Nuclear Safety

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The safety of nuclear energy is a central aspect of technical implementation, as is the controversial debate about the use of nuclear energy .

The many dangers and risks in the handling of radioactive materials such as liberated in nuclear destructive power were long before the energy commercially used ( Yankee Rowe Nuclear Power Station , Dresden Generating Station known around 1960). The peaceful use of nuclear energy was promoted and promoted under the umbrella of international organizations such as the IAEA and the European Atomic Energy Community . The initially hoped for broad application of the technology in various areas of life did not materialize.

Mastering nuclear energy requires complex safety philosophies. After this, technical and organizational precautions are taken on the basis of accident scenarios, which should exclude the occurrence of theoretically conceivable catastrophes or at least make them extremely improbable. Protection against abuse and terrorism makes social control measures necessary; an accident can cause massive cuts in the lives of thousands or even hundreds of thousands of people. Even relatively small amounts of radiating material can cause serious damage.

Fundamental challenges

The safety-related design of nuclear facilities and the safety measures in the area relate to four central risk sections.

Safe handling of radioactive materials

The essential high hazard potential of radioactive substances (= radionuclides ) is based not only on possible chain reactions but also on the possible hazard from ionizing radiation, such as the extremely high toxic effect ( toxicity ) in some cases . Humans can also perceive many other poisons with one or more of their senses (for example smell or taste), but radiation cannot. The incorporation of radionuclides therefore initially goes unnoticed and in some cases only has an effect after a long latency period and exposure, sometimes with drastic consequences. Preventing the proliferation and misuse of nuclear fuels and radioactive materials throughout the entire fuel cycle is therefore of central importance.

During normal operation, very small amounts of radioactive material escape from the nuclear power plant into the environment. This material includes radioactive noble gases (e.g. krypton -85) and the unstable hydrogen isotope tritium , the escape of which is measured and subject to conditions. The leukemia cluster in the Elbmarsch was partially attributed to the neighboring nuclear plants, a connection was discussed and sought more intensely than has been proven so far. A local problem of the statistical ( epidemiological ) evidence of such effects is the low number of cases - between 1990 and 2005 there were a dozen more fatal diseases than statistically expected - and the low radiation doses mentioned above. In addition, such clusters do not generally occur in nuclear facilities. A possible connection is also to be assumed with chemical pollution, the environment of large construction sites and intensive agriculture.

Mastery of nuclear fission

Furthermore, the safe control of the splitting process must be guaranteed. The possible bursting of the reactor pressure vessel (RPV) during operation as well as failure of cooling and moderation and a core meltdown , i.e. melting of the fuel elements and melting of this glowing mass ( corium ) through the bottom of the containment , must be prevented.

Ongoing operation and litigation

Nuclear power plants and other nuclear facilities are subject to comparatively strict controls by nuclear supervisory authorities compared to other areas of technology . High demands must be placed on the materials, on their installation, on the process management and on the employees employed there. Material defects, material aging (steel embrittled by radioactive radiation) or human error in particular were nevertheless causes of incidents , serious accidents and disasters . In contrast to many other technologies, the technological history of nuclear power goes back less to learning by doing from the smallest beginnings, precisely because of the serious risks , but included extensive safety concepts in dealing with large projects well before commercial use. In the USA, this was embodied by David E. Lilienthal , who initially worked for the Tennessee Valley Authority and then for the Atomic Energy Commission . The exchange of experience on nuclear safety issues at the international level was coordinated at an early stage in the peaceful use of nuclear energy across bloc and worldwide.

Based on experiences and studies on experimental reactors in Germany in AVR (Jülich) , an attempt is possible major risks in the process flow planning foresee to exclude them and run incidents controlled and limited. This is also increasingly the goal in advanced reactors. In contrast to military applications, an extensive release of energy is not the main risk. Even in the Chernobyl disaster, little more than the equivalent of a hundred tons of coal units were released.

disposal

The final challenge is the long-term safe storage of the radioactive waste generated during operation. In addition to reprocessing , partitioning and transmutation, the direct final storage of highly radioactive, strongly heat-generating residues in deep geological rock formations comes into question.

