New nuclear plants

EDF has said its third-generation EPR Flamanville 3 project (seen here in 2010) will be delayed until 2018, due to "both structural and economic reasons," and the project's total cost has climbed to EUR 11 billion in 2012.^[71] Similarly, the cost of the EPR being built at Olkiluoto, Finland has escalated dramatically, and the project is well behind schedule. The initial low cost forecasts for these megaprojects exhibited "optimism bias".^[72]

The economics of new nuclear power plants is a controversial subject, since there are diverging views on this topic, and multibillion-dollar investments ride on the choice of an energy source. Nuclear power plants typically have high capital costs for building the plant, but low direct fuel costs (with much of the costs of fuel extraction, processing, use and long-term storage externalized). Therefore, comparison with other power generation methods is strongly dependent on assumptions about construction timescales and capital financing for nuclear plants. Cost estimates also need to take into account plant decommissioning and nuclear waste storage costs. 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.

In recent years there has been a slowdown of electricity demand growth and financing has become more difficult, which impairs large projects such as nuclear reactors, with very large upfront costs and long project cycles which carry a large variety of risks.^[73] In Eastern Europe, a number of long-established projects are struggling to find finance, notably Belene in Bulgaria and the additional reactors at Cernavoda in Romania, and some potential backers have pulled out.^[73] The reliable availability of cheap gas poses a major economic disincentive for nuclear projects.^[73]

Analysis of the economics of nuclear power must take into account who bears the risks of future uncertainties. To date all operating nuclear power plants were developed by state-owned or regulated utility monopolies^[74] where many of the risks associated with construction costs, operating performance, fuel price, and other factors were borne by consumers rather than suppliers. 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.^[75]

Following the 2011 Fukushima Daiichi nuclear disaster, costs are likely to go up for currently operating and new nuclear power plants, due to increased requirements for on-site spent fuel management and elevated design basis threats.^[76]

New nuclear power plants require significant upfront investment which was so far mostly caused by highly customized designs of large plants but can be driven down by standardized, reusable designs (as did South Korea^[77]). While new nuclear power plants are more expensive than new renewable energy in upfront investment, the cost of the latter is expected to grow as the grid is saturated with intermittent sources and energy storage as well as land usage becomes a primary barrier to their expansion.^[78] A fleet of Small Modular Reactors can be also significantly cheaper than an equivalent single conventional size reactor due to standardized design and much smaller complexity.^[78]

In 2020 International Energy Agency called for creation of a global nuclear power licensing framework as in the existing legal situation each plant design needs to be licensed separately in each country.^[79]

Cost of decommissioning nuclear plants

The price of energy inputs and the environmental costs of every nuclear power plant continue long after the facility has finished generating its last useful electricity. Both nuclear reactors and uranium enrichment facilities must be decommissioned, returning the facility and its parts to a safe enough level to be entrusted for other uses. After a cooling-off period that may last as long as a century, reactors must be dismantled and cut into small pieces to be packed in containers for final disposal. The process is very expensive, time-consuming, potentially hazardous to the natural environment, and presents new opportunities for human error, accidents or sabotage.^[80] However, despite these risks, according to the World Nuclear Association, "In over 50 years of civil nuclear power experience, the management and disposal of civil nuclear waste has not caused any serious health or environmental problems, nor posed any real risk to the general public."^[81]

The total energy required for decommissioning can be as much as 50% more than the energy needed for the original construction. In most cases, the decommissioning process costs between US$300 million to US$5.6 billion. Decommissioning at nuclear sites which have experienced a serious accident are the most expensive and time-consuming. In the U.S. there are 13 reactors that have permanently shut down and are in some phase of decommissioning, and none of them have completed the process.^[80]

Current UK plants are expected to exceed £73 billion in decommissioning costs.^[82]

Subsidies

George W. Bush signing the Energy Policy Act of 2005, which was designed to promote US nuclear reactor construction, through incentives and subsidies, including cost-overrun support up to a total of $2 billion for six new nuclear plants.^[83]

U.S. 2014 Electricity Generation By Type.^[84]

Critics of nuclear power claim that it is the beneficiary of inappropriately large economic subsidies, taking the form of research and development, financing support for building new reactors and decommissioning old reactors and waste, and that these subsidies are often overlooked when comparing the economics of nuclear against other forms of power generation.^[85][86]

Nuclear power proponents argue that competing energy sources also receive subsidies. Fossil fuels receive large direct and indirect subsidies, such as tax benefits and not having to pay for the greenhouse gases they emit, such as through a carbon tax. Renewable energy sources receive proportionately large direct production subsidies and tax breaks in many nations, although in absolute terms they are often less than subsidies received by non-renewable energy sources.^[87]

