Nuclear Energy

Nuclear energy is the energy in the nucleus, or core, of an atom. Nuclear energy can be used to create electricity, but it must first be released from the atom.

Engineering, Physics

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Nuclear energy is the energy in the nucleus , or core, of an atom . Atoms are tiny units that make up all matter in the universe , and energy is what holds the nucleus together. There is a huge amount of energy in an atom 's dense nucleus . In fact, the power that holds the nucleus together is officially called the " strong force ." Nuclear energy can be used to create electricity , but it must first be released from the atom . In the process of  nuclear fission , atoms are split to release that energy. A nuclear reactor , or power plant , is a series of machines that can control nuclear fission to produce electricity . The fuel that nuclear reactors use to produce nuclear fission is pellets of the element uranium . In a nuclear reactor , atoms of uranium are forced to break apart. As they split, the atoms release tiny particles called fission products. Fission products cause other uranium atoms to split, starting a chain reaction . The energy released from this chain reaction creates heat. The heat created by nuclear fission warms the reactor's cooling agent . A cooling agent is usually water, but some nuclear reactors use liquid metal or molten salt . The cooling agent , heated by nuclear fission , produces steam . The steam turns turbines , or wheels turned by a flowing current . The turbines drive generators , or engines that create electricity . Rods of material called nuclear poison can adjust how much electricity is produced. Nuclear poisons are materials, such as a type of the element xenon , that absorb some of the fission products created by nuclear fission . The more rods of nuclear poison that are present during the chain reaction , the slower and more controlled the reaction will be. Removing the rods will allow a stronger chain reaction and create more electricity . As of 2011, about 15 percent of the world's electricity is generated by nuclear power plants . The United States has more than 100 reactors, although it creates most of its electricity from fossil fuels and hydroelectric energy . Nations such as Lithuania, France, and Slovakia create almost all of their electricity from nuclear power plants . Nuclear Food: Uranium Uranium is the fuel most widely used to produce nuclear energy . That's because uranium atoms split apart relatively easily. Uranium is also a very common element, found in rocks all over the world. However, the specific type of uranium used to produce nuclear energy , called U-235 , is rare. U-235 makes up less than one percent of the uranium in the world.

Although some of the uranium the United States uses is mined in this country, most is imported . The U.S. gets uranium from Australia, Canada, Kazakhstan, Russia, and Uzbekistan. Once uranium is mined, it must be extracted from other minerals . It must also be processed before it can be used. Because nuclear fuel can be used to create nuclear weapons as well as nuclear reactors , only nations that are part of the Nuclear Non-Proliferation Treaty (NPT) are allowed to import uranium or plutonium , another nuclear fuel . The treaty promotes the peaceful use of nuclear fuel , as well as limiting the spread of nuclear weapons . A typical nuclear reactor uses about 200 tons of uranium every year. Complex processes allow some uranium and plutonium to be re-enriched or recycled . This reduces the amount of mining , extracting , and processing that needs to be done. Nuclear Energy and People Nuclear energy produces electricity that can be used to power homes, schools, businesses, and hospitals. The first nuclear reactor to produce electricity was located near Arco, Idaho. The Experimental Breeder Reactor began powering itself in 1951. The first nuclear power plant designed to provide energy to a community was established in Obninsk, Russia, in 1954. Building nuclear reactors requires a high level of technology , and only the countries that have signed the Nuclear Non-Proliferation Treaty can get the uranium or plutonium that is required. For these reasons, most nuclear power plants are located in the developed world. Nuclear power plants produce renewable, clean energy . They do not pollute the air or release  greenhouse gases . They can be built in urban or rural areas , and do not radically alter the environment around them. The steam powering the turbines and generators is ultimately recycled . It is cooled down in a separate structure called a cooling tower . The steam turns back into water and can be used again to produce more electricity . Excess steam is simply recycled into the atmosphere , where it does little harm as clean water vapor . However, the byproduct of nuclear energy is radioactive material. Radioactive material is a collection of unstable atomic nuclei . These nuclei lose their energy and can affect many materials around them, including organisms and the environment. Radioactive material can be extremely toxic , causing burns and increasing the risk for cancers , blood diseases, and bone decay .

Radioactive waste is what is left over from the operation of a nuclear reactor . Radioactive waste is mostly protective clothing worn by workers, tools, and any other material that have been in contact with radioactive dust. Radioactive waste is long-lasting. Materials like clothes and tools can stay radioactive for thousands of years. The government regulates how these materials are disposed of so they don't contaminate anything else. Used fuel and rods of nuclear poison are extremely radioactive . The used uranium pellets must be stored in special containers that look like large swimming pools. Water cools the fuel and insulates the outside from contact with the radioactivity. Some nuclear plants store their used fuel in dry storage tanks above ground. The storage sites for radioactive waste have become very controversial in the United States. For years, the government planned to construct an enormous nuclear waste facility near Yucca Mountain, Nevada, for instance. Environmental groups and local citizens protested the plan. They worried about radioactive waste leaking into the water supply and the Yucca Mountain environment, about 130 kilometers (80 miles) from the large urban area of Las Vegas, Nevada. Although the government began investigating the site in 1978, it stopped planning for a nuclear waste facility in Yucca Mountain in 2009. Chernobyl Critics of nuclear energy worry that the storage facilities for radioactive waste will leak, crack, or erode . Radioactive material could then contaminate the soil and groundwater near the facility . This could lead to serious health problems for the people and organisms in the area. All communities would have to be evacuated . This is what happened in Chernobyl, Ukraine, in 1986. A steam explosion at one of the power plants four nuclear reactors caused a fire, called a plume . This plume was highly radioactive , creating a cloud of radioactive particles that fell to the ground, called fallout . The fallout spread over the Chernobyl facility , as well as the surrounding area. The fallout drifted with the wind, and the particles entered the water cycle as rain. Radioactivity traced to Chernobyl fell as rain over Scotland and Ireland. Most of the radioactive fallout fell in Belarus.

The environmental impact of the Chernobyl disaster was immediate . For kilometers around the facility , the pine forest dried up and died. The red color of the dead pines earned this area the nickname the Red Forest . Fish from the nearby Pripyat River had so much radioactivity that people could no longer eat them. Cattle and horses in the area died. More than 100,000 people were relocated after the disaster , but the number of human victims of Chernobyl is difficult to determine . The effects of radiation poisoning only appear after many years. Cancers and other diseases can be very difficult to trace to a single source. Future of Nuclear Energy Nuclear reactors use fission, or the splitting of atoms , to produce energy. Nuclear energy can also be produced through fusion, or joining (fusing) atoms together. The sun, for instance, is constantly undergoing nuclear fusion as hydrogen atoms fuse to form helium . Because all life on our planet depends on the sun, you could say that nuclear fusion makes life on Earth possible. Nuclear power plants do not have the capability to safely and reliably produce energy from nuclear fusion . It's not clear whether the process will ever be an option for producing electricity . Nuclear engineers are researching nuclear fusion , however, because the process will likely be safe and cost-effective.

Nuclear Tectonics The decay of uranium deep inside the Earth is responsible for most of the planet's geothermal energy, causing plate tectonics and continental drift.

Three Mile Island The worst nuclear accident in the United States happened at the Three Mile Island facility near Harrisburg, Pennsylvania, in 1979. The cooling system in one of the two reactors malfunctioned, leading to an emission of radioactive fallout. No deaths or injuries were directly linked to the accident.

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What is Nuclear Energy?

Nuclear power is generated by splitting atoms to release the energy held at the core, or nucleus, of those atoms. This process, nuclear fission, generates heat that is directed to a cooling agent—usually water. The resulting steam spins a turbine connected to a generator, producing electricity.

About 450 nuclear reactors provide about 11 percent of the world's electricity. The countries generating the most nuclear power are, in order, the United States, France, China, Russia, and South Korea.

The most common fuel for nuclear power is uranium, an abundant metal found throughout the world. Mined uranium is processed into U-235, an enriched version used as fuel in nuclear reactors because its atoms can be split apart easily.

In a nuclear reactor, neutrons—subatomic particles that have no electric charge—collide with atoms, causing them to split. That collision—called nuclear fission—releases more neutrons that react with more atoms, creating a chain reaction. A byproduct of nuclear reactions, plutonium , can also be used as nuclear fuel.

Types of nuclear reactors

In the U.S. most nuclear reactors are either boiling water reactors , in which the water is heated to the boiling point to release steam, or pressurized water reactors , in which the pressurized water does not boil but funnels heat to a secondary water supply for steam generation. Other types of nuclear power reactors include gas-cooled reactors, which use carbon dioxide as the cooling agent and are used in the U.K., and fast neutron reactors, which are cooled by liquid sodium.

Nuclear energy history

The idea of nuclear power began in the 1930s , when physicist Enrico Fermi first showed that neutrons could split atoms. Fermi led a team that in 1942 achieved the first nuclear chain reaction, under a stadium at the University of Chicago. This was followed by a series of milestones in the 1950s: the first electricity produced from atomic energy at Idaho's Experimental Breeder Reactor I in 1951; the first nuclear power plant in the city of Obninsk in the former Soviet Union in 1954; and the first commercial nuclear power plant in Shippingport, Pennsylvania, in 1957. ( Take our quizzes about nuclear power and see how much you've learned: for Part I, go here ; for Part II, go here .)

Nuclear power, climate change, and future designs

Nuclear power isn't considered renewable energy , given its dependence on a mined, finite resource, but because operating reactors do not emit any of the greenhouse gases that contribute to global warming , proponents say it should be considered a climate change solution . National Geographic emerging explorer Leslie Dewan, for example, wants to resurrect the molten salt reactor , which uses liquid uranium dissolved in molten salt as fuel, arguing it could be safer and less costly than reactors in use today.

Others are working on small modular reactors that could be portable and easier to build. Innovations like those are aimed at saving an industry in crisis as current nuclear plants continue to age and new ones fail to compete on price with natural gas and renewable sources such as wind and solar.

The holy grail for the future of nuclear power involves nuclear fusion, which generates energy when two light nuclei smash together to form a single, heavier nucleus. Fusion could deliver more energy more safely and with far less harmful radioactive waste than fission, but just a small number of people— including a 14-year-old from Arkansas —have managed to build working nuclear fusion reactors. Organizations such as ITER in France and Max Planck Institute of Plasma Physics are working on commercially viable versions, which so far remain elusive.

Nuclear power risks

When arguing against nuclear power, opponents point to the problems of long-lived nuclear waste and the specter of rare but devastating nuclear accidents such as those at Chernobyl in 1986 and Fukushima Daiichi in 2011 . The deadly Chernobyl disaster in Ukraine happened when flawed reactor design and human error caused a power surge and explosion at one of the reactors. Large amounts of radioactivity were released into the air, and hundreds of thousands of people were forced from their homes . Today, the area surrounding the plant—known as the Exclusion Zone—is open to tourists but inhabited only by the various wildlife species, such as gray wolves , that have since taken over .

In the case of Japan's Fukushima Daiichi, the aftermath of the Tohoku earthquake and tsunami caused the plant's catastrophic failures. Several years on, the surrounding towns struggle to recover, evacuees remain afraid to return , and public mistrust has dogged the recovery effort, despite government assurances that most areas are safe.

Other accidents, such as the partial meltdown at Pennsylvania's Three Mile Island in 1979, linger as terrifying examples of nuclear power's radioactive risks. The Fukushima disaster in particular raised questions about safety of power plants in seismic zones, such as Armenia's Metsamor power station.

Other issues related to nuclear power include where and how to store the spent fuel, or nuclear waste, which remains dangerously radioactive for thousands of years. Nuclear power plants, many of which are located on or near coasts because of the proximity to water for cooling, also face rising sea levels and the risk of more extreme storms due to climate change.

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Nuclear Energy

Explore global data on nuclear energy production, and the safety of nuclear technologies..

As the world attempts to transition its energy systems away from fossil fuels towards low-carbon sources of energy, we have a range of energy options: renewable energy technologies such as hydropower, wind and solar, but also nuclear power. Nuclear energy and renewable technologies typically emit very little CO 2 per unit of energy production, and are also much better than fossil fuels in limiting levels of local air pollution.

But whilst some countries are investing heavily in increasing their nuclear energy supply, others are taking their plants offline. The role that nuclear energy plays in the energy system is therefore very specific to the given country.

How much of our energy comes from nuclear power? How is its role changing over time? In this article we look at levels and changes in nuclear energy generation across the world, and its safety record in comparison to other sources of energy.

Nuclear energy generation

Global generation of nuclear energy.

Nuclear energy – alongside hydropower – is one of our oldest low-carbon energy technologies.

Nuclear power generation has been around since the 1960s, but saw massive growth globally in the 1970s, 80s and 90s. In the interactive chart shown we see how global nuclear generation has changed over the past half-century.

Following fast growth during the 1970s to 1990s, global generation has slowed significantly. In fact, we see a sharp dip in nuclear output following the Fukushima tsunami in Japan in 2011 [we look at the impacts of this disaster later in this article] , as countries took plants offline due to safety concerns.

But we also see that in recent years, production has once again increased.

Nuclear energy generation by country

The global trend in nuclear energy generation masks the large differences in what role it plays at the country level.

Some countries get no energy at all from nuclear – or are aiming to eliminate it completely – whilst others get the majority of their power from it.

This interactive chart shows the amount of nuclear energy generated by country. We see that France, the USA, China, Russia and Canada all produce relatively large amounts of nuclear power.

Nuclear in the energy and electricity mix

What share of primary energy comes from nuclear.

We previously looked nuclear output in terms of energy units – how much each country produces in terawatt-hours. But to understand how large of a role nuclear plays in the energy system we need to put this in perspective of total energy consumption.

This interactive chart shows the share of primary energy that comes from nuclear sources.

Note that this data is based on primary energy calculated by the 'substitution method' which attempts to correct for the inefficiencies in fossil fuel production. It does this by converting non-fossil fuel sources to their 'input equivalents': the amount of primary energy that would be required to produce the same amount of energy if it came from fossil fuels. Here we describe this adjustment in more detail.

In 2019, just over 4% of global primary energy came from nuclear power.

Note that this is based on nuclear energy's share in the energy mix. Energy consumption represents the sum of electricity, transport and heating. We look at the electricity mix below.

What share of electricity comes from nuclear?

In the sections above we looked at the role of nuclear in the total energy mix . This includes not only electricity, but also transport and heating. Electricity forms only one component of energy consumption.

Since transport and heating tend to be harder to decarbonize – they are more reliant on oil and gas – nuclear and renewables tend to have a higher share in the electricity mix versus the total energy mix.

This interactive chart shows the share of electricity that comes from nuclear sources.

Globally, around 10% of our electricity comes from nuclear. But some countries rely on it heavily: it provides more than 70% of electricity in France, and more than 40% in Sweden.

Safety of nuclear energy

Energy has been critical to the human progress we’ve seen over the last few centuries. As the United Nations rightly says : “energy is central to nearly every major challenge and opportunity the world faces today.”

But while energy brings us massive benefits, it’s not without its downsides. Energy production can have negative impacts on human health and the environment in three ways.

The first is air pollution : millions of people die prematurely every year as a result of air pollution . Fossil fuels and the burning of biomass – wood, dung, and charcoal – are responsible for most of those deaths.

The second is accidents . This includes accidents that happen in the mining and extraction of the fuels – coal, uranium, rare metals, oil, and gas. And it also includes accidents that occur in the transport of raw materials and infrastructure, the construction of the power plant, or their maintenance.

The third is greenhouse gas emissions : fossil fuels are the main source of greenhouse gases, the primary driver of climate change. In 2020, 91% of global CO 2 emissions came from fossil fuels and industry. 1

No energy source is completely safe. They all have short-term impacts on human health, either through air pollution or accidents. And they all have long-term impacts by contributing to climate change.

But, their contribution to each differs enormously. Fossil fuels are both the dirtiest and most dangerous in the short term, and emit the most greenhouse gases per unit of energy. This means that there are thankfully no trade-offs here: low-carbon energy sources are also the safest. From the perspective of both human health and climate change, it matters less whether we transition to nuclear power or renewable energy, and more that we stop relying on fossil fuels.

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Nuclear and renewables are far, far safer than fossil fuels

Before we consider the long-term impacts of climate change, let’s look at how each source stacks up in terms of short-term health risks.

To make these comparisons fair we can’t just look at the total deaths from each source: fossil fuels still dominate our global electricity mix, so we would expect that they would kill more people.

Instead, we compare them based on the estimated number of deaths they cause per unit of electricity . This is measured in terawatt-hours. One terawatt-hour is about the same as the annual electricity consumption of 150,000 citizens in the European Union. 2

This includes deaths from air pollution and accidents in the supply chain. 3

Let’s look at this comparison in the chart. Fossil fuels and biomass kill many more people than nuclear and modern renewables per unit of electricity. Coal is, by far, the dirtiest.

Even then, these estimates for fossil fuels are likely to be very conservative. They are based on power plants in Europe, which have good pollution controls, and are based on older models of the health impacts of air pollution. As I discuss in more detail at the end of this article, global death rates from fossil fuels based on the most recent research on air pollution are likely to be even higher.

Our perceptions of the safety of nuclear energy are strongly influenced by two accidents: Chernobyl in Ukraine in 1986, and Fukushima in Japan in 2011. These were tragic events. However, compared to the millions that die from fossil fuels every year the final death tolls were very low. To calculate the death rates used here I assume a death toll of 433 from Chernobyl, and 2,314 from Fukushima. 4 If you are interested in this, I look at how many died in each accident in detail in a related article .

The other source which is heavily influenced by a few large-scale accidents is hydropower. Its death rate since 1965 is 1.3 deaths per TWh. This rate is almost completely dominated by one event: the Banqiao Dam Failure in China in 1975. It killed approximately 171,000 people. Otherwise, hydropower was very safe, with a death rate of just 0.04 deaths per TWh – comparable to nuclear, solar, and wind.

Finally, we have solar and wind. The death rates from both of these sources are low, but not zero. A small number of people die in accidents in supply chains – ranging from helicopter collisions with turbines; fires during the installation of turbines or panels; and drownings on offshore wind sites.

People often focus on the marginal differences at the bottom of the chart – between nuclear, solar, and wind. This comparison is misguided: the uncertainties around these values mean they are likely to overlap.

The key insight is that they are all much, much safer than fossil fuels.

Nuclear energy, for example, results in 99.9% fewer deaths than brown coal; 99.8% fewer than coal; 99.7% fewer than oil; and 97.6% fewer than gas. Wind and solar are just as safe.

Putting death rates from energy in perspective

Looking at deaths per terawatt-hour can seem abstract. Let’s try to put it in perspective.

Let’s consider how many deaths each source would cause for an average town of 150,000 people in the European Union, which – as I’ve said before – consumes one terawatt-hour of electricity per year. Let’s call this town ‘Euroville’.

If Euroville was completely powered by coal we’d expect at least 25 people to die prematurely every year from it.  Most of these people would die from air pollution.

This is how a coal-powered Euroville would compare with towns powered entirely by each energy source:

  • Coal: 25 people would die prematurely every year;
  • Oil: 18 people would die prematurely every year;
  • Gas: 3 people would die prematurely every year;
  • Hydropower: In an average year 1 person would die;
  • Wind: In an average year nobody would die. A death rate of 0.04 deaths per terawatt-hour means every 25 years a single person would die;
  • Nuclear: In an average year nobody would die – only every 33 years would someone die.
  • Solar: In an average year nobody would die – only every 50 years would someone die.

The safest energy sources are also the cleanest

The good news is that there is no trade-off between the safest sources of energy in the short term, and the least damaging for the climate in the long term. They are one and the same, as the chart below shows.

In the chart, on the left-hand side, we have the same comparison of death rates from accidents and air pollution that we just looked at. On the right, we have the amount of greenhouse gas that are emitted per unit of electricity production.

These are not just the emissions from the burning of fuels, but also from the mining, transportation and maintenance over a power plant’s lifetime. 5

Coal, again, is the dirtiest fuel. It emits much more greenhouse gases than other sources – hundreds of times more than nuclear, solar, and wind.

Oil and gas are also much worse than nuclear and renewables, but to a lesser extent than coal.