Historical development

Military beginnings

Drawing of the first Chicago Pile reactor , in which the reactor core was openly piled up in a sports hall. Safety measures included, among other things, a reactor shutdown that was triggered by an ax blow

The development of large-scale nuclear technology can initially be traced back to military developments during World War II. It was initially based on the efforts that began after the end of the war in the USA in 1946 to transfer the utilization of nuclear energy to civilian hands. The Americans had to recognize early on that their monopoly on nuclear technology would by no means endure and began to work in an international context for global control and monitoring of the military proliferation of technology and its peaceful use.

In the Soviet Union, too, the economic use of nuclear energy was more of a by-product of war research, and basic knowledge of nuclear physics and technology was acquired in the context of military nuclear research. Even later, essential technical knowledge and technologies, such as breeder technology, initially came from the military sector and were only later adapted for civil use.

Overall, it is doubtful whether the huge investments in basic research in nuclear technology would have been raised if, in the early 1940s, it was not military survival issues but rather uncertain prospects for the economic use of nuclear fission that were at stake.

The first Soviet reactor construction line RBMK , which became known worldwide during the nuclear disaster of Chernobyl , offered better possibilities for the construction of nuclear weapons for reasons of nuclear physics than the light water moderated reactors commercially successful in the West.

Warning of dangerous radioactive substances

The article focuses on the risks of civilian use of nuclear energy as an energy source. It should not be overlooked that the legacies of military use in the USA and the Soviet Union alone are among the most significant and expensive environmental risks. The quantities of radioactivity that have already been released in the military sector exceed those of civil energy generation by orders of magnitude. For the USA, the remediation of the nuclear contaminated sites for the 1998 price level was estimated at around 384 billion DM, which was probably the most important environmental program in the world at the time. At that time, costs of around DM 1,200 (!) Billion DM were estimated for Russia, while the remediation of the remains of the Bismut in 1998 was around DM 13 billion.

Atoms for Peace initiative by Dwight D. Eisenhower

In the wake of the Atoms for Peace initiative of American President Dwight D. Eisenhower in 1953 at the UN General Assembly , ideas about the peaceful use of nuclear energy were presented under the umbrella of an international atomic energy organization. A safe and peaceful use of the radioactive material and the associated technology should be guaranteed. For this purpose, the International Atomic Energy Agency (IAEA) was founded in Vienna on July 29, 1957 . At that time, which resulted in a real atomic euphoria, nuclear energy was supposed to be used for energy generation, in the form of electricity and heat, as well as a variety of areas of application such as medicine , combating infectious diseases , mega-engineering (see Operation Plowshare ), agriculture and nutrition . The exaggerated expectations after the classic hype cycle were only realized on a much more modest scale.

Security through international cooperation

A network of national and international organizations works together to counter the risks of nuclear power plants and nuclear facilities through appropriate regulations and controls: at the UN, the International Atomic Energy Agency (IAEA) and the United Nations Scientific Committee on the Effect of Atomic Radiation UNSCEAR and the World Health Organization WHO ; the Nuclear Energy Agency NEA of the OECD , the International Commission on Radiological Protection, ICRP ; at the national level in Germany the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety with the Federal Office for Radiation Protection and the Federal Environment Agency and the environmental ministries of the federal states with the respective nuclear supervisory authority . The Swedish radiation protection authority Strålsäkerhetsmyndigheten (before 2008 SKI ) is a national authority with a strong international focus .

Regional particularities

Development and security discussion in (West) Germany

Atomic euphoria of the 1950s

The historian Joachim Radkau completed his habilitation on the history of the German nuclear industry from 1945 to 1975. He criticized the sparse public discussion of both the various nuclear developments and the various safety philosophies and concepts during the entire development period of nuclear power in West Germany. In the discussion about the safety of nuclear power plants in the Federal Republic, he distinguishes between an early and a late phase. According to Radkau, there was initially a public and, above all, from significant scientific side a real atomic euphoria, which urged the state to become involved in atomic energy. In 1955/56 the Ministry of Atomic Energy, the German Atomic Energy Commission as a high-level advisory body and the nuclear research center in Karlsruhe were established, and the European Atomic Energy Community Euratom began work in 1957 . Initially, there was a positive public consensus about the technology and considerable expectations of its potential effects. Until the end of the 1960s, however, the state pressured the electricity companies in vain to get into nuclear energy on a large scale. It was the major chemical companies and plant manufacturers who initially got involved in this area. The result was an uncoordinated coexistence of too many reactor lines and hasty development and commissioning of individual types.