In Europe, the FP7 research program has more subsidies for nuclear power than for renewable and energy efficiency together; over 70% of this is directed at the ITER fusion project.^[88][89] In the US, public research money for nuclear fission declined from 2,179 to 35 million dollars between 1980 and 2000.^[87]

A 2010 report by Global Subsidies Initiative compared relative subsidies of most common energy sources. It found that nuclear energy receives 1.7 US cents per kilowatt hour (kWh) of energy it produces, compared to fossil fuels receiving 0.8 US cents per kWh, renewable energy receiving 5.0 US cents per kWh and biofuels receiving 5.1 US cents per kWh.^[90]

Carbon taxation is a significant positive driver in the economy of both nuclear plants and renewable energy sources, all of which are low emissions in their life-cycle greenhouse-gas emissions.^[78]

In 2019 a heated debate happened in the European Union on creation of a "green finance taxonomy" list intended to create investment opportunities for zero-emission energy technologies. Initially the basic criterion for inclusion was life-cycle emissions at 100 gCO2eq/kWh or less which would include nuclear power which falls well under this threshold (12). Under lobbying from European Greens and Germany an additional "do no harm" criterion was introduced specifically to exclude nuclear power which in their intention should exclude nuclear power from the list.^[91][92]

In July 2020 W. Gyude Moore, former Liberia's Minister for Public Works, called international bodies to start (or restart) funding for nuclear projects in Africa, following the example of US Development Finance Corporation. Moore accused high-income countries like Germany and Australia of "hypocrisy" and "pulling up the ladder behind them", as they have built their strong economy over decades of cheap fossil or nuclear power, and now are effectively preventing African countries from using the only low-carbon and non-intermittent alternative, the nuclear power.^[93]

Also in July 2020 Hungary declared its nuclear power will be used as low-emission source of energy to produce hydrogen,^[94] while Czechia began the process of approval of public loan to CEZ nuclear power station.^[95]

EU Taxonomy

A comprehensive debate on the role of nuclear power continued since 2020 as part of regulatory work on European Union Taxonomy of environmentally sustainable technologies.^[125] Low carbon intensity of nuclear power was not disputed, but opponents raised nuclear waste and thermal pollution as not sustainable element that should exclude it from the sustainable taxonomy. Detailed technical analysis was delegated to the European Commission Joint Research Centre (JRC) which looked at all potential issues of nuclear power from scientific, engineering and regulatory point of view and in March 2021 published a 387-page report which concluded:^[26]

The analyses did not reveal any science-based evidence that nuclear energy does more harm to human health or to the environment than other electricity production technologies already included in the Taxonomy as activities supporting climate change mitigation.

— Technical assessment of nuclear energy with respect to the ‘do no significant harm’ criteria of Regulation (EU) 2020/852 (‘Taxonomy Regulation’)

The EU tasked two further expert commissions to validate JRC findings—the Euratom Article 31 expert group on radiation protection and SCHEER (Scientific Committee on Health, Environmental and Emerging Risks). Both groups published their reports in July 2021, largely confirming JRC conclusions, with a number of topics that require further investigation.^[126]

The SCHEER is of the opinion that the findings and recommendations of the report with respect of the non-radiological impacts are in the main comprehensive. (...) The SCHEER broadly agrees with these statements, however, the SCHEER is of the view that dependence on an operational regulatory framework is not in itself sufficient to mitigate these impacts, e.g. in mining and milling where the burden of the impacts are felt outside Europe.

— SCHEER review of the JRC report on Technical assessment of nuclear energy with respect to the ‘do no significant harm’ criteria of Regulation (EU) 2020/852 (‘Taxonomy Regulation’)

SCHEER also pointed out that JRC conclusion that nuclear power "does less harm" as the other (e.g. renewable) technologies against which it was compared is not entirely equivalent to the "do no significant harm" criterion postulated by the taxonomy. The JRC analysis of thermal pollution doesn't fully take into account limited water mixing in shallow waters.^[127]

The Article 31 group confirmed JRC findings:^[128]

The conclusions of the JRC report are based on well-established results of scientific research, reviewed in detail by internationally recognised organisations and committees.

— Opinion of the Group of Experts referred to in Article 31 of the Euratom Treaty on the Joint Research Centre’s Report Technical assessment of nuclear energy with respect to the ‘do no significant harm’ criteria of Regulation (EU) 2020/852 (‘Taxonomy Regulation’)

Also in July 2021 a group of 87 members of European Parliament signed an open letter calling European Commission to include nuclear power in the sustainable taxonomy following favourable scientific reports, and warned against anti-nuclear coalition that "ignore scientific conclusions and actively oppose nuclear power".^[129]

In February 2022 European Commission published the Complementary Climate Delegated Act to the taxonomy, that set specific criteria under which nuclear power may be included in sustainable energy funding schemes.^[130] Inclusion of nuclear power and fossil gas in the taxonomy was justified by scientific reports mentioned above and based primarily on very large potential of nuclear power to decarbonize electricity production.^[131] For nuclear power, the Taxonomy covers research and development of new Generation IV reactors, new nuclear power plants built with Generation III reactors and life-time extension of existing nuclear power plants. All projects must satisfy requirements as to the safety, thermal pollution and waste management.