Unfortunately, the global electricity mix is still dominated by fossil fuels: coal, oil, and gas account for around 60% . If we want to stop climate change we have a great opportunity in front of us: we can transition away from them to nuclear and renewables, and also reduce deaths from accidents and air pollution as a side effect. 6

This transition will not only protect future generations, but it will also come with huge health benefits for the current one.

Methodology and notes

Global average death rates from fossil fuels are likely to be even higher than reported in the chart above.

The death rates from coal, oil, and gas that we use in these comparisons are sourced from the paper of Anil Markandya and Paul Wilkinson (2007) in the medical journal, The Lancet . To date, these are the best, peer-reviewed references I could find on the death rates from these sources. These rates are based on electricity production in Europe.

However, there are three key reasons why I think that these death rates are likely to be very conservative, and the global average death rates could be substantially higher.

  • European fossil fuel plants have strict pollution controls . Power plants in Europe tend to produce less pollution than the global average, and much less than plants in many low-to-middle-income countries. This means that the pollution generated per unit of electricity is likely to be higher in other parts of the world.
  • In other countries, more people will live closer to power plants and therefore be exposed to more pollution . If two countries produce the same amount of coal power, and both have the same pollution controls, the country where power plants are closer to urban centers and cities will have a higher death toll per TWh. This is because more people will be exposed to higher levels of pollution. Power plants in countries such as China, tend to be located closer to cities in many countries than they are in Europe, so we would expect the death rate to be higher than the European figures found by Markandya and Wilkinson (2007). 7
  • More recent research on air pollution suggests the health impacts are more severe than earlier research suggested . The analysis by Markandya and Wilkinson was published in 2007. Since then, our understanding of the health impacts of air pollution has increased significantly. More recent research suggests the health impacts are more severe. My colleague, Max Roser, shows this evolution of the research on air pollution deaths in his review of the literature here . Another reason to suspect that the global average rates are much higher is the following: if we take the death rates from Markandya and Wilkinson (2007) and multiply them by global electricity production, the resulting estimates of total global deaths from fossil fuel electricity are much lower than the most recent research. If I multiply the Markandya and Wilkinson (2007) death rates for coal, oil, and gas by their respective global electricity outputs in 2021, I get a total death toll of 280,000 people . 8 This is much lower than the estimates from more recent research. For example, Leliveld et al. (2018) estimate that 3.6 million die from fossil fuels every year. 9 Vohra et al. (2021) even estimate more than double this figure: 8.7 million. 10 Not all of these deaths from fossil fuel air pollution are due to electricity production. But we can estimate how many deaths do. In a recent paper, Leliveld and his colleagues estimated the breakdown of air pollution deaths by sector. They estimate that 12% of all (fossil fuel and pollution from other sources) air pollution deaths come from electricity production. 11

By my calculations, we would expect that 1.1 million to 2.55 million people die from fossil fuels used for electricity production each year. 12 The estimates we get from Markandya and Wilkinson (2007) death rates undercount by a factor of 4 to 9. This would suggest that actual death rates from fossil fuels could be 4 to 9 times higher. That would give a global average death rate from coal of 93 to 224 deaths per TWh . Unfortunately, we do not have more up-to-date death rates for coal, oil, and gas to reference here but improved estimates are sorely needed. The current death rates shown are likely to be underestimated.

We need a timely global database on accidents in energy supply chains

The figures we reference on accidents from nuclear, solar, and wind are based on the most comprehensive figures we have to date. However, they are not perfect, and no timely dataset tracking these accidents exists. This is a key gap in our understanding of the safety of energy sources – and how their safety is changing over time.

To estimate death rates from renewable energy technologies, Sovacool et al. (2016) compiled a database of energy-related accidents across academic databases and news reports. They define an accident as “an unintentional incident or event at an energy facility that led to either one death (or more) or at least $50,000 in property damage,” which is consistent with definitions in the research literature.

This raises several questions as to which incidents should and shouldn’t be attributed to a given energy technology. For example, included in this database were deaths related to an incident where water from a water tank ruptured during a construction test at a solar factory. It’s not clear whether these supply chain deaths should or shouldn’t be attributed to solar technologies.

The comparability of these incidents across the different energy technologies is therefore difficult to assess with high certainty. One additional issue with this analysis by Sovacool et al. (2016) is that its database search was limited to English reports, or non-English reports that had been translated. Some of these comparisons could therefore be a slight over- or underestimate. It is, however, unlikely that the position of these technologies would change significantly – renewable and nuclear technologies would consistently come out with a much lower death rate than fossil fuels. Consistent data collection and tracking of incidents across all energy technologies would greatly improve these comparisons.

We need improved estimates of the health impacts of the mining of minerals and materials for all energy sources

The figures presented in this research that I rely on do not include any health impacts from radiation exposure from the mining of metals and minerals used in supply chains.

While we might think that this would only have an impact on nuclear energy, analyses suggest that the carcinogenic toxicity of other sources – including solar, wind, hydropower, coal and gas are all significantly higher across their supply chains. 13

These figures only measure potential exposure to toxic elements for workers. They do not give us estimates of potential death rates, which is why we do not include them in our referenced figures above.

However, the inclusion of these figures would not change the relative results, overall. Fossil fuels – coal, in particular – have a higher carcinogenic toxicity than both nuclear and renewables. Hence the relative difference between them would actually increase, rather than decrease. The key insight would still be the same: fossil fuels are much worse for human health, and both nuclear and modern renewables are similarly safe alternatives.

However, estimates of the health burden of rare minerals in energy supply chains is still an important gap to fill, so that we can learn about their impact and ultimately reduce these risks moving forward.

What was the death toll from Chernobyl and Fukushima?

Nuclear energy is an important source of low-carbon energy. But, there is strong public opposition to it, often because of concerns around safety.

These concerns are often sparked by memories of two nuclear accidents: the Chernobyl disaster in Ukraine in 1986, and Fukushima in Japan in 2011. 14

These two events were by far the largest nuclear accidents in history; the only disasters to receive a level 7 (the maximum classification) on the International Nuclear Event Scale.

How many people died in these nuclear disasters, and what can we learn from them?

How many died from the nuclear accident in Chernobyl?

In April 1986, the core of one of the four reactors at Chernobyl nuclear plant, in Ukraine, melted down and exploded. It was the worst nuclear disaster in human history.

There are several categories of deaths linked to the disaster – for some we have a good idea of how many died, for others we have a range of plausible deaths.

Direct deaths from the accident

30 people died during or very soon after the incident.

Two plant workers died almost immediately in the explosion from the reactor. Overall, 134 emergency workers, plant operators, and firemen were exposed to levels of radiation high enough to suffer from acute radiation syndrome (ARS). 28 of these 134 workers died in the weeks that followed, which takes the total to 30. 15

Later deaths of workers and firemen

A point of dispute is whether any more of the 134 workers with ARS died as a result of radiation exposure. In 2008, several decades after the incident, the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) published a large synthesis of the latest scientific evidence. 15 It reported that a further 19 ARS survivors had died by 2006 . But many of these deaths were not related to any condition caused by radiation exposure. Seven were related to diseases not related to cancers including tuberculosis, liver disease, and stroke; six were from heart attacks; one from a trauma incident; and five died from cancers. 16 It’s difficult to say how many of these deaths could be attributed to the Chernobyl accident – it’s not implausible it played a role in at least some of them, especially the five cancer deaths.

Thyroid cancer deaths in children through contaminated milk

Most of the population was not exposed to levels of radiation that would put them at risk of negative health impacts. However, the slow response to the disaster meant that some individuals were exposed to the short-lived radionuclide Iodine-131 ( 131 I) through the contamination of milk. Radioactive fallout settled on pasture grass across the region; this contaminated milk supplies and leafy vegetables that were consumed in the days immediately after the incident.

This exposure to 131 I has not been linked to increased cancer risk in the adult population, but several studies have shown an increased incidence of thyroid cancer in those who were children and adolescents around this time. Figuring out how many cases of thyroid cancer in this young population were caused by the accident is not straightforward. This is because there was a large increase in screening efforts in the aftermath of the disaster. It’s not uncommon for thyroid cancer cases to go undetected – and have no negative impact on an individual’s life. Increased screening, particularly in child populations, would result in finding many cases of cancer that would normally go undetected.

In 2018, UNSCEAR published its latest findings on thyroid cancers attributed to the Chernobyl disaster. Over the period from 1991 to 2015, there were 19,233 cases of thyroid cancer in patients who were younger than 18 at the time of the disaster across Ukraine, Belarus, and exposed regions of Russia. UNSCEAR concluded that around one-quarter of these cases could be linked to radiation exposure. That would mean 4,808 thyroid cancer cases. 17

By 2005, it was reported that 15 of these thyroid cancer cases had been fatal . 18 However, it was likely that this figure would increase: at least some of those still living with thyroid cancer will eventually die from it.

It’s therefore not possible to give a definitive number, but we can look at survival rates and outcomes to get an estimate. Thankfully the prognosis for thyroid cancer in children is very good. Many patients that have undergone treatment have seen either a partial or complete remission. 19 Large-scale studies report a 20-year survival rate of 92% for thyroid cancer. 20 . Others show an even better prognosis, with a survival rate of 98% after 40 years. 21

If we combine standard survival rates with our number of radiation-induced cancer cases – 4,808 cases – we might estimate that the number of deaths could be in the range of 96 to 385 . This comes from the assumption of a survival rate of 92% to 98% (or, to flip it, a mortality rate of 2% to 8%). 22 This figure comes with significant uncertainty.

Deaths in the general population

Finally, there has been significant concern about cancer risks to the wider population across Ukraine, Belarus, Russia, and other parts of Europe. This topic remains controversial. Some reports in the early 2000s estimated much higher death tolls ranging from 16,000 to 60,000. 23 In its 2005 report, the WHO estimated a potential death toll of 4,000. 24 These estimates were based on the assumption that a large number of people were exposed to elevated levels of radioactivity, and that radioactivity increases cancer risk, even at very low levels of exposure (the so-called ‘ linear no-threshold model ’ of radiation exposure).

More recent studies suggest that these estimates were too high. In 2008, the UNSCEAR concluded that radioactive exposure to the general public was very low, and that it does not expect adverse health impacts in the countries affected by Chernobyl, or the rest of Europe. 25 In 2018 it published a follow-up report, which came to the same conclusion.

If the health impacts of radiation were directly and linearly related to the level of exposure, we would expect to find that cancer rates were highest in regions closest to the Chernobyl site, and would decline with distance from the plant. But studies do not find this. Cancer rates in Ukraine, for example, were not higher in locations closer to the site 26 This suggests that there is a lower limit to the level at which radiation exposure has negative health impacts. And that most people were not exposed to doses higher than this.

Combined death toll from Chernobyl

To summarize the previous paragraphs:

  • 2 workers died in the blast.
  • 15 people died from thyroid cancer due to milk contamination . These deaths were among children who were exposed to 131 I from milk and food in the days after the disaster. This could increase to between 96 and 384 deaths, however, this figure is highly uncertain.
  • There is currently no evidence of adverse health impacts in the general population across affected countries, or wider Europe .

Combined, the confirmed death toll from Chernobyl is less than 100. We still do not know the true death toll of the disaster. My best approximation is that the true death toll is in the range of 300 to 500 based on the available evidence. 27

How many died from the nuclear accident in Fukushima?

In March 2011, there was an accident at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. This accident was caused by the 2011 Tōhoku earthquake and tsunami – the most powerful earthquake recorded in Japan’s history.

Despite it being such a large event, so far, only one death has been attributed to the disaster. This includes both the direct impact of the accident itself and the radiation exposure that followed. However, it’s estimated that several thousand died indirectly from the stress and disruption of evacuation.

Direct and cancer deaths from the accident

No one died directly from the disaster. However, 40 to 50 people were injured as a result of physical injury from the blast, or radiation burns.

In 2018, the Japanese government reported that one worker has since died from lung cancer as a result of radiation exposure from the event.

Over the last decade, many studies have assessed whether there has been any increased cancer risk for local populations. There appears to be no increased risk of cancer or other radiation-related health impacts .

In 2016, the World Health Organization noted that there was a very low risk of increased cancer deaths in Japan. 28

Deaths from evacuation

A more difficult question is how many people died indirectly through the response and evacuation of locals from the area around Fukushima. Within a few weeks of the accident more than 160,000 people had moved away, either from official evacuation efforts or voluntarily from fear of further radioactive releases. Many were forced to stay in overcrowded gyms, schools, and public facilities for several months until more permanent emergency housing became available.

The year after the 2011 disaster, the Japanese government estimated that 573 people had died indirectly as a result of the physical and mental stress of evacuation. 29 Since then, more rigorous assessments of increased mortality have been done, and this figure was revised to 2,313 deaths in September 2020.

These indirect deaths were attributed to the overall physical and mental stress of evacuation; being moved out of care settings; and disruption to healthcare facilities.

It’s important to bear in mind that the region was also trying to deal with the aftermath of an earthquake and tsunami: this makes it difficult to completely separate the indirect deaths related to the nuclear disaster disruptions, and those of the tsunami itself.

Combined, the confirmed death toll from Fukushima is therefore 2,314.

What can we learn from these nuclear disasters?

The context and response to these disasters were very different, and this is reflected in what people died from in the aftermath.

Many more people died from Chernobyl than from Fukushima. There are several reasons for this.

The first was reactor design . The nuclear reactors at Chernobyl were poorly designed to deal with this meltdown scenario. Its fatal RBMK reactor had no containment structure, allowing radioactive material to spill into the atmosphere. Fukushima’s reactors did have steel-and-concrete containment structures, although it’s likely that at least one of these was also breached.

Crucially, the cooling systems of both plants worked very differently; at Chernobyl, the loss of cooling water as steam actually served to accelerate reactivity levels in the reactor core, creating a positive feedback loop toward the fatal explosion. The opposite is true of Fukushima, where the reactivity reduced as temperatures rose, effectively operating as a self-shutdown measure.

The second factor was government response . In the case of Fukushima, the Japanese government responded quickly to the crisis with evacuation efforts extending rapidly from a 3-kilometer (km), to a 10-km, to a 20-km radius whilst the incident at the site continued to unfold. In contrast, the response in the former Soviet Union was one of denial and secrecy.

It’s reported that in the days which followed the Chernobyl disaster, residents in surrounding areas were uninformed of the radioactive material in the air around them. In fact, it took at least three days for the Soviet Union to admit an accident had taken place, and did so after radioactive sensors at a Swedish plant were triggered by dispersing radionuclides. As we saw above, it’s estimated that approximately 4,808 thyroid cancer cases in children and adolescents could be linked to radiation exposure from contaminated milk and foods. This could have been prevented by an earlier response.

Finally, while an early response from the Japanese government may have prevented a significant number of deaths, many have questioned whether the scale of the evacuation effort – where more than 160,000 people were displaced – was necessary. 30 As we see from the figures above, evacuation stress and disruption are estimated to have contributed to several thousand early deaths. Only one death has been linked to the impact of radiation. We don’t know what the possible death toll would have been without any evacuation. That’s why a no-evacuation strategy, if a future accident was to occur, seems unlikely. However, many have called for governments to develop early assessments and protocols of radiation risks, the scale of evacuation needed, and infrastructure to make sure that the disruption to those that are displaced is kept to a minimum. 31

Nuclear is one of the safest energy sources

No energy source comes with zero negative impact. We often think of nuclear energy as being more dangerous than other sources because these low-frequency but highly-visible events come to mind.

However, when we compare the death rates from nuclear energy to other sources, we see that it’s one of the safest. The numbers that have died from nuclear accidents are very small in comparison to the millions that die from air pollution from fossil fuels every year . As the linked post shows, the death rate from nuclear is roughly comparable with most renewable energy technologies.

Since nuclear is also a key source of low-carbon energy, it can play a key role in a sustainable energy mix alongside renewables.

​​Pierre Friedlingstein, Matthew W. Jones, Michael O'Sullivan, Robbie M. Andrew, Dorothee, C. E. Bakker, Judith Hauck, Corinne Le Quéré, Glen P. Peters, Wouter Peters, Julia Pongratz, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Rob B. Jackson, Simone R. Alin, Peter Anthoni, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Laurent Bopp, Thi Tuyet Trang Chau, Frédéric Chevallier, Louise P. Chini, Margot Cronin, Kim I. Currie, Bertrand Decharme, Laique M. Djeutchouang, Xinyu Dou, Wiley Evans, Richard A. Feely, Liang Feng, Thomas Gasser, Dennis Gilfillan, Thanos Gkritzalis, Giacomo Grassi, Luke Gregor, Nicolas Gruber, Özgür Gürses, Ian Harris, Richard A. Houghton, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Ingrid T. Luijkx, Atul Jain, Steve D. Jones, Etsushi Kato, Daniel Kennedy, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Arne Körtzinger, Peter Landschützer, Siv K. Lauvset, Nathalie Lefèvre, Sebastian Lienert, Junjie Liu, Gregg Marland, Patrick C. McGuire, Joe R. Melton, David R. Munro, Julia E.M.S Nabel Shin-Ichiro Nakaoka, Yosuke Niwa, Tsuneo Ono, Denis Pierrot, Benjamin Poulter, Gregor Rehder, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Thais M Rosan, Jörg Schwinger, Clemens Schwingshackl, Roland Séférian, Adrienne J. Sutton, Colm Sweeney, Toste Tanhua, Pieter P Tans, Hanqin Tian, Bronte Tilbrook, Francesco Tubiello, Guido van der Werf, Nicolas Vuichard, Chisato Wada Rik Wanninkhof, Andrew J. Watson, David Willis, Andrew J. Wiltshire, Wenping Yuan, Chao Yue, Xu Yue, Sönke Zaehle, Jiye Zeng. Global Carbon Budget 2021, Earth Syst. Sci. Data, 2021.

Per capita electricity consumption in the EU-27 in 2021 was around 6,400 kWh.

1 terawatt-hour is equal to 1,000,000,000 kilowatt-hours. So, we get this figure by dividing 1,000,000,000 by 6,400 ≈ 150,000 people.

The following sources were used to calculate these death rates.

Fossil fuels and biomass = these figures are taken directly from Markandya, A., & Wilkinson, P. (2007). Electricity generation and health . The Lancet , 370(9591), 979-990.

Nuclear = I have calculated these figures based on the assumption of 433 deaths from Chernobyl and 2314 from Fukushima. These figures are based on the most recent estimates from UNSCEAR and the Government of Japan. In a related article , I detail where these figures come from.

I have calculated death rates by dividing this figure by cumulative global electricity production from nuclear from 1965 to 2021, which is 96,876 TWh.

Hydropower = The paper by Sovacool et al. (2016) provides a death rate for hydropower from 1990 to 2013. However, this period excludes some very large hydropower accidents which occurred prior to 1990. I have therefore calculated a death rate for hydropower from 1965 to 2021 based on the list of hydropower accidents provided in Sovacool et al. (2016), which extends back to the 1950s. Since this database ends in 2013, I have also included the Saddle Dam accident in Laos in 2018, which killed 71 people.

The total number of deaths from hydropower accidents from 1965 to 2021 was approximately 176,000. 171,000 of these deaths were from the Banqian Dam Failure in China in 1975.

I have calculated death rates by dividing this figure by cumulative global electricity production from hydropower from 1965 to 2021, which is 138,175 TWh.

Solar and wind = these figures are taken directly from: Sovacool, B. K., Andersen, R., Sorensen, S., Sorensen, K., Tienda, V., Vainorius, A., … & Bjørn-Thygesen, F. (2016). Balancing safety with sustainability: assessing the risk of accidents for modern low-carbon energy systems . Journal of Cleaner Production , 112, 3952-3965. In this analysis the authors compiled a database of as many energy-related accidents as possible based on an extensive search of academic databases and news reports, and derived death rates for each source over the period from 1990 to 2013. Since this database has not been extended since then, it’s not possible to provide post-2013 death rates.

UNSCEAR (2008). Sources and effects of Ionizing Radiation. UNSCEAR 2008 Report to the General Assembly with Scientific Annexes. Available online .

