 1.84 million air pollution-related deaths and the emission of about 64 billion tonnes of carbon dioxide equivalent that would have otherwise resulted from the burning of fossil fuels.
There is a debate about nuclear power. Proponents, such as the World Nuclear Association and Environmentalists for Nuclear Energy, contend that nuclear power is a safe, sustainable energy source that reduces carbon emissions. Opponents, such as Greenpeace and NIRS, contend that nuclear power poses many threats to people and the environment.
Accidents in nuclear power plants include the Chernobyl disaster in the Soviet Union in 1986, the Fukushima Daiichi nuclear disaster in Japan in 2011, and the more contained Three Mile Island accident in the United States in 1979. There have also been some nuclear submarine accidents. Nuclear reactors have caused the lowest number of fatalities per unit of energy generated when compared to fossil fuels and hydropower. Coal, petroleum, natural gas and hydroelectricity each have caused a greater number of fatalities per unit of energy, due to air pollution and accidents.
Collaboration on research and development towards greater efficiency, safety and recycling of spent fuel in future generation IV reactors presently includes Euratom and the co-operation of more than 10 permanent member countries globally.
In 1932 physicist Ernest Rutherford discovered that when lithium atoms were "split" by protons from a proton accelerator, immense amounts of energy were released in accordance with the principle of mass–energy equivalence. However, he and other nuclear physics pioneers Niels Bohr and Albert Einstein believed harnessing the power of the atom for practical purposes anytime in the near future was unlikely.
The same year, his doctoral student James Chadwick discovered the neutron, which was immediately recognized as a potential tool for nuclear experimentation because of its lack of an electric charge. Experiments bombarding materials with neutrons led Frédéric and Irène Joliot-Curie to discover induced radioactivity in 1934, which allowed the creation of radium-like elements. Further work by Enrico Fermi in the 1930s focused on using slow neutrons to increase the effectiveness of induced radioactivity. Experiments bombarding uranium with neutrons led Fermi to believe he had created a new, transuranic element, which was dubbed hesperium.
In 1938, German chemists Otto Hahn and Fritz Strassmann, along with Austrian physicist Lise Meitner and Meitner's nephew, Otto Robert Frisch, conducted experiments with the products of neutron-bombarded uranium, as a means of further investigating Fermi's claims. They determined that the relatively tiny neutron split the nucleus of the massive uranium atoms into two roughly equal pieces, contradicting Fermi. This was an extremely surprising result: all other forms of nuclear decay involved only small changes to the mass of the nucleus, whereas this process—dubbed "fission" as a reference to biology—involved a complete rupture of the nucleus. Numerous scientists, including Leó Szilárd, who was one of the first, recognized that if fission reactions released additional neutrons, a self-sustaining nuclear chain reaction could result. Once this was experimentally confirmed and announced by Frédéric Joliot-Curie in 1939, scientists in many countries (including the United States, the United Kingdom, France, Germany, and the Soviet Union) petitioned their governments for support of nuclear fission research, just on the cusp of World War II, for the development of a nuclear weapon.
In the United States, where Fermi and Szilárd had both emigrated, the discovery of the nuclear chain reaction led to the creation of the first man-made reactor, the research reactor known as Chicago Pile-1, which achieved self-sustaining power/criticality on December 2, 1942. The reactor's development was part of the Manhattan Project, the Allied effort to create atomic bombs during World War II. It led to the building of larger single-purpose production reactors, such as the X-10 Pile, for the production of weapons-grade plutonium for use in the first nuclear weapons. The United States tested the first nuclear weapon in July 1945, the Trinity test, with the atomic bombings of Hiroshima and Nagasaki taking place one month later.
In August 1945, the first widely distributed account of nuclear energy, in the form of the pocketbook The Atomic Age, discussed the peaceful future uses of nuclear energy and depicted a future where fossil fuels would go unused. Nobel laureate Glenn Seaborg, who later chaired the Atomic Energy Commission, is quoted as saying "there will be nuclear powered earth-to-moon shuttles, nuclear powered artificial hearts, plutonium heated swimming pools for SCUBA divers, and much more".
In the same month, with the end of the war, Seaborg and others would file hundreds of initially classifed patents, most notably Eugene Wigner and Alvin Weinberg's Patent #2,736,696, on a conceptual light water reactor (LWR) that would later become the United States' primary reactor for naval propulsion and later take up the greatest share of the commercial fission-electric landscape.
The United Kingdom, Canada, and the USSR proceeded to research and develop nuclear energy over the course of the late 1940s and early 1950s.
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. In 1953, American President Dwight Eisenhower gave his "Atoms for Peace" speech at the United Nations, emphasizing the need to develop "peaceful" uses of nuclear power quickly. This was followed by the 1954 Amendments to the Atomic Energy Act which allowed rapid declassification of U.S. reactor technology and encouraged development by the private sector.
The first organization to develop nuclear power was the U.S. Navy, with the S1W reactor for the purpose of propelling submarines and aircraft carriers. The first nuclear-powered submarine, USS Nautilus, was put to sea in January 1954. The trajectory of civil reactor design was heavily influenced by Admiral Hyman G. Rickover, who with Weinberg as a close advisor, selected the PWR/Pressurized Water Reactor design, in the form of a 10 MW reactor for the Nautilus, a decision that would result in the PWR receiving a government commitment to develop, an engineering lead that would result in a lasting impact on the civilian electricity market in the years to come. The United States Navy Nuclear Propulsion design and operation community, under Rickover's style of attentive management retains a continuing record of zero reactor accidents (defined as the uncontrolled release of fission products to the environment resulting from damage to a reactor core). with the U.S. Navy fleet of nuclear-powered ships, standing at some 80 vessels as of 2018.
On June 27, 1954, the USSR's Obninsk Nuclear Power Plant, based on what would become the prototype of the RBMK reactor design, became the world's first nuclear power plant to generate electricity for a power grid, producing around 5 megawatts of electric power.
On July 17, 1955 the BORAX III reactor, the prototype to later Boiling Water Reactors, became the first to generate electricity for an entire community, the town of Arco, Idaho. A motion picture record of the demonstration, of supplying some 2 megawatts(2 MW) of electricity, was presented to the United Nations, Where at the "First Geneva Conference", the world's largest gathering of scientists and engineers, met to explore the technology in that year. 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 at Windscale, England, was opened in 1956 with an initial capacity of 50 MW per reactor (200 MW total), it was the first of a fleet of dual-purpose MAGNOX reactors, though officially code-named PIPPA(Pressurized Pile Producing Power and Plutonium) by the UKAEA to denote the plant's dual commercial and military role.
The U.S. Army, nuclear power program, formally commenced in 1954. Under its management, the 2 megawatt SM-1, at Fort Belvoir, Virginia, was the first in the United States to supply electricity in an industrial capacity to the commercial grid (VEPCO), in April 1957.
The 3 MW SL-1 was a U.S. Army experimental nuclear power reactor at the National Reactor Testing Station in eastern Idaho, derived from the Borax Boiling water reactor(BWR) design, it first achieved operational criticality/connection to the grid in 1958. For reasons unknown, in 1961 a technician removed a control rod about 22 inches farther than the prescribed 4 inches. This resulted in a steam explosion which killed the three crew members and caused a meltdown. The event was eventually rated at 4 on the seven-level INES scale.
In service from 1963 and operated as the experimental testbed for the later Alfa-class submarine fleet, one of the two liquid metal cooled reactors onboard the Soviet submarine K-27, underwent a Fuel element failure accident in 1968, with the emission of gaseous fission products into the surrounding air, producing 9 crew fatalities and 83 injuries.
The total global 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 worldwide capacity has risen much more slowly, reaching 366 GW in 2005. Between around 1970 and 1990, more than 50 GW of capacity was under construction (peaking at over 150 GW in the late 1970s and early 1980s)—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. A total of 63 nuclear units were canceled in the United States between 1975 and 1980.
In 1972 Alvin Weinberg, co-inventor of the light water reactor design (the most common nuclear reactors today) was fired from his job at Oak Ridge National Laboratory by the Nixon administration, "at least in part" over his raising of concerns about the safety and wisdom of ever larger scaling-up of his design, especially above a power rating of ~500 MWe, as in a loss of coolant accident scenario, the decay heat generated from such large compact solid-fuel cores was thought to be beyond the capabilities of passive/natural convection cooling to prevent a rapid fuel rod melt-down and resulting in then, potential far reaching fission product pluming. While considering the LWR, well suited at sea for the submarine and naval fleet, Weinberg did not show complete support for its use by utilities on land at the power output that they were interested in for supply scale reasons, and would request for a greater share of AEC research funding to evolve his team's demonstrated, Molten-Salt Reactor Experiment, a design with greater inherent safety in this scenario and with that an envisioned greater economic growth potential in the market of large-scale civilian electricity generation.
Similar to the earlier BORAX reactor safety experiments, conducted by Argonne National Laboratory, in 1976 Idaho National Laboratory began a test program focused on LWR reactors under various accident scenarios, with the aim of understanding the event progression and mitigating steps necessary to respond to a failure of one or more of the disparate systems, with much of the redundant back-up safety equipment and nuclear regulations drawing from these series of destructive testing investigations.
During the 1970s and 1980s rising economic costs (related to extended construction times largely due to regulatory changes and pressure-group litigation) and falling fossil fuel prices made nuclear power plants then under construction less attractive. In the 1980s in the U.S. and 1990s in Europe, the flat electric grid growth and electricity liberalization also made the addition of large new baseload energy generators economically unattractive.
The 1973 oil crisis had a significant effect on countries, such as France and Japan, which had relied more heavily on oil for electric generation (39% and 73% respectively) to invest in nuclear power. The French plan, known as the Messmer plan, was for the complete independence from oil, with an envisaged construction of 80 reactors by 1985 and 170 by 2000. France would construct 25 fission-electric stations, installing 56 mostly PWR design reactors over the next 15 years, though foregoing the 100 reactors initially charted in 1973, for the 1990s. In 2017, 72% of French electricity was generated by 58 reactors, the highest percentage by any nation in the world.
Some local opposition to nuclear power emerged in the U.S. in the early 1960s, beginning with the proposed Bodega Bay station in California, in 1958, which produced conflict with local citizens and by 1964 the concept was ultimately abandoned. In the late 1960s some members of the scientific community began to express pointed concerns. These anti-nuclear concerns related to nuclear accidents, nuclear proliferation, nuclear terrorism and radioactive waste disposal. In the early 1970s, there were large protests about a proposed nuclear power plant in Wyhl, Germany. The project was cancelled in 1975 the anti-nuclear success at Wyhl inspired opposition to nuclear power in other parts of Europe and North America. By the mid-1970s anti-nuclear activism gained a wider appeal and influence, and nuclear power began to become an issue of major public protest. In some countries, the nuclear power conflict "reached an intensity unprecedented in the history of technology controversies". In May 1979, an estimated 70,000 people, including then governor of California Jerry Brown, attended a march against nuclear power in Washington, D.C. Anti-nuclear power groups emerged in every country that had a nuclear power programme.
Globally during the 1980s one new nuclear reactor started up every 17 days on average.
Starting in the early 1970s in the U.S. and occurring within a atmosphere of increased public hostility, involving the public opposition to the AEC and the eventual founding of its replacement, the Nuclear Regulatory Commission, both had attempted to respond to public opinion by lengthening the license procurement process, tightening engineering regulations and increasing the requirements for safety equipment in what is considered the beginning of the regulatory-ratcheting phase of commercial development. Together with relatively minor percentage increases in the total quantity of steel, piping, cabling and concrete per unit of installed nameplate capacity, the more notable changes to the regulatory open public hearing-response cycle for the granting of construction licenses, had the effect of what was once an initial 16 months for project initiation to the pouring of first concrete in 1967, escalating to 32 months in 1972 and finally 54 months in 1980, which ultimately, quadrupled the price of power reactors.