Effect on greenhouse gas emissions

According to a 2012 study by Yale University the mean value from nuclear power ranged from 11–25 g/kWh of total life cycle CO₂ emissions with a median of 12 g/kWh^[132]

An average nuclear power plant prevents emission of 2,000,000 metric tons of CO₂, 5,200 metric tons of SO₂ and 2,200 metric tons of NO_x in a year as compared to an average fossil fuel plant.^[133]

While nuclear power does not directly emit greenhouse gases, emissions occur, as with every source of energy, over a facility's life cycle: mining and fabrication of construction materials, plant construction, operation, uranium mining and milling, and plant decommissioning.

The Intergovernmental Panel on Climate Change found a median value of 12 g (0.42 oz) equivalent lifecycle carbon dioxide emissions per kilowatt hour (kWh) for nuclear power, being one of the lowest among all energy sources and comparable only with wind power.^[134][135] Data from the International Atomic Energy Agency showed a similar result, with nuclear energy having the lowest emissions of any energy source when accounting for both direct and indirect emissions from the entire energy chain.^[14]

Climate and energy scientists James Hansen, Ken Caldeira, Kerry Emanuel and Tom Wigley have released an open letter^[136] stating, in part, that

Renewables like wind and solar and biomass will certainly play roles in a future energy economy, but those energy sources cannot scale up fast enough to deliver cheap and reliable power at the scale the global economy requires. While it may be theoretically possible to stabilize the climate without nuclear power, in the real world there is no credible path to climate stabilization that does not include a substantial role for nuclear power.

The statement was widely discussed in the scientific community, with voices both against and in favor.^[137] It has been also recognized that the life-cycle CO₂ emissions of nuclear power will eventually increase once high-grade uranium ore is used up and lower-grade uranium needs to be mined and milled using fossil fuels, although there is controversy over when this might occur.^[138][139]

As the nuclear power debate continues, greenhouse gas emissions are increasing. Predictions estimate that even with draconian emission reductions within the ten years, the world will still pass 650 ppm of carbon dioxide and a catastrophic 4 °C (7.2 °F) average rise in temperature.^[140] Public perception is that renewable energies such as wind, solar, biomass and geothermal are significantly affecting global warming.^[141] All of these sources combined only supplied 1.3% of global energy in 2013 as 8 billion tonnes (1.8×10¹³ lb) of coal was burned annually.^[142] This "too little, too late" effort may be a mass form of climate change denial, or an idealistic pursuit of green energy.

In 2015 an open letter from 65 leading biologists worldwide described nuclear power as one of the energy sources that are the most friendly to biodiversity due to its high energy density and low environmental footprint:^[143]

Much as leading climate scientists have recently advocated the development of safe, next-generation nuclear energy systems to combat climate change, we entreat the conservation and environmental community to weigh up the pros and cons of different energy sources using objective evidence and pragmatic trade-offs, rather than simply relying on idealistic perceptions of what is 'green'.

— Brave New Climate open letter

In response to 2016 Paris Agreement a number of countries explicitly listed nuclear power as part of their commitment to reduce greenhouse gas emissions.^[144] In June 2019, an open letter to "the leadership and people of Germany", written by almost 100 Polish environmentalists and scientist, urged Germany to "reconsider the decision on the final decommissioning of fully functional nuclear power plants" for the benefit of the fight against global warming.^[145]

In 2020 a group of European scientists published an open letter to the European Commission calling for inclusion of nuclear power as "element of stability in carbon-free Europe".^[146] Also in 2020 a coalition of 30 European nuclear industry companies and research bodies published an open letter highlighting that nuclear power remains the largest single source of zero-emissions energy in European Union.^[147]

In 2021 prime ministers of Hungary, France, Czech Republic, Romania, Slovak Republic, Poland and Slovenia, signed an open letter to European Commission calling for recognition of important role of nuclear power as the only non-intermittent low-carbon energy source currently available at industrial scale in Europe.^[148]

In 2021 UNECE described suggested pathways of building sustainable energy supply with increased role of low-carbon nuclear power.^[149] In April 2021 US President's Joe Biden Infrastructure Plan called for 100% of US electricity being generated from low-carbon sources of which nuclear power would be a significant component.^[150]