Report of the United Nations Scientific Committee on the Effects of Atomic Radiation. General Assembly Official Records, Sixty-eighth session, Supplement No. 46. New York: United Nations, Sixtieth session, May 27–31, 2013.

Schlömer S., T. Bruckner, L. Fulton, E. Hertwich, A. McKinnon, D. Perczyk, J. Roy, R. Schaeffer, R. Sims, P. Smith, and R. Wiser, 2014: Annex III: Technology-specific cost and performance parameters. In: Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Edenhofer, O., R. Pichs-Madruga, Y. Sokona, E. Farahani, S. Kadner, K. Seyboth, A. Adler, I. Baum, S. Brunner, P. Eickemeier, B. Kriemann, J. Savolainen, S. Schlömer, C. von Stechow, T. Zwickel and J.C. Minx (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

The IPCC AR5 report was published in 2014, and relies on studies conducted several years prior to its publication. For technologies which have been developing rapidly – namely solar, wind and other renewables, production technologies and intensities have changed significantly since then, and will continue to change as energy systems decarbonize. Life-cycle figures for nuclear, solar, wind and hydropower have therefore been adopted by the more recent publication by Pehl et al. (2017), published in Nature Energy.

Pehl, M., Arvesen, A., Humpenöder, F., Popp, A., Hertwich, E. G., & Luderer, G. (2017). Understanding future emissions from low-carbon power systems by integration of life-cycle assessment and integrated energy modelling . Nature Energy , 2(12), 939-945.

The Carbon Brief provides a clear discussion of the significance of these more recent lifecycle analyses in detail here .

Since oil is conventionally not used for electricity production, it is not included in the IPCC’s reported figures per kilowatt-hour. Figures for oil have therefore been taken from Turconi et al. (2013). It reports emissions in kilograms of CO2eq per megawatt-hour. Emissions factors for all other technologies are consistent with results from the IPCC. The range it gives for oil is 530–900: I have here taken the midpoint estimate (715 kgCO2eq/MWh, which is also 715 gCO2eq/kWh).

Turconi, R., Boldrin, A., & Astrup, T. (2013). Life cycle assessment (LCA) of electricity generation technologies: Overview, comparability and limitations . Renewable and Sustainable Energy Reviews , 28, 555-565.

Burgherr, P., & Hirschberg, S. (2014). Comparative risk assessment of severe accidents in the energy sector . Energy Policy, 74, S45-S56.

McCombie, C., & Jefferson, M. (2016). Renewable and nuclear electricity: Comparison of environmental impacts. Energy Policy, 96, 758-769.

Hirschberg, S., Bauer, C., Burgherr, P., Cazzoli, E., Heck, T., Spada, M., & Treyer, K. (2016). Health effects of technologies for power generation: Contributions from normal operation, severe accidents and terrorist threat . Reliability Engineering & System Safety, 145, 373-387.

Luderer, G., Pehl, M., Arvesen, A., Gibon, T., Bodirsky, B. L., de Boer, H. S., … & Mima, S. (2019). Environmental co-benefits and adverse side-effects of alternative power sector decarbonization strategies . Nature Communications, 10(1), 1-13.

Hertwich, E. G., Gibon, T., Bouman, E. A., Arvesen, A., Suh, S., Heath, G. A., … & Shi, L. (2015). Integrated life-cycle assessment of electricity-supply scenarios confirms global environmental benefit of low-carbon technologies . Proceedings of the National Academy of Sciences, 112(20), 6277-6282.

Xie, L., Huang, Y., & Qin, P. (2018). Spatial distribution of coal-fired power plants in China. Environment and Development Economics, 23(4), 495-515.

Coal: 24.62 deaths per TWh * 10,042 TWh = 247,000 deaths Oil: 18.43 deaths per TWh * 852 TWh = 16,000 deaths Gas: 2.82 deaths per TWh * 6,098 TWh = 17,000 deaths. This sums to a total of 280,000 people.

Lelieveld, J., Klingmüller, K., Pozzer, A., Burnett, R. T., Haines, A., & Ramanathan, V. (2019). Effects of fossil fuel and total anthropogenic emission removal on public health and climate . Proceedings of the National Academy of Sciences, 116(15), 7192-7197.

Vohra, K., Vodonos, A., Schwartz, J., Marais, E. A., Sulprizio, M. P., & Mickley, L. J. (2021). Global mortality from outdoor fine particle pollution generated by fossil fuel combustion: Results from GEOS-Chem . Environmental Research, 195, 110754.

Chowdhury, S., Pozzer, A., Haines, A., Klingmueller, K., Münzel, T., Paasonen, P., ... & Lelieveld, J. (2022). Global health burden of ambient PM2.5 and the contribution of anthropogenic black carbon and organic aerosols . Environment International, 159, 107020.

Leliveld et al. (2019) estimate that 8.8 million people die from all sources of air pollution each year. If we multiply this figure by 12%, we get 1.1 million people. Vohra et al. (2021) estimate that the death toll is 2.4 times higher than Leliveld et al. (2019). This would give a figure of 2.55 million deaths [1.1 million * 2.4]

UNECE (2021). Lifecycle Assessment of Electricity Generation Options . United Nations Economic Commission for Europe.

The third incident that often comes to mind was the Three Mile Island accident in the US in 1979. This was rated as a level five event (“Accident with Wider Consequences”) on the seven-point International Nuclear Event Scale .

No one died directly from this incident, and follow-up epidemiological studies have not found a clear link between the incident and long-term health impacts.Hatch, M. C., Beyea, J., Nieves, J. W., & Susser, M. (1990). Cancer near the Three Mile Island nuclear plant: radiation emissions . American Journal of Epidemiology , 132(3), 397-412.

Hatch, M. C., Wallenstein, S., Beyea, J., Nieves, J. W., & Susser, M. (1991). Cancer rates after the Three Mile Island nuclear accident and proximity of residence to the plant . American Journal of Public Healt h, 81(6), 719-724.

The UNSCEAR (2008) report lists the causes of death in each of these survivors in Table D4 of the appendix.

25% of 19,233 is 4808 cases.

This figure was included in the UNSCEAR’s 2008 report. I found no updated figure for fatalities in its 2018 report.

Reiners, C. (2011). Clinical experiences with radiation induced thyroid cancer after Chernobyl. Genes, 2(2), 374-383.

Hogan, A. R., Zhuge, Y., Perez, E. A., Koniaris, L. G., Lew, J. I., & Sola, J. E. (2009). Pediatric thyroid carcinoma: incidence and outcomes in 1753 patients. Journal of Surgical Research, 156(1), 167-172.

Hay, I. D., Gonzalez-Losada, T., Reinalda, M. S., Honetschlager, J. A., Richards, M. L., & Thompson, G. B. (2010). Long-term outcome in 215 children and adolescents with papillary thyroid cancer treated during 1940 through 2008. World Journal of Surgery , 34(6), 1192-1202.

2% of 4808 is 96, and 8% is 385.

Cardis et al. (2006). Estimates of the cancer burden in Europe from radioactive fallout from the Chernobyl accident. International Journal of Cancer. Available online .

Fairlie and Sumner (2006). An independent scientific evaluation of health and environmental effects 20 years after the nuclear disaster providing critical analysis of a recent report by the International Atomic Energy Agency (IAEA) and the World Health Organisation (WHO). Available online .

IAEA, WHO (2005/06). Chernobyl’s Legacy: Health, Environmental and Socio-Economic Impacts .

As it details in its report:“The vast majority of the population were exposed to low levels of radiation comparable, at most, to a few times the annual natural background radiation levels and need not live in fear of serious health consequences. This is true for the populations of the three countries most affected by the Chernobyl accident, Belarus, the Russian Federation and Ukraine, and even more so for the populations of other European countries.”

“To date, there has been no persuasive evidence of any other health effect in the general population that can be attributed to radiation exposure”

Leung, K. M., Shabat, G., Lu, P., Fields, A. C., Lukashenko, A., Davids, J. S., & Melnitchouk, N. (2019). Trends in solid tumor incidence in Ukraine 30 years after chernobyl . Journal of Global Oncology , 5 , 1-10.

When we report on the safety of energy sources – in this article – I take the upper number of 433 deaths to be conservative.

World Health Organization (2016). FAQs: Fukushima Five Years On. Available online at: https://www.who.int/ionizing_radiation/a_e/fukushima/faqs-fukushima/en/.{/ref } Several reports from the UN Scientific Committee on the Effects of Atomic Radiation came to the same conclusion: they report that any increase in radiation exposure for local populations was very low and they do not expect any increase in radiation-related health impacts.{ref}To quote UNSCEAR directly: “The doses to the general public, both those incurred during the first year and estimated for their lifetimes, are generally low or very low. No discernible increased incidence of radiation-related health effects are expected among exposed members of the public or their descendants.”

Report of the United Nations Scientific Committee on the Effects of Atomic Radiation. General Assembly Official Records , Sixty-eighth session, Supplement No. 46. New York: United Nations, Sixtieth session, May 27–31, 2013.

The Yomiuri Shimbun, 573 deaths ‘related to nuclear crisis’, The Yomiuri Shimbun, 5 February 2012, https://wayback.archive-it.org/all/20120204190315/http://www.yomiuri.co.jp/dy/national/T120204003191.htm.

Hayakawa, M. (2016). Increase in disaster-related deaths: risks and social impacts of evacuation . Annals of the ICRP, 45(2_suppl), 123-128.

Normile (2021). Nuclear medicine: After 10 years advising survivors of the Fukushima disaster about radiation, Masaharu Tsubokura thinks the evacuations posed a far bigger health risk . Science .

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A brief history of nuclear fusion

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Nuclear Power in the World Today

(Updated November 2023)

  • The first commercial nuclear power stations started operation in the 1950s.
  • Nuclear energy now provides about 10% of the world's electricity from about 440 power reactors.
  • Nuclear provides about one-quarter of the world’s low-carbon electricity.
  • Nuclear is the world's second largest source of low-carbon power (26% of the total in 2020). 
  • Over 50 countries utilize nuclear energy in about 220 research reactors. In addition to research, these reactors are used for the production of medical and industrial isotopes, as well as for training.

Nuclear technology uses the energy released by splitting the atoms of certain elements. It was first developed in the 1940s, and during the Second World War research initially focused on producing bombs. In the 1950s attention turned to the peaceful use of nuclear fission, controlling it for power generation. For more information, see page on  History of Nuclear Energy .

Civil nuclear power can now boast more than 20,000 reactor years of experience, and nuclear power plants are operational in 31 countries (plus Taiwan) worldwide. In fact, through regional transmission grids, many more countries depend in part on nuclear-generated power, particularly in Europe.

When the commercial nuclear industry began in the 1960s, there were clear boundaries between the industries of the East and West. Today, the nuclear industry is characterized by international commerce. A reactor under construction in Asia today may have components supplied from South Korea, Canada, Japan, France, Germany, Russia, and other countries. Similarly, uranium from Australia or Namibia may end up in a reactor in the UAE, having been converted in France, enriched in the Netherlands, deconverted in the UK and fabricated in South Korea.

The uses of nuclear technology extend well beyond the provision of low-carbon energy. It helps control the spread of disease, assists doctors in their diagnosis and treatment of patients, and powers our most ambitious missions to explore space. These varied uses position nuclear technologies at the heart of the world's efforts to achieve sustainable development. For more information, see page on Nuclear Energy and Sustainable Development .

In 2022 nuclear plants supplied 2545 TWh of electricity, down from 2653 TWh in 2021.

nuclear power generation by region 1970-2022

Figure 1: Nuclear electricity production (source: World Nuclear Association, IAEA PRIS)

World electricity production 2022

Figure 2: World electricity production by source 2020 (source: International Energy Agency)

Thirteen countries in 2022 produced at least one-quarter of their electricity from nuclear. France gets up to around 70% of its electricity from nuclear energy, while Ukraine, Slovakia, Belgium and Hungary get about half from nuclear. Japan was used to relying on nuclear power for more than one-quarter of its electricity and is expected to return to somewhere near that level.

nuclear power generation by country 2022

Figure 3: Nuclear generation by country 2022 (source: IAEA PRIS)

Developments in 2023 

Grid connections

Construction starts

Reactor shutdowns

Need for new generating capacity

There is a clear need for new generating capacity around the world, both to replace old fossil fuel units, especially coal-fired ones, which emit a lot of carbon dioxide, and to meet increased demand for electricity in many countries. In 2020, 61% of electricity was generated from the burning of fossil fuels. Despite the strong support for, and growth in, intermittent renewable electricity sources in recent years, the fossil fuel contribution to power generation has not changed significantly in the last 15 years or so (66.5% in 2005).

The OECD International Energy Agency publishes annual scenarios related to energy. In its World Energy Outlook 2023 1 there is an ambitious ‘Net Zero Emissions by 2050 Scenario' (NZE), which "maps out a way to achieve a 1.5°C stablisation in the rise in global average temperatures, alongside universal access to modern energy by 2030." The NZE in WEO 2023 sees nuclear capacity increase to 916 GWe by 2050.

World overview

All parts of the world are involved in nuclear power development, and some examples are outlined below.

For up-to-date data on operable, under construction and planned reactors worldwide, see table of  World Nuclear Power Reactors & Uranium Requirements .

For detailed country-level information, see the  Country Profiles section of World Nuclear Association's Information Library.

North America

Canada  has 19 operable nuclear reactors, with a combined net capacity of 13.6 GWe. In 2022, nuclear generated 13.6% of the country's electricity.

All but one of the country's 19 nuclear reactors are sited in Ontario. The four units at Darlington and units 1-6 at Bruce are undergoing lifetime extension refurbishment.

The programme will extend the operating lifetimes by 30-35 years. Similar refurbishment work enabled Ontario to phase out coal in 2014, achieving one of the cleanest electricity mixes in the world.

Mexico has two operable nuclear reactors, with a combined net capacity of 1.6 GWe. In 2022, nuclear generated 4.5% of the country's electricity.

The USA has 93 operable nuclear reactors, with a combined net capacity of 95.8 GWe. In 2022, nuclear generated 18.2 % of the country's electricity.

There had been four AP1000 reactors under construction, but two of these have been cancelled. One of the reasons for the hiatus in new build in the USA to date has been the extremely successful evolution in maintenance strategies. Over the last 15 years, improved operational performance has increased utilisation of US nuclear power plants, with the increased output equivalent to 19 new 1000 MWe plants being built.

2016 saw the first new nuclear power reactor enter operation in the country for 20 years. Despite this, the number of operable reactors has reduced in recent years, from a peak of 104 in 2012. Early closures have been brought on by a combination of factors including cheap natural gas, market liberalization, over-subsidy of renewable sources, and political campaigning.

South America

Argentina has three reactors, with a combined net capacity of 1.6 GWe. In 2022, the country generated 5.4% of its electricity from nuclear. 

Brazil has two reactors, with a combined net capacity of 1.9 GWe. In 2022, nuclear generated 2.5% of the country's electricity.  

West & Central Europe

Belgium  has five operable nuclear reactors, with a combined net capacity of 5.9 GWe. In 2022, nuclear generated 46.4% of the country's electricity.

Finland  has five operable nuclear reactors, with a combined net capacity of 4.4 GWe. In 2022, nuclear generated 35.0% of the country's electricity. Finland's fifth reactor – a 1600 MWe (net) EPR – was connected to the grid in March 2022.

France has 56 operable nuclear reactors, with a combined net capacity of 61.4 GWe. In 2022, nuclear generated 62.5% of the country's electricity.

Government policy, set under a former administration in 2014, aimed to reduce nuclear's share of electricity generation to 50% by 2025. This target was delayed in 2019 to 2035, before being abandoned in 2023.

One reactor is currently under construction in France – a 1750 MWe EPR at Flamanville.

The Netherlands has a single operable nuclear reactor, with a net capacity of 0.5 GWe. In 2022, nuclear generated 3.3% of the country's electricity.

Spain  has seven operable nuclear reactors, with a combined net capacity of 7.1 GWe. In 2022, nuclear generated 20.3% of the country's electricity.

Sweden  has six operable nuclear reactors, with a combined net capacity of 6.9 GWe. In 2022, nuclear generated 29.4% of the country's electricity.

The country is closing down some older reactors, but has invested heavily in operating lifetime extensions and uprates.

Switzerland  has four operable nuclear reactors, with a combined net capacity of 3.0 GWe. In 2022, nuclear generated 36.4% of the country's electricity.

The United Kingdom  has 9 operable nuclear reactors, with a combined net capacity of 5.9 GWe. In 2022, nuclear generated 14.2% of the country's electricity.

A UK government energy paper in mid-2006 endorsed the replacement of the country’s ageing fleet of nuclear reactors with new nuclear build. Construction has commenced on the first of a new-generation of plants.

Central and East Europe, Russia

Armenia  has a single nuclear power reactor with a net capacity of 0.4 GWe. In 2022, nuclear generated 31.0% of the country's electricity. 

Belarus  has two operable nuclear power reactors, with a combined net capacity of 2.2 GWe. Almost all the rest of the country's electricity is produced from natural gas. In 2021, nuclear generated 14.1% of the country's electricity.

Bulgaria  has two operable nuclear reactors, with a combined net capacity of 2.0 GWe. In 2022, nuclear generated 32.6% of the country's electricity.

The Czech Republic  has six operable nuclear reactors, with a combined net capacity of 3.9 GWe. In 2022, nuclear generated 36.7% of the country's electricity.

Hungary  has four operable nuclear reactors, with a combined net capacity of 1.9 GWe. In 2022, nuclear generated 47.0% of the country's electricity.

Romania  has two operable nuclear reactors, with a combined net capacity of 1.3 GWe. In 2022, nuclear generated 19.4% of the country's electricity.

Russia has 37 operable nuclear reactors, with a combined net capacity of 27.7 GWe. In 2022, nuclear generated 19.6% of the country's electricity.

A government decree in 2016 specified construction of 11 nuclear power reactors by 2030, in addition to those already under construction. At the start of 2023, Russia had three reactors under construction, with a combined capacity of 2.7 GWe.

The strength of Russia's nuclear industry is reflected in its dominance of export markets for new reactors. The country's national nuclear industry is currently involved in new reactor projects in Belarus, China, Hungary, India, Iran and Turkey, and to varying degrees as an investor in Algeria, Bangladesh, Bolivia, Indonesia, Jordan, Kazakhstan, Nigeria, South Africa, Tajikistan and Uzbekistan among others.

Slovakia  has four operable nuclear reactors, with a combined net capacity of 1.8 GWe. In 2022, nuclear generated 59.2% of the country's electricity. A further two units are under construction.

Slovenia  has a single operable nuclear reactor with a net capacity of 0.7 GWe. In 2022, Slovenia generated 42.6% its electricity from nuclear.

Ukraine has 15 operable nuclear reactors, with a combined net capacity of 13.1 GWe. In 2022, nuclear generated an estimated 58.7 TWh of electricity.

Turkey commenced construction of its first nuclear power plant in April 2018, with start of operation expected in 2023.

Bangladesh  started construction on the first of two planned Russian VVER-1200 reactors in 2017. Construction on the second started in 2018. It plans to have the first unit in operation by 2023. The country currently produces virtually all of its electricity from fossil fuels.

China has 55 operable nuclear reactors, with a combined net capacity of 53.3 GWe. In 2022, nuclear generated 5.0% of the country's electricity.

The country continues to dominate the market for new nuclear build, with 25 reactors under construction at the end of October 2023. In 2018 China became the first country to commission two new designs – the AP1000 and the EPR. China is marketing the Hualong One for export, a largely indigenous reactor design.

The strong impetus for developing new nuclear power in China comes from the need to improve urban air quality and reduce greenhouse gas emissions.

India  has 22 operable nuclear reactors, with a combined net capacity of 6.8 GWe. In 2022, nuclear generated 3.1% of the country's electricity.

The Indian government is committed to growing its nuclear power capacity as part of its massive infrastructure development programme. The government in 2010 set an ambitious target to have 14.6 GWe nuclear capacity online by 2024. At the end of October 2023 eight reactors were under construction in India, with a combined capacity of 6.7 GWe.

Japan  has 33 operable nuclear reactors, with a combined net capacity of 31.7 GWe. As of October 2023, 11 reactors had been brought back online, with a further 16 in the process of restart approval, following the  Fukushima accident in 2011. In the past, 30% of the country's electricity has come from nuclear; in 2022, the figure was just 6.1%.

