Is the sun electric or nuclear

Nuclear energy

Lexicon> Letter K> Nuclear Energy

Definition: Energy obtained with the help of nuclear reactions

Alternative terms: atomic energy, nuclear energy, nuclear energy

More specific terms: nuclear fission energy, nuclear fusion energy

English: nuclear energy, nuclear power

Categories: Basic Concepts, Nuclear Energy

Author: Dr. Rüdiger Paschotta

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Original creation: 05/01/2011; last change: 13.03.2021

URL: https://www.energie-lexikon.info/kernenergie.html

Also read the extra article "What can we learn from the Fukushima nuclear disaster?"! The Nuclear Errors and Propaganda page has other additional nuclear articles that may be of interest to you.

As Nuclear energy (also Atomic energy or nuclear energy) is the term used to describe energy that is released during nuclear reactions. As a rule, this means civil use. However, nuclear energy is also suitable for military use in nuclear weapons (nuclear weapons).

The most important type of nuclear energy use is the generation of electrical energy in nuclear power plants. These contain a nuclear reactor in which the fission of a suitable nuclear fuel is carried out. This creates a large amount of heat, which is partially converted into mechanical energy with the help of a steam turbine and finally into electrical energy in a generator. Smaller nuclear reactors are suitable for propelling ships and submarines, as well as for generating process heat for industry. Occasionally, nuclear energy is used to power satellites, particularly for spy satellites and for those satellites that explore planets far from the Sun (where photovoltaics are difficult to use). The remainder of this article relates essentially to the large-scale use of nuclear energy, primarily for electricity generation.

It is conceivable that future generations will use another form of nuclear energy, namely nuclear fusion. Corresponding research work has been carried out with great effort for decades, but the use of this type of nuclear energy will fail, at least for the next few decades, due to the lack of technical feasibility. This is why this article only refers to nuclear energy from fission in the following.

On a very small scale, nuclear energy can also be used without nuclear fission and nuclear fusion, simply by using the heat that is generated during spontaneous radioactive decay. This happens especially in radionuclide batteries. The short-lived emitters required for this usually have to be produced in a very complex process in nuclear reactors and are therefore extremely expensive.

Characteristics of nuclear energy

Compared to other energy sources, e.g. based on fossil fuels, nuclear energy offers some important advantages:

  • The energy density of nuclear fuels is extremely high, so a nuclear reactor can deliver very large amounts of energy with the help of very small amounts of fuel. This means that relatively small amounts of fuel have to be extracted, processed and transported. This is put into perspective to a certain extent by the fact that uranium ores usually only contain very low concentrations of uranium, which means that the quantities of ore to be extracted and the quantities of problematic (radioactive) overburden are far higher than the quantity of nuclear fuel obtained. In addition, mostly the small amount of uranium 235 is used (only approx. 0.7% of natural uranium). Nevertheless, the mining activities that have been carried out for z. B. are necessary for the one-year operation of a nuclear power plant, a very small amount compared to those for a coal-fired power plant.
  • Because of this, nuclear fuels are also very inexpensive in relation to the amount of energy they contain compared to fossil fuels; in fact, fuel costs play only a minor role in total costs.
  • Another positive consequence of the high energy density is that large amounts of energy can be stored in a small space and easily transported. This makes it possible to reduce the dependency on fuel supplies.
  • The generation of energy from nuclear fission does not release any climate-damaging exhaust gases - at least not directly, and indirectly (→ gray energy) only in relatively small quantities. Otherwise, as long as no serious incident occurs, the environmental impact of operating a nuclear power plant is likely to be fairly low.

On the other hand, the use of nuclear energy also has serious disadvantages:

  • The operation of nuclear reactors involves great dangers. Serious reactor accidents can radioactively contaminate large areas in such a way that they become uninhabitable for a long time. The article on reactor safety deals with this issue.
  • During the extraction of nuclear fuel, particularly in uranium mining, considerable damage often occurs in the area. Radioactive overburden is often stored in the open air, is spread by the wind and leads to increased radiation exposure over a wide area. However, this damage is likely to be small, for example, compared to that caused by the extraction of crude oil, and it could be significantly reduced with corresponding additional effort.
  • Spent nuclear fuel is highly radioactive and extremely dangerous. Since some of this radioactive waste is extremely long-lived, this hazard persists for hundreds of thousands of years. It is therefore necessary to safely prevent nuclear waste from entering the biosphere for many generations. The extremely long periods of time make this long-term storage very problematic and controversial; it's a kind of perpetual cost.
  • When spent nuclear fuel is reprocessed, additional radioactive emissions and handling hazards arise. On the other hand, less natural uranium is required, so that the dangers and environmental pollution associated with uranium mining and enrichment are reduced.
  • The civil use of atomic energy is difficult to reliably separate from the military use. A civil nuclear program of a state is the practically indispensable prerequisite for the clandestine start of a nuclear weapons program, as it offers an alibi for the procurement of various materials and apparatus and provides facilities with which, for example, uranium can be highly enriched or plutonium can be bred. Only the global phase-out of the use of nuclear energy could therefore provide a high level of certainty that no nuclear weapons programs can be advanced undetected. On the other hand, long-term worldwide use of nuclear energy would presumably necessitate the entry into a plutonium economy with many breeder reactors, which should significantly increase the risk of proliferation.
  • Nuclear power plants and other facilities for the use of nuclear energy are also dangerous due to the possibility of terrorist attacks. It is conceivable not only that a serious nuclear accident could be triggered in a power plant, but also that highly radioactive material could be stolen to build a “dirty bomb”.
  • The dangers of the use of atomic energy and the measures necessary to counter it have in part had a dubious effect in terms of democratic politics.