Radkau blamed nuclear energy for the later protest movement because it had failed to adequately deal with the scope of the security problem. It was not until 1969 that an energy company, RWE, placed the first order for a power plant; the commercial breakthrough was achieved with light water reactors of American design.

Commercial energy generation from the 1960s

Many of the processes and measures that are considered state-of-the-art today are consequences of the first decades of reactor technology, which initially served to develop nuclear weapons. This resulted in extensive releases of radioactivity from significantly smaller reactors (see also list of accidents in nuclear facilities ). The commercial use of nuclear reactors for power generation did not begin until later. A large number of reactor concepts had been developed in Germany in advance. In this format war, the boiling water reactor , a sub-type of the light water reactor , became commercially viable . Heinrich Mandel prevailed against the will of the Reactor Safety Commission , among other things . The boiling water reactor is a technology that is more risky in terms of radioactivity release, but it is easier to use and cheaper to implement.

Almost all commercially operated nuclear reactors are light water reactors. Some of its characteristics - for example a power density of up to 100 MW / m³ (i.e. in a room of one cubic meter a thermal output of 100 MW = 1 million light bulbs of 100 watts) as well as a high operating temperature and a high operating pressure - imply large Risks. The heavy water reactor has a comparatively significantly lower power density; But that also means: to build an equally powerful heavy water reactor, you need significantly more steel. In the reactor core of a pressurized water reactor , water is typically heated to about 320 degrees Celsius at a pressure of about 150 bar .

A large nuclear reactor contains 80–150 tons of radioactive nuclear fuels , which, including their fission products, are not allowed to escape. In addition, almost all nuclear power plants have decay basins in which even larger quantities of radioactive material - mostly spent fuel elements - are stored.

Second generation of reactors in the west

The state funding then focused on the nuclear research centers in Karlsruhe and Jülich to develop breeders and high-temperature reactors (HTR), which have now been designated as "second generation" reactors. This reorientation led to the construction of a state-financed breeder and HTR power plant at the beginning of the seventies, with dramatic increases in costs and construction time. The second phase of costly government nuclear activities also started from wrong perspectives.

For many years the pebble bed reactor according to Farrington Daniels and Rudolf Schulten was considered very safe . In 2000, however, the operators of the Jülich pebble bed reactor AVR Jülich admitted that the beta contamination ( strontium -90) of the AVR reactor is the highest of all reactors and nuclear plants in the world and is also present in the most unfavorable form - namely dust-bound. A larger reactor from THTR Hamm-Uentrop , planned as early as 1971 and commissioned in 1987, was shut down a good two years later. Schulten and other proponents repeatedly emphasized the alleged system-immanent safety of this type of reactor, which does not have to be "produced" by active measures or techniques. However, they apparently ignored or misjudged two massive inherent problems of this type of reactor, which Rainer Moormann pointed out from 2006:

  • the spherical fuel elements of the THTR-300 are combustible (ignition temperature approx. 650 ° C); an accident with air entering the reactor would have resulted in a graphite fire with a high level of radioactivity being released.
  • Leakages of the steam generator with water and / or steam ingress into the core lead to chemical reactions with graphite, which produce flammable and explosive gases ( hydrogen and carbon monoxide ).

For more information on the development of the pebble bed concept, see here .

The initial euphoria tipped and turned away after 1975

By the mid-1970s, technical developments had stabilized, but public consensus quickly faded and referred to the chaos previously experienced. In Germany, according to Radkau, from 1975 onwards a risk of nuclear power, which should not be underestimated, but which in Germany itself was purely hypothetical, drove the anti-nuclear movement.