South Korea has 25 operable nuclear reactors, with a combined net capacity of 24.4 GWe. In 2022, nuclear generated 6.1% of the country's electricity.

The country has three new reactors under construction domestically and is constructing a four-unit plant in the United Arab Emirates.

Pakistan  has six operable nuclear reactors, with a combined net capacity of 3.3 GWe. In 2022, nuclear generated 16.2% of the country's electricity.

Egypt started construction in July 2022 of the first of four Russian-designed VVER units to be built at the El Dabaa site on the Mediterranean coast. The second unit began construction in November 2022. The third began construction in May 2023. All four reactors are expected to be operational by 2030.

South Africa has two operable nuclear reactors, with a combined net capacity of 1.9 GWe, and is the only African country currently producing electricity from nuclear. In 2022, nuclear generated 4.9% of the country's electricity. South Africa remains committed to plans for further capacity, but financing constraints are significant.

Middle East

Iran  has a single operable nuclear reactor with a net capacity of 0.9 GWe. In 2021, nuclear generated 1.7% of the country's electricity. A second Russian-designed VVER-1000 unit is under construction.

The United Arab Emirates  has three operable nuclear reactors with a capacity of 6.8 GWe. A fourth unit is under construction at the same plant (Barakah). In 2022, nuclear generated 6.8% of the country's electricity.

Emerging nuclear energy countries

As outlined above, Bangladesh, Turkey and the United Arab Emirates are all constructing their first nuclear power plants. A number of other countries are moving towards use of nuclear energy for power production. For more information, see page on  Emerging Nuclear Energy Countries .

Improved performance from existing reactors

The performance of nuclear reactors has improved substantially over time. Over the last 40 years the proportion of reactors reaching high capacity factors has increased significantly.

long-term trends in capacity factor of nuclear power plants

Figure 4: Long-term trends in capacity factors (source: World Nuclear Association, IAEA PRIS)

It is also notable that there is no significant age-related trend in the mean capacity factor for reactors over the last five years.

mean capacity factor of nuclear power plants 2018-2022

Figure 5: Mean capacity factor 2018-2022 by age of reactor (source: World Nuclear Association, IAEA PRIS)

Other nuclear reactors

In addition to commercial nuclear power plants, there are about 220 research reactors operating in over 50 countries, with more under construction. As well as being used for research and training, many of these reactors produce medical and industrial isotopes.

The use of reactors for marine propulsion is mostly confined to the major navies where it has played an important role for five decades, providing power for submarines and large surface vessels. Over 160 ships, mostly submarines, are propelled by some 200 nuclear reactors and over 13,000 reactor years of experience have been gained with marine reactors. Russia and the USA have decommissioned many of their nuclear submarines from the Cold War era.

Russia also operates a fleet of large nuclear-powered icebreakers and has more under construction. It has also connected a floating nuclear power plant with two 32 MWe reactors to the grid in the remote arctic region of Pevek. The reactors are adapted from those powering icebreakers.

For more information see page on The Many Uses of Nuclear Technology . 

Notes & references

References .

1. OECD International Energy Agency, World Energy Outlook 2023  [ Back ] 2. OECD International Energy Agency Statistics [ Back ]

General references

World Nuclear Association, World Nuclear Performance Report 2023

Related information

Financing nuclear energy, nuclear energy and sustainable development, plans for new reactors worldwide, the many uses of nuclear technology, what is uranium how does it work, world energy needs and nuclear power, you may also be interested in.

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cooling towers of power plant near forested area

President-elect Joe Biden comes into office at a time when phasing out fossil fuels is critical. The Intergovernmental Panel on Climate Change (IPCC) has warned that we must keep the planet from warming more than 1.5˚C above pre-industrial levels by 2030. Every pathway the IPCC envisioned to achieve this goal requires an increase in nuclear energy—of 59 to 106 percent more than 2010 levels by 2030. Biden’s $2 trillion climate plan , recognizing this urgency, includes support for the development of nuclear energy. What is the current state of nuclear energy in the U.S., and what role could it play in a decarbonized future?

Nuclear energy’s role in fighting climate change

Nuclear power is the second largest source of clean energy after hydropower. The energy to mine and refine the uranium that fuels nuclear power and manufacture the concrete and metal to build nuclear power plants is usually supplied by fossil fuels, resulting in CO2 emissions; however, nuclear plants do not emit any CO2 or air pollution as they operate. And despite their fossil fuel consumption, their carbon footprints are almost as low as those of renewable energy. One study  calculated that a kilowatt hour of nuclear-generated electricity has a carbon footprint of 4 grams of CO2 equivalent, compared to 4 grams for wind and 6 grams for solar energy — versus 109 grams for coal, even with carbon capture and storage.

In the last 50 years, nuclear energy has precluded the creation of 60 gigatons of carbon dioxide, according to the International Energy Agency. Without nuclear energy, the power it generated would have been supplied by fossil fuels, which would have increased carbon emissions and resulted in air pollution that could have caused millions more deaths each year.

The state of nuclear energy today

Around the world, 440 nuclear reactors currently provide over 10 percent of global electricity. In the U.S., nuclear power plants have generated almost 20 percent of electricity for the last 20 years.

Indian Point power plant

Most of the nuclear plants operating today were designed to last 25 to 40 years and with an average age of 35 years, a quarter of them in developed countries will likely be shut down by 2025. After the Fukushima meltdown, a number of countries began to consider phasing out their nuclear programs, with Germany expected to shut down its entire nuclear fleet by 2022.

The U.S. has 95 nuclear reactors in operation, but only one new reactor has started up in the last 20 years. Over 100 new nuclear reactors are being planned in other countries, and 300 more are proposed, with China, India, and Russia leading the way.

How nuclear reactors work

All commercial reactors generate heat through nuclear fission, wherein the nucleus of a uranium atom is split into smaller atoms (called the fission products). The splitting releases neutrons that trigger a chain reaction in other uranium atoms.

diagram showing how atoms are split in nuclear fission

As the atoms split, they release a tremendous amount of energy—a kilogram of uranium undergoing fission releases three million times more energy than a kilogram of coal being burned. Coolant, often water, circulates around the reactor core to absorb the heat that fission creates; the heat boils the water, creating pressurized steam to turn a turbine and generate electricity.

Reactor fuel is usually uranium in pellets that are placed in fuel rods and arranged in the reactor’s core. A 1,000MW nuclear reactor might contain as many as 51,000 rods with over 18 million pellets.

spent fuel rods

After it fuels the reactor for four to six years, the spent fuel is replaced with new fuel rods. The highly radioactive and hot spent fuel rods are transferred to a pool of water on-site that cools and shields them.

After about five years, when enough of the energy has decayed, the fuel is transferred to dry casks that are stored on-site in concrete bunkers. This is how most of the nuclear waste that has been produced over the years is currently stored.

The challenges facing nuclear energy

The nuclear industry in the U.S. faces resistance due to a number of factors.

Nuclear accidents

The American public has misgivings about nuclear power because of three nuclear accidents that occurred: the Three Mile Island partial meltdown in 1979, the Chernobyl meltdown and explosion in 1986, and the Fukushima meltdown in 2011 precipitated by an earthquake and a tsunami.

empty classroom

Both the Three Mile Island and Fukushima accidents began after the reactors were shut down and a lack of power prevented the pumps from circulating water to cool the decaying fuel. Similar light water reactors, cooled with ordinary water, make up the majority of the nuclear reactors in use.

While nuclear accidents are rare, the consequences are catastrophic. Fukushima’s meltdown drove over 200,000 people from their homes. Chernobyl’s reactor site will be radioactive for tens of thousands of years.

Nuclear proliferation

The uranium found in nature consists of mostly uranium-238, and a tiny amount of uranium-235, which is what is needed for fission. The process of concentrating and increasing the U-235 in relation to U-238 is called enrichment. However, enrichment is controversial because the process can sometimes be used to create uranium for nuclear weapons, as can reprocessing spent fuel to recover uranium and plutonium to recycle them for fresh fuel.

“The U.S. position since the Ford administration has been to not reprocess fuel, because we don’t really want other countries reprocessing their fuel,” said Matt Bowen, a research scholar focusing on nuclear energy at Columbia University’s Center on Global Energy Policy.

To prevent nuclear proliferation, most countries have signed onto international agreements to limit nuclear weapons, and the International Atomic Energy Agency regularly inspects nuclear facilities to monitor their nuclear materials.

Nuclear waste

There is still no viable way to permanently dispose of the radioactive material that is produced at every stage of a nuclear power plant’s life, from the mining and enrichment of uranium through operation to the spent fuel. Of this radioactive material, three percent—mostly spent fuel—is considered high-level waste, meaning that it is extremely dangerous and will be radioactive for tens of thousands of years; it needs to be cooled, then safely contained virtually forever. Seven percent is intermediate waste, material from the reactor’s core and other reactor parts; this is also dangerous but can be contained in canisters. The rest, made up of building materials, plastics and other miscellany, is considered low-level waste, but also needs to be stored.

containers

A Greenpeace report estimates that there are 250,000 tons of high-level waste in 14 countries that are sitting in temporary storage. The U.S. itself has almost 90,000 tons of high-level waste awaiting permanent disposal. While governments and industry agree that deep burial is the best solution for nuclear waste, no country has a site for deep burial in operation. One nuclear expert said  that “there is no scientifically proven way” of disposing of high- and intermediate- level waste.

In 1987, Yucca Mountain in Nevada was selected to be a disposal site for U.S. nuclear waste, but it has been opposed by state leaders and residents, and its fate is in limbo.

New nuclear reactors can cost over $7 billion, which makes them expensive propositions, especially when natural gas is so cheap. Some of the newest nuclear projects have gone far over schedule and over budget. Bowen said that Westinghouse’s failure to build two of four new-and-improved AP1000 reactors planned for South Carolina and Georgia has had serious consequences for the whole nuclear industry. After costing $9 billion dollars, the two South Carolina reactors were canceled. “It’s not the materials that are resulting in the high costs, but a doubling of the construction time,” he said. “For the AP1000s, it is widely acknowledged that the construction was begun at a relatively low design maturity. It’s not that Westinghouse wasn’t completely aware that they were beginning construction before they finished the design, and [that] there was some risk involved. They just didn’t think it would go as badly as it went.”

Bowen added that he thinks the cancellation of South Carolina’s AP1000s is “the shadow that’s cast over the whole U.S. industry. It took down a utility—which should make other utilities more cautious about building a first-of-a-kind nuclear reactor.”

The Georgia reactors, also late and over budget, are scheduled to begin operation in 2021 and 2022.

The evolution of nuclear reactors

The first generation of nuclear reactors was developed in the 1950s; by 2015, these had all shut down. Generation II reactors are the ones mostly in operation today. While they were designed to last only 40 years, as of 2018, the Nuclear Regulatory Agency had granted license renewals to 89 reactors for an additional 20 years. (Three of those reactors have since shut down.) A few plants have been relicensed out to 80 years. Relicensing usually involves upgrading or replacing old equipment and technology, and is less costly than constructing a brand-new reactor.

Advanced reactors, sometimes called  Generation III and III+,  are operating in Japan and being built in other countries. Generation IV reactors are still in the design stage.

person standing in front of a screen

Many of the new nuclear plant designs that are in advanced planning stages, under construction, or being researched in North America, Europe, Japan, Russia and China address the main challenges of nuclear energy. They incorporate improvements in safety and cost, as well as in reliability, proliferation resistance and waste reduction.

Whereas traditional reactors depended on mechanical systems to deal with malfunctions, many new reactors utilize passive safety measures that don’t need outside operators. This entails systems that rely on gravity, convection or tolerance of high temperatures to prevent accidents. Some are designed more simply, which means there are fewer components that can malfunction. Others have a more standardized design so that modular components, which can be manufactured in a factory, can be used, reducing construction time and costs; older nuclear reactors usually had to be fabricated on-site. Many new reactors also use fuel more efficiently and produce less waste, and some are designed to consume nuclear waste as fuel.

Some new reactors

Here are just a few of the many new reactors being planned with a variety of technologies and designs. The first two listed were chosen by the Department of Energy’s (DOE) Advanced Reactor Demonstration Program. They each will receive $80 million this year and an additional $400 million to $4 billion over the next five to seven years. The DOE also plans to make two to five more awards totaling $30 million for advanced reactor designs by December.

TerraPower , co-founded by Bill Gates, and GE Hitachi Nuclear Energy are developing a 345MW Natrium reactor that will use molten sodium metal as a coolant. Sodium has a much higher boiling point than water so the coolant would not need to be pressurized, making operation simpler. Moreover, it saves on costs because there is no need to construct a large containment structure. The heat in the sodium will be transferred to molten salt, to either drive a steam turbine or be stored for later use. This allows the system to boost its output to 500MW for over five and a half hours if necessary. The Natrium will also use more highly enriched uranium, which would enable it to burn fuel more efficiently. The Natrium reactor is expected to be operational in the late 2020s.

The 80MW high temperature reactor , Xe-100 , developed by X-Energy, uses fuel in pebble form, which cannot melt down. The 220,000 balls of graphite filled with ceramic uranium-filled kernels slowly make their way down through the core and exit out the bottom when they are spent. They are cooled by pressurized helium, which heats up to 750˚C to produce steam for electricity. The reactor’s simpler design uses components that can be manufactured in a factory then assembled, and due to its modular design, it can be combined with other 80MW reactors to produce 320MW or more. Bowen noted that the higher efficiency of this reactor means it can produce a smaller amount of waste per megawatt-hour generated.

Terrapower’s traveling wave reactor  is a liquid sodium cooled reactor operating at atmospheric pressure. It uses fuel made from depleted uranium, a byproduct of the fuel enrichment process that is often disposed of. The used fuel is kept in the core so there is no need for storage. Terrapower claims that the traveling wave reactor will eventually eliminate enrichment and reprocessing, thus reducing proliferation risk. Over its 60-year lifetime, the total amount of waste it produces would fill only one and a half rail cars. With the design almost complete and engineering begun, it’s expected to begin operation in the mid-2020s.

illustration of future nuclear power plant

NuScale  is developing a small modular light water reactor that will generate 77MW. It will occupy the space of only one percent of a conventional reactor. The design has been simplified to eliminate pumps and other moving parts, which makes it safer, and the reactor can shut itself down and cool itself without any need for an outside operator. Its compact size enables it to be used for communities that need less power as well as for medical and military installations. Twelve small modular reactors could be placed together to form a 924MW power plant, with some modules producing electricity while others provide heat for industry. The Department of Energy has partnered with NuScale and Utah Associated Municipal Power Systems to develop this reactor, but recently eight of the 36 utilities involved backed out. Nevertheless, NuScale is scheduled to bring the first module online by mid-2029 and the remaining 11 modules by 2030 to align with when UAMPS’ coal-fired plants retire, according to NuScale’s Diane Hughes. The total budget is projected to be $6.1 billion.

There are many designs of fast neutron reactors in development with sodium, lead, gas, and molten salt coolants. Because these coolants enable neutrons to move faster than water does, fast reactors have the potential to yield 60 times more energy from uranium than traditional light water reactors. In any reactor, some of the U-238 is turned into different forms of plutonium during its operation, and some then undergo fission to produce heat. Fast neutron reactors can optimize this process so that it actually “breeds” more fuel. While fast reactors have been around since the 1950s, there is more interest in them today because of the pileup of nuclear waste, and the ability of these reactors to destroy through fission the elements in spent fuel that make it highly radioactive for so long—instead of the waste being toxic for tens of thousands of years, it is toxic for a hundred years.

Microreactors  that can fit in the back of a semi-truck could produce from one to 20MW of power and be used for heat or electricity. Their small size makes them able to generate energy for industrial processes along with heating and cooling in remote areas, natural disaster areas, and military bases around the world; in addition they can be easily integrated with renewable energy in microgrids. Oklo Power is developing its Aurora micro modular fast reactor , which will deliver 1.5MW of power and heat at Idaho National Laboratory. The compact design incorporates solar panels, and will use a new kind of “high-assay, low-enriched uranium” fuel called HALEU. This means the uranium is enriched to have a higher concentration of the U-235 needed for fission, which allows the reactor to get more power from the fuel and be refueled less often. HALEU isn’t yet commercially available.

Other uses for nuclear energy

Nuclear energy will need to play a key role in decarbonizing the economy because it is difficult for renewable energy to muster the intense heat needed in industrial processes, such as steel and cement production. These kinds of industrial processes comprise 10 percent of global emissions, according to Columbia University’s Center on Global Energy Policy. Some advanced reactors, such as the high-temperature gas-cooled reactor, can provide both electricity and heat for petroleum refining, or for the production of fertilizer and chemicals. Nuclear reactors could also be used to produce the electricity needed to split water into hydrogen and oxygen; clean hydrogen could then be used to generate heat for steel manufacturing and other industrial activities, to fuel vehicles, produce synthetic fuel, or store energy for the grid.

Most desalination plants that convert seawater into drinking water require a great deal of energy that usually comes from fossil fuels. Small modular reactors located by the ocean could generate the electricity needed for desalination.

The prospects for nuclear energy

Biden’s climate plan supports research into “affordable, game-changing technologies to help America achieve our 100 percent clean energy target,” with a focus on small modular reactors and the issues that challenge nuclear energy development: cost, safety and waste disposal. Biden could potentially get Republican buy-in for climate legislation through nuclear energy, since nuclear energy bills have received bipartisan support in the past. Since 2018, two acts that would speed the modernization of the Nuclear Regulatory Commission, support the development of advanced reactor fuel, and help nuclear developers collaborate with universities and the national labs, received bipartisan support in Congress and were signed into law. The bipartisan Nuclear Energy Leadership Act introduced in 2019 would help advanced nuclear reactor concepts go from research to commercialization by matching private capital to build two demo reactors by 2025 and potentially five more by 2035.  The Nuclear Waste Administration Act of 2019 was introduced by a bipartisan group of senators to create a new entity to focus on nuclear waste management.

“It makes sense from a risk management point of view to have investments in nuclear be part of the solution [to climate change],” said Bowen. “But the generation that we’re talking about is going to need years to sort of mature and they will still have to build their first unit relatively close to on time and on budget. Otherwise, there isn’t going to be a second unit.” And despite the Congressional acts and the many plans for new reactors, he thinks we may not see many new reactors in the U.S. unless Congress passes a federal clean energy standard. Bowen believes relicensing may actually be the key to more nuclear energy. “I have more confidence that there will be measures to maintain the existing fleet, which is just a much lighter lift,” he said. “I’m optimistic that there’s going to be more and more of the subsequent relicensing where we’re extending the plant operations from 60 to 80 years.”

As for new reactors, Nuscale’s small modular reactors are farthest along and won’t be operating until 2030 at this point. But if the company can successfully bring the project in reasonably on time, and if there is a national climate policy driving us to zero carbon emissions, Bowen thinks more nuclear power plants could get built to substantially support the decarbonization of the electric grid by the 2050s.

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https://en.wikipedia.org/wiki/Nuclear_reprocessing#:~:text=On%207%20April%201977%2C%20President%20Jimmy%20Carter%20banned,encourage%20other%20nations%20to%20follow%20the%20USA%20lead .

Why dont we reprocess https://youtu.be/5t-j8pVsnc0

James E Hopf

This article is 0 for 3 on the subjects of accidents, proliferation and waste.

The effects of even worst-case nuclear accidents are NOT catastrophic! TMI had no affect at all (other than loss of plant). Chernobyl is simply not applicable to the risks of modern nuclear power. Fukushima, the only significant release of pollution in non-Soviet nuclear power’s entire history caused (and will cause) few if any deaths and will never have any measurable public health impact. Meanwhile, pollution from fossil power generation causes ~1000 deaths every single day, along with global warming. Thus, fossil generations’ *daily* impact is far worse than the “catastrophic” impact of a worst-case meltdown.

The long-term evacuations at Fukushima were not justified. No areas around Fukushima were as unhealth a place to live as most of the world’s large cities. Almost all of the “impacts” on people’s lives are not from nuclear accidents themselves, but unjustified *over-reactions* to them.