Utility proposals in the U.S for nuclear generating stations, peaked at 52 in 1974, fell to 12 in 1976 and have never recovered, in large part due to the pressure-group litigation strategy, of launching lawsuits against each proposed U.S construction proposal, keeping private utilities tied up in court for years, one of which having reached the supreme court in 1978. With permission to build a nuclear station in the U.S. eventually taking longer than in any other industrial country, the spectre facing utilities of having to pay interest on large construction loans while the anti-nuclear movement used the legal system to produce delays, increasingly made the viablity of financing construction, less certain. By the close of the 1970s it became clear that nuclear power would not grow nearly as dramatically as once believed.
Over 120 reactor proposals in the United States were ultimately cancelled and the construction of new reactors ground to a halt. A cover story in the February 11, 1985, issue of Forbes magazine commented on the overall failure of the U.S. nuclear power program, saying it "ranks as the largest managerial disaster in business history".
According to some commentators, the 1979 accident at Three Mile Island (TMI) played a major part in the reduction in the number of new plant constructions in many other countries. According to the NRC, TMI was the most serious accident in "U.S. commercial nuclear power plant operating history, even though it led to no deaths or injuries to plant workers or members of the nearby community." The regulatory uncertainty and delays eventually resulted in an escalation of construction related debt that led to the bankruptcy of Seabrook's major utility owner, Public Service Company of New Hampshire. At the time, the fourth largest bankruptcy in United States corporate history.
Amongst US engineers, the cost increases from implementing the regulatory changes that resulted from the TMI accident were, when eventually finalized, only a few percent of total construction costs for new reactors, primarily relating to the prevention of safety systems from being turned off. With the most significant engineering result of the TMI accident, the recognition that better operator training was needed and that the existing emergency core cooling system of PWRs worked better in a real-world emergency than members of the anti-nuclear movement had routinely claimed.
The already slowing rate of new construction along with the shutdown in the 1980s of two existing demonstration nuclear power stations in the Tennessee Valley, US, when they couldn’t economically meet the NRC's new tightened standards, shifted electricity generation to coal-fired power plants. In 1977, following the first oil shock, U.S. President Jimmy Carter made a speech calling the energy crisis the "moral equivalent of war" and prominently supporting nuclear power. However, nuclear power could not compete with cheap oil and gas, particularly after public opposition and regulatory hurdles made new nuclear prohibitively expensive.
In 2006 The Brookings Institution, a public policy organization, stated that new nuclear units had not been built in the United States because of soft demand for electricity, the potential cost overruns on nuclear reactors due to regulatory issues and resulting construction delays.
In 1982, amongst a backdrop of ongoing protests directed at the construction of the first commercial scale breeder reactor in France, a later member of the Swiss Green Party fired five RPG-7 rocket-propelled grenades at the still under construction containment building of the Superphenix reactor. Two grenades hit and caused minor damage to the reinforced concrete outer shell. It was the first time protests reached such heights. After examination of the superficial damage, the prototype fast breeder reactor started and operated for over a decade.
According to some commentators, the 1986 Chernobyl disaster played a major part in the reduction in the number of new plant constructions in many other countries: Unlike the Three Mile Island accident the much more serious Chernobyl accident did not increase regulations or engineering changes affecting Western reactors; because the RBMK design, which lacks safety features such as "robust" containment buildings, was only used in the Soviet Union. Over 10 RBMK reactors are still in use today. However, changes were made in both the RBMK reactors themselves (use of a safer enrichment of uranium) and in the control system (preventing safety systems being disabled), amongst other things, to reduce the possibility of a similar accident. Russia now largely relies upon, builds and exports a variant of the PWR, the VVER, with over 20 in use today.
An international organization to promote safety awareness and the professional development of operators in nuclear facilities, the World Association of Nuclear Operators (WANO), was created as a direct outcome of the 1986 Chernobyl accident. The organization was created with the intent to share and grow the adoption of nuclear safety culture, technology and community, where before there was an atmosphere of cold war secrecy.
Numerous countries, including Austria (1978), Sweden (1980) and Italy (1987) (influenced by Chernobyl) have voted in referendums to oppose or phase out nuclear power.
In the early 2000s, the nuclear industry was expecting a nuclear renaissance, an increase in the construction of new reactors, due to concerns about carbon dioxide emissions. However, in 2009, Petteri Tiippana, the director of STUK's nuclear power plant division, told the BBC that it was difficult to deliver a Generation III reactor project on schedule because builders were not used to working to the exacting standards required on nuclear construction sites, since so few new reactors had been built in recent years.
In 2018 the MIT Energy Initiative study on the future of nuclear energy concluded that, together with the strong suggestion that government should financially support development and demonstration of new Generation IV nuclear technologies, for a worldwide renaissance to commence, a global standardization of regulations needs to take place, with a move towards serial manufacturing of standardized units akin to the other complex engineering field of aircraft and aviation. At present it is common for each country to demand bespoke changes to the design to satisfy varying national regulatory bodies, often to the benefit of domestic engineering supply firms. The report goes on to note that the most cost-effective projects have been built with multiple (up to six) reactors per site using a standardized design, with the same component suppliers and construction crews working on each unit, in a continuous work flow.
Following the Tōhoku earthquake on 11 March 2011, one of the largest earthquakes ever recorded, and a subsequent tsunami off the coast of Japan, the Fukushima Daiichi Nuclear Power Plant suffered three core meltdowns due to failure of the emergency cooling system for lack of electricity supply. This resulted in the most serious nuclear accident since the Chernobyl disaster.
The Fukushima Daiichi nuclear accident prompted a re-examination of nuclear safety and nuclear energy policy in many countries and raised questions among some commentators over the future of the renaissance. Germany approved plans to close all its reactors by 2022. Italian nuclear energy plans ended when Italy banned the generation, but not consumption of, nuclear electricity in a June 2011 referendum. China, Switzerland, Israel, Malaysia, Thailand, United Kingdom, and the Philippines reviewed their nuclear power programs.
In 2011 the International Energy Agency halved its prior estimate of new generating capacity to be built by 2035. Nuclear power generation had the biggest ever fall year-on-year in 2012, with nuclear power plants globally producing 2,346 TWh of electricity, a drop of 7% from 2011. This was caused primarily by the majority of Japanese reactors remaining offline that year and the permanent closure of eight reactors in Germany.
The Fukushima Daiichi nuclear accident sparked controversy about the importance of the accident and its effect on nuclear's future. The crisis prompted countries with nuclear power to review the safety of their reactor fleet and reconsider the speed and scale of planned nuclear expansions. In 2011, The Economist opined that nuclear power "looks dangerous, unpopular, expensive and risky", and suggested a nuclear phase-out. Jeffrey Sachs, Earth Institute Director, disagreed claiming combating climate change would require an expansion of nuclear power. Investment banks were also critical of nuclear soon after the accident.
In 2011 German engineering giant Siemens said it would withdraw entirely from the nuclear industry in response to the Fukushima accident. In 2017, Siemens set the "milestone" of supplying the first additive manufacturing part to a nuclear power station, at the Krško Nuclear Power Plant in Slovenia, which it regards as an "industry breakthrough".
The Associated Press and Reuters reported in 2011 the suggestion that the safety and survival of the younger Onagawa Nuclear Power Plant, the closest reactor facility to the epicenter and on the coast, demonstrate that it is possible for nuclear facilities to withstand the greatest natural disasters. The Onagawa plant was also said to show that nuclear power can retain public trust, with the surviving residents of the town of Onagawa taking refuge in the gymnasium of the nuclear facility following the destruction of their town.
Following an IAEA inspection in 2012, the agency stated that "The structural elements of the [Onagawa] NPS (nuclear power station) were remarkably undamaged given the magnitude of ground motion experienced and the duration and size of this great earthquake,”.
In August 2015, following 4 years of near zero fission-electricity generation, Japan began restarting its nuclear reactors, after safety upgrades were completed, beginning with Sendai Nuclear Power Plant.
By 2015, the IAEA's outlook for nuclear energy had become more promising. "Nuclear power is a critical element in limiting greenhouse gas emissions," the agency noted, and "the prospects for nuclear energy remain positive in the medium to long term despite a negative impact in some countries in the aftermath of the [Fukushima-Daiichi] accident...it is still the second-largest source worldwide of low-carbon electricity. And the 72 reactors under construction at the start of last year were the most in 25 years." As of 2015 the global trend was for new nuclear power stations coming online to be balanced by the number of old plants being retired. Eight new grid connections were completed by China in 2015.
As of 2018, there are over 150 nuclear reactors planned including 50 under construction. However, while investment on upgrades of existing plant and life-time extensions continues, investment in new nuclear is declining, reaching a 5-year-low in 2017.
In 2016, the U.S. Energy Information Administration projected for its “base case” that world nuclear power generation would increase from 2,344 terawatt hours (TWh) in 2012 to 4,500 TWh in 2040. Most of the predicted increase was expected to be in Asia.
The future of nuclear power varies greatly between countries, depending on government policies. Some countries, most notably, Germany, have adopted policies of nuclear power phase-out. At the same time, some Asian countries, such as China and India, have committed to rapid expansion of nuclear power. Many other countries, such as the United Kingdom and the United States, have policies in between. Japan generated about 30% of its electricity from nuclear power before the Fukushima accident. In 2015 the Japanese government committed to the aim of restarting its fleet of 40 reactors by 2030 after safety upgrades, and to finish the construction of the Generation III Ōma Nuclear Power Plant. This would mean that approximately 20% of electricity would come from nuclear power by 2030. As of 2018, some reactors have restarted commercial operation following inspections and upgrades with new regulations. While South Korea has a large nuclear power industry, the new government in 2017, influenced by a vocal anti-nuclear movement, committed to halting nuclear development after the completion of the facilities presently under construction.
The nuclear power industry in some western nations have a history of construction delays, cost overruns, plant cancellations, and nuclear safety issues, despite significant government subsidies and support. These problems are related to very strict safety requirements, uncertain regulatory environment, slow rate of construction, and large stretches of time with no nuclear construction and consequent loss of know-how. Commentators therefore argue that new nuclear is impractical in western countries because of popular opposition, regulatory uncertainty, soft demand for multiple reactor units and high costs. The bankruptcy of Westinghouse in March 2017 due to US$9 billion of losses from the halting of construction at Virgil C. Summer Nuclear Generating Station, in the U.S. is considered an advantage for eastern companies, for the future export and design of nuclear fuel and reactors. In 2016, Greenpeace and the wind industry company Ecotricity criticized the high cost of the Hinkley Point C nuclear power station and threatened to take action in British or French courts or lodge a complaint with the European Commission, in order to trigger an investigation, which they said could last as long as a year.
The greatest new build activity is occurring in Asian countries like South Korea, India and China. In January 2019, China had 45 reactors in operation, 13 under construction, and plans to build 43 more, which would make it the world's largest generator of nuclear electricity.
In 2016 the BN-800 sodium cooled fast reactor in Russia, began commercial electricity generation, while plans for a BN-1200 were initially conceived the future of the fast reactor program in Russia awaits the results from MBIR, an under construction multi-loop Generation IV research facility for testing the chemically more inert lead, lead-bismuth and gas coolants, it will similarly run on recycled MOX (mixed uranium and plutonium oxide) fuel. An on-site pyrochemical processing, closed fuel-cycle facility, is planned, to recycle the spent fuel/"waste" and reduce the necessity for a growth in uranium mining and exploration. In 2017 the manufacture program for the reactor commenced with the facility open to collaboration under the "International Project on Innovative Nuclear Reactors and Fuel Cycle", it has a construction schedule, that includes an operational start in 2020. As planned, it will be the world's most-powerful research reactor.