This is in contrast to Japan, for example, where considerable chemical poisoning and heavy metal pollution had shaped the early environmental movement there. According to Radkau, the anti-nuclear movement in Germany was a rational response to concerns that arose from a combination of many observations and information. He refers to the theses of a standard work on reactor technology from the 1950s, which later could only be found in anti-nuclear literature. The initial exaggerated nuclear euphoria of the time was openly addressed at the time, as was the high risk associated with nuclear energy.

Radkau attributes the success of the environmental and anti-nuclear movement in Germany to the USDA compared to their low recognition in Japan (cf. Michiko Ishimure ) less to technical than social causes. The dynamism of the German and American environmental movement emerged in 1970 from the interplay between administrative elites, initiatives from science and the media. It was based on a broad base of strengthening citizens, parliaments and institutions and an elite that was relatively open to newcomers. Successes of the anti-nuclear movement at the regional level, for example preventing the planned reactor block in Wyhl in southern Baden (whose large components were then used as the Philippsburg II nuclear power plant without encountering comparable resistance) were much easier to achieve in Germany than, for example, in centralized France.

The smiling sun with the inscription Atomkraft? No thanks in the respective national language is considered the most famous logo of the international anti-nuclear power movement

Nuclear phase-out

The Fukushima nuclear disaster (from March 2011) prompted many countries to look at and assess the risks in a new or more impartial manner than before. The EU produced an extensive study known as the "stress test" (see below ). Italy had already made a complete phase-out from the generation of atomic energy, and other countries such as Germany , Belgium and Switzerland have announced or initiated a phase-out of nuclear power. Austria did not put its completed Zwentendorf nuclear power plant into operation, and other countries canceled some of the nuclear programs that were well advanced.

Development in the GDR

VEB nuclear power plant Rheinsberg 1966
Demonstration in February 1990 in Berlin against the Greifswald nuclear power plant

The atomic euphoria of the 1950s was also widespread in the GDR. Energy scientists predicted a nuclear power plant output of over 20,000 MW for the country by 1985. The general public was given the prospect that the cheap electrical energy that would soon be available in abundance could meet the energy needs of fully air-conditioned cities in a wide variety of climate zones and that nuclear-powered aircraft, ships and trains could meet. It was not until December 1973 that the 440 MWe pressurized water reactor at the VEB nuclear power plant Greifswald Bruno Leuschner went online. Measured against the high expectations, only four reactors with a total output of 1760 MWe had been completed by 1980. In March 1972 the GDR signed an agreement with the IAEA on control measures over the fate of the nuclear fuel and participated in the establishment of Interatominstrument for cooperation in the development of nuclear devices in the Comecon and subsequently the Interatomenergo .

According to the official GDR reading, the location in Greifswald was chosen because the northern districts of the GDR had to be supplied with expensive energy from other districts. However, the nuclear reactor was built in a sparsely populated region and the location was chosen in such a way that the radioactive cloud to be feared in the event of an accident would most likely drift seaward. In the GDR, too, the lack of concern for stress and the risk of accidents, which was initially exhibited, gave way to increasingly critical assessments, especially by official and scientific bodies.

A near-catastrophe caused by an electrician in 1975 and other incidents and fires did not become public knowledge until after 1989. A few hours after the incident, however, the Soviet authorities informed the IAEA , which first classified the accident in INES  4 and later corrected it in INES 3 (precursor to an accident, here a "station blackout" melting scenario). The intensive evaluations of the processes showed that an experienced operating team can compensate for system-related weak points. The incident was therefore included as the standard accident scenario for WWER-440 in the simulator training in Greifswald after 1990.

For years, neglected repair measures and serious safety concerns due to the increasing embrittlement of the reactor pressure vessels led to the final shutdown of units 1–4 shortly after the fall of the Wall. The much more modern units 5 and 6 were also subsequently decommissioned.