Nuclear power simply does not have a significant impact on weapons proliferation. In particular, adding more nuclear plants in countries that already have nuclear power, or the bomb, as zero proliferation impact. As long as developing nations do not employ enrichment or reprocessing facilities, the proliferation impacts of nuclear power, worldwide, will be negligible. And there is no real need for enrichment or reprocessing facilities in such nations.

The discussion of nuclear waste is the worst of all. Literally the opposite of the truth. Not only has the waste “problem” been technically solved for a long time, but nuclear is the ONLY energy source that has a technically viable plan to contain its wastes for as long as they remain hazardous. NRC has concluded that Yucca Mtn. would meet that impeccable, un precedented requirements. Other repositories (in Finland, etc.) have been approved and are moving forward. Unlike the waste streams and pollution from other energy sources, nuclear waste has never harmed anyone, and almost certainly never will.

The toxic waste streams from other energy sources and industries are many orders of magnitude larger in volume, are in a much harder to contain physical/chemical form (compared to nuclear waste which is in the form of ceramic pellets inside corrosion-resistant metal rods), actually last *longer* than nuclear waste (forever, vs. decaying away exponentially) and are disposed of with infinitely less care. Non-nuclear toxic waste streams are simply shallow-buried or are released directly into the environment. For all these reasons, the waste streams from other energy sources pose a far *larger* long-term hazard than nuclear wastes.

Nuclear’s only real problem is cost, but that is largely a symptom of the extreme over-reaction to the three “problems” listed above.

Nuclear is not lacking in technical merit. We don’t need advanced reactors or fuel cycles to solve those hyped to non-existent “problems”. Nuclear already is the safest and lowest environmental / public health impact source. Nuclear’s high costs are also not due to lack of technical merit, but are instead due to double standards and unlevel policy and regulatory playing fields. Regulatory reform and technology-neutral climate policies (such as carbon pricing) can’t come soon enough.

William Klein

Ask any 10 people if they are in favor of Nuclear power and the large majority will say no. The biggest hurdles for Nuclear power are not technical but overcoming stupidity.

Mike Zajdel

It is the human element, not ignorance, but zealots with advanced technical abilities with a desire to burn the planet. Eliminate that element – oh, wait, that goes back to sentence number one. Further, your individual assessment of the environmental impacts of Fukushima and Chernobyl are not at all correct. TMI, yeah, we got REALLY LUCKY. After all that being said, I don’t know that we eventyually will not have any other options.

Martin Braun

You are right and , thus, along with the “smart folks” in our minority. In fact, by the time most Americans and Europens find out-, the news of Chernobyl: that it was not the nationwide disaster nor did it cause mass die offs of animals or people. . People, being greedy, will hopefully-(probably) have returned to area that was marked off as permanently poisoned. In fact, the animals have returned and none are having moter or deformed offspring. Chernobyl will be a new eden for the animals and people ewho ignore the alleged “threats” of nuclear radiation. In fact, humans and animals have lived with and as a consequence of the earth’s nuclear radiation since the beginning of life-As the half life of rqadioactive materials was earten away, the living things both in the oceans and on land, learned to develop in the presence of radiation. The one example no one ever looks at is France. In 1976, France, also seriously affected by the oil shock, and having no oil or gas & coal of its own, decided to push ahead with a national “fleet” of atomic fission (nuclear) plants. Within 20 years-by 19995, France became the first and only,(so far), nation to run it’s entire electrical “grid” and system, off of it’s nuclear power reactors. Since then, because the “Green” party(s) are so powerful in Western Europe- many solar and wind farms were constructed to show the world that aside from developing the first home computer, first internet-WWWeb,(the Minitel), and the first absolte zero emission electricity and power generation system, that France could also bild (un needed), Green or free solar and wind power. The only rsult has been that the nuclear powr reactors now no longer need to to run all the time, but to prove to other Green Party advocates-and anti nuclear ignoramuses, that G+France could also do the “stupid” and build highly toxic, poorly thought out solar farms that are filled with toxic parts which are expensive to deconstruct-being all but impossible to bury, needing very expensive decommissioning. This is similarly so for when the enormous blades of wind turbines have to cut up. There is no place to bury them. The change will be expensive but humans have lived with radiation since long before we had written language-long before we could talk-and when we shared the planet with numerous other groups of intelligent hominims. If we don’t ALL make the switch (kind of a world wide kicking of the cigarette & tobacco habit)- we will all watch as we all die, with a few, like Elon Musk, trying to build a billionaire’s outpost-much like “Farham’s Freehold”, surrounded by patrol boats and armed on one of the Hawaiian islands, to prevent the ingress of non wealthy, non white Europeans, like Australia and , similar to Japan’s treatment of castaway sailors in the era before the end of the Tokugawa shogunate-Musk may also order the foreigners either enslaved, or used as food or fishbait. Australia is doing pretty much the same thing with anyone trying to enter their version of “South African minority” heaven. Our one , “common” to all way out of this deadly “maze of death” is to build lots of standardized, nuclear reactors so we have enough power to begin decarbonizing the atmosphere. The concept of de-carbonizing oil. gas or coal is an unworkable idea-it won’t work and, allows for driller/pipeline owners to fake results, both by emptying gas into the air-or, simply pretending to remove carbon-do you know if you can tell if billions of cubic ft of gas in a pipe has been stripped of C12? I can’t-So I turned off my gas and use a microwave. Our companies selling hydrocarbons are not trustworthy. We need more nuclear and we need to build it now-even if we claim we can’t afford it-as our kids and grand-kids will kills us before they die from our greed and thoughtlessness. We’ll have deserved a painful and miserable death-like the Terror, in revolutionary France,(they also gave the world the first planetary style dictator!).

Erin Stanton

Nuclear energy is going to play a big role in reversing climate change, given its net-negative carbon footprint.

Yes, there are safety and economical challenges that are commonly associated with nuclear energy and nuclear power plants, but the amount of funding and research going into developing nuclear technologies is quickly solving those issues. The Energy Impact Center launched its OPEN100 project in February 2020 that’s the world’s first open-source blueprint for the design, construction and financing of nuclear power plants and has already received $3 million in funding. ( https://venturebeat.com/2020/02/25/last-energy-raises-3-million-to-fight-climate-change-with-nuclear-energy/ ) OPEN100’s main goal is to collaborate with leaders across industries to develop plans and schematics that require less time and less money to build.

As for additional funding, along with the $160 million awarded to TerraPower and X-energy, mentioned already, in September 2020 the US Department of Energy also awarded $72 million in federal funding to support the development and advancement of carbon capture technologies. $21 million of that went to 18 projects for technologies that remove CO2 from the atmosphere. ( https://www.energy.gov/articles/department-energy-invests-72-million-carbon-capture-technologies )

Jean-Pierre Boespflug

We can’t wait for new nuclear technologies which won’t be at full maturity best case by 2035. To avoid climate disaster, we must to keep building nuclear technology of the type which has served us so well in the past and whose life we keep extending as you explain in this piece (Gen2 reactors). We are frozen now because we are trying to build new Gen3+ Monsters which are way too expensive and nobody can afford – the North Carolina type. We would have killed civil aviation if we had tried to build the perfect airplane rather than iterating along the way. For 20% cost increase we can produce a Gen2+ addressing immediate concerns and forget the cost prohibitive Gen3+ alternative which has frozen progress. Solar and Wind which are only giving us 9% of our electricity today, and will never give us more than 30% by 2050 because of storage limitations. Restarting proven nuclear providing 20% of our electricity today is the only way to have a 100% decarbonized system by 2050. We may stream in more sophisticated nuclear, of the type you are describing at some point but let’s not wait for that. The urgency is today!!

Krista kefauver

Your not accounting for freezing or moving rivers this only works for deserts. Nuclear waste must be buried. You not accounting for data thereof.. AT ALL…. if your studying Americas watersheds you would know better.

Gravity energy, solar, water vortex engines, power cells, and shadow generators are the future. Not more toxic waste. Sustainable energy.

Learn, Publish, Educate.*

Working nationally in bioremediation and sustainable buisness I have seen it all.

Nucular waste is riddling our largest water-systems. Forever toxins are found in all of America’s largest watersheds that water decontamination facilities cannot filter out with out Breaking up the water at a molecular level and sponging out toxins from our environment.

Jonathan Richardson

Flibe energy is working on a LFTR. The lithium- fluoride rhodium reactor.it will use thorium as a “fertile” fuel.when thethorium is dissolves in molten salt made of lithium fluoride. The thorium as dissolved in a “blanket” of salt surrounded the reactor.when hit with a neutron it absorbs it and transmutates to protactinium233 and then a half-life of 27 days decoys to uranium233(fissile element that powers reactor. Thorium is cheap,it is Abyproduct of processes at rare earth mines. LFTR cannot melt down( three mile island,fukushima)or produce a steam pressure explosion(Chernobyl) because the fuel is already melted in the salt that has liquid range of 400C to1400C at normal atmosphere(no pressurization) . the salt cannot come close to the 1400C point where the liquid salt will turn to a gas because the reactor is dynamically responsive to load amd heat. As the salt becomes hotter the U233 is farther apart,less reactions occur amd the salt will cool down, shoud there be a plant blackout( no power available from reactor,grid,or backup generators,like fukushima)a pipe on the bottom of the reactor is plugged with Flibe salt coiled by refrigerated blower on pipe,with no power to the blower the plug melts and the Flibe will drain into a safety tank that has no grafite moderators and quickly passively cools the salt into a solid safely contained in the tank.even if they reactor were to burst open there is a catch pan that drains to the safety tank.if that fails the worst scenario would be solid salt on the floors that can ne cleaned up .the reactor burns up 99% of the uranics AMD trans_uranics.the 1%left is an isotope of plutonium that NASA would love to have,it has powdered all space probes past the asteroid belt ans it is rare.Gases in the salt,like xenon135( usually a challenge for reactor operators and a contributing factor in the Chernobyl accident) bubble out of the salt like bubbles come out of soda pop amd can be collected.other elements can be removed chemecaly from the salt . the daughter products that have no use are then “waste” and are dangerous for only 300 years vs 10000 + years for solid fuel waste and will fit in a coffee can vs 2 million of those uranium oxide pellets for the same amount of electricity. Two isotopes that can be produced by this machine are medically valuable. Melebnium99 is uses to perform a list of diagnostics tests by doctors and its is getting rare as reactors that make it are getting old and being shut down. Another isotope is bismith213,produces exclusively by the decoy of thorium.Bismuth 213 has just the right amount of radioactivity and half life that doctors want to attached it to antibodies that could attack and kill luekemia and tough cancer’s(like pancreatic cancer which is usually a death sentence). Anothe advantage is the reactor does not require a river or lake for water and am ultimate heat sink. Generators could be run with heated gases like helium. Also the “waste” heat could ne used to desalinate sea water or other industrial processes. Lasty, there is enough thorium on the planet to provide power for centuries to come!

Jacob Burgess

Why don’t we stop using nuclear plants and fossil fuel and just use solar panels yea you may have limited electricity but it’s better then contaminating the air we breath everyday people are dieing way younger then normal and having many different health problems at a young age stuff people go thur in their 50’s or 60’s people 25 to 40 are going thur

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All sections, the history of nuclear warfare and the future of nuclear energy.

The first atomic strike in 1945 changed the world forever.

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On August 6, 1945, the world changed forever when the first atomic bomb hit Hiroshima, Japan, killing thousands of people instantly. Three days later, a second atomic bomb was dropped on Nagasaki, decisively ending Japan’s involvement in World War II. Thousands of people died from radiation poisoning within a year. Since that earth-shattering day, the world has grappled with a controversial technology that not only poses strategic risks in its ability to wipe out humanity but also provides a potential solution to problems of sustainable energy.  

The Hoover Institution has a long relationship with nuclear history. The Library & Archives house the original strike orders and footage taken of the nuclear strikes on Hiroshima and Nagasaki, acquired from Harold Agnew, along with his papers. Agnew worked at the Los Alamos Scientific Laboratory during World War II and was an observer on The Great Artiste , a B-29 that flew behind the Enola Gay on the first atomic strike mission. The Agnew atomic bomb footage is the most-requested motion picture film in Hoover’s collections. His papers include newspaper clippings from the time documenting how people grappled with the news of the attack. The clippings evince an air of newfound terror tinged with fascination about nuclear technology. The Library & Archives also house collections of newspapers from the Marshall Islands during the nuclear testing at Bikini Atoll in the 1940s and 1950s, and the papers of nuclear physicist Edward Teller and nuclear strategist Albert Wohlstetter, as well as some of the papers of physicist Sidney Drell.

Since the first atomic bomb dropped, world leaders have been forced to contend with the strategic reality of nuclear arms. Few understand this better than former secretary of state and Thomas W. and Susan B. Ford Distinguished Fellow George Shultz. In his book Learning from Experience , Shultz wrote about his vision for global nuclear disarmament:

Out of office and out of Washington, I and my good friends and colleagues Sid Drell, Henry Kissinger, Bill Perry, and Sam Nunn try to keep the flame burning so that when and if the global atmosphere improves, the ideas stand ready to help lessen our dependence on nuclear weapons with their ability to wipe out humanity.

From the beginning of our appeals, my colleagues and I have stressed that the world is complicated. We highlight the regional conflicts that would have to be settled. We point out that a world without nuclear weapons would not be the world as it is, minus nuclear weapons. Steps to create the conditions for a world without nuclear weapons cannot be ignored. For Instance, conflicts have driven decisions to acquire nuclear weapons in Northeast Asia, South Asia, and the Middle East. ( Learning from Experience , pp. 86–87)

Today, Hoover fellows including George Shultz, Admiral James O. Ellis Jr., Jim Timbie, Jeremy Carl, James Goodby, and many others continue to research and consider the risks of nuclear arms, while also recognizing the benefits of nuclear energy. Ellis and Shultz write , “Nuclear power alone will not solve our energy problems. But we do not think they can be solved without it. . . . One of us, between other jobs, built nuclear plants for a living; between other jobs, the other helped make them safer. In many respects, this is a personal topic for us both.” They acknowledge America’s strategic position as the world’s largest nuclear power generator. They argue that America needs to bring the country’s brightest minds and technologies to navigate nuclear energy research and development responsibly and ensure that is a part of a cleaner global energy system. Though the decades since the first atomic bomb was dropped have brought fear about such powerful weapons, it is perhaps to be hoped that the possibilities of nuclear energy can make the future bright.

Resources on nuclear energy, warfare, and disarmament by Hoover Fellows:

  • Redefining Energy Security
  • Nuclear Arms: No Time for Complacency
  • Chapter 11: Redefining Energy Security 
  • The Benefits of Nuclear Power
  • Reinventing Nuclear Energy
  • A Crack In the Ice: The Legacy of the Reykjavik Summit
  • No Nukes Is Good Nukes: Nuclear Proliferation
  • Chain Reactions
  • Let’s Talk about Nuclear Security—Informally
  • At 90, Perry Driven by Vision of a Nuclear-Free World
  • Spending Less on Nuclear Weapons Could Actually Make Us Safer
  • Nuclear Birthday
  • Area 45: Trump’s Energy Strategy, the Nuclear Option, Featuring Jeremy Carl
  • The Ultimate Defense
  • War Games on the Korean Peninsula
  • How North Korea Is Ensuring a Nuclear Arms Race in Asia
  • The New Nuclear Arms Race
  • World-Renowned Nuclear Experts Analyze Risks and Rewards of the Nuclear Enterprise in a New Book Edited by George P. Shultz and Sidney D. Drell
  • We Participated in INF Negotiations. Abandoning It Threatens Our Very Existence.
  • George Shultz: We Must Preserve This Nuclear Treaty
  • Reinventing Nuclear Power 

Library & Archives Nuclear Collections:

  • Harold M. Agnew miscellaneous papers, 1943–1994
  • Edward Teller papers, 1910–2005
  • Albert J. and Roberta Wohlstetter papers, 1919–2007
  • Sidney D. Drell papers, 1945–2015
  • Conference on the Discontinuance of Nuclear Weapon Tests proceedings, 1961
  • The Nuclear Age video tape, 1988
  • New Documentation Relating to “Project A” of the Manhattan Project Donated to Hoover Archives

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  • v.45(Suppl 1); 2016 Jan

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Nuclear power in the 21st century: Challenges and possibilities

Akos horvath.

MTA Centre for Energy Research, KFKI Campus, P.O.B. 49, Budapest 114, 1525 Hungary

Elisabeth Rachlew

Department of Physics, Royal Institute of Technology, KTH, 10691 Stockholm, Sweden

The current situation and possible future developments for nuclear power—including fission and fusion processes—is presented. The fission nuclear power continues to be an essential part of the low-carbon electricity generation in the world for decades to come. There are breakthrough possibilities in the development of new generation nuclear reactors where the life-time of the nuclear waste can be reduced to some hundreds of years instead of the present time-scales of hundred thousand of years. Research on the fourth generation reactors is needed for the realisation of this development. For the fast nuclear reactors, a substantial research and development effort is required in many fields—from material sciences to safety demonstration—to attain the envisaged goals. Fusion provides a long-term vision for an efficient energy production. The fusion option for a nuclear reactor for efficient production of electricity has been set out in a focussed European programme including the international project of ITER after which a fusion electricity DEMO reactor is envisaged.

Introduction

All countries have a common interest in securing sustainable, low-cost energy supplies with minimal impact on the environment; therefore, many consider nuclear energy as part of their energy mix in fulfilling policy objectives. The discussion of the role of nuclear energy is especially topical for industrialised countries wishing to reduce carbon emissions below the current levels. The latest report from IPCC WGIII ( 2014 ) (see Box 1 for explanations of all acronyms in the article) says: “Nuclear energy is a mature low-GHG emission source of base load power, but its share of global electricity has been declining since 1993. Nuclear energy could make an increasing contribution to low-carbon energy supply, but a variety of barriers and risks exist ”.

Demand for electricity is likely to increase significantly in the future, as current fossil fuel uses are being substituted by processes using electricity. For example, the transport sector is likely to rely increasingly on electricity, whether in the form of fully electric or hybrid vehicles, either using battery power or synthetic hydrocarbon fuels. Here, nuclear power can also contribute, via generation of either electricity or process heat for the production of hydrogen or other fuels.

In Europe, in particular, the public opinion about safety and regulations with nuclear power has introduced much critical discussions about the continuation of nuclear power, and Germany has introduced the “Energiewende” with the goal to close all their nuclear power by 2022. The contribution of nuclear power to the electricity production in the different countries in Europe differs widely with some countries having zero contribution (e.g. Italy, Lithuania) and some with the major part comprising nuclear power (e.g. France, Hungary, Belgium, Slovakia, Sweden).

Current status

The use of nuclear energy for commercial electricity production began in the mid-1950s. In 2013, the world’s 392 GW of installed nuclear capacity accounted for 11 % of electricity generation produced by around 440 nuclear power plants situated in 30 countries (Fig.  1 ). This share has declined gradually since 1996, when it reached almost 18 %, as the rate of new nuclear additions (and generation) has been outpaced by the expansion of other technologies. After hydropower, nuclear is the world’s second-largest source of low-carbon electricity generation (IEA 2014 1 ).

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Total number of operating nuclear reactors worldwide. The total number of reactors also include six in Taiwan (source: IAEA 2015) ( https://www.iaea.org/newscenter/focus/nuclear-power )

The Country Nuclear Power Profiles (CNPP 2 ) compiles background information on the status and development of nuclear power programmes in member states. The CNPP’s main objectives are to consolidate information about the nuclear power infrastructures in participating countries, and to present factors related to the effective planning, decision-making and implementation of nuclear power programmes that together lead to safe and economical operations of nuclear power plants.

Within the European Union, 27 % of electricity production (13 % of primary energy) is obtained from 132 nuclear power plants in January 2015 (Fig.  1 ). Across the world, 65 new reactors are under construction, mainly in Asia (China, South Korea, India), and also in Russia, Slovakia, France and Finland. Many other new reactors are in the planning stage, including for example, 12 in the UK.