In the United States, licenses of almost half of the operating nuclear reactors have been extended to 60 years. The U.S. NRC and the U.S. Department of Energy have initiated research into Light water reactor sustainability which is hoped will lead to allowing extensions of reactor licenses beyond 60 years, provided that safety can be maintained, to increase energy security and preserve low-carbon generation sources. Research into nuclear reactors that can last 100 years, known as Centurion Reactors, is being conducted.
Just as many conventional thermal power stations generate electricity by harnessing the thermal energy released from burning fossil fuels, nuclear power plants convert the energy released from the nucleus of an atom via nuclear fission that takes place in a nuclear reactor. When a neutron hits the nucleus of a uranium-235 or plutonium atom, it can split the nucleus into two smaller nuclei. The reaction is called nuclear fission. The fission reaction releases energy and neutrons. The released neutrons can hit other uranium or plutonium nuclei, causing new fission reactions, which release more energy and more neutrons. This is called a chain reaction. The reaction rate is controlled by control rods that absorb excess neutrons. The controllability of nuclear reactors depends on the fact that a small fraction of neutrons resulting from fission are delayed. The time delay between the fission and the release of the neutrons slows down changes in reaction rates and gives time for moving the control rods to adjust the reaction rate.
A fission nuclear power plant is generally composed of a nuclear reactor, in which the nuclear reactions generating heat take place; a cooling system, which removes the heat from inside the reactor; a steam turbine, which transforms the heat in mechanical energy; an electric generator, which transform the mechanical energy into electrical energy.
A nuclear reactor is only part of the fuel life-cycle for nuclear power. The process starts with mining (see Uranium mining). Uranium mines are underground, open-pit, or in-situ leach mines. 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 generally enriched using various techniques. Some reactor designs can also use natural uranium without enrichment. The enriched uranium, containing more than the natural 0.7% uranium-235, is generally used to make rods of the proper composition and geometry for the particular reactor that the fuel is destined for. In modern light-water reactors the fuel rods will spend about 3 operational cycles (typically 6 years total now) 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 spent fuel pool the spent fuel is radioactively and thermally cool enough to handle, and can be moved to dry storage casks or reprocessed.
Uranium is a fairly common element in the Earth's crust: it is approximately as common as tin or germanium, and is about 40 times more common than silver. Uranium is present in trace concentrations in most rocks, dirt, and ocean water, but is generally economically extracted only where it is present in high concentrations. As of 2011 the world's known resources of uranium, economically recoverable at the arbitrary price ceiling of US$130/kg, were enough to last for between 70 and 100 years.
The OECD's red book of 2011 said that conventional uranium resources had grown by 12.5% since 2008 due to increased exploration, with this increase translating into greater than a century of uranium available if the rate of use were to continue at the 2011 level. In 2007, the OECD estimated 670 years of economically recoverable uranium in total conventional resources and phosphate ores assuming the then-current use rate.
Light water reactors make relatively inefficient use of nuclear fuel, mostly fissioning only the very rare uranium-235 isotope. Nuclear reprocessing can make this waste reusable. Newer generation III reactors also achieve a more efficient use of the available resources than the generation II reactors which make up the vast majority of reactors worldwide. With a pure fast reactor fuel cycle with a burn up of all the Uranium and actinides (which presently make up the most hazardous substances in nuclear waste), there is an estimated 160,000 years worth of Uranium in total conventional resources and phosphate ore at the price of 60–100 US$/kg.
Unconventional uranium resources also exist. Uranium is naturally present in seawater at a concentration of about 3 micrograms per liter, with 4.5 billion tons of uranium considered present in seawater at any time. In 2012 it was estimated that this fuel source could be extracted at 10 times the current price of uranium.
In 2014, with the advances made in the efficiency of seawater uranium extraction, it was suggested that it would be economically competitive to produce fuel for light water reactors from seawater if the process was implemented at large scale. Uranium extracted on an industrial scale from seawater would constantly be replenished by both river erosion of rocks and the natural process of uranium dissolved from the surface area of the ocean floor, both of which maintain the solubility equilibria of seawater concentration at a stable level. Some commentators have argued that this strengthens the case for Nuclear power to be considered a renewable energy
As opposed to light water reactors which use uranium-235 (0.7% of all natural uranium), fast breeder reactors use uranium-238 (99.3% of all natural uranium) or thorium. A number of fuel cycles and breeder reactor combinations are considered to be sustainable and/or renewable sources of energy. In 2006 it was estimated that with seawater extraction, there was likely some five billion years' worth of uranium-238 for use in breeder reactors.
Breeder technology has been used in several reactors, but the high cost of reprocessing fuel safely, at 2006 technological levels, requires uranium prices of more than US$200/kg before becoming justified economically. Breeder reactors are however being pursued as they have the potential to burn up all of the actinides in the present inventory of nuclear waste while also producing power and creating additional quantities of fuel for more reactors via the breeding process.
As of 2017, there are two breeders producing commercial power, BN-600 reactor and the BN-800 reactor, both in Russia. The BN-600, with a capacity of 600 MW, was built in 1980 in Beloyarsk and is planned to produce power until 2025. The BN-800 is an updated version of the BN-600, and started operation in 2014. The Phénix breeder reactor in France was powered down in 2009 after 36 years of operation.
Another alternative to fast breeders is thermal breeder reactors that use uranium-233 bred from thorium as fission fuel in the thorium fuel cycle. Thorium is about 3.5 times more common than uranium in the Earth's crust, and has different geographic characteristics. This would extend the total practical fissionable resource base by 450%. India's three-stage nuclear power programme features the use of a thorium fuel cycle in the third stage, as it has abundant thorium reserves but little uranium.
The most important waste stream from nuclear power reactors is spent nuclear fuel. From LWRs, it is typically composed of 95% uranium, 4% fission products from the energy generating nuclear fission reactions, as well as about 1% transuranic actinides (mostly reactor grade plutonium, neptunium and americium) from unavoidable neutron capture events. The plutonium and other transuranics are responsible for the bulk of the long-term radioactivity, whereas the fission products are responsible for the bulk of the short-term radioactivity.
The high-level radioactive waste/spent fuel that is generated from power production, requires treatment, management and isolation from the environment. The technical issues in accomplishing this are considerable, due to the extremely long periods some particularly sublimation prone, mildly radioactive wastes, remain potentially hazardous to living organisms, namely the long-lived fission products, Technetium-99 (half-life 220,000 years) and Iodine-129 (half-life 15.7 million years), which dominate the waste stream in radioactivity after the more intensely radioactive short-lived fission products(SLFPs) have decayed into stable elements, which takes approximately 300 years. To successfully isolate the LLFP waste from the biosphere, either separation and transmutation, or some variation of a synroc treatment and deep geological storage, is commonly suggested.
While in the US, spent fuel is presently in its entirety, federally classified as a nuclear waste and is treated similarly, in other countries it is largely reprocessed to produce a partially recycled fuel, known as mixed oxide fuel or MOX. For spent fuel that does not undergo reprocessing, the most concerning isotopes are the medium-lived transuranic elements, which are led by reactor grade plutonium (half-life 24,000 years).
Some proposed reactor designs, such as the American Integral Fast Reactor and the Molten salt reactor can more completely use or burnup the spent reactor grade plutonium fuel and other minor actinides, generated from light water reactors, as under the designed fast fission spectrum, these elements are more likely to fission and produce the aforementioned fission products in their place. This offers a potentially more attractive alternative to deep geological disposal.
The thorium fuel cycle results in similar fission products, though builds up much less transuranic elements from neutron capture events within a reactor and therefore spent thorium fuel, breeding the true fuel of fissile U-233, is somewhat less concerning from a radiotoxic and security standpoint.
The nuclear industry also produces a large 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. Low-level waste can be stored on-site until radiation levels are low enough to be disposed as ordinary waste, or it can be sent to a low-level waste disposal site.
In countries with nuclear power, radioactive wastes account for less than 1% of total industrial toxic wastes, much of which remains hazardous for long periods. Overall, nuclear power produces far less waste material by volume than fossil-fuel based power plants. Coal-burning plants are particularly noted for producing large amounts of toxic and mildly radioactive ash due to concentrating naturally occurring metals and mildly radioactive material in coal. A 2008 report from Oak Ridge National Laboratory concluded that coal power actually results in more radioactivity being released into the environment than nuclear power operation, and that the population effective dose equivalent, or dose to the public from radiation from coal plants is 100 times as much as from the operation of nuclear plants. Although coal ash is much less radioactive than spent nuclear fuel on a weight per weight basis, coal ash is produced in much higher quantities per unit of energy generated, and this is released directly into the environment as fly ash, whereas nuclear plants use shielding to protect the environment from radioactive materials, for example, in dry cask storage vessels.
Disposal of nuclear waste is often considered the most politically divisive aspect in the lifecycle of a nuclear power facility. Presently, waste is mainly stored at individual reactor sites and there are over 430 locations around the world where radioactive material continues to accumulate. Some experts suggest that centralized underground repositories which are well-managed, guarded, and monitored, would be a vast improvement. There is an "international consensus on the advisability of storing nuclear waste in deep geological repositories", with the lack of movement of nuclear waste in the 2 billion year old natural nuclear fission reactors in Oklo, Gabon being cited as "a source of essential information today."
There are no commercial scale purpose built underground high-level waste repositories in operation. However, in Finland the Onkalo spent nuclear fuel repository is under construction as of 2015. The Waste Isolation Pilot Plant (WIPP) in New Mexico has been taking nuclear waste since 1999 from production reactors, but as the name suggests is a research and development facility. In 2014 a radiation leak caused by violations in the use of chemically reactive packaging brought renewed attention to the need for quality control management, along with some initial calls for more R&D into the alternative methods of disposal for radioactive waste and spent fuel. In 2017, the facility was formally reopened after three years of investigation and cleanup, with the resumption of new storage taking place later that year.
Most thermal reactors run on a once-through fuel cycle, mainly due to the low price of fresh uranium, though many can also fuel made by recycling the fissionable materials in spent nuclear fuel. The most common fissionable material that is recycled is the reactor-grade plutonium (RGPu) that is extracted from spent fuel, mixed with uranium oxide and fabricated into mixed-oxide or MOX fuel. The potential for recycling the spent fuel a second time is limited by undesirable neutron economy issues using second-generation MOX fuel in thermal-reactors. These issues do not affect fast reactors, which are therefore preferred in order to achieve the full energy potential of the original uranium. The only commercial demonstration of triple burnup to date occurred in the Phénix fast reactor.
Because thermal LWRs remain the most common and economically competitive reactor worldwide, the most common form of commercial spent fuel recycling is to recycle the plutonium a single time as MOX fuel, as is done in France, where it is thought to increase the sustainability of the nuclear fuel cycle, reduce the attractiveness of spent fuel to theft and lower the volume of high level nuclear waste. Reprocessing of civilian fuel from power reactors is also currently done in the United Kingdom, Russia, Japan, and India.