IEA "Net Zero by 2050" pathways published in 2021 assume growth of nuclear power capacity by 104% accompanied by 714% growth of renewable energy sources, mostly solar power.^[151] In June 2021 over 100 organisations published a position paper for the COP26 climate conference highlighting the fact that nuclear power is low-carbon dispatchable energy source that has been the most successful in reducing CO₂ emissions from the energy sector.^[152]

In August 2021 United Nations Economic Commission for Europe (UNECE) described nuclear power as important tool to mitigate climate change that has prevented 74 Gt of CO₂ emissions over the last half century, that provides 20% of energy in Europe and 43% of low-carbon energy.^[153]

Faced with increasing fossil gas prices and reopening of new coal and gas power plants, a number of European leaders questioned the anti-nuclear policies of Belgium and Germany. European Commissioner for the Internal Market Thierry Breton described shutting down of operational nuclear power plants as depriving Europe of low-carbon energy capacity. Organizations such as Climate Bonds Initiative, Stand Up for Nuclear, Nuklearia and Mothers for Nuclear Germany-Austria-Switzerland are organizing periodic events in defense of the plants due to be closed.^[154]

High-level radioactive waste

Spent nuclear fuel stored underwater and uncapped at the Hanford site in Washington

The world's nuclear fleet creates about 10,000 metric tons (22,000,000 pounds) of high-level spent nuclear fuel each year.^[14][155] High-level radioactive waste management concerns management and disposal of highly radioactive materials created during production of nuclear power. This requires the use of "geological disposal", or burial, due to the extremely long periods of time that radioactive waste remain deadly to living organisms. Of particular concern are two long-lived fission products, technetium-99 (half-life 220,000 years) and iodine-129 (half-life 15.7 million years),^[156] which dominate spent nuclear fuel radioactivity after a few thousand years. The most troublesome transuranic elements in spent fuel are neptunium-237 (half-life two million years) and plutonium-239 (half-life 24,000 years).^[157] However, many nuclear power by-products are usable as nuclear fuel themselves; extracting the usable energy producing contents from nuclear waste is called "nuclear recycling". About 80% of the byproducts can be reprocessed and recycled back into nuclear fuel,^[158] negating this effect. The remaining high-level radioactive waste requires sophisticated treatment and management to successfully isolate it from the biosphere. This usually necessitates treatment, followed by a long-term management strategy involving permanent storage, disposal or transformation of the waste into a non-toxic form.^[159]

About 95% of nuclear waste by volume is classified as very low-level waste (VLLW) or low-level waste (LLW), with 4% being intermediate-level waste (ILW) and less than 1% being high-level waste (HLW).^[160] From 1954 (the start of nuclear energy production) until the end of 2016, about 390,000 tons of spent fuel were generated worldwide. About one-third of this had been reprocessed, with the remainder being in storage.^[160]

Governments around the world are considering a range of waste management and disposal options, usually involving deep-geologic placement, although there has been limited progress toward implementing long-term waste management solutions.^[161] This is partly because the timeframes in question when dealing with radioactive waste range from 10,000 to millions of years,^[162][163] according to studies based on the effect of estimated radiation doses.^[164]

Anti-nuclear protest near nuclear waste disposal centre at Gorleben in northern Germany

Since the fraction of a radioisotope's atoms decaying per unit of time is inversely proportional to its half-life, the relative radioactivity of a quantity of buried human radioactive waste would diminish over time compared to natural radioisotopes (such as the decay chain of 120 trillion tons of thorium and 40 trillion tons of uranium which are at relatively trace concentrations of parts per million each over the crust's 3×10¹⁹ ton mass).^{[165][166][167]}

For instance, over a timeframe of thousands of years, after the most active short half-life radioisotopes decayed, burying U.S. nuclear waste would increase the radioactivity in the top 2,000 feet (610 m) of rock and soil in the United States (100 million km² or 39 million sq mi) by approximately 0.1 parts per million over the cumulative amount of natural radioisotopes in such a volume, although the vicinity of the site would have a far higher concentration of artificial radioisotopes underground than such an average.^{[168][broken link]}

Nuclear waste disposal is one of the most controversial facets of the nuclear power debate. Presently, waste is mainly stored at individual reactor sites and there are over 430 locations around the world where radioactive material continues to accumulate. Experts agree that centralized underground repositories which are well-managed, guarded, and monitored, would be a vast improvement.^[169] There is an international consensus on the advisability of storing nuclear waste in deep underground repositories,^[170] but no country in the world has yet opened such a site as of 2009.^{[170][171][172][173]} There are dedicated waste storage sites at the Waste Isolation Pilot Plant in New Mexico and two in German salt mines, the Morsleben Repository and the Schacht Asse II.