Apart from one first Generation “Magnox” reactor still operating in the UK, the remainder of the operating fleet is of the second or third Generation type (Fig.  2 ). The predominant technology is the Light Water Reactor (LWR) developed originally in the United States by Westinghouse and then exploited massively by France and others in the 1970s as a response to the 1973 oil crisis. The UK followed a different path and pursued the Advanced Gas-cooled Reactor (AGR). Some countries (France, UK, Russia, Japan) built demonstration scale fast neutron reactors in the 1960s and 70s, but the only commercial reactor of this type currently operating is in Russia.

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Nuclear reactor generations from the pioneering age to the next decade (reproduced with permission from Ricotti 2013 )

Future evolution

The fourth Generation reactors, offering the potential of much higher energy recovery and reduced volumes of radioactive waste, are under study in the framework of the “Generation IV International Forum” (GIF) 3 and the “International Project on Innovative Nuclear Reactors and Fuel Cycles” (INPRO). The European Commission in 2010 launched the European Sustainable Nuclear Industrial Initiative (ESNII), which will support three Generation IV fast reactor projects as part of the EU’s plan to promote low-carbon energy technologies. Other initiatives supporting biomass, wind, solar, electricity grids and carbon sequestration are in parallel. ESNII will take forward: the Astrid sodium-cooled fast reactor (SFR) proposed by France, the Allegro gas-cooled fast reactor (GFR) supported by central and eastern Europe and the MYRRHA lead- cooled fast reactor (LFR) technology pilot proposed by Belgium.

The generation of nuclear energy from uranium produces not only electricity but also spent fuel and high-level radioactive waste (HLW) as a by-product. For this HLW, a technical and socially acceptable solution is necessary. The time scale needed for the radiotoxicity of the spent fuel to drop to the level of natural uranium is very long (i.e. of the order of 200 000–300 000 years). The preferred solution for disposing of spent fuel or the HLW resulting from classical reprocessing is deep geological storage. Whilst there are no such geological repositories operating yet in the world, Sweden, Finland and France are on track to have such facilities ready by 2025 (Kautsky et al. 2013 ). In this context it should also be mentioned that it is only for a minor fraction of the HLW that recycling and transmutation is required since adequate separation techniques of the fuel can be recycled and again fed through the LWR system.

The “Strategic Energy Technology Plan” (SET-Plan) identifies fission energy as one of the contributors to the 2050 objectives of a low-carbon energy mix, relying on the Generation-3 reactors, closed fuel cycle and the start of implementation of Generation IV reactors making nuclear energy more sustainable. The EU Energy Roadmap 2050 provides decarbonisation scenarios with different assumptions from the nuclear perspective: two scenarios contemplate a nuclear phase-out by 2050, whilst three others consider that 15–20 % of electricity will be produced by nuclear energy. If by 2050 a generation capacity of 20 % nuclear electricity (140 GWe) is to be secured, 100–120 nuclear power units will have to be built between now and 2050, the precise number depending on the power rating (Garbil and Goethem 2013 ).

Despite the regional differences in the development plans, the main questions are of common interest to all countries, and require solutions in order to maintain nuclear power in the power mix of contributing to sustainable economic growth. The questions include (i) maintaining safe operation of the nuclear plants, (ii) securing the fuel supplies, (iii) a strategy for the management of radioactive waste and spent nuclear fuel.

Safety and non-proliferation risks are managed in accordance with the international rules issued both by IAEA and EURATOM in the EU. The nuclear countries have signed the corresponding agreements and the majority of them have created the necessary legal and regulatory structure (Nuclear Safety Authority). As regards radioactive wastes, particularly high-level wastes (HLW) and spent fuel (SF) most of the countries have long-term policies. The establishment of new nuclear units and the associated nuclear technology developments offer new perspectives, which may need reconsideration of fuel cycle policies and more active regional and global co-operation.

Open and closed fuel cycle

In the frame of the open fuel cycle, the spent fuel will be taken to final disposal without recycling. Deep geological repositories are the only available option for isolating the highly radioactive materials for a very long time from the biosphere. Long-term (80–100 years) near soil intermediate storages are realised in e.g. France and the Netherlands which will allow for permanent access and inspection. The main advantage of the open fuel cycle is its simplicity. The spent fuel assemblies are first stored in interim storage for several years or decades, then they will be placed in special containers and moved into deep underground storage facilities. The technology for producing such containers and for excavation of the underground system of tunnels exists today (Hózer et al. 2010 ; Kautsky et al. 2013 ).

The European Academies Science Advisory Board recently released the report on “Management of spent nuclear fuel and its waste” (EASAC 2014 ). The report discusses the challenges associated with different strategies to manage spent nuclear fuel, in respect of both open cycles and steps towards closing the nuclear fuel cycle. It integrates the conclusions on the issues raised on sustainability, safety, non-proliferation and security, economics, public involvement and on the decision-making process. Recently Vandenbosch et al. ( 2015 ) critically discussed the issue of confidence in the indefinite storage of nuclear waste. One complication of the nuclear waste storage problem is that the minor actinides represent a high activity (see Fig.  3 ) and pose non-proliferation issues to be handled safely in a civil used plant. This might be a difficult challenge if the storage is to be operated economically together with the fuel fabrication.

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Radiotoxicity of radioactive waste

The open (or ‘once through’) cycle only uses part of the energy stored in the fuel, whilst effectively wasting substantial amounts of energy that could be recovered through recycling. The conventional closed fuel cycle strategy uses the reprocessing of the spent fuel following interim storage. The main components which can be further utilised (U and Pu) are recycled to fuel manufacturing (MOX (Mixed Oxide) fuel fabrication), whilst the smaller volume of residual waste in appropriately conditioned form—e.g. vitrified and encapsulated—is disposed of in deep geological repositories.

The advanced closed fuel cycle strategy is similar to the conventional one, but within this strategy the minor actinides are also removed during reprocessing. The separated isotopes are transmuted in combination with power generation and only the net reprocessing wastes and those conditioned wastes generated during transmutation will be, following appropriate encapsulation, disposed of in deep geological repositories. The main factor that determines the overall storage capacity of a long-term repository is the heat content of nuclear waste, not its volume. During the anticipated repository time, the specific heat generated during the decay of the stored HLW must always stay below a dedicated value prescribed by the storage concept and the geological host information. The waste that results from reprocessing spent fuel from thermal reactors has a lower heat content (after a period of cooling) than does the spent fuel itself. Thus, it can be stored more densely.

A modern light water reactor of 1 GWe capacity will typically discharge about 20–25 tonnes of irradiated fuel per year of operation. About 93–94 % of the mass of typical uranium oxide irradiated fuel comprises uranium (mostly 238 U), with about 4–5 % fission products and ~1 % plutonium. About 0.1–0.2 % of the mass comprises minor actinides (neptunium, americium and curium). These latter elements accumulate in nuclear fuel because of neutron capture, and they contribute significantly to decay heat loading and neutron output, as well as to the overall radiotoxic hazard of spent fuel. Although the total minor actinide mass is relatively small—20 to 25 kg per year from a 1 GWe LWR—it has a disproportionate impact on spent fuel disposal because of its long radioactive decay times (OECD Nuclear Energy Agency 2013 ).

Generation IV development

To address the issue of sustainability of nuclear energy, in particular the use of natural resources, fast neutron reactors (FNRs) must be developed, since they can typically multiply by over a factor 50 the energy production from a given amount of uranium fuel compared to current reactors. FNRs, just as today’s fleet, will be primarily dedicated to the generation of fossil-free base-load electricity. In the FNR the fuel conversion ratio (FCR) is optimised. Through hardening the spectrum a fast reactor can be designed to burn minor actinides giving a FCR larger than unity which allows breeding of fissile materials. FNRs have been operated in the past (especially the Sodium-cooled Fast Reactor in Europe), but today’s safety, operational and competitiveness standards require the design of a new generation of fast reactors. Important research and development is currently being coordinated at the international level through initiatives such as GIF.

In 2002, six reactor technologies were selected which GIF believe represent the future of nuclear energy. These were selected from the many various approaches being studied on the basis of being clean, safe and cost-effective means of meeting increased energy demands on a sustainable basis. Furthermore, they are considered being resistant to diversion of materials for weapons proliferation and secure from terrorist attacks. The continued research and development will focus on the chosen six reactor approaches. Most of the six systems employ a closed fuel cycle to maximise the resource base and minimise high-level wastes to be sent to a repository. Three of the six are fast neutron reactors (FNR) and one can be built as a fast reactor, one is described as epithermal, and only two operate with slow neutrons like today’s plants. Only one is cooled by light water, two are helium-cooled and the others have lead–bismuth, sodium or fluoride salt coolant. The latter three operate at low pressure, with significant safety advantage. The last has the uranium fuel dissolved in the circulating coolant. Temperatures range from 510 to 1000 °C, compared with less than 330 °C for today’s light water reactors, and this means that four of them can be used for thermochemical hydrogen production.

The sizes range from 150 to 1500 MWe, with the lead-cooled one optionally available as a 50–150 MWe “battery” with long core life (15–20 years without refuelling) as replaceable cassette or entire reactor module. This is designed for distributed generation or desalination. At least four of the systems have significant operating experience already in most respects of their design, which provides a good basis for further research and development and is likely to mean that they can be in commercial operation well before 2030. However, when addressing non-proliferation concerns it is significant that fast neutron reactors are not conventional fast breeders, i.e. they do not have a blanket assembly where plutonium-239 is produced. Instead, plutonium production happens to take place in the core, where burn-up is high and the proportion of plutonium isotopes other than Pu-239 remains high. In addition, new reprocessing technologies will enable the fuel to be recycled without separating the plutonium.

In January 2014, a new GIF Technology Roadmap Update was published. 4 It confirmed the choice of the six systems and focused on the most relevant developments of them so as to define the research and development goals for the next decade. It suggested that the Generation IV technologies most likely to be deployed first are the SFR, the lead-cooled fast reactor (LFR) and the very high temperature reactor technologies. The molten salt reactor and the GFR were shown as furthest from demonstration phase.

Europe, through sustainable nuclear energy technology platform (SNETP) and ESNII, has defined its own strategy and priorities for FNRs with the goal to demonstrate Generation IV reactor technologies that can close the nuclear fuel cycle, provide long-term waste management solutions and expand the applications of nuclear fission beyond electricity production to hydrogen production, industrial heat and desalination; The SFR as a proven concept, as well as the LFR as a short-medium term alternative and the GFR as a longer-term alternative technology. The French Commissariat à l’Energie Atomique (CEA) has chosen the development of the SFR technology. Astrid (Advanced Sodium Technological Reactor for Industrial Demonstration) is based on about 45 reactor-years of operational experience in France and will be rated 250 to 600 MWe. It is expected to be built at Marcoule from 2017, with the unit being connected to the grid in 2022.

Other countries like Belgium, Italy, Sweden and Romania are focussing their research and development effort on the LFR whereas Hungary, Czech Republic and Slovakia are investing in the research and development on GFR building upon the work initiated in France on GFR as an alternative technology to SFR. Allegro GFR is to be built in eastern Europe, and is more innovative. It is rated at 100 MWt and would lead to a larger industrial demonstration unit called GoFastR. The Czech Republic, Hungary and Slovakia are making a joint proposal to host the project, with French CEA support. Allegro is expected to begin construction in 2018 operate from 2025. The industrial demonstrator would follow it.

In mid-2013, four nuclear research institutes and engineering companies from central Europe’s Visegrád Group of Nations (V4) agreed to establish a centre for joint research, development and innovation in Generation IV nuclear reactors (the Czech Republic, Hungary, Poland and Slovakia) which is focused on gas-cooled fast reactors such as Allegro.

The MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) 5 project proposed in Belgium by SCK•CEN could be an Experimental Technological Pilot Plant (ETPP) for the LFR technology. Later, it could become a European fast neutron technology pilot plant for lead and a multi-purpose research reactor. The unit is rated at 100 thermal MW and has started construction at SCK-CEN’s Mol site in 2014 planned to begin operation in 2023. A reduced-power model of Myrrha called Guinevere started up at Mol in March 2010. ESNII also includes an LFR technology demonstrator known as Alfred, also about 100 MWt, seen as a prelude to an industrial demonstration unit of about 600 MWe. Construction on Alfred could begin in 2017 and the unit could start operating in 2025.

Research and development topics to meet the top-level criteria established within the GIF forum in the context of simultaneously matching economics as well as stricter safety criteria set-up by the WENRA FNR demand substantial improvements with respect to the following issues:

  • Primary system design simplification,
  • Improved materials,
  • Innovative heat exchangers and power conversion systems,
  • Advanced instrumentation, in-service inspection systems,
  • Enhanced safety,

and those for fuel cycle issues pertain to:

  • Partitioning and transmutation,
  • Innovative fuels (including minor actinide-bearing) and core performance,
  • Advanced separation both via aqueous processes supplementing the PUREX process as well as pyroprocessing, which is mandatory for the reprocessing of the high MA-containing fuels,
  • Develop a final depository.

Beyond the research and development, the demonstration projects mentioned above are planned in the frame of the SET-Plan ESNII for sustainable fission. In addition, supporting research infrastructures, irradiation facilities, experimental loops and fuel fabrication facilities, will need to be constructed.

Regarding transmutation, the accelerator-driven transmutation systems (ADS) technology must be compared to FNR technology from the point of view of feasibility, transmutation efficiency and cost efficiency. It is the objective of the MYRRHA project to be an experimental demonstrator of ADS technology. From the economical point of view, the ADS industrial solution should be assessed in terms of its contribution to closing the fuel cycle. One point of utmost importance for the ADS is its ability for burning larger amounts of minor actinides (the typical maximum in a critical FNR is about 2 %).

The concept of partitioning and transmutation (P&T) has three main goals: reduce the radiological hazard associated with spent fuel by reducing the inventory of minor actinides, reduce the time interval required to reach the radiotoxicity of natural uranium and reduce the heat load of the HLW packages to be stored in the geological disposal hence reducing the foot print of the geological disposal.

Advanced management of HLW through P&T consists in advanced separation of the minor actinides (americium, curium and neptunium) and some fission products with a long half-life present in the nuclear waste and their transmutation in dedicated burners to reduce the radiological and heat loads on the geological disposal. The time scale needed for the radiotoxicity of the waste to drop to the level of natural uranium will be reduced from a ‘geological’ value (300 000 years) to a value that is comparable to that of human activities (few hundreds of years) (OECD/NEA 2006 ; OECD 2012 ; PATEROS 2008 6 ). Transmutation of the minor actinides is achieved through fission reactions and therefore fast neutrons are preferred in dedicated burners.

At the European level, four building blocks strategy for Partitioning and Transmutation have been identified. Each block poses a serious challenge in terms of research & development to be done in order to reach industrial scale deployment. These blocks are:

  • Demonstration of advanced reprocessing of spent nuclear fuel from LWRs, separating Uranium, Plutonium and Minor Actinides;
  • Demonstration of the capability to fabricate at semi-industrial level dedicated transmuter fuel heavily loaded in minor actinides;
  • Design and construct one or more dedicated transmuters;
  • Fabrication of new transmuter fuel together with demonstration of advanced reprocessing of transmuter fuel.

MYRRHA will support this Roadmap by playing the role of an ADS prototype (at reasonable power level) and as a flexible irradiation facility providing fast neutrons for the qualification of materials and fuel for an industrial transmuter. MYRRHA will be not only capable of irradiating samples of such inert matrix fuels but also of housing fuel pins or even a limited number of fuel assemblies heavily loaded with MAs for irradiation and qualification purposes.

Options for nuclear fusion beyond 2050

Nuclear fusion research, on the basis of magnetic confinement, considered in this report, has been actively pursued in Europe from the mid-60s. Fusion research has the goal to achieve a clean and sustainable energy source for many generations to come. In parallel with basic high-temperature plasma research, the fusion technology programme is pursued as well as the economy of a future fusion reactor (Ward et al. 2005 ; Ward 2009 ; Bradshaw et al. 2011 ). The goal-oriented fusion research should be driven with an increased effort to be able to give the long searched answer to the open question, “will fusion energy be able to cover a major part of mankind’s electricity demand?”. ITER, the first fusion reactor to be built in France by the seven collaborating partners (Europe, USA, Russia, Japan, Korea, China, India) is hoped to answer most of the open physics and many of the remaining technology/material questions. ITER is expected to start operation of the first plasma around 2020 and D-T operation 2027.

The European fusion research has been successful through the organisation of EURATOM to which most countries in Europe belong (the fission programme is also included in EURATOM). EUROfusion, the European Consortium for the Development of Fusion Energy, manages European fusion research activities on behalf of EURATOM. The organisation of the research has resulted in a well-focused common fusion research programme. The members of the EUROfusion 7 consortium are 29 national fusion laboratories. EUROfusion funds all fusion research activities in accordance with the “EFDA Fusion electricity. Roadmap to the realisation of fusion energy” (EFDA 2012 , Fusion electricity). The Roadmap outlines the most efficient way to realise fusion electricity. It is the result of an analysis of the European Fusion Programme undertaken by all Research Units within EUROfusion’s predecessor agreement, the European Fusion Development Agreement, EFDA.

The most successful confinement concepts are toroidal ones like tokamaks and helical systems like stellarators (Wagner 2012 , 2013 ). To avoid drift losses, two magnetic field components are necessary for confinement and stability—the toroidal and the poloidal field component. Due to their superposition, the magnetic field winds helically around a system of nested toroids. In both cases, tokamak and stellarator, the toroidal field is produced by external coils; the poloidal field arises from a strong toroidal plasma current in tokamaks. In case of helical systems all necessary fields are produced externally by coils which have to be superconductive when steady-state operation is intended. Europe is constructing the most ambitious stellarator, Wendelstein 7-X in Germany. It is a fully optimised system with promising features. W7-X goes into operation in 2015. 8

Fusion research has now reached plasma parameters needed for a fusion reactor, even if not all parameters are reached simultaneously in a single plasma discharge (see Fig.  4 ). Plotted is the triple product n•τ E• T i composed of the density n, the confinement time τ E and the ion temperature T i . For ignition of a deuterium–tritium plasma, when the internal α-particle heating from the DT-reaction takes over and allows the external heating to be switched off, the triple product has to be about >6 × 10 21  m −3  s keV). The record parameters given as of today are shown together with the fusion experiment of its achievement in Fig.  4 . The achieved parameters and the missing factors to the ultimate goal of a fusion reactor are summarised below:

  • Temperature: 40 keV achieved (JT-60U, Japan); the goal is surpassed by a factor of two
  • Density n surpassed by factor 5 (C-mod,USA; LHD,Japan)
  • Energy confinement time: a factor of 4 is missing (JET, Europe)
  • Fusion triple product (see Fig.  4 : a factor of 6 is missing (JET, Europe)
  • The first scientific goal is achieved: Q (fusion power/external heating power) ~1 (0,65) (JET, Europe)
  • D-T operation without problems (TFTR (USA), JET, small tritium quantities have been used, however)
  • Maximal fusion power for short pulse: 16 MW (JET)
  • Divertor development (ASDEX, ASDEX-Upgrade, Germany)
  • Design for the first experimental reactor complete (ITER, see below)
  • The optimisation of stellarators (W7-AS, W7-X, Germany)

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Progress in fusion parameters. Derived in 1955, the Lawson criterion specifies the conditions that must be met for fusion to produce a net energy output (1 keV × 12 million K). From this, a fusion “triple product” can be derived, which is defined as the product of the plasma ion density, ion temperature and energy confinement time. This product must be greater than about 6 × 10 21  keV m −3  s for a deuterium–tritium plasma to ignite. Due to the radioactivity associated with tritium, today’s research tokamaks generally operate with deuterium only ( solid dots ). The large tokamaks JET(EU) and TFTR(US), however, have used a deuterium–tritium mix ( open dots ). The rate of increase in tokamak performance has outstripped that of Moore’s law for the miniaturisation of silicon chips (Pitts et al. 2006 ). Many international projects (their names are given by acronyms in the figure) have contributed to the development of fusion plasma parameters and the progress in fusion research which serves as the basis for the ITER design

After 50 years of fusion research there is no evidence for a fundamental obstacle in the basic physics. But still many problems have to be overcome as detailed below:

Critical issues in fusion plasma physics based on magnetic confinement

  • confine a plasma magnetically with 1000 m 3 volume,
  • maintain the plasma stable at 2–4 bar pressure,
  • achieve 15 MA current running in a fluid (in case of tokamaks, avoid instabilities leading to disruptions),
  • find methods to maintain the plasma current in steady-state,
  • tame plasma turbulence to get the necessary confinement time,
  • develop an exhaust system (divertor) to control power and particle exhaust, specifically to remove the α-particle heat deposited into the plasma and to control He as the fusion ash.