The main constituent of spent fuel from the most common light water reactor, is uranium that is slightly more enriched than natural uranium, which can be recycled, though there is a lower incentive to do so. Most of this "recovered uranium", or at times referred to as reprocessed uranium, remains in storage. It can however be used in a fast reactor, used directly as fuel in CANDU reactors, or re-enriched for another cycle through an LWR. The direct use of recovered uranium to fuel a CANDU reactor was first demonstrated at Quishan, China. The first re-enriched uranium reload to fuel a commercial LWR, occurred in 1994 at the Cruas unit 4, France. Re-enriching of reprocessed uranium is common in France and Russia. When reprocessed uranium, namely Uranium-236, is part of the fuel of LWRs, it generates a spent fuel and plutonium isotope stream with greater inherent self-protection, than the once-thru fuel cycle.
While reprocessing offers the potential recovery of up to 95% of the remaining uranium and plutonium fuel, in spent nuclear fuel and a reduction in long term radioactivity within the remaining waste. Reprocessing has been politically controversial because of the potential to contribute to nuclear proliferation and varied perceptions of increasing the vulnerability to nuclear terrorism and because of its higher fuel cost, compared to the once-through fuel cycle. Similarly, while reprocessing reduces the volume of high-level waste, it does not reduce the fission products that are the primary residual heat generating and radioactive substances for the first few centuries outside the reactor, thus still requiring an almost identical container-spacing for the initial first few hundred years, within proposed geological waste isolation facilities.
In the United States, spent nuclear fuel is currently not reprocessed. A major recommendation of the Blue Ribbon Commission on America's Nuclear Future was that "the United States should undertake...one or more permanent deep geological facilities for the safe disposal of spent fuel and high-level nuclear waste".
The French La Hague reprocessing facility has operated commercially since 1976 and is responsible for half the world's reprocessing as of 2010. Having produced MOX fuel from spent fuel derived from France, Japan, Germany, Belgium, Switzerland, Italy, Spain and the Netherlands, with the non-recyclable part of the spent fuel eventually sent back to the user nation. More than 32,000 tonnes of spent fuel had been reprocessed as of 2015, with the majority from France, 17% from Germany, and 9% from Japan. Once a source of criticism from Greenpeace, more recently the organization have ceased attempting to criticize the facility on technical grounds, having succeeded at performing the process without serious incidents that have been frequent at other such facilities around the world. In the past, the antinuclear movement argued that reprocessing would not be technically or economically feasible.
The financial costs of every nuclear power plant continues for some time after the facility has finished generating its last useful electricity. Once no longer economically viable, nuclear reactors and uranium enrichment facilities are generally decommissioned, returning the facility and its parts to a safe enough level to be entrusted for other uses, such as greenfield status. After a cooling-off period that may last decades, reactor core materials are dismantled and cut into small pieces to be packed in containers for interim storage or transmutation experiments.
In the United States a Nuclear Waste Policy Act and Nuclear Decommissioning Trust Fund is legally required, with utilities banking 0.1 to 0.2 cents/kWh during operations to fund future decommissioning. They must report regularly to the Nuclear Regulatory Commission (NRC) on the status of their decommissioning funds. About 70% of the total estimated cost of decommissioning all U.S. nuclear power reactors has already been collected (on the basis of the average cost of $320 million per reactor-steam turbine unit).
In the United States in 2011, there are 13 reactors that had permanently shut down and are in some phase of decommissioning. With Connecticut Yankee Nuclear Power Plant and Yankee Rowe Nuclear Power Station having completed the process in 2006–2007, after ceasing commercial electricity production circa 1992. The majority of the 15 years, was used to allow the station to naturally cool-down on its own, which makes the manual disassembly process both safer and cheaper. Decommissioning at nuclear sites which have experienced a serious accident are the most expensive and time-consuming.
Nuclear fission power stations, excluding the contribution from naval nuclear fission reactors, provided 11% of the world's electricity in 2012, somewhat less than that generated by hydro-electric stations at 16%. Since electricity accounts for about 25% of humanity's energy usage with the majority of the rest coming from fossil fuel reliant sectors such as transport, manufacture and home heating, nuclear fission's contribution to the global final energy consumption was about 2.5%. This is a little more than the combined global electricity production from wind, solar, biomass and geothermal power, which together provided 2% of global final energy consumption in 2014.
Nuclear power's share of global electricity production has fallen from 16.5% in 1997 to about 10% in 2017, in large part because the economics of nuclear power have become more difficult.
Regional differences in the use of nuclear power are large. The United States produces the most nuclear energy in the world, with nuclear power providing 20% of the electricity it consumes, while France produces the highest percentage of its electrical energy from nuclear reactors—72% as of 2017. In the European Union as a whole nuclear power provides 30% of the electricity. Nuclear power is the single largest low-carbon electricity source in the United States, and accounts for two-thirds of the European Union's low-carbon electricity. Nuclear energy policy differs among European Union countries, and some, such as Austria, Estonia, Ireland and Italy, have no active nuclear power stations.
Many military and some civilian (such as some icebreakers) ships use nuclear marine propulsion. A few space vehicles have been launched using nuclear reactors: 33 reactors belong to the Soviet RORSAT series and one was the American SNAP-10A.
International research is continuing into additional uses of process heat such as hydrogen production (in support of a hydrogen economy), for desalinating sea water, and for use in district heating systems.
Both fission and fusion appear promising for space propulsion applications, generating higher mission velocities with less reaction mass. This is due to the much higher energy density of nuclear reactions: some 7 orders of magnitude (10,000,000 times) more energetic than the chemical reactions which power the current generation of rockets.
Radioactive decay has been used on a relatively small scale (few kW), mostly to power space missions and experiments by using radioisotope thermoelectric generators such as those developed at Idaho National Laboratory.
The economics of new nuclear power plants is a controversial subject, since there are diverging views on this topic, and multibillion-dollar investments depend on the choice of an energy source. Nuclear power plants typically have high capital costs for building the plant, but low fuel costs. Comparison with other power generation methods is strongly dependent on assumptions about construction timescales and capital financing for nuclear plants as well as the future costs of fossil fuels and renewables as well as for energy storage solutions for intermittent power sources. On the other hand, measures to mitigate global warming, such as a carbon tax or carbon emissions trading, may favor the economics of nuclear power.
Analysis of the economics of nuclear power must also take into account who bears the risks of future uncertainties. To date all operating nuclear power plants have been developed by state-owned or regulated electric utility monopolies Many countries have now liberalized the electricity market where these risks, and the risk of cheaper competitors emerging before capital costs are recovered, are borne by plant suppliers and operators rather than consumers, which leads to a significantly different evaluation of the economics of new nuclear power plants.
Nuclear power plants, though capable of some grid-load following, are typically run as much as possible to keep the cost of the generated electrical energy as low as possible, supplying mostly base-load electricity.
Internationally the price of nuclear plants rose 15% annually in 1970–1990. With PWR stations, having total costs in 2012 of about $96 per megawatt hour (MWh), most of which involves capital construction costs, compared with (in 2018) solar power at $36-44 per MWh, (in 2018) onshore wind at $29-56 per MWH and natural gas at the low end at $64 per MWh. The Fukushima Daiichi nuclear disaster, is expected to increase the costs of operating and new LWR power stations, due to increased requirements for on-site spent fuel management and elevated design basis threats.
Nuclear reactors have three unique characteristics that affect their safety, as compared to other power plants. Firstly, intensely radioactive materials are present in a nuclear reactor. Their release to the environment could be hazardous. Secondly, the fission products, which make up most of the intensely radioactive substances in the reactor, continue to generate a significant amount of decay heat even after the fission chain reaction has stopped. If the heat cannot be removed from the reactor, the fuel rods may overheat and release radioactive materials. Thirdly, a rapid increase of the reactor power is possible if the chain reaction cannot be controlled in certain reactor designs. These three characteristics have to be taken into account when designing nuclear reactors.
Reactors are designed so that an uncontrolled increase of the reactor power is prevented by natural feedback mechanisms: if the temperature or the amount of steam in the reactor increases, the fission power inherently decreases. The chain reaction can be manually stopped by inserting control rods into the reactor core. Emergency core cooling systems can remove the decay heat from the reactor if normal cooling systems fail. Multiple physical barriers limit the release of radioactive materials to the environment even in the case of an accident. The last barrier is the containment.
Some serious nuclear and radiation accidents have occurred. The severity of nuclear accidents is generally classified using the International Nuclear Event Scale (INES) introduced by the International Atomic Energy Agency (IAEA). The scale ranks anomalous events or accidents on a scale from 0 (a deviation from normal operation that poses no safety risk) to 7 (a major accident with widespread effects). There have been 3 accidents of level 5 or higher in the civilian nuclear power industry, two of which, the Chernobyl accident and the Fukushima accident, are ranked at level 7.
The Chernobyl accident in 1986 caused approximately 50 deaths from direct and indirect effects, and some temporary serious injuries. The future predicted mortality from cancer increases, is usually estimated at some 4000 in the decades to come. A higher number of the routinely treatable Thyroid cancer, set to be the only type of causal cancer, will likely be seen in future large studies.
The Fukushima Daiichi nuclear accident was caused by the 2011 Tohoku earthquake and tsunami. The accident has not caused any radiation related deaths, but resulted in radioactive contamination of surrounding areas. The difficult Fukushima disaster cleanup will take 40 or more years, and is expected to cost tens of billions of dollars. The Three Mile Island accident in 1979 was a smaller scale accident, rated at INES level 5. There were no direct or indirect deaths caused by the accident.
According to Benjamin K. Sovacool, fission energy accidents ranked first among energy sources in terms of their total economic cost, accounting for 41 percent of all property damage attributed to energy accidents. Another analysis presented in the international journal Human and Ecological Risk Assessment found that coal, oil, Liquid petroleum gas and hydroelectric accidents (primarily due to the Banqiao dam burst) have resulted in greater economic impacts than nuclear power accidents.
Nuclear power works under an insurance framework that limits or structures accident liabilities in accordance with the Paris convention on nuclear third-party liability, the Brussels supplementary convention, the Vienna convention on civil liability for nuclear damage and the Price-Anderson Act in the United States. It is often argued that this potential shortfall in liability represents an external cost not included in the cost of nuclear electricity; but the cost is small, amounting to about 0.1% of the levelized cost of electricity, according to a CBO study. These beyond-regular-insurance costs for worst-case scenarios are not unique to nuclear power, as hydroelectric power plants are similarly not fully insured against a catastrophic event such as the Banqiao Dam disaster, where 11 million people lost their homes and from 30,000 to 200,000 people died, or large dam failures in general. As private insurers base dam insurance premiums on limited scenarios, major disaster insurance in this sector is likewise provided by the state.
In terms of lives lost per unit of energy generated, nuclear power has caused fewer accidental deaths per unit of energy generated than all other major sources of energy generation. Energy produced by coal, petroleum, natural gas and hydropower has caused more deaths per unit of energy generated due to air pollution and energy accidents. This is found when comparing the immediate deaths from other energy sources to both the immediate nuclear related deaths from accidents and also including the latent, or predicted, indirect cancer deaths from nuclear energy accidents. When the combined immediate and indirect fatalities from nuclear power and all fossil fuels are compared, including fatalities resulting from the mining of the necessary natural resources to power generation and to air pollution, the use of nuclear power has been calculated to have prevented about 1.8 million deaths between 1971 and 2009, by reducing the proportion of energy that would otherwise have been generated by fossil fuels, and is projected to continue to do so. Following the 2011 Fukushima nuclear disaster, it has been estimated that if Japan had never adopted nuclear power, accidents and pollution from coal or gas plants would have caused more lost years of life.