Public debate on the subject frequently focuses of nuclear waste only, ignoring the fact that existing deep geologic repositories globally (including Canada and Germany) already exist and store highly toxic waste such as arsenic, mercury and cyanide, which, unlike nuclear waste, does not lose toxicity over time.^[174] Numerous media reports about alleged "radioactive leaks" from nuclear storage sites in Germany also confused waste from nuclear plants with low-level medical waste (such as irradiated X-ray plates and devices).^[175]

European Commission Joint Research Centre report of 2021 (see above) concluded:^[26]

Management of radioactive waste and its safe and secure disposal is a necessary step in the lifecycle of all applications of nuclear science and technology (nuclear energy, research, industry, education, medical, and other). Radioactive waste is therefore generated in practically every country, the largest contribution coming from the nuclear energy lifecycle in countries operating nuclear power plants. Presently, there is broad scientific and technical consensus that disposal of high-level, long-lived radioactive waste in deep geologic formations is, at the state of today’s knowledge, considered as an appropriate and safe means of isolating it from the biosphere for very long time scales.

Prevented mortality

In March 2013, climate scientists Pushker Kharecha and James Hansen published a paper in Environmental Science & Technology, entitled Prevented mortality and greenhouse gas emissions from historical and projected nuclear power.^[176] It estimated an average of 1.8 million lives saved worldwide by the use of nuclear power instead of fossil fuels between 1971 and 2009. The paper examined mortality levels per unit of electrical energy produced from fossil fuels (coal and natural gas) as well as nuclear power. Kharecha and Hansen assert that their results are probably conservative, as they analyze only deaths and do not include a range of serious but non-fatal respiratory illnesses, cancers, hereditary effects and heart problems, nor do they include the fact that fossil fuel combustion in developing countries tends to have a higher carbon and air pollution footprint than in developed countries.^[177] The authors also conclude that the emission of some 64 billion tonnes (7.1×10¹⁰ tons) of carbon dioxide equivalent have been avoided by nuclear power between 1971 and 2009, and that between 2010 and 2050, nuclear power could additionally avoid up to 80–240 billion tonnes (8.8×10¹⁰–2.65×10¹¹ tons).

A 2020 study on Energiewende found that if Germany had postponed the nuclear phase out and phased out coal first it could have saved 1,100 lives and $12 billion in social costs per year.^[178][179]

In 2020 the Vatican has praised "peaceful nuclear technologies" as significant factor to "alleviation of poverty and the ability of countries to meet their development goals in a sustainable way".^[180]

Chernobyl steam explosion

Map showing caesium-137 contamination in Belarus, Russia, and Ukraine as of 1996.

The Chernobyl steam explosion was a nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in Ukraine. A steam explosion and graphite fire released large quantities of radioactive contamination into the atmosphere, which spread over much of Western USSR and Europe. It is considered the worst nuclear power plant accident in history, and is one of only two classified as a level 7 event on the International Nuclear Event Scale (the other being the Fukushima Daiichi nuclear disaster).^[200] The battle to contain the contamination and avert a greater catastrophe ultimately involved over 500,000 workers and cost an estimated 18 billion rubles, crippling the Soviet economy.^[201] The accident raised concerns about the safety of the nuclear power industry, slowing its expansion for a number of years.^[202]

Despite the fact the Chernobyl disaster became a nuclear power safety debate icon, there were other nuclear accidents in USSR at the Mayak nuclear weapons production plant (nearby Chelyabinsk, Russia) and total radioactive emissions in Chelyabinsk accidents of 1949, 1957 and 1967 together were significantly higher than in Chernobyl.^[203] However, the region near Chelyabinsk was and is much more sparsely populated than the region around Chernobyl.

The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has conducted 20 years of detailed scientific and epidemiological research on the effects of the Chernobyl accident. Apart from the 57 direct deaths in the accident itself, UNSCEAR predicted in 2005 that up to 4,000 additional cancer deaths related to the accident would appear "among the 600 000 persons receiving more significant exposures (liquidators working in 1986–87, evacuees, and residents of the most contaminated areas)".^[204] According to BBC, "It is conclusive that around 5,000 cases of thyroid cancer—most of which were treated and cured—were caused by the contamination. Many suspect that the radiation has caused or will cause other cancers, but the evidence is patchy. Amid reports of other health problems—including birth defects—it still is not clear if any can be attributed to radiation".^[205] Russia, Ukraine, and Belarus have been burdened with the continuing and substantial decontamination and health care costs of the Chernobyl disaster.^[206]

Fukushima disaster

The 2011 Fukushima Daiichi nuclear disaster, the worst nuclear incident in 25 years, displaced 50,000 households after radioactive material leaked into the air, soil and sea.^[207] Whereas the radiation level never was an immediate life hazard outside the plant, the displacement was the direct cause of over 1500 deaths.^[208][209] Radiation checks led to bans on some shipments of vegetables and fish.^[210]