Critical issues in fusion plasma technology

  • build a system with 200 MKelvin in the plasma core and 4 Kelvin about 2 m away,
  • build magnetic system at 6 Tesla (max field 12 Tesla) with 50 GJ energy,
  • develop heating systems to heat the plasma to the fusion temperature and current drive systems to maintain steady-state conditions for the tokamak,
  • handle neutron-fluxes of 2 MW/m 2 leading to 100 dpa in the surrounding material,
  • develop low activation materials,
  • develop tritium breeding technologies,
  • provide high availability of a complex system using an appropriate remote handling system,
  • develop the complete physics and engineering basis for system licensing.

The goals of ITER

The major goals of ITER (see Fig.  5 ) in physics are to confine a D-T plasma with α-particle self-heating dominating all other forms of plasma heating, to produce about ~500 MW of fusion power at a gain Q  = fusion power/external heating power, of about 10, to explore plasma stability in the presence of energetic α-particles, and to demonstrate ash-exhaust and burn control.

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Schematic layout of the ITER reactor experiment (from www.iter.org )

In the field of technology, ITER will demonstrate fundamental aspects of fusion as the self-heating of the plasma by alpha-particles, show the essentials to a fusion reactor in an integrated system, give the first test a breeding blanket and assess the technology and its efficiency, breed tritium from lithium utilising the D-T fusion neutron, develop scenarios and materials with low T-inventories. Thus ITER will provide strong indications for vital research and development efforts necessary in the view of a demonstration reactor (DEMO). ITER will be based on conventional steel as structural material. Its inner wall will be covered with beryllium to surround the plasma with low-Z metal with low inventory properties. The divertor will be mostly from tungsten to sustain the high α-particle heat fluxes directed onto target plates situated inside a divertor chamber. An important step in fusion reactor development is the achievement of licensing of the complete system.

The rewards from fusion research and the realisation of a fusion reactor can be described in the following points:

  • fusion has a tremendous potential thanks to the availability of deuterium and lithium as primary fuels. But as a recommendation, the fusion development has to be accelerated,

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Fusion time strategy towards the fusion reactor on the net (EFDA 2012 , Fusion electricity. A roadmap to the realisation of fusion energy)

In addition, there is the fusion technology programme and its material branch, which ultimately need a neutron source to study the interaction with 14 MeV neutrons. For this purpose, a spallation source IFMIF is presently under design. As a recommendation, ways have to be found to accelerate the fusion development. In general, with ITER, IFMIF and the DEMO, the programme will move away from plasma science more towards technology orientation. After the ITER physics and technology programme—if successful—fusion can be placed into national energy supply strategies. With fusion, future generations can have access to a clean, safe and (at least expected of today) economic power source.

The fission nuclear power continues to be an essential part of the low-carbon electricity generation in the world for decades to come. There are breakthrough possibilities in the development of new generation nuclear reactors where the life-time of the nuclear waste can be reduced to some hundreds of years instead of the present time-scales of hundred thousand of years. Research on the fourth generation reactors is needed for the realisation of this development. For the fast nuclear reactors a substantial research and development effort is required in many fields—from material sciences to safety demonstration—to attain the envisaged goals. Fusion provides a long-term vision for an efficient energy production. The fusion option for a nuclear reactor for efficient production of electricity should be vigorously pursued on the international arena as well as within the European energy roadmap to reach a decision point which allows to critically assess this energy option.

Box 1 Explanations of abbreviations used in this article

Biographies.

is Professor in Energy Research and Director of MTA Center for Energy Research, Budapest, Hungary. His research interests are in the development of new fission reactors, new structural materials, high temperature irradiation resistance, mechanical deformation.

is Professor of Applied Atomic and Molecular Physics at Royal Institute of Technology, (KTH), Stockholm, Sweden. Her research interests are in basic atomic and molecular processes studied with synchrotron radiation, development of diagnostic techniques for analysing the performance of fusion experiments in particular development of photon spectroscopic diagnostics.

1 http://www.iea.org/ .

2 https://cnpp.iaea.org/pages/index.htm .

3 GenIV International forum: ( http://www.gen-4.org/index.html ).

4 https://www.gen-4.org/gif/jcms/c_60729/technology-roadmap-update-2013 .

5 http://myrrha.sckcen.be/ .

6 www.sckcen.be/pateros/ .

7 https://www.euro-fusion.org/ .

8 https://www.ipp.mpg.de/ippcms/de/pr/forschung/w7x/index.html .

Contributor Information

Akos Horvath, Email: [email protected] .

Elisabeth Rachlew, Email: es.htk@kre .

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Argonne National Laboratory

Science 101: nuclear energy.

Nuclear power is the world’s largest and most reliable source of clean energy, and supplies electricity to the homes of tens of millions in America each and every day. To fight climate change, the world will need new and better ways of leveraging this energy source, which is produced by nuclear reactors through a process that generates zero greenhouse gases. But how do nuclear reactors deliver so much power without emissions? — It all starts with heat.

Heat is released in a nuclear reactor when atoms split, a process known as fission. Atoms, the building blocks of matter, are made of three particles — neutrons and protons which are bound together, forming what’s known as the nucleus of the atom, and electrons, which are negatively charged particles that orbit the nucleus.

Nuclear reactors split atoms of uranium, a mildly radioactive element, to form heat. This process releases heat and neutrons. Some of these neutrons go on to collide with other uranium atoms, causing them to fission, which keeps the nuclear reaction going.

These series of fission reactions all take place inside a part of the nuclear reactor known as the fuel rod, a long, welded-shut cylindrical tube that contains the uranium. A fuel assembly describes a packed bundle of 100 to 200 of these rods. The entire reactor core is made up of hundreds of fuel assemblies packed together into a large cylinder shape, so there are typically tens of thousands of fuel rods in a reactor core.

In a typical nuclear power plant, water flows over the fuel rods in the reactor core to cool it. This heat raises the temperature of the water causing it to turn into steam. This steam is sent to a turbine that’s connected to a generator.  The steam pressure makes the turbine spin, a bit like a windmill. The generator, like all other electricity generators, uses the mechanical movement of the turbine to generate electricity. Finally, after passing through the turbine, the steam is cooled down, converting it back to water so it can be used again. Unlike the burning of fossil fuels, fission does not release carbon dioxide, soot or other harmful chemicals, which is why it is a zero-emission energy source.

While the two most common types are the pressurized water reactor ( PWR ) and the boiling water reactor ( BWR ), new designs for nuclear reactors have been developed. Development of nuclear reactors continues today because these and newer advanced reactor technologies can help meet the world’s growing energy demands without contributing to global warming . At the forefront of advancing nuclear energy are laboratories like the U.S. Department of Energy’s ( DOE ) Argonne National Laboratory.

With support from the DOE , Argonne scientists are investigating new reactor designs and fuel recycling technologies that can enhance safety, make nuclear plant operations more efficient, reduce the amount of nuclear waste and reduce construction time and costs. Their work builds on the long legacy of nuclear research from which the laboratory was founded. Starting in the 1940s, Argonne has led the way in developing peaceful uses for nuclear power. While Argonne research, designs and experiments form the foundation of all commercial nuclear reactors used today, its researchers are also at the forefront of new advances for the next generation of reactors.

What is Nuclear Energy?

A reliable, clean power source that can play a vital role in decarbonizing the U.S. economy.

Uranium in a nuclear reactor produces heat when it splits, or fissions, which is what happens when a fragile uranium -235 (U-235) atomic nucleus is hit by a neutron. At the same time, fission produces several neutrons that can go on to cause yet more fissions, providing a smooth, stable supply of heat that is used to produce electricity. Huge amounts of heat — and, in turn, electricity — are produced using extremely tiny amounts of fuel.

background research on nuclear energy

background research on nuclear energy

What is The Brief History of Nuclear Energy

  • November 7, 2023

Have you ever wondered how nuclear energy came to be and its profound impact on our world? Join us on a journey through the captivating history of nuclear energy, from its initial discoveries to the creation of the first power plants. You’ll delve into the groundbreaking work of key figures like Rontgen, the Curies, and Rutherford, and explore the pivotal moment of atomic fission explained by Meitner and Frisch. Discover the challenges, milestones, and international implications that have shaped the history of nuclear energy and continue to shape our world today.

Early Discoveries and Advances in Nuclear Physics

You discovered the early breakthroughs in nuclear physics that laid the foundation for the development of nuclear energy. The history of nuclear energy is intertwined with the discovery of nuclear physics and the understanding of atomic fission. In the late 19th and early 20th centuries, scientists made significant strides in understanding the nature of radiation and the behavior of atomic particles.

Key discoveries included the identification of uranium as a radioactive element, the isolation of polonium and radium, the discovery of the neutron, and the splitting of uranium atoms through fission.

These early discoveries paved the way for the harnessing of nuclear fission and the development of nuclear power. Scientists like Otto Hahn and Fritz Strassmann demonstrated that fission released additional neutrons, which could lead to chain reactions. Niels Bohr proposed that fission was more likely in uranium-235 and with slow-moving neutrons, leading to the need for uranium enrichment. The control of nuclear reactions through neutron absorption was also demonstrated.

The first nuclear power plant to produce electricity was the Experimental Breeder Reactor (EBR-1) in the United States. This marked a significant milestone in the commercialization of nuclear energy . As nuclear power expanded, challenges arose, such as accidents at Three Mile Island and Chernobyl, which highlighted the importance of safety measures.

Discovery and Understanding of Atomic Fission

The discovery and understanding of atomic fission revolutionized the field of nuclear physics and paved the way for the development of nuclear energy. Atomic fission, the process of splitting the nucleus of an atom, was first demonstrated by Otto Hahn and Fritz Strassmann in 1938. This groundbreaking discovery marked a turning point in nuclear history, as it revealed the immense amount of energy that could be released through this process.

Further understanding of atomic fission was provided by Lise Meitner and Otto Frisch, who explained the mechanism of fission through neutron capture. This understanding was confirmed by Albert Einstein’s paper on mass-energy equivalence, which solidified the scientific basis for harnessing nuclear energy.

The discovery of atomic fission had profound implications, leading to the development of nuclear power plants. It was recognized that fission reactions could release additional neutrons, creating a chain reaction that could be controlled and harnessed for the generation of electricity.

The first nuclear reactor to produce electricity was the Experimental Breeder Reactor (EBR-1) in the United States. This marked a significant milestone in the history of nuclear energy, as it demonstrated the practical application of atomic fission for power generation.

Since then, nuclear energy has played a crucial role in meeting the world’s growing demand for electricity. It has provided a reliable and efficient source of power, while also raising important questions about safety, waste management, and the potential for nuclear weapons proliferation. Nonetheless, the discovery and understanding of atomic fission laid the foundation for the development of nuclear power plants, shaping the course of energy production for decades to come.

Harnessing Nuclear Fission

To harness the power of atomic fission, scientists and engineers devised innovative methods to control and utilize the energy released from splitting the nucleus of an atom. This marked a significant milestone in the development of nuclear energy, leading to the exploration of its potential for electricity generation. Here are four key aspects of harnessing nuclear fission:

Nuclear Energy Invention

The invention of nuclear energy can be attributed to the work of Otto Hahn and Fritz Strassmann, who demonstrated atomic fission in 1938. This discovery paved the way for further research and understanding of nuclear reactions.

Nuclear Background

The background of nuclear energy dates back to early discoveries in nuclear physics, such as the identification of alpha and beta radiation by Ernest Rutherford and the discovery of neutrons by James Chadwick. These foundational findings laid the groundwork for the harnessing of nuclear fission.

When was Nuclear Energy First Used

The first use of nuclear energy for electricity generation occurred in 1951 when an experimental liquid-metal cooled reactor in Idaho produced the first nuclear-generated electricity. This marked a significant milestone in the practical application of nuclear energy.

US First Nuclear Power Plant

The first commercial nuclear power plant in the United States was the Shippingport reactor, which began operation in 1957. This plant utilized a design similar to that of the nuclear-powered submarines developed by the US Navy. It demonstrated the feasibility and potential of nuclear energy for large-scale electricity production.

The harnessing of nuclear fission revolutionized the field of energy production and opened up new possibilities for electricity generation. The development of nuclear power plants and the continued advancements in nuclear technology have further solidified the role of nuclear energy in meeting the world’s growing demand for electricity.

Russian Contributions to Nuclear Physics

Russian scientists have made significant contributions to nuclear physics throughout history, continuing their research even during World War II. When it comes to the invention of nuclear power, several key figures played important roles. Igor Kurchatov, often referred to as the “father of the Soviet atomic bomb,” led the Soviet Union’s nuclear program during World War II and was instrumental in the development of the first nuclear reactor in the USSR.

It was under his leadership that the Soviet Union successfully tested its first atomic bomb in 1949. Another notable figure is Georgy Flerov, who made significant contributions to the discovery of superheavy elements and nuclear reactions. Flerov was a key figure in the synthesis of elements 104 (rutherfordium) and 105 (dubnium), and his work laid the foundation for further advancements in nuclear physics. These Russian scientists played a crucial role in the development of nuclear energy and their contributions continue to shape the field to this day.

Development of Nuclear Energy and Weapons

Explore the pivotal role of nuclear energy and weapons in shaping the course of history. Nuclear energy and weapons have had a profound impact on scientific advancement, warfare, and the generation of electricity. Here are four key developments that have defined the development of nuclear energy and weapons:

The Manhattan Project

The United States spearheaded the development of atomic weapons during World War II through the Manhattan Project. This project led to the successful testing of the first atomic bomb in New Mexico in 1945, forever changing the nature of warfare.

The Soviet Bomb

After receiving intelligence reports suggesting atomic bomb development in other countries, Stalin initiated a research program that resulted in the Soviet Union successfully developing its own atomic bomb. This development intensified the arms race between the United States and the Soviet Union during the Cold War.

Early Development of Nuclear Energy

The first nuclear reactor to produce electricity was the Experimental Breeder Reactor (EBR-1) in the United States. This breakthrough paved the way for the commercialization of nuclear energy and the construction of nuclear power plants around the world.

Commercialization of Nuclear Energy

Westinghouse designed the first fully commercial pressurized water reactor (PWR), known as Yankee Rowe, which started operating in 1960. This marked a significant milestone in the expansion of nuclear power as a reliable source of electricity.

These developments have not only shaped the course of history but have also raised important ethical and safety concerns surrounding the use of nuclear energy and weapons. The ongoing debate surrounding nuclear power and disarmament underscores the complexity and lasting impact of these advancements.

During the early development of nuclear energy, you will delve into the advancements and breakthroughs that paved the way for harnessing the power of atomic reactions. Uranium, discovered in 1789 by Martin Klaproth, played a crucial role in the understanding of nuclear physics. Wilhelm Rontgen’s discovery of ionizing radiation in 1895 and Henri Becquerel’s observation of pitchblende’s impact on photographic plates further expanded our knowledge.

The isolation of polonium and radium from pitchblende by Pierre and Marie Curie, along with Samuel Prescott’s demonstration of radiation’s ability to destroy bacteria in food, contributed to the understanding of radioactivity . Ernest Rutherford’s discovery of different elements created by radioactivity and Frederick Soddy’s identification of naturally-radioactive elements with different isotopes added to the growing body of knowledge.

The discovery of the neutron by James Chadwick and the production of nuclear transformations by bombarding atoms with protons by Cockcroft and Walton were significant milestones. The breakthrough of atomic fission by Otto Hahn and Fritz Strassmann, and its explanation by Lise Meitner and Otto Frisch, marked a turning point in the development of nuclear energy. The subsequent understanding of critical mass by Francis Perrin and the control of nuclear reactions through neutron absorption by Perrin’s group further propelled the field forward. The early development of nuclear energy culminated in the construction of the Experimental Breeder reactor (EBR-1) in the USA, which became the first nuclear reactor to produce electricity.

To understand the commercialization of nuclear energy, you need to delve into the advancements and breakthroughs that paved the way for harnessing the power of atomic reactions. Here are four key factors that contributed to the commercialization of nuclear energy:

Discovery of atomic fission

In 1938, Otto Hahn and Fritz Strassmann demonstrated that atomic fission had occurred, leading to the understanding that splitting the nucleus of an atom could release a tremendous amount of energy. This discovery laid the foundation for the development of nuclear power.

Enrichment of uranium-235

Bohr’s proposal in the 1930s that fission would be more likely in uranium-235 and with slow-moving neutrons led to the need for enriching uranium-235. This process involves increasing the concentration of uranium-235 in natural uranium, making it suitable for use as fuel in nuclear reactors.

Controlled nuclear reactions

Scientists such as Francis Perrin demonstrated the control of nuclear reactions through neutron absorption, which allowed for the regulation and moderation of the energy released during fission. This control was essential for the safe and efficient operation of nuclear power plants.

Development of commercial reactors:

The first fully commercial pressurized water reactor (PWR), called Yankee Rowe, was designed by Westinghouse and started up in 1960. This marked a significant milestone in the commercialization of nuclear energy, as it demonstrated the feasibility and viability of nuclear power as a source of electricity.

These advancements and breakthroughs paved the way for the commercialization of nuclear energy, leading to the construction of numerous nuclear power plants worldwide and the establishment of nuclear energy as a significant contributor to the global energy mix.

Expansion and Standardization of Nuclear Power

In the 1960s and 1970s, nuclear power expanded rapidly as countries around the world standardized the construction of nuclear power plants. This period marked a significant shift towards the widespread adoption of nuclear energy as a source of electricity generation. The standardization of nuclear power plant designs allowed for efficient construction processes, reducing costs and increasing the speed of deployment.

During this time, many countries recognized the potential of nuclear power as a reliable and clean source of energy. The United States, for example, built multiple nuclear reactors, with 104 reactors in total, accounting for approximately 20% of its electricity production. France also made a major push for nuclear energy, resulting in 75% of its electricity coming from nuclear reactors.

However, the expansion of nuclear power was not without its challenges. Labor shortages and construction delays increased the cost of building nuclear reactors, slowing down their growth. Furthermore, accidents such as the Three Mile Island incident in 1979 and the Chernobyl disaster in 1986 raised concerns about the safety of nuclear energy.

Despite these challenges, the standardization and expansion of nuclear power in the 1960s and 1970s laid the foundation for the modern nuclear energy industry. Today, nuclear power continues to be an important source of electricity in many countries, providing a reliable and low-carbon alternative to fossil fuels.

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Fusion experiments at the US National Ignition Facility have achieved a significant milestone

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Nuclear reactors and power plants have complex safety and security features

An uncontrolled nuclear reaction in a nuclear reactor could result in widespread contamination of air and water. The risk of this happening at nuclear power plants in the United States is small because of the diverse and redundant barriers and safety systems in place at nuclear power plants, the training and skills of the reactor operators, testing and maintenance activities, and the regulatory requirements and oversight of the U.S. Nuclear Regulatory Commission. A large area surrounding a nuclear power plant is restricted and guarded by armed security teams. U.S. reactors also have containment vessels that are designed to withstand extreme weather events and earthquakes.

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A containment dome on a nuclear reactor

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Nuclear reactors in the United States may have large concrete domes covering the reactor. A containment structure is required to contain accidental releases of radiation. Not all nuclear power plants have cooling towers. Some nuclear power plants use water from lakes, rivers, or the ocean for cooling.

Nuclear power reactors do not produce direct carbon dioxide emissions

Unlike fossil fuel-fired power plants, nuclear reactors do not produce air pollution or carbon dioxide while operating. However, the processes for mining and refining uranium ore and making reactor fuel all require large amounts of energy. Nuclear power plants also have large amounts of metal and concrete, which require large amounts of energy to manufacture. If fossil fuels are used for mining and refining uranium ore, or if fossil fuels are used when constructing the nuclear power plant, then the emissions from burning those fuels could be associated with the electricity that nuclear power plants generate.