With regard to the costs of using nuclear energy, the picture is mixed. This is covered in the next section.

Cost of using nuclear energy

The start of the use of nuclear energy a few decades ago occurred with the expectation that extremely cheap energy would be obtained in abundance (“too cheap to meter” - electricity meters become superfluous). This expectation has long been refuted. It has been shown that the investment costs, especially for nuclear power plants, have not decreased over many years with increasing experience, but have even increased steadily - in large part due to increased safety requirements resulting from experience. The total costs are dominated by these capital costs and the associated capital costs, while fuel costs and other operating costs do not play a major role.

Worldwide, new nuclear power plants can only be financed where politicians relieve the majority of the financial risks from the operators and burden the general public.

New nuclear power plants can be financed in very few countries today, because on the one hand the costs have risen enormously and on the other hand very long-term investments have become more difficult in an environment increasingly characterized by privatization and competition. In addition, there is increasing competition from renewable energies, some of which are rapidly becoming cheaper. For these reasons, new construction projects around the world only have a chance where politics relieves the operators of the majority of the financial risks and burdens the general public. The rise in prices caused by emissions trading for fossil fuels in some places is by no means sufficient to make nuclear power plants competitive.

So far, only a small part of the nuclear power plants built has been taken out of service and dismantled. As a result, there is relatively little experience with the costs of dismantling the power plants. The reserves made for this during the operating time vary greatly in different countries, and there is concern that in many cases they will not be sufficient and that the general public will then have to pay for the costs.

The costs of long-term storage of radioactive waste are unknown and highly controversial. Naturally, these costs cannot be determined until a definitive disposal concept is available, and such a concept does not yet exist anywhere. A weighty aspect for the costs is likely to be whether the retrievability of the waste should be guaranteed.

Various external costs are also difficult to quantify, for example the costs of serious nuclear accidents and the indirect subsidization that is common worldwide through the free assumption of a large part of the accident risk by the general public. (The article on reactor safety discusses this aspect.) On the other hand, the external costs of fossil fuels are also very difficult to determine and possibly very high because of the climate hazards, and the use of renewable energies is also often expensive.

Is a sustainable use of nuclear energy possible?

Theoretically, the goal of sustainability could be achieved with a modern form of using nuclear energy. For this purpose, nuclear reactors would have to be used, which on the one hand can use nuclear fuels far more efficiently and on the other hand generate less long-lived radioactive waste. In principle, this is possible with fast breeder reactors, but not with the light water reactors that are almost exclusively used today. However, although breeder reactors would significantly reduce central problems of nuclear energy, they would increase others, in particular the risk of serious reactor accidents and the proliferation of nuclear weapons. Finding effective solutions to this seems very difficult. An overall concept that would allow a really sustainable use of nuclear energy has apparently not yet been found due to such difficulties.

Worldwide use of nuclear energy; Future prospects

Around 30 countries around the world use nuclear energy to generate electricity. In some countries a relatively large part of the electrical energy is generated in this way; France leads by far, which generates around 80% of its electrical energy in this way. On the global average, however, this share is 16%.

The share of nuclear energy in the global energy supply is small and is likely to continue to fall - mainly for economic reasons that prevent old reactors from being replaced by new ones.

Compared to the total energy turnover (not only for electrical energy, but also for heat, etc.), the global share of nuclear energy is quite small: Worldwide, nuclear energy currently covers 2.5% of the final energy demand, or around 6% of the primary energy. For this reason, for example, a relevant contribution of nuclear energy to climate protection would require that the corresponding capacities are massively expanded. However, this is not to be expected for the time being. New nuclear power plants are currently being built in some countries, but this number will not even come close to compensating for the decommissioning of old power plants. The global generation of electricity through nuclear energy is therefore likely to decrease for the time being (even if only a few countries practice a consistent nuclear phase-out), while the total energy turnover is still increasing significantly. A reversal of this tendency appears unlikely, since not only did the acceptance of the use of nuclear energy suffer, especially as a result of the Chernobyl and Fukushima disasters, but also the massive increases in the cost of building new power plants call economic viability into question.

A Prognos study [6] already came to the result in 2009 that a renaissance of nuclear energy is not to be expected at least until 2030. Rather, it was expected that the number of nuclear power plants operated worldwide will decrease by approx. 29% by 2030 and that a large part of the new construction projects announced by 2030 will not be realized. The Fukushima disaster is likely to accelerate this development considerably; New construction projects have already been put on hold or given up in several countries. The World Nuclear Industry Status Report 2020 [7] reports in detail about the abandonment of nuclear energy projects in many countries, massive problems with many current construction projects worldwide and about dramatic price losses in the shares of companies that build or operate nuclear power plants. The few projects currently being carried out in Europe all suffer from enormous problems [4].

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See also: nuclear power plant, nuclear reactor, fission, nuclear fuel, nuclear fuel tax, reprocessing, radioactivity, radionuclide battery, nuclear fusion, atomic energy or nuclear energy, nuclear phase-out
as well as other articles in the categories Basic Concepts, Nuclear Energy