Following an earthquake, tsunami, and failure of cooling systems at Fukushima I Nuclear Power Plant and issues concerning other nuclear facilities in Japan on 11 March 2011, a nuclear emergency was declared. This was the first time a nuclear emergency had been declared in Japan, and 140,000 residents within 20 km (12 mi) of the plant were evacuated.^[211] Explosions and a fire resulted in increased levels of radiation, sparking a stock market collapse and panic-buying in supermarkets.^[212] The UK, France and some other countries advised their nationals to consider leaving Tokyo, in response to fears of spreading nuclear contamination. The accidents drew attention to ongoing concerns over Japanese nuclear seismic design standards and caused other governments to re-evaluate their nuclear programs. John Price, a former member of the Safety Policy Unit at the UK's National Nuclear Corporation, said that it "might be 100 years before melting fuel rods can be safely removed from Japan's Fukushima nuclear plant".^[213]

Three Mile Island accident

President Jimmy Carter leaving Three Mile Island for Middletown, Pennsylvania, 1 April 1979.

The Three Mile Island accident was a core meltdown in Unit 2 (a pressurized water reactor manufactured by Babcock & Wilcox) of the Three Mile Island Nuclear Generating Station in Dauphin County, Pennsylvania near Harrisburg, United States in 1979. It was the most significant accident in the history of the US commercial nuclear power generating industry, resulting in the release of approximately 2.5 million curies of radioactive noble gases, and approximately 15 curies of iodine-131.^[214] Cleanup started in August 1979 and officially ended in December 1993, with a total cleanup cost of about $1 billion.^[215] The incident was rated a five on the seven-point International Nuclear Event Scale: Accident With Wider Consequences.^[216][217]

The health effects of the Three Mile Island nuclear accident are widely, but not universally, agreed to be very low level. However, there was an evacuation of 140,000 pregnant women and pre-school age children from the area.^{[218][219][220]} The accident crystallized anti-nuclear safety concerns among activists and the general public, resulted in new regulations for the nuclear industry, and has been cited as a contributor to the decline of new reactor construction that was already underway in the 1970s.^[221]

New reactor designs

The nuclear power industry has moved to improve engineering design. Generation IV reactors are now in late stage design and development to improve safety, sustainability, efficiency, and cost. Key to the latest designs is the concept of passive nuclear safety. Passive nuclear safety does not require operator actions or electronic feedback in order to shut down safely in the event of a particular type of emergency (usually overheating resulting from a loss of coolant or loss of coolant flow). This is in contrast to older-yet-common reactor designs, where the natural tendency for the reaction was to accelerate rapidly from increased temperatures. In such a case, cooling systems must be operative to prevent meltdown. Past design mistakes like Fukushima in Japan did not anticipate that a tsunami generated by an earthquake would disable the backup systems that were supposed to stabilize the reactor after the earthquake.^[222] New reactors with passive nuclear safety eliminate this failure mode.

The United States Nuclear Regulatory Commission has formally engaged in pre-application activities with four applicants who have Generation IV reactors. Of those four applicants' designs, two are molten salt reactors, one is a compact fast reactor, and one is a Modular High temperature gas-cooled reactor.^[223]

Health effects on population near nuclear power plants and workers

Fishermen near the now-dismantled Trojan Nuclear Power Plant in Oregon. The reactor dome is visible on the left, and the cooling tower on the right.

A major concern in the nuclear debate is what the long-term effects of living near or working in a nuclear power station are. These concerns typically center on the potential for increased risks of cancer. However, studies conducted by non-profit, neutral agencies have found no compelling evidence of correlation between nuclear power and risk of cancer.^[224]

There has been considerable research done on the effect of low-level radiation on humans. Debate on the applicability of Linear no-threshold model versus Radiation hormesis and other competing models continues, however, the predicted low rate of cancer with low dose means that large sample sizes are required in order to make meaningful conclusions. A study conducted by the National Academy of Sciences found that carcinogenic effects of radiation does increase with dose.^[225] The largest study on nuclear industry workers in history involved nearly a half-million individuals and concluded that a 1–2% of cancer deaths were likely due to occupational dose. This was on the high range of what theory predicted by LNT, but was "statistically compatible".^[226]

The Nuclear Regulatory Commission (NRC) has a factsheet that outlines 6 different studies. In 1990 the United States Congress requested the National Cancer Institute to conduct a study of cancer mortality rates around nuclear plants and other facilities covering 1950 to 1984 focusing on the change after operation started of the respective facilities. They concluded in no link. In 2000 the University of Pittsburgh found no link to heightened cancer deaths in people living within 5 miles of plant at the time of the Three Mile Island accident. The same year, the Illinois Public Health Department found no statistical abnormality of childhood cancers in counties with nuclear plants. In 2001 the Connecticut Academy of Science and Engineering confirmed that radiation emissions were negligibly low at the Connecticut Yankee Nuclear Power Plant. Also that year, the American Cancer Society investigated cancer clusters around nuclear plants and concluded no link to radiation noting that cancer clusters occur regularly due to unrelated reasons. Again in 2001, the Florida Bureau of Environmental Epidemiology reviewed claims of increased cancer rates in counties with nuclear plants, however, using the same data as the claimants, they observed no abnormalities.^[227]