Forced evacuation from a nuclear accident may lead to social isolation, anxiety, depression, psychosomatic medical problems, reckless behavior, even suicide. Such was the outcome of the 1986 Chernobyl nuclear disaster in Ukraine. A comprehensive 2005 study concluded that "the mental health impact of Chernobyl is the largest public health problem unleashed by the accident to date". Frank N. von Hippel, an American scientist, commented on the 2011 Fukushima nuclear disaster, saying that a disproportionate radiophobia, or "fear of ionizing radiation could have long-term psychological effects on a large portion of the population in the contaminated areas". A 2015 report in Lancet explained that serious impacts of nuclear accidents were often not directly attributable to radiation exposure, but rather social and psychological effects. Evacuation and long-term displacement of affected populations created problems for many people, especially the elderly and hospital patients. In January 2015, the number of Fukushima evacuees was around 119,000, compared with a peak of around 164,000 in June 2012.
Terrorists could target nuclear power plants in an attempt to release radioactive contamination into the community. The United States 9/11 Commission has said that nuclear power plants were potential targets originally considered for the September 11, 2001 attacks. An attack on a reactor's spent fuel pool could also be serious, as these pools are less protected than the reactor core. The release of radioactivity could lead to thousands of near-term deaths and greater numbers of long-term fatalities.
In the United States, the NRC carries out "Force on Force" (FOF) exercises at all nuclear power plant sites at least once every three years. In the United States, plants are surrounded by a double row of tall fences which are electronically monitored. The plant grounds are patrolled by a sizeable force of armed guards.
Insider sabotage is also a threat because insiders can observe and work around security measures. Successful insider crimes depended on the perpetrators' observation and knowledge of security vulnerabilities. A fire caused 5–10 million dollars worth of damage to New York's Indian Point Energy Center in 1971. The arsonist turned out to be a plant maintenance worker. Some reactors overseas have also reported varying levels of sabotage by workers.
Many technologies and materials associated with the creation of a nuclear power program have a dual-use capability, in that they can be used to make nuclear weapons if a country chooses to do so. When this happens a nuclear power program can become a route leading to a nuclear weapon or a public annex to a "secret" weapons program. The concern over Iran's nuclear activities is a case in point.
As of April 2012 there were thirty one countries that have civil nuclear power plants, of which nine have nuclear weapons, with the vast majority of these nuclear weapons states having first produced weapons, before commercial fission electricity stations. Moreover, the re-purposing of civilian nuclear industries for military purposes would be a breach of the Non-proliferation treaty, of which 190 countries adhere to.
A fundamental goal for global security is to minimize the nuclear proliferation risks associated with the expansion of nuclear power. The Global Nuclear Energy Partnership was an international effort to create a distribution network in which developing countries in need of energy would receive nuclear fuel at a discounted rate, in exchange for that nation agreeing to forgo their own indigenous develop of a uranium enrichment program. The France-based Eurodif/European Gaseous Diffusion Uranium Enrichment Consortium is a program that successfully implemented this concept, with Spain and other countries without enrichment facilities buying a share of the fuel produced at the French controlled enrichment facility, but without a transfer of technology. Iran was an early participant from 1974, and remains a shareholder of Eurodif via Sofidif.
A 2009 United Nations report said that:
the revival of interest in nuclear power could result in the worldwide dissemination of uranium enrichment and spent fuel reprocessing technologies, which present obvious risks of proliferation as these technologies can produce fissile materials that are directly usable in nuclear weapons.
On the other hand, power reactors can also reduce nuclear weapons arsenals when military grade nuclear materials are reprocessed to be used as fuel in nuclear power plants. The Megatons to Megawatts Program, the brainchild of Thomas Neff of MIT, is the single most successful non-proliferation program to date. Up to 2005, the Megatons to Megawatts Program had processed $8 billion of high enriched, weapons grade uranium into low enriched uranium suitable as nuclear fuel for commercial fission reactors by diluting it with natural uranium. This corresponds to the elimination of 10,000 nuclear weapons. For approximately two decades, this material generated nearly 10 percent of all the electricity consumed in the United States (about half of all U.S. nuclear electricity generated) with a total of around 7 trillion kilowatt-hours of electricity produced. Enough energy to energize the entire United States electric grid for about two years. In total it is estimated to have cost $17 billion, a "bargain for US ratepayers", with Russia profiting $12 billion from the deal. Much needed profit for the Russian nuclear oversight industry, which after the collapse of the Soviet economy, had difficulties paying for the maintenance and security of the Russian Federations highly enriched uranium and warheads.
The Megatons to Megawatts Program was hailed as a major success by anti-nuclear weapon advocates as it has largely been the driving force behind the sharp reduction in the quantity of nuclear weapons worldwide since the cold war ended. However without an increase in nuclear reactors and greater demand for fissile fuel, the cost of dismantling and down blending has dissuaded Russia from continuing their disarmament. As of 2013 Russia appears to not be interested in extending the program.
Nuclear power is one of the leading low carbon power generation methods of producing electricity, and in terms of total life-cycle greenhouse gas emissions per unit of energy generated, has emission values comparable to or lower than renewable energy. A 2014 analysis of the carbon footprint literature by the Intergovernmental Panel on Climate Change (IPCC) reported that the embodied total life-cycle emission intensity of fission electricity has a median value of 12 g CO2eq/kWh, which is the lowest out of all commercial baseload energy sources. This is contrasted with coal and natural gas at 820 and 490 g CO2 eq/kWh. From the beginning of its commercialization in the 1970s, nuclear power has prevented the emission of about 64 billion tonnes of carbon dioxide equivalent that would have otherwise resulted from the burning of fossil fuels in thermal power stations.
The variation in a person's absorbed natural background radiation, averages 2.4 mSv/a globally but frequently varies between 1 mSv/a and 13 mSv/a depending in most part on the geology a person resides upon. According to the United Nations (UNSCEAR), regular NPP/nuclear power plant operations including the nuclear fuel cycle, increases this amount to 0.0002 millisieverts (mSv) per year of public exposure as a global average. The average dose from operating NPPs to the local populations around them is less than 0.0001 mSv/a. The average dose to those living within 50 miles of a coal power plant is over three times this dose, 0.0003 mSv/a.
As of a 2008 report, Chernobyl resulted in the most affected surrounding populations and male recovery personnel receiving an average initial 50 to 100 mSv over a few hours to weeks, while the remaining global legacy of the worst nuclear power plant accident in average exposure is 0.002 mSv/a and is continually dropping at the decaying rate, from the initial high of 0.04 mSv per person averaged over the entire populace of the Northern Hemisphere in the year of the accident in 1986.
Slowing global warming requires a transition to a low-carbon economy, mainly by burning far less fossil fuel. Limiting global warming to 1.5 degrees C is technically possible if no new fossil fuel power plants are built from 2019. This has generated considerable interest and dispute in determining the best path forward to rapidly replace fossil-based fuels in the global energy mix, with the intense academic debate, having notably involved the filing of a lawsuit by one of the lead advocates for a proposed 100% renewable energy future.
While an approximate doubling of present world hydro capacity is considered possible in developing nations, in western nations by contrast, the economically feasible geography for new hydropower is lacking, with every geographically suitable area largely already exploited.
Some analysts argue that conventional renewable energy sources, wind and solar do not offer the scalability necessary for a large scale decarbonization of the electric grid, mainly due to intermittency-related considerations. Along with other commentators who have questioned the links between the anti-nuclear movement and the fossil fuel industry. These commentators point, in support of the assessment, to the expansion of the coal burning Lippendorf Power Station in Germany and in 2015 the opening of a large, 1730 MW coal burning power station in Moorburg, the only such coal burning facility of its kind to commence operations, in Western Europe in the 2010s. Germany is likely to miss its 2020 emission reduction target.
Several studies suggest that it might be theoretically possible to cover a majority of world energy generation with new renewable sources. The Intergovernmental Panel on Climate Change (IPCC) has said that if governments were supportive, renewable energy supply could account for close to 80% of the world's energy use by 2050.
Analysis in 2015 by professor and chair of Environmental Sustainability Barry W. Brook and his colleagues on the topic of replacing fossil fuels entirely, from the electric grid of the world, has determined that at the historically modest and proven-rate at which nuclear energy was added to and replaced fossil fuels in France and Sweden during each nation's building programs in the 1980s, nuclear energy could displace or remove fossil fuels from the electric grid completely within 10 years, "allow[ing] the world to meet the most stringent greenhouse-gas mitigation targets".
In a similar analysis, Brook had earlier determined that 50% of all global energy, that is not solely electricity, but transportation synthetic fuels etc. could be generated within approximately 30 years, if the global nuclear fission build rate was identical to each of these nation's already proven installation rates in units of installed nameplate capacity, GW per year, per unit of global GDP (GW/year/$). This is in contrast to the conceptual studies for a 100% renewable energy world, which would require an orders of magnitude more costly global investment per year, which has no historical precedent, along with far greater land that would have to be devoted to the wind, wave and solar projects, and the inherent assumption that humanity will use less, and not more, energy in the future. As Brook notes, the "principal limitations on nuclear fission are not technical, economic or fuel-related, but are instead linked to complex issues of societal acceptance, fiscal and political inertia, and inadequate critical evaluation of the real-world constraints facing [the other] low-carbon alternatives."
In some countries which aim to burn a lot less fossil fuels, such as the UK, there is a lack of seasonal energy storage, so having renewables supply over 60% of electricity would be expensive. Whether interconnectors or new nuclear would be more expensive than taking renewables over 60% is currently (2019] being researched and debated.
Nuclear power is comparable to, and in some cases lower, than many renewable energy sources in terms of lives lost per unit of electricity delivered. However, as opposed to renewable energy, conventional designs for nuclear reactors produce a smaller volume of manufacture and operations related waste, most notably, the intensely radioactive spent fuel that needs to be stored or reprocessed. A nuclear plant also needs to be disassembled and removed and much of the disassembled nuclear plant needs to be stored as low level nuclear waste for a few decades.
In an EU wide 2018 assessment of progress in reducing greenhouse gas emissions per capita, France and Sweden were the only two large industrialized nations within the EU to receive a positive rating, as every other country received a "poor" to "very poor" grade.
A 2018 analysis by MIT argued that, to be much more cost-effective as they approach deep decarbonization, electricity systems should integrate baseload low carbon resources, such as nuclear, with renewables, storage and demand response.
Nuclear power stations require approximately one square kilometer of land per typical reactor whilst to produce the same electrical output, a wind farm requires 360 sq kilometers of land without obstructions. At the commonly proposed level of acreage increase for inland wind farms, on the order of 1,000,000 sq km, environmentalists and conservationists have begun to question the global renewable energy expansion proposals, as they are opposed to the frequently controversial use of once forested land to situate renewable energy systems. Seventy five academic conservationists signed a letter, suggesting a more effective policy to mitigate climate change involving the reforestation of this land proposed for renewable energy production, to its prior natural landscape, by means of the native trees that previously inhabited it, in tandem with the lower land use footprint of nuclear energy, as the path to assure both the commitment to carbon emission reductions and to succeed with landscape rewilding programs that are part of the global native species protection and re-introduction initiatives.
These, mostly biological scientists, argue that government commitments to increase renewable energy usage while simultaneously making commitments to expand areas of biological conservation, are two competing land use outcomes, in opposition to one another, that are increasingly coming into conflict. With the existing protected areas for conservation at present regarded as insufficient to safeguard biodiversity "the conflict for space between energy production and habitat will remain one of the key future conservation issues to resolve."
The nuclear power debate concerns the controversy which has surrounded the deployment and use of nuclear fission reactors to generate electricity from nuclear fuel for civilian purposes. The debate about nuclear power peaked during the 1970s and 1980s, when it "reached an intensity unprecedented in the history of technology controversies", in some countries.