Nuclear energy produces radioactive waste

A major environmental concern related to nuclear power is the creation of radioactive wastes such as uranium mill tailings, spent (used) reactor fuel, and other radioactive wastes. These materials can remain radioactive and dangerous to human health for thousands of years. Radioactive wastes are subject to special regulations that govern their handling, transportation, storage, and disposal to protect human health and the environment. The U.S. Nuclear Regulatory Commission (NRC) regulates the operation of nuclear power plants.

Radioactive wastes are classified as low-level waste or high-level waste. The radioactivity of these wastes can range from a little higher than natural background levels, such as for uranium mill tailings, to the much higher radioactivity of used (spent) reactor fuel and parts of nuclear reactors. The radioactivity of nuclear waste decreases over time through a process called radioactive decay. The amount of time it takes for the radioactivity of radioactive material to decrease to half its original level is called the radioactive half-life. Radioactive waste with a short half-life is often stored temporarily before disposal to reduce potential radiation doses to workers who handle and transport the waste. This storage system also reduces the radiation levels at disposal sites.

By volume, most of the waste related to the nuclear power industry has a relatively low level of radioactivity. Uranium mill tailings contain the radioactive element radium, which decays to produce the radioactive gas radon. Most uranium mill tailings are placed near the processing facility, or mill , where they come from. Uranium mill tailings are covered with a sealing barrier of material such as clay to prevent radon from escaping into the atmosphere. The sealing barrier is covered by a layer of soil, rocks, or other materials to prevent erosion of the sealing barrier.

The other types of low-level radioactive waste are the tools, protective clothing, wiping cloths, and other disposable items that become contaminated with small amounts of radioactive dust or particles at nuclear fuel processing facilities and nuclear power plants. These materials are subject to special regulations for their handling, storage, and disposal so they will not come in contact with the outside environment.

High-level radioactive waste consists of irradiated , or spent , nuclear reactor fuel (fuel that is no longer useful for producing electricity). The spent reactor fuel is in a solid form, consisting of small fuel pellets in long metal tubes called rods.

Spent reactor fuel storage and reactor decommissioning

Spent reactor fuel assemblies are highly radioactive and, initially, must be stored in specially designed pools of water. The water cools the fuel and acts as a radiation shield. Spent reactor fuel assemblies can also be stored in specially designed dry storage containers. An increasing number of reactor operators now store their older spent fuel in dry storage facilities using special outdoor concrete or steel containers with air cooling. The United States does not currently have a permanent disposal facility for high-level nuclear waste.

When a nuclear reactor stops operating, it must be decommissioned. Decommissioning involves safely removing from service the reactor and all equipment that has become radioactive and reducing radioactivity to a level that permits other uses of the property. The U.S. Nuclear Regulatory Commission has strict rules governing nuclear power plant decommissioning that involve cleanup of radioactively contaminated power plant systems and structures and removing the radioactive fuel.

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The Joint European Torus

Energy based on power of stars is step closer after nuclear fusion heat record

Feat by scientists at Oxfordshire facility described as ‘fitting swansong’ for pioneering project as reactor is decommissioned

The prospect of a green energy source based on the power of the stars has received a boost after scientists set a world record for the amount of energy created by fusing atoms together.

Researchers at the Joint European Torus (JET), an experimental fusion reactor at the Culham Centre for Fusion Energy in Oxfordshire, generated 69 megajoules of energy over five seconds from a mere 0.2 milligrams of fuel in the final fusion experiment performed at the facility.

The burst of energy, equivalent to 16.5kg of TNT, was described as a “fitting swansong” for the project, which has pioneered technology for future commercial fusion reactors since it began operating in 1983. It beat the previous record of 59 megajoules of heat, set by the same facility in 2022.

If fusion power is shown to be viable at scale, future reactors could drive a green energy revolution. One kilogram of fusion fuel contains about 10m times more energy than a kilogram of coal, oil or gas, and fusion reactions do not release greenhouse gases.

The Joint European Torus

The JET facility ended its scientific work in December. It will now be decommissioned in a 17-year process that researchers will document in painstaking detail to inform the building and dismantling of fusion reactors in the decades ahead. More than 300 scientists and engineers from a consortium called EUROfusion contributed to the experiments.

Prof Ian Chapman, chief executive of the UK Atomic Energy Authority, said: “JET has operated as close to powerplant conditions as is possible with today’s facilities and its legacy will be pervasive in all future power plants. It has a critical role in bringing us closer to a safe and sustainable future.”

The reactor at the Culham Centre for Fusion Energy is known as a tokamak, a structure that uses powerful magnetic fields to confine plasmas, or highly ionised gases, in a doughnut shape. The gases are heated to 150m celsius, about 10 times hotter than the centre of the sun.

The extreme conditions in the tokamak drive fusion reactions in which atomic nuclei bind together to form new elements, releasing enormous amounts of energy in the process. Stars are powered by the same reactions, but do not require such high temperatures as their gravity is strong enough to do some of the work.

Experiments at JET have explored the feasibility of using two isotopes of hydrogen, known as deuterium and tritium, as fuel. In fusion reactions, the two combine to produce helium gas. The record-breaking pulse of energy, announced on Thursday, is encouraging for Iter, a larger fusion project being built in the south of France. That reactor aims to start burning fusion fuel in 2035 with the goal of generating more energy that is used to heat the plasma.

Andrew Bowie, the minister for nuclear and networks, said: “JET’s final fusion experiment is a fitting swansong after all the groundbreaking work that has gone into the project since 1983. We are closer to fusion energy than ever before.”

The experiment in the JET

If the next generation of experimental fusion facilities, such as Iter, prove the technology is viable at scale, researchers plan to build a European demonstration plant that generates more power than it uses.

Dr Aneeqa Khan, a research fellow in nuclear fusion at the University of Manchester, said: “These results are really exciting for the fusion community and a great end to the operations of JET which has provided the scientific community with really valuable data over its lifetime, feeding into the designs for new projects.

“However, to put this in context of commercial fusion, there was still no net energy produced.”

She added: “This is a great scientific result, but we are still a way off commercial fusion. We need to be training up a huge number of people with the skills to work in the field and I hope the technology will be used in the latter half of the century.”

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Fusion research facility's final tritium experiments yield new energy record

by EUROfusion

Fusion research facility JET's final tritium experiments yield new energy record

The Joint European Torus (JET), one of the world's largest and most powerful fusion machines, has demonstrated the ability to reliably generate fusion energy, while simultaneously setting a world record in energy output.

These notable accomplishments represent a significant milestone in the field of fusion science and engineering.

In JET's final deuterium-tritium experiments (DTE3), high fusion power was consistently produced for five seconds, resulting in a ground-breaking record of 69 megajoules using a mere 0.2 milligrams of fuel.

JET is a tokamak, a design which uses powerful magnetic fields to confine a plasma in the shape of a doughnut. Most approaches to creating commercial fusion favor the use of two hydrogen variants—deuterium and tritium. When deuterium and tritium fuse together they produce helium and vast amounts of energy, a reaction that will form the basis of future fusion powerplants.

Dr. Fernanda Rimini, JET Senior Exploitation Manager, said, "We can reliably create fusion plasmas using the same fuel mixture to be used by commercial fusion energy powerplants, showcasing the advanced expertise developed over time."

Professor Ambrogio Fasoli, Program Manager (CEO) at EUROfusion, said, "Our successful demonstration of operational scenarios for future fusion machines like ITER and DEMO, validated by the new energy record, instill greater confidence in the development of fusion energy. Beyond setting a new record, we achieved things we've never done before and deepened our understanding of fusion physics."

Dr. Emmanuel Joffrin, EUROfusion Tokamak Exploitation Task Force Leader from CEA, said, "Not only did we demonstrate how to soften the intense heat flowing from the plasma to the exhaust, we also showed in JET how we can get the plasma edge into a stable state thus preventing bursts of energy reaching the wall. Both techniques are intended to protect the integrity of the walls of future machines. This is the first time that we've ever been able to test those scenarios in a deuterium-tritium environment."

Over 300 scientists and engineers from EUROfusion—a consortium of researchers across Europe, contributed to these landmark experiments at the UK Atomic Energy Authority (UKAEA) site in Oxford, showcasing the unparalleled dedication and effectiveness of the international team at JET.

Fusion research facility JET's final tritium experiments yield new energy record

The results solidify JET's pivotal role in advancing safe, low-carbon, and sustainable fusion energy.

UK Minister for Nuclear and Networks, Andrew Bowie, said, "JET's final fusion experiment is a fitting swansong after all the groundbreaking work that has gone into the project since 1983. We are closer to fusion energy than ever before thanks to the international team of scientists and engineers in Oxfordshire."

"The work doesn't stop here. Our Fusion Futures program has committed £650 million to invest in research and facilities, cementing the UK's position as a global fusion hub."

JET concluded its scientific operations at the end of December 2023.

Professor Sir Ian Chapman, UKAEA CEO, said, "JET has operated as close to powerplant conditions as is possible with today's facilities, and its legacy will be pervasive in all future powerplants. It has a critical role in bringing us closer to a safe and sustainable future."

JET's research findings have critical implications not only for ITER—a fusion research mega-project being built in the south of France—but also for the UK's STEP prototype powerplant, Europe's demonstration powerplant, DEMO, and other global fusion projects, pursuing a future of safe, low-carbon, and sustainable energy.

Dr. Pietro Barabaschi, ITER Director-General, said, "Throughout its lifecycle, JET has been remarkably helpful as a precursor to ITER: in the testing of new materials, in the development of innovative new components, and nowhere more than in the generation of scientific data from Deuterium-Tritium fusion."

"The results obtained here will directly and positively impact ITER, validating the way forward and enabling us to progress faster toward our performance goals. On a personal note, it has been for me a great privilege having myself been at JET for a few years. There I had the opportunity to learn from many exceptional people."

Fusion research facility JET's final tritium experiments yield new energy record

JET has been instrumental in advancing fusion energy for over four decades, symbolizing international scientific collaboration, engineering excellence, and the commitment to harness the power of fusion energy—the same reactions that fuel the sun and stars.

JET demonstrated sustained fusion over five seconds at high power and set a world record in 2021. JET's first deuterium-tritium experiments took place in 1997.

As it transitions into the next phase of its life cycle for repurposing and decommissioning, a celebration in late February 2024 will honor its founding vision and the collaborative spirit that has driven its success.

The achievements at JET, from the major scientific milestones to the setting of energy records, underscores the facility's enduring legacy in the evolution of fusion technology.

Its contributions to fusion science and engineering have played a crucial role in accelerating the development of fusion energy, which promises to be a safe, low carbon and sustainable part of the world's future energy supply.

Fusion energy's potential

Fusion, the process that powers stars like our sun, promises a clean baseload source of heat and electricity for the long term, using small amounts of fuel that can be sourced worldwide from inexpensive materials.

When a mix of two forms of hydrogen (deuterium and tritium) is heated to form a controlled plasma at extreme temperatures —10 times hotter than the core of the sun—they fuse together to create helium and release energy which can be harnessed to produce electricity.

Fusion research facility JET's final tritium experiments yield new energy record

Deuterium and tritium are two heavier variants of ordinary hydrogen and together offer the highest reactivity of all fusion fuels. At a temperature of 150 million degrees Celsius, deuterium and tritium fuse together to form helium and release a tremendous amount of heat energy without any greenhouse contributions. Fusion is inherently safe in that it cannot start a run-away process and produces no long-lived waste.

There is more than one way of achieving fusion. Our approach is to hold the hot plasma using strong magnets in a ring-shaped machine called a "tokamak," and then to harness this heat to produce electricity in a similar way to existing power stations.

About the fusion energy fuel

Most approaches to creating commercial fusion favor the use of two hydrogen variants—deuterium and tritium. When deuterium and tritium fuse together they produce helium and vast amounts of energy—a reaction that will form the basis of future fusion powerplants.

Deuterium is plentiful and can be extracted from water. Tritium is a radioactive variant of hydrogen with a half-life of about 12 years. Tritium can be farmed from lithium.

About the final deuterium-tritium experiments (DTE3)

JET is the only tokamak fusion machine in operation capable of handling tritium fuel. The third round of experiments using deuterium and tritium fuel were conducted over seven weeks from 31 August to 14 October 2023. They focused on three areas—plasma science, materials science and neutronics.

JET's fusion energy record is a result of the advanced capability in operating deuterium-tritium plasmas. These experiments were primarily designed as the first-ever opportunity to demonstrate the feasibility of minimizing heat loads on the wall in a deuterium-tritium environment, crucial for ITER scenarios.

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IMAGES

  1. Nuclear Energy Wallpapers

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  2. Nuclear Reactor Wallpapers

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  3. Use of Operating Experience Strengthens Safety of Research Reactors

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  4. DOE awards $65M for nuclear research, technology projects

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  5. Why is nuclear energy not an ESG priority for asset managers?

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COMMENTS

  1. Nuclear Energy

    Article Vocabulary Nuclear energy is the energy in the nucleus, or core, of an atom. Atoms are tiny units that make up all matter in the universe, and energy is what holds the nucleus together. There is a huge amount of energy in an atom 's dense nucleus. In fact, the power that holds the nucleus together is officially called the " strong force ."

  2. History of Nuclear Energy

    In 1932 James Chadwick discovered the neutron. Also in 1932 Cockcroft and Walton produced nuclear transformations by bombarding atoms with accelerated protons, then in 1934 Irene Curie and Frederic Joliot found that some such transformations created artificial radionuclides.

  3. Nuclear energy

    nuclear energy, energy that is released in significant amounts in processes that affect atomic nuclei, the dense cores of atoms. It is distinct from the energy of other atomic phenomena such as ordinary chemical reactions, which involve only the orbital electrons of atoms.

  4. A fresh look at nuclear energy

    Nuclear is already the largest source of low-carbon energy in the United States and Europe and the second-largest source worldwide (after hydropower).

  5. What is Nuclear Energy? The Science of Nuclear Power

    Nuclear energy is a form of energy released from the nucleus, the core of atoms, made up of protons and neutrons. This source of energy can be produced in two ways: fission - when nuclei of atoms split into several parts - or fusion - when nuclei fuse together.

  6. Nuclear energy facts and information

    Nuclear power isn't considered renewable energy, given its dependence on a mined, finite resource, but because operating reactors do not emit any of the greenhouse gases that contribute to...

  7. Nuclear Energy

    As the world attempts to transition its energy systems away from fossil fuels towards low-carbon sources of energy, we have a range of energy options: renewable energy technologies such as hydropower, wind and solar, but also nuclear power. Nuclear energy and renewable technologies typically emit very little CO 2 per unit of energy production, and are also much better than fossil fuels in ...

  8. Nuclear energy

    Nuclear energy - Latest research and news | Nature nature subjects nuclear energy Nuclear energy articles from across Nature Portfolio Atom RSS Feed Featured A boost for laser fusion...

  9. US nuclear power: Status, prospects, and climate implications

    In 2020, the world added 1 5.521 GW (billion watts) of nuclear generating capacity—just above the 5.491 GW 2 of lithium-ion batteries added to power grids. The average reactor was then 29 years old—39 in the United States, whose fleet is the world's largest—so it's not surprising that in 2020, maintenance or upgrade costs, safety concerns, and often simple operational ...

  10. A brief history of nuclear fusion

    The tokamak leap. During the early 1960s, pioneering results of nuclear fusion research were presented at the first FEC in Salzburg, Austria, in 1961 and at the second FEC in Culham, United ...

  11. The History of

    The History Of Nuclear Energy Although they are tiny, atoms have a large amount of energy holding their nuclei together. Certain isotopes of some elements can be split and will release part of their energy as heat. This splitting is called fission. The heat released in fission can be used to help generate electricity in powerplants.

  12. Nuclear Power Today

    In 2020, 61% of electricity was generated from the burning of fossil fuels. Despite the strong support for, and growth in, intermittent renewable electricity sources in recent years, the fossil fuel contribution to power generation has not changed significantly in the last 15 years or so (66.5% in 2005).

  13. The State of Nuclear Energy Today

    The energy to mine and refine the uranium that fuels nuclear power and manufacture the concrete and metal to build nuclear power plants is usually supplied by fossil fuels, resulting in CO2 emissions; however, nuclear plants do not emit any CO2 or air pollution as they operate.

  14. What is the History of Nuclear Energy?

    In 1938, German scientists Otto Hann and Fritz Strassman shot neutrons at uranium atoms and discovered that a significant amount of energy was being released. With the help of Lise Meitner and...

  15. The History Of Nuclear Warfare And The Future Of Nuclear Energy

    On August 6, 1945, the world changed forever when the first atomic bomb hit Hiroshima, Japan, killing thousands of people instantly. Three days later, a second atomic bomb was dropped on Nagasaki, decisively ending Japan's involvement in World War II. Thousands of people died from radiation poisoning within a year.

  16. PDF NUCLEAR TECHNOLOGY REVIEW

    Foreword In response to requests by Member States, the Secretariat produces a comprehensive Nuclear Technology Review each year. The Nuclear Technology Review 2020 covers the following select areas: power applications, advanced fission and fusion, accelerator and research reactor applications, radioisotopes and

  17. Nuclear power in the 21st century: Challenges and possibilities

    The Country Nuclear Power Profiles (CNPP 2) compiles background information on the status and development of nuclear power programmes in member states.The CNPP's main objectives are to consolidate information about the nuclear power infrastructures in participating countries, and to present factors related to the effective planning, decision-making and implementation of nuclear power ...

  18. Nuclear Energy

    Abstract Nuclear energy grew rapidly during the 1960-1975 period in countries such as France, the United States, and Norway. But nuclear energy ran into problems in the 1970s because of public concern over the radioactive waste it generates, and this concern suppressed the further expansion of nuclear power.

  19. Science 101: Nuclear Energy

    Science 101: Nuclear Energy. Nuclear power is the world's largest and most reliable source of clean energy, and supplies electricity to the homes of tens of millions in America each and every day. To fight climate change, the world will need new and better ways of leveraging this energy source, which is produced by nuclear reactors through a ...

  20. Nuclear research

    Nuclear science, technology and research represent the underlying foundation of all nuclear applications. Nuclear applications contribute in many ways to health, development and security worldwide. They are used in a broad range of areas, from power production to medicine, agriculture, food safety, environment, forensics, industry, and the analysis of artefacts.

  21. What is The Brief History of Nuclear Energy?

    The history of nuclear energy is intertwined with the discovery of nuclear physics and the understanding of atomic fission. In the late 19th and early 20th centuries, scientists made significant strides in understanding the nature of radiation and the behavior of atomic particles.

  22. Frontiers in Energy Research

    Articles. See all (413) Part of an innovative journal, this section publishes significant research on nuclear energy science and technology covering both fission and fusion.

  23. Nuclear fusion reaction releases almost twice the energy put in

    Physics Nuclear fusion reaction releases almost twice the energy put in. The US National Ignition Facility has achieved even higher energy yields since breaking even for the first time in 2022 ...

  24. Nuclear fusion: new record brings dream of clean energy closer

    Nuclear fusion has produced more energy than ever before in an experiment, bringing the world a step closer to the dream of limitless, clean power. The new world record has been set at the UK ...

  25. Nuclear power and the environment

    A major environmental concern related to nuclear power is the creation of radioactive wastes such as uranium mill tailings, spent (used) reactor fuel, and other radioactive wastes. These materials can remain radioactive and dangerous to human health for thousands of years.

  26. Energy based on power of stars is step closer after nuclear fusion heat

    The prospect of a green energy source based on the power of the stars has received a boost after scientists set a world record for the amount of energy created by fusing atoms together.

  27. Nuclear fusion: Scientists just set a new energy record in a step ...

    Scientists and engineers near the English city of Oxford have set a nuclear fusion energy record, they announced Thursday, bringing the clean, futuristic power source another step closer to ...

  28. Fusion research facility's final tritium experiments yield new energy

    The results solidify JET's pivotal role in advancing safe, low-carbon, and sustainable fusion energy. UK Minister for Nuclear and Networks, Andrew Bowie, said, "JET's final fusion experiment is a ...