Scientists learned about exposure to high level radiation from studies of the effects of bombing populations at Hiroshima and Nagasaki. However, it is difficult to trace the relationship of low level radiation exposure to resulting cancers and mutations. This is because the latency period between exposure and effect can be 25 years or more for cancer and a generation or more for genetic damage. Since nuclear generating plants have a brief history, it is early to judge the effects.^[228]

Most human exposure to radiation comes from natural background radiation. Natural sources of radiation amount to an average annual radiation dose of 295 millirems (0.00295 sieverts). The average person receives about 53 mrem (0.00053 Sv) from medical procedures and 10 mrem from consumer products per year, as of May 2011.^[229] According to the National Safety Council, people living within 50 miles (80 km) of a nuclear power plant receive an additional 0.01 mrem per year. Living within 50 miles of a coal plant adds 0.03 mrem per year.^[230]

In its 2000 report, "Sources and effects of ionizing radiation",^[231] the UNSCEAR also gives some values for areas where the radiation background is very high.^[232] You can for example have some value like 370 nanograys per hour (0.32 rad/a) on average in Yangjiang, China (meaning 3.24 mSv per year or 324 mrem), or 1,800 nGy/h (1.6 rad/a) in Kerala, India (meaning 15.8 mSv per year or 1580 mrem). They are also some other "hot spots", with some maximum values of 17,000 nGy/h (15 rad/a) in the hot springs of Ramsar, Iran (that would be equivalent to 149 mSv per year pr 14,900 mrem per year). The highest background seem to be in Guarapari with a reported 175 mSv per year (or 17,500 mrem per year), and 90,000 nGy/h (79 rad/a) maximum value given in the UNSCEAR report (on the beaches).^[232] A study made on the Kerala radiation background, using a cohort of 385,103 residents, concludes that "showed no excess cancer risk from exposure to terrestrial gamma radiation" and that "Although the statistical power of the study might not be adequate due to the low dose, our cancer incidence study [...] suggests it is unlikely that estimates of risk at low doses are substantially greater than currently believed."^[233]

Current guidelines established by the NRC, require extensive emergency planning, between nuclear power plants, Federal Emergency Management Agency (FEMA), and the local governments. Plans call for different zones, defined by distance from the plant and prevailing weather conditions and protective actions. In the reference cited, the plans detail different categories of emergencies and the protective actions including possible evacuation.^[234]

A German study on childhood cancer in the vicinity of nuclear power plants called "the KiKK study" was published in December 2007.^[235] According to Ian Fairlie, it "resulted in a public outcry and media debate in Germany which has received little attention elsewhere". It has been established "partly as a result of an earlier study by Körblein and Hoffmann^[236] which had found statistically significant increases in solid cancers (54%), and in leukemia (76%) in children aged less than 5 within 5 km (3.1 mi) of 15 German nuclear power plant sites. It red a 2.2-fold increase in leukemias and a 1.6-fold increase in solid (mainly embryonal) cancers among children living within 5 km of all German nuclear power stations."^[237] In 2011 a new study of the KiKK data was incorporated into an assessment by the Committee on Medical Aspects of Radiation in the Environment (COMARE) of the incidence of childhood leukemia around British nuclear power plants. It found that the control sample of population used for comparison in the German study may have been incorrectly selected and other possible contributory factors, such as socio-economic ranking, were not taken into consideration. The committee concluded that there is no significant evidence of an association between risk of childhood leukemia (in under 5-year olds) and living in proximity to a nuclear power plant.^[238]

European Commission Joint Research Centre report of 2021 (see above) concluded:^[26]

The average annual exposure to a member of the public, due to effects attributable to nuclear energy-based electricity production is about 0.2 microsievert, which is ten thousand times less than the average annual dose due to the natural background radiation. According to the LCIA (Life Cycle Impact Analysis) studies analysed in Chapter 3.4 of Part A, the total impact on human health of both the radiological and non-radiological emissions from the nuclear energy chain are comparable with the human health impact from offshore wind energy.

Safety culture in host nations

Some developing countries which plan to go nuclear have very poor industrial safety records and problems with political corruption.^[239] Inside China, and outside the country, the speed of the nuclear construction program has raised safety concerns. Prof. He Zuoxiu, who was involved with China's atomic bomb program, has said that plans to expand production of nuclear energy twentyfold by 2030 could be disastrous, as China was seriously underprepared on the safety front.