Proponents of nuclear energy regard it as a sustainable energy source that reduces carbon emissions and increases energy security by decreasing dependence on imported energy sources. M. King Hubbert, who popularized the concept of peak oil, saw oil as a resource that would run out and considered nuclear energy its replacement. Proponents also claim that the present quantity of nuclear waste is small and can be reduced through the latest technology of newer reactors, and that the operational safety record of fission-electricity is unparalleled.
Opponents believe that nuclear power poses many threats to people and the environment such as the risk of nuclear weapons proliferation and terrorism. They also contend that reactors are complex machines where many things can and have gone wrong. In years past, they also argued that when all the energy-intensive stages of the nuclear fuel chain are considered, from uranium mining to nuclear decommissioning, nuclear power is neither a low-carbon nor an economical electricity source.
Current fission reactors in operation around the world are second or third generation systems, with most of the first-generation systems having been already retired. Research into advanced generation IV reactor types was officially started by the Generation IV International Forum (GIF) based on eight technology goals, including to improve economics, safety, proliferation resistance, natural resource utilization and the ability to consume existing nuclear waste in the production of electricity. Most of these reactors differ significantly from current operating light water reactors, and are expected to be available for commercial construction after 2030.
Hybrid nuclear power is a proposed means of generating power by use of a combination of nuclear fusion and fission processes. The concept dates to the 1950s, and was briefly advocated by Hans Bethe during the 1970s, but largely remained unexplored until a revival of interest in 2009, due to delays in the realization of pure fusion. When a sustained nuclear fusion power plant is built, it has the potential to be capable of extracting all the fission energy that remains in spent fission fuel, reducing the volume of nuclear waste by orders of magnitude, and more importantly, eliminating all actinides present in the spent fuel, substances which cause security concerns.
Nuclear fusion reactions have the potential to be safer and generate less radioactive waste than fission. These reactions appear potentially viable, though technically quite difficult and have yet to be created on a scale that could be used in a functional power plant. Fusion power has been under theoretical and experimental investigation since the 1950s.
Several experimental nuclear fusion reactors and facilities exist. The largest and most ambitious international nuclear fusion project currently in progress is ITER, a large tokamak under construction in France. ITER is planned to pave the way for commercial fusion power by demonstrating self-sustained nuclear fusion reactions with positive energy gain. Construction of the ITER facility began in 2007, but the project has run into many delays and budget overruns. The facility is now not expected to begin operations until the year 2027—11 years after initially anticipated. A follow on commercial nuclear fusion power station, DEMO, has been proposed. There are also suggestions for a power plant based upon a different fusion approach, that of an inertial fusion power plant.
Fusion powered electricity generation was initially believed to be readily achievable, as fission-electric power had been. However, the extreme requirements for continuous reactions and plasma containment led to projections being extended by several decades. In 2010, more than 60 years after the first attempts, commercial power production was still believed to be unlikely before 2050.
Nuclear power has lower electricity related health risks than Coal, Oil, & gas. ...the health burdens are appreciably smaller for generation from natural gas, and lower still for nuclear power. This study includes the latent or indirect fatalities, for example those caused by the inhalation of fossil fuel created particulate matter, smog induced cardiopulmonary events, black lung etc. in its comparison.
world average concentration in seawater is 0.05 μg/L (Harmsen and De Haan 1980)
Today's primary sources of energy are mainly non-renewable: natural gas, oil, coal, peat, and conventional nuclear power. There are also renewable sources, including wood, plants, dung, falling water, geothermal sources, solar, tidal, wind, and wave energy, as well as human and animal muscle-power. Nuclear reactors that produce their own fuel ('breeders') and eventually fusion reactors are also in this category
Collectively, life cycle assessment literature shows that nuclear power is similar to other renewable and much lower than fossil fuel in total life cycle GHG emissions.
The anti-nuclear movement is a social movement that opposes various nuclear technologies. Some direct action groups, environmental movements, and professional organisations have identified themselves with the movement at the local, national, or international level. Major anti-nuclear groups include Campaign for Nuclear Disarmament, Friends of the Earth, Greenpeace, International Physicians for the Prevention of Nuclear War, Peace Action and the Nuclear Information and Resource Service. The initial objective of the movement was nuclear disarmament, though since the late 1960s opposition has included the use of nuclear power. Many anti-nuclear groups oppose both nuclear power and nuclear weapons. The formation of green parties in the 1970s and 1980s was often a direct result of anti-nuclear politics.Scientists and diplomats have debated nuclear weapons policy since before the atomic bombings of Hiroshima and Nagasaki in 1945. The public became concerned about nuclear weapons testing from about 1954, following extensive nuclear testing in the Pacific. In 1963, many countries ratified the Partial Test Ban Treaty which prohibited atmospheric nuclear testing.Some local opposition to nuclear power emerged in the early 1960s, and in the late 1960s some members of the scientific community began to express their concerns. In the early 1970s, there were large protests about a proposed nuclear power plant in Wyhl, West Germany. The project was cancelled in 1975 and anti-nuclear success at Wyhl inspired opposition to nuclear power in other parts of Europe and North America. Nuclear power became an issue of major public protest in the 1970s and while opposition to nuclear power continues, increasing public support for nuclear power has re-emerged over the last decade in light of growing awareness of global warming and renewed interest in all types of clean energy (see the Pro-nuclear movement).
A protest against nuclear power occurred in July 1977 in Bilbao, Spain, with up to 200,000 people in attendance. Following the Three Mile Island accident in 1979, an anti-nuclear protest was held in New York City, involving 200,000 people. In 1981, Germany's largest anti-nuclear power demonstration took place to protest against the Brokdorf Nuclear Power Plant west of Hamburg; some 100,000 people came face to face with 10,000 police officers. The largest protest was held on June 12, 1982, when one million people demonstrated in New York City against nuclear weapons. A 1983 nuclear weapons protest in West Berlin had about 600,000 participants. In May 1986, following the Chernobyl disaster, an estimated 150,000 to 200,000 people marched in Rome to protest against the Italian nuclear program. In the US, public opposition preceded the shutdown of the Shoreham, Yankee Rowe, Millstone 1, Rancho Seco, Maine Yankee, and many other nuclear power plants.
For many years after the 1986 Chernobyl disaster nuclear power was off the policy agenda in most countries, and the anti-nuclear power movement seemed to have won its case. Some anti-nuclear groups disbanded. In the 2000s (decade), however, following public relations activities by the nuclear industry, advances in nuclear reactor designs, and concerns about climate change, nuclear power issues came back into energy policy discussions in some countries. The 2011 Japanese nuclear accidents subsequently undermined the nuclear power industry's proposed renaissance and revived nuclear opposition worldwide, putting governments on the defensive. As of 2016, countries such as Australia, Austria, Denmark, Greece, Malaysia, New Zealand, and Norway have no nuclear power stations and remain opposed to nuclear power. Germany, Italy, Spain, and Switzerland are phasing-out nuclear power Sweden formerly had a nuclear phase-out policy, aiming to end nuclear power generation in Sweden by 2010. On 5 February 2009, the Government of Sweden announced an agreement allowing for the replacement of existing reactors, effectively ending the phase-out policy.
Globally, more nuclear power reactors have closed than opened in recent years.Chernobyl Nuclear Power Plant
The Chernobyl Nuclear Power Plant or Chernobyl Nuclear Power Station (Ukrainian: Чорнобильська атомна електростанція, Chornobyls'ka Atomna Elektrostantsiya, Russian: Чернобыльская АЭС, Chernobyl'skaya AES) is a decommissioned nuclear power station near the city of Pripyat, Ukraine, 14.5 km (9.0 mi) northwest of the city of Chernobyl, 16 km (9.9 mi) from the Belarus–Ukraine border, and about 110 km (68 mi) north of Kiev. Reactor Number 4 was the site of the Chernobyl disaster in 1986 and the power plant is now within a large restricted area known as the Chernobyl Exclusion Zone. Both the zone and the former power plant are administered by the State Agency of Ukraine of the Exclusion Zone (Ministry of Ecology and Natural Resources). All four reactors have been shut down.
The nuclear power plant site clean-up is scheduled for completion in 2065. On January 3, 2010, a Ukrainian law stipulating a programme toward this objective came into effect.Fukushima Daiichi Nuclear Power Plant
The Fukushima Daiichi Nuclear Power Plant (福島第一原子力発電所, Fukushima Daiichi Genshiryoku Hatsudensho) is a disabled nuclear power plant located on a 3.5-square-kilometre (860-acre) site in the towns of Ōkuma and Futaba in the Fukushima Prefecture, Japan. The plant suffered major damage from the magnitude 9.0 earthquake and tsunami that hit Japan on March 11, 2011. The chain of events caused radiation leaks and permanently damaged several reactors, making them impossible to restart. By political decision, the remaining reactors were not restarted.
First commissioned in 1971, the plant consists of six boiling water reactors. These light water reactors drove electrical generators with a combined power of 4.7 GWe, making Fukushima Daiichi one of the 15 largest nuclear power stations in the world. Fukushima was the first nuclear plant to be designed, constructed and run in conjunction with General Electric and Tokyo Electric Power Company (TEPCO).The March 2011 disaster disabled the reactor cooling systems, leading to releases of radioactivity and triggering a 30 km evacuation zone surrounding the plant; the releases continue to this day. On April 20, 2011, the Japanese authorities declared the 20 km evacuation zone a no-go area which may only be entered under government supervision.
In April 2012, Units 1-4 were decommissioned. Units 2-4 were decommissioned on April 19, while Unit 1 was the last of these four units to be decommissioned on April 20 at midnight. In December 2013 TEPCO decided none of the undamaged units will reopen.