Practical implementation

Safe handling of radioactive materials

The primary protection goal for every nuclear facility is the safe containment of radioactivity. As long as the first barrier ( crystal lattice of the fuel) is retained, the vast majority of the radioactivity is safely retained. Due to the presence of the other barriers, a destruction of the crystal lattice does not automatically mean the release of large amounts of radioactivity. A larger scale destruction of the crystal lattice is technically possible by melting the reactor core (or a considerable part of it). The risk of a radiological weapon or dirty bomb in the event of misuse of radioactive material requires extensive safety measures and an exact inventory of radioactive material as a whole in large reactors.

Mastery of nuclear fission

Construction of a reactor building

In the following the systematic procedure for modern light water reactors is described. With other reactor types, especially those from the former Eastern Bloc , the situation is clearly different. In almost all commercial light water reactors, six barriers serve to hold back the radioactive substances:

  • The crystal lattice of the fuel [within 6]
During nuclear fission in a reactor, the fission products arise as foreign atoms in the crystal lattice of the uranium dioxide . As long as this remains intact, most of the fission products are very reliably retained in the crystal lattice. This does not apply to the gaseous fission products (about 5 - 10% share).
The uranium dioxide is pressed into tablets, filled into roughly finger-thick Zircaloy tubes (strength properties similar to steel) and these tubes are then welded gas-tight at the top and bottom. As long as all weld seams are tight and no other hole appears in a cladding tube, the cladding tubes keep all fission products inside. However, despite the high neutron permeability, structural changes due to radiation and corrosion occur even during normal operation . They cause cracks in a small part of the cladding tubes, which can lead to the escape of gaseous fission products. These are i. d. R. Isotopes (iodine, xenon, krypton) with medium half-lives.
The reactor pressure vessel consists of a steel wall approx. 20 to 25 cm thick. Together with the pipelines, it forms a closed cooling system in which any fission products that may emerge from the cladding tubes are also enclosed.
  • If the reactor is not able to shut down, it must be ensured that the chain reaction does not escalate in an uncontrolled manner. This is ensured by a negative Doppler coefficient (temperature coefficient of reactivity ), which has the effect that when the fissile material is heated, its reactivity automatically decreases. A negative Doppler coefficient can be achieved through the reactor construction and the design of the fuel assemblies. The EURATOM agreements stipulate that only nuclear reactors with a negative Doppler coefficient may be permitted to operate in the contracting states.
  • The thermal shield [4]
This serves primarily to shield against direct radiation from the reactor core. Since it does not have a completely closed construction, it can only partially hold back fission products.
This gas-tight and pressure-resistant "containment" made of approx. 4 cm thick steel (sometimes also made of prestressed concrete) is designed in such a way that in the event of a leak in the reactor cooling circuit it can safely absorb the entire escaping water / steam mixture with any fission products it may contain.
  • The surrounding reinforced concrete shell [1]
The entire containment is surrounded by an approximately 1.5 to 2 m thick reinforced concrete shell, which is primarily exposed to external influences - such as B. Destruction by a plane crash - to prevent, but can also hold back radioactive materials in their interior.

Other reactors, especially those of the former Eastern Bloc , have z. Sometimes fewer and qualitatively poorer barriers. But not all western (or German) reactors are protected, for example, by a reinforced concrete shell [1] that would be strong enough to withstand the impact (e.g. crash) of a larger aircraft.

Ongoing operation and litigation

The distinction between, goes back to the RWE manager Heinrich Mandel

  • on the one hand, the design basis accident agreed for the approval of a nuclear power plant, the control of which the safety systems must be designed,
  • on the other hand, imaginable chains of accidents that go far beyond the design basis accident (due to plane crash, warlike actions, simultaneous independent failure of several safety devices or bursting of the reactor pressure vessel), which are not included in the design due to their low probability of occurrence.

The design basis accident is also referred to as the “largest assumed accident” (GAU). If this GAU is mastered, it was previously believed that all other incidents could also be safely mastered. Today we know that this is by no means always the case. Instead of the one design basis accident, a whole spectrum of design basis accidents has been used, the control of which must be proven individually.

When considering accidents and malfunctions or when analyzing the causes , the assumption is made that a serious failure of technical equipment does not occur by chance, but rather due to a chain (or several chains) of causes and effects. If these chains of effects are identified