China's fast-expanding nuclear sector is opting for cheap technology that "will be 100 years old by the time dozens of its reactors reach the end of their lifespans", according to diplomatic cables from the US embassy in Beijing.^[240] The rush to build new nuclear power plants may "create problems for effective management, operation and regulatory oversight" with the biggest potential bottleneck being human resources—"coming up with enough trained personnel to build and operate all of these new plants, as well as regulate the industry".^[240] The challenge for the government and nuclear companies is to "keep an eye on a growing army of contractors and subcontractors who may be tempted to cut corners".^[241] China is advised to maintain nuclear safeguards in a business culture where quality and safety are sometimes sacrificed in favor of cost-cutting, profits, and corruption. China has asked for international assistance in training more nuclear power plant inspectors.^[241]

Vulnerability of plants to attack

Development of covert and hostile nuclear installations was occasionally prevented by military operations in what is described as "radical counter-proliferation" activities.^[249][250]

• Operation Gunnerside (1943), by Allies, against heavy water factory in German-occupied Norway^[250]
• Operation Scorch Sword (1980), by Iran, against construction site of Osirak nuclear complex construction site in Iraq.
• Operation Opera (1981), by Israel, against the same Osirak site in Iraq.
• Iraqi air force attacks on unfinished Bushehr nuclear plant in Iran during Iraq-Iran war (1986, 1987).^[250]
• Operation Outside the Box (2007), by Israel, against a suspected Al Kibar nuclear construction site in Syria.

No military operations were targeted against live nuclear reactors and no operations resulted in nuclear incidents. No terrorist attacks targeted live reactors, with the only recorded quasi-terrorist attacks on a nuclear power plant construction sites by anti-nuclear activists:

• 1977–1982 ETA performed numerous attacks, including bombings and kidnappings, against Lemóniz Nuclear Power Plant constructions site and its personnel
• 18 January 1982 when environmental activist Chaïm Nissim fired RPG rockets at Superphénix reactor construction site in France, causing no damage

According to a 2004 report by the U.S. Congressional Budget Office, "The human, environmental, and economic costs from a successful attack on a nuclear power plant that results in the release of substantial quantities of radioactive material to the environment could be great."^[251] The United States 9/11 Commission has said that nuclear power plants were potential targets originally considered for the 11 September 2001 attacks. If terrorist groups could sufficiently damage safety systems to cause a core meltdown at a nuclear power plant, and/or sufficiently damage spent fuel pools, such an attack could lead to a widespread radioactive contamination.^[252]

New reactor designs have features of passive safety, such as the flooding of the reactor core without active intervention by reactor operators. But these safety measures have generally been developed and studied with respect to accidents, not to the deliberate reactor attack by a terrorist group. However, the US Nuclear Regulatory Commission now also requires new reactor license applications to consider security during the design stage.^[252]

Use of waste byproduct as a weapon

There is a concern if the by-products of nuclear fission (the nuclear waste generated by the plant) were to be left unprotected it could be stolen and used as a radiological weapon, colloquially known as a "dirty bomb". No actual terrorist attacks involving "dirty bomb" were ever recorded, although cases of illegal trade of fissile material happened.^{[253][254][255][256]}

There are additional concerns that the transportation of nuclear waste along roadways or railways opens it up for potential theft. The United Nations has since called upon world leaders to improve security in order to prevent radioactive material falling into the hands of terrorists,^[257] and such fears have been used as justifications for centralized, permanent, and secure waste repositories and increased security along transportation routes.^[258]

The spent fissile fuel is not radioactive enough to create any sort of effective nuclear weapon, in a traditional sense where the radioactive material is the means of explosion. Nuclear reprocessing plants also acquire uranium from spent reactor fuel and take the remaining waste into their custody.

Sources

• Letcher, Trevor M., ed. (2020). Future Energy: Improved, Sustainable and Clean Options for our Planet (Third ed.). Elsevier. ISBN 978-0081028865.
• MacKay, David J. C. (2008). Sustainable energy – without the hot air. UIT Cambridge. ISBN 978-0954452933. OCLC 262888377. Archived from the original on 28 August 2021.
• IPCC (2014). Edenhofer, O.; Pichs-Madruga, R.; Sokona, Y.; Farahani, E.; et al. (eds.). Climate Change 2014: Mitigation of Climate Change: Working Group III contribution to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. ISBN 978-1107058217. OCLC 892580682. Archived from the original on 26 January 2017.
• IPCC (2018). Masson-Delmotte, V.; Zhai, P.; Pörtner, H.-O.; Roberts, D.; et al. (eds.). Global Warming of 1.5 °C. An IPCC Special Report on the impacts of global warming of 1.5 °C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty (PDF) (Report). Archived (PDF) from the original on 20 November 2020.