The sister nuclear plant Fukushima Daini ("number two"), 12 km (7.5 mi) to the south, is also run by TEPCO. It also suffered serious damages during the tsunami, especially at the seawater intakes of all four units, but could be shut down and brought to a safe state through extraordinary actions by the plant crew.Fukushima Daiichi nuclear disaster
The Fukushima Daiichi nuclear disaster (福島第一原子力発電所事故, Fukushima Dai-ichi (pronunciation) genshiryoku hatsudensho jiko) was an energy accident at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima Prefecture, initiated primarily by the tsunami following the Tōhoku earthquake on 11 March 2011. Immediately after the earthquake, the active reactors automatically shut down their sustained fission reactions. However, the ensuing tsunami disabled the emergency generators that would have provided power to control and operate the pumps necessary to cool the reactors. The insufficient cooling led to three nuclear meltdowns, hydrogen-air explosions, and the release of radioactive material in Units 1, 2 and 3 from 12 to 15 March. Loss of cooling also raised concerns over the recently loaded spent fuel pool of Reactor 4, which increased in temperature on 15 March due to the decay heat from the freshly added spent fuel rods but did not boil down to exposure.On 5 July 2012, the Fukushima Nuclear Accident Independent Investigation Commission (NAIIC) found that the causes of the accident had been foreseeable, and that the plant operator, Tokyo Electric Power Company (TEPCO), had failed to meet basic safety requirements such as risk assessment, preparing for containing collateral damage, and developing evacuation plans. On 12 October 2012, TEPCO admitted for the first time that it had failed to take necessary measures for fear of inviting lawsuits or protests against its nuclear plants.The Fukushima disaster was the most significant nuclear incident since the 26 April 1986 Chernobyl disaster and the second disaster to be given the Level 7 event classification of the International Nuclear Event Scale. As of September 2018, one cancer fatality was the subject of a financial settlement, to the family of a former station workman. The United Nations Scientific Committee on the Effects of Atomic Radiation and World Health Organization report that there will be no increase in miscarriages, stillbirths or physical and mental disorders in babies born after the accident. Controversially, an estimated 1,600 deaths are believed to have occurred, primarily in the elderly, who had earlier lived in nursing homes, due to the resultant poor ad hoc evacuation conditions.There is an ongoing intensive Fukushima disaster cleanup program to both decontaminate affected areas and decommission the plant, which the plant management estimate will take some 30 or 40 years. A frozen soil barrier has been constructed in an attempt to prevent further contamination of seeping groundwater, but in July 2016 TEPCO revealed that the ice wall had failed to totally stop groundwater from flowing in and mixing with highly radioactive water inside the wrecked reactor buildings, adding that they are "technically incapable of blocking off groundwater with the frozen wall".In February 2017, TEPCO released images taken inside Reactor 2 by a remote-controlled camera that show there is a 2-meter (6.5 ft) wide hole in the metal grating under the pressure vessel in the reactor's primary containment vessel, which could have been caused by fuel escaping the pressure vessel, indicating a meltdown/melt-through had occurred, through this layer of containment. Radiation levels of about 210 Sv per hour were subsequently detected inside the Unit 2 containment vessel. These values are in the context of undamaged spent fuel which has typical values of 270 Sv/h, after 10 years of cold shutdown, with no shielding.List of nuclear power stations
The following page lists all nuclear power stations that are larger than 1,000 MW in current net capacity. Those power stations that are smaller than 1,000 MW, and those that are only at a planning or proposal stage, may be found in regional lists at the end of the page or in the list of nuclear reactors. The list is based on figures from PRIS (Power Reactor Information System) maintained by International Atomic Energy Agency.Madras Atomic Power Station
Madras Atomic Power Station (MAPS) located at Kalpakkam about 80 kilometres (50 mi) south of Chennai, India, is a comprehensive nuclear power production, fuel reprocessing, and waste treatment facility that includes plutonium fuel fabrication for fast breeder reactors (FBRs). It is also India's first fully indigenously constructed nuclear power station, with two units each generating 220 MW of electricity. The first and second units of the station went critical in 1983 and 1985 respectively. The station has reactors housed in a reactor building with double shell containment improving protection also in the case of a loss-of-coolant accident. An Interim Storage Facility (ISF) is also located in Kalpakkam.Nuclear Power School
Nuclear Power School is a technical school operated by the U.S. Navy in Goose Creek, South Carolina to train enlisted sailors, officers, KAPL civilians and Bettis civilians for shipboard nuclear power plant operation and maintenance of surface ships and submarines in the U.S. nuclear navy.
The United States Navy currently operates 95 total nuclear power plants including 71 submarines (each with one reactor), 10 aircraft carriers (each with two reactors), and 4 training/research prototype plants.Nuclear and radiation accidents and incidents
A nuclear and radiation accident is defined by the International Atomic Energy Agency (IAEA) as "an event that has led to significant consequences to people, the environment or the facility." Examples include lethal effects to individuals, radioactive isotope to the environment, or reactor core melt." The prime example of a "major nuclear accident" is one in which a reactor core is damaged and significant amounts of radioactive isotopes are released, such as in the Chernobyl disaster in 1986.The impact of nuclear accidents has been a topic of debate since the first nuclear reactors were constructed in 1954, and has been a key factor in public concern about nuclear facilities. Technical measures to reduce the risk of accidents or to minimize the amount of radioactivity released to the environment have been adopted, however human error remains, and "there have been many accidents with varying impacts as well near misses and incidents". As of 2014, there have been more than 100 serious nuclear accidents and incidents from the use of nuclear power. Fifty-seven accidents have occurred since the Chernobyl disaster, and about 60% of all nuclear-related accidents have occurred in the USA. Serious nuclear power plant accidents include the Fukushima Daiichi nuclear disaster (2011), Chernobyl disaster (1986), Three Mile Island accident (1979), and the SL-1 accident (1961). Nuclear power accidents can involve loss of life and large monetary costs for remediation work.Nuclear-powered submarine accidents include the K-19 (1961), K-11 (1965), K-27 (1968), K-140 (1968), K-429 (1970), K-222 (1980), and K-431 (1985). Serious radiation incidents/accidents include the Kyshtym disaster, Windscale fire, radiotherapy accident in Costa Rica, radiotherapy accident in Zaragoza, radiation accident in Morocco, Goiania accident, radiation accident in Mexico City, radiotherapy unit accident in Thailand, and the Mayapuri radiological accident in India.The IAEA maintains a website reporting recent accidents.Nuclear power by country
Nuclear power plants currently operate in 31 countries.
Most are in Europe, North America, East Asia and South Asia.
The United States is the largest producer of nuclear power, while France has the largest share of electricity generated by nuclear power.
In 2010, before the Fukushima Daiichi nuclear disaster, it was reported that an average of about 10 nuclear reactors were expected to become operational per year, although according to the World Nuclear Association, of the 17 civilian reactors planned to become operational between 2007 and 2009, only five actually came on stream.
Global nuclear electricity generation in 2012 was at its lowest level since 1999.China has the fastest growing nuclear power program with 28 new reactors under construction, and a considerable number of new reactors are also being built in India, Russia and South Korea.
At the same time, at least 100 older and smaller reactors will "most probably be closed over the next 10–15 years".Some countries operated nuclear reactors in the past but have currently no operating nuclear plants.
Among them, Italy closed all of its nuclear stations by 1990 and nuclear power has since been discontinued because of the 1987 referendums on which Italians voted.
Lithuania, Kazakhstan and Armenia are planning to reintroduce nuclear power in the future.
Several countries are currently operating nuclear power plants but are planning a nuclear power phase-out.
These are Belgium, Germany, Spain, and Switzerland.
Other countries, like Netherlands, Sweden, and Taiwan are also considering a phase-out.
Austria never started to use its first nuclear plant that was completely built.
Due to financial, political and technical reasons, Cuba, Libya, North Korea, and Poland never completed the construction of their first nuclear plants, and Australia, Azerbaijan, Georgia, Ghana, Ireland, Kuwait, Oman, Peru, Singapore, and Venezuela never built their planned first nuclear plants.Nuclear power debate
The nuclear power debate is a long-running controversy about the risks and benefits of using nuclear reactors to generate electricity for civilian purposes. The debate about nuclear power peaked during the 1970s and 1980s, as more and more reactors were built and came online, and "reached an intensity unprecedented in the history of technology controversies" in some countries. Thereafter, the nuclear industry created jobs, focused on safety and public concerns mostly waned. In the last decade, however, with growing public awareness about climate change and the critical role that carbon dioxide and methane emissions plays in causing the heating of the earth's atmosphere, there's been a resurgence in the intensity nuclear power debate once again. Nuclear power advocates and those who are most concerned about climate change point to nuclear power's reliable, emission-free, high-density energy and a generation of young physicists and engineers working to bring a new generation of nuclear technology into existence to replace fossil fuels. On the other hand, skeptics can point to two frightening nuclear accidents, the Chernobyl disaster in 1986 and subsequently the Fukushima Daiichi nuclear disaster, combined with escalating acts of global terrorism, to argue against continuing use of the technology.
The debate continues today between those who fear the power of nuclear and those who fear what will happen to the earth if humanity doesn't use nuclear power. At the 1963 ground-breaking for what would become the world's largest nuclear power plant, President John F. Kennedy declared that nuclear power was a "step on the long road to peace," and that by using "science and technology to achieve significant breakthroughs" that we could "conserve the resources" to leave the world in better shape. Yet he also acknowledged that the Atomic Age was a "dreadful age" and "when we broke the atom apart, we changed the history of the world."Proponents of nuclear energy argue that nuclear power is a clean and sustainable energy source which provides huge amounts of uninterrupted energy without polluting the atmosphere or emitting the carbon emissions that cause global warming. Use of nuclear power provides plentiful, well-paying jobs, energy security, reduces a dependence on imported fuels and exposure to price risks associated with resource speculation and Middle East politics. Proponents advance the notion that nuclear power produces virtually no air pollution, in contrast to the massive amount of pollution and carbon emission generated from burning fossil fuels like coal, oil and natural gas. Modern society demands always-on energy to power communications, computer networks, transportation, industry and residences at all times of day and night. In the absence of nuclear power, utilities need to burn fossil fuels to keep the energy grid reliable, even with access to solar and wind energy, because those sources are intermittent. Proponents also believe that nuclear power is the only viable course for a country to achieve energy independence while also meeting their "ambitious" nationally determined contributions (NDC's) to reduce carbon emissions in accordance with the Paris Agreement signed by 195 nations. They emphasize that the risks of storing waste are small and existing stockpiles can be reduced by using this waste to produce fuels for the latest technology in newer reactors. The operational safety record of nuclear is excellent when compared to the other major kinds of power plants and by preventing pollution, actually saves lives every year.Opponents say that nuclear power poses numerous threats to people and the environment and point to studies in the literature that question if it will ever be a sustainable energy source. These threats include health risks, accidents and environmental damage from uranium mining, processing and transport. Along with the fears associated with nuclear weapons proliferation, nuclear power opponents fear sabotage by terrorists of nuclear plants, diversion and misuse of radioactive fuels or fuel waste, as well as naturally-occurring leakage from the unsolved and imperfect long-term storage process of radioactive nuclear waste. They also contend that reactors themselves are enormously complex machines where many things can and do go wrong, and there have been many serious nuclear accidents. Critics do not believe that these risks can be reduced through new technology. They further argue that when all the energy-intensive stages of the nuclear fuel chain are considered, from uranium mining to nuclear decommissioning, nuclear power is not a low-carbon electricity source.Nuclear power in China
As of September 2018, China has 44 nuclear reactors in operation with a capacity of 40.6 GW and 13 under construction with a capacity of 14 GW.
Additional reactors are planned for an additional 36 GW.
China was planning to have 58 GW of capacity by 2020. However, few plants have commenced construction since 2015, and it is now unlikely that this target will be met.Nuclear power contributed 3% of the total electricity production in 2015, with 170 TWh, and was the fastest-growing electricity source, with 29% growth over 2014.
Nuclear generation increased again in 2016 to 213 TWh, a 25% increase, and in 2017 to 246 TWh, a 15% increase.
China ranks fourth in the world in total nuclear power capacity installed, and third by nuclear power generated.
Due to increasing concerns about air quality, climate change and fossil fuel shortages, nuclear power has been looked into as an alternative to coal.
China's National Development and Reform Commission has indicated the intention to raise the percentage of China's electricity produced by nuclear power from the current 3% to 6% by 2020 (compared to 20% in the United States and 74% in France).
More long-term plans for future capacity are 120-150 GW by 2030.
China has two major nuclear power companies, the China National Nuclear Corporation operating mainly in north-east China, and the China General Nuclear Power Group, - formerly known as China Guangdong Nuclear Power Group, - operating mainly in south-east China.China aims to maximize self-reliance on nuclear reactor technology manufacturing and design, although international cooperation and technology transfer are also encouraged.
Advanced pressurized water reactors such as the Hualong One and the AP1000 are the mainstream technology in the near future, and the Hualong One is also planned to be exported.
By mid-century fast neutron reactors are seen as the main technology, with a planned 1400 GW capacity by 2100.
China is also involved in the development of nuclear fusion reactors through its participation in the ITER project, having constructed an experimental nuclear fusion reactor known as EAST located in Hefei, as well as research and development into the thorium fuel cycle as a potential alternative means of nuclear fission.Nuclear power in India
Nuclear power is the fifth-largest source of electricity in India after coal, gas, hydroelectricity and wind power. As of March 2018, India has 22 nuclear reactors in operation in 7 nuclear power plants, having a total installed capacity of 6,780 MW. Nuclear power produced a total of 35 TWh and supplied 3.22% of Indian electricity in 2017. 6 more reactors are under construction with a combined generation capacity of 4,300 MW.
In October 2010, India drew up a plan to reach a nuclear power capacity of 63 GW in 2032, but after the 2011 Fukushima nuclear disaster in Japan people around proposed Indian nuclear power plant sites have launched protests, raising questions about atomic energy as a clean and safe alternative to fossil fuels.
There have been mass protests against the French-backed 9,900 MW Jaitapur Nuclear Power Project in Maharashtra and the Russian-backed 2,000 MW Kudankulam Nuclear Power Plant in Tamil Nadu.
The state government of West Bengal, has also refused permission to a proposed 6,000 MW facility near the town of Haripur that intended to host six Russian reactors.
A Public Interest Litigation (PIL) has also been filed against the government’s civil nuclear programme at the Supreme Court.The capacity factor of Indian reactors was at 79% in the year 2011-12 compared to 71% in 2010-11.
Nine out of twenty Indian reactors recorded 97% capacity factor during 2011-12.
With the imported uranium from France, the 220 MW Kakrapar 2 PHWR reactors recorded 99% capacity factor during 2011-12.
The Availability factor for the year 2011-12 was at 89%.
India has been making advances in the field of thorium-based fuels, working to design and develop a prototype for an atomic reactor using thorium and low-enriched uranium, a key part of India's three stage nuclear power programme. The country has also recently re-initiated its involvement in the LENR research activities, in addition to supporting work done in the fusion power area through the ITER initiative.Nuclear power in Pakistan
As of 2017, nuclear power in Pakistan is provided by 5 commercial nuclear power plants. Pakistan is the first Muslim country in the world to construct and operate civil nuclear power plants. The Pakistan Atomic Energy Commission (PAEC), the scientific and nuclear governmental agency, is solely responsible for operating these power plants.
As of 2012, the electricity generated by commercial nuclear power plants constitutes roughly ~3.6% of electricity generated in Pakistan, compared to ~62% from fossil fuel, ~33% from hydroelectric power and ~0.3% from coal electricity. Pakistan is not a party to the Nuclear Non-Proliferation Treaty but is a member of the International Atomic Energy Agency. Pakistan plans on constructing 32 nuclear power plants by 2050.Nuclear power in the United Kingdom
Nuclear power in the United Kingdom generates around a quarter of the country's electricity as of 2016, projected to rise to a third by 2035. The UK has 15 operational nuclear reactors at seven plants (14 advanced gas-cooled reactors (AGR) and one pressurised water reactor (PWR)), as well as nuclear reprocessing plants at Sellafield and the Tails Management Facility (TMF) operated by Urenco in Capenhurst.
The United Kingdom established the world's first civil nuclear programme, opening a nuclear power station, Calder Hall at Windscale, England, in 1956. At the peak in 1997, 26% of the nation's electricity was generated from nuclear power. Since then several reactors have closed and by 2012 the share had declined to 19%. The older AGR reactors have been life-extended, and further life-extensions across the AGR fleet are likely.In October 2010 the British Government gave permission for private suppliers to construct up to eight new nuclear power plants. The Scottish Government, with the backing of the Scottish Parliament, has stated that no new nuclear power stations will be constructed in Scotland. In March 2012, E.ON UK and RWE npower announced they would be pulling out of developing new nuclear power plants, placing the future of nuclear power in the UK in doubt. Despite this, EDF Energy is still planning to build four new reactors at two sites, with public consultation completed and initial groundwork beginning on the first two reactors, sited at Hinkley Point in Somerset. Horizon Nuclear Power have plans for 4 to 6 new reactors at their sites, Wylfa and Oldbury. Three reactors were also proposed at the Moorside Nuclear Project but the future of these is now in doubt. An agreement has also been made which allows for Chinese-designed reactors to be built on the site of the Bradwell nuclear power station.
EDF Energy owns and manages the seven currently operating reactor sites, with a combined capacity of about 9 GW. Six new plants are proposed to be built in the next few decades. All nuclear installations in the UK are overseen by the Office for Nuclear Regulation.Nuclear power in the United States
Nuclear power in the United States is provided by 99 commercial reactors with a net capacity of 100,350 megawatts (MW), 65 pressurized water reactors and 34 boiling water reactors. In 2016 they produced a total of 805.3 terawatt-hours of electricity, which accounted for 19.7% of the nation's total electric energy generation. In 2016, nuclear energy comprised nearly 60 percent of U.S. emission-free generation.As of September 2017, there are two new reactors under construction with a gross electrical capacity of 2,500 MW, while 34 reactors have been permanently shut down. The United States is the world's largest producer of commercial nuclear power, and in 2013 generated 33% of the world's nuclear electricity.As of October 2014, the NRC has granted license renewals providing a 20-year extension to a total of 74 reactors. In early 2014, the NRC prepared to receive the first applications of license renewal beyond 60 years of reactor life, as early as 2017, a process which by law requires public involvement. Licenses for 22 reactors are due to expire before the end of the next decade if no renewals are granted. The Fort Calhoun Nuclear Generating Station was the most recent nuclear power plant to be decommissioned, on October 24, 2016. Another five aging reactors were permanently closed in 2013 and 2014 before their licenses expired because of high maintenance and repair costs at a time when natural gas prices have fallen: San Onofre 2 and 3 in California, Crystal River 3 in Florida, Vermont Yankee in Vermont, and Kewaunee in Wisconsin, and New York State is seeking to close Indian Point in Buchanan, 30 miles from New York City.Most reactors began construction by 1974; following the Three Mile Island accident in 1979 and changing economics, many planned projects were canceled. More than 100 orders for nuclear power reactors, many already under construction, were canceled in the 1970s and 1980s, bankrupting some companies. Up until 2013, there had also been no ground-breaking on new nuclear reactors at existing power plants since 1977. Then in 2012, the NRC approved construction of four new reactors at existing nuclear plants. Construction of the Virgil C. Summer Nuclear Generating Station Units 2 and 3 began on March 9, 2013 but was abandoned on July 31, 2017. On March 12, 2013 construction began on the Vogtle Electric Generating Plant Units 3 and 4, but has been stalled as the reactor supplier Westinghouse filed for bankruptcy protection on March 29, 2017. On October 19, 2016 TVA's Unit-2 reactor at the Watts Bar Nuclear Generating Station became the first US reactor to enter commercial operation since 1996.There was a revival of interest in nuclear power in the 2000s, with talk of a "nuclear renaissance", supported particularly by the Nuclear Power 2010 Program. A number of applications were made, but facing economic challenges, and later in the wake of the Fukushima Daiichi nuclear disaster, most of these projects have been cancelled, and as of 2012, "nuclear industry officials said in 2012 they expect five new reactors to enter service by 2020 – Southern's two Vogtle reactors, two at Summer in South Carolina and one at Watts Bar in Tennessee"; these are all at existing plants. As of August 1, 2017, there are construction delays at Vogtle and construction at Summer has been abandoned.Nuclear power phase-out
A nuclear power banned is the discontinuation of usage of nuclear power for energy production. Often initiated because of concerns about nuclear power, phase-outs usually include shutting down nuclear power plants and looking towards fossil fuels and renewable energy.
Three nuclear accidents have influenced the discontinuation of nuclear power: the 1979 Three Mile Island partial nuclear meltdown in the United States, the 1986 Chernobyl disaster in the USSR, and the 2011 Fukushima nuclear disaster in Japan.
As of 2018, Italy is the only country that operated nuclear reactors but has since phased out nuclear power completely.
Following the March 2011 Fukushima nuclear disaster, Germany has permanently shut down eight of its 17 reactors and pledged to close the rest by the end of 2022. Italy voted overwhelmingly to keep their country non-nuclear. Switzerland and Spain have banned the construction of new reactors. Japan’s prime minister has called for a dramatic reduction in Japan’s reliance on nuclear power. Taiwan’s president did the same. Shinzō Abe, the prime minister of Japan since December 2012, announced a plan to re-start some of the 54 Japanese nuclear power plants (NPPs) and to continue some NPP sites under construction.As of 2016, countries including Australia, Austria, Denmark, Greece, Ireland, Italy, Latvia, Liechtenstein, Luxembourg, Malaysia, Malta, New Zealand, Norway, Philippines, and Portugal have no nuclear power stations and remain opposed to nuclear power. Belgium, Germany, Spain and Switzerland are phasing-out nuclear power.
Globally, more nuclear power reactors have closed than opened in recent years but overall capacity has increased.Italy is the only country that has permanently closed all of its functioning nuclear plants. Lithuania and Kazakhstan have shut down their only nuclear plants, but plan to build new ones to replace them, while Armenia shut down its only nuclear plant but subsequently restarted it. Austria never used its first nuclear plant that was completely built. Due to financial, political and technical reasons Cuba, Libya, North Korea and Poland never completed the construction of their first nuclear plants (although North Korea and Poland plan to). Azerbaijan, Georgia, Ghana, Ireland, Kuwait, Oman, Peru, Singapore, Venezuela have planned, but not constructed their first nuclear plants. Between 2005 and 2015 the global production of nuclear power declined by 0.7%.Nuclear power plant
A nuclear power plant or nuclear power station is a thermal power station in which the heat source is a nuclear reactor. As it is typical of thermal power stations, heat is used to generate steam that drives a steam turbine connected to a generator that produces electricity. As of 23 April 2014, the IAEA report there are 450 nuclear power reactors in operation operating in 31 countries.Nuclear plants are usually considered to be base load stations since fuel is a small part of the cost of production and because they cannot be easily or quickly dispatched. Their operations and maintenance (O&M) and fuel costs are, along with hydropower stations, at the low end of the spectrum and make them suitable as base-load power suppliers. The cost of spent fuel management, however, is somewhat uncertain.Nuclear reactor
A nuclear reactor, formerly known as an atomic pile, is a device used to initiate and control a self-sustained nuclear chain reaction. Nuclear reactors are used at nuclear power plants for electricity generation and in propulsion of ships. Heat from nuclear fission is passed to a working fluid (water or gas), which in turn runs through steam turbines. These either drive a ship's propellers or turn electrical generators' shafts. Nuclear generated steam in principle can be used for industrial process heat or for district heating. Some reactors are used to produce isotopes for medical and industrial use, or for production of weapons-grade plutonium. Some are run only for research. As of early 2019, the IAEA reports there are 454 nuclear power reactors and 226 nuclear research reactors in operation around the world.Pressurized water reactor
Pressurized water reactors (PWRs) constitute the large majority of the world's nuclear power plants (notable exceptions being Japan and Canada) and are one of three types of light water reactor (LWR), the other types being boiling water reactors (BWRs) and supercritical water reactors (SCWRs). In a PWR, the primary coolant (water) is pumped under high pressure to the reactor core where it is heated by the energy released by the fission of atoms. The heated water then flows to a steam generator where it transfers its thermal energy to a secondary system where steam is generated and flows to turbines which, in turn, spin an electric generator. In contrast to a boiling water reactor, pressure in the primary coolant loop prevents the water from boiling within the reactor. All LWRs use ordinary water as both coolant and neutron moderator.
PWRs were originally designed to serve as nuclear marine propulsion for nuclear submarines and were used in the original design of the second commercial power plant at Shippingport Atomic Power Station.
PWRs currently operating in the United States are considered Generation II reactors. Russia's VVER reactors are similar to U.S. PWRs. France operates many PWRs to generate the bulk of its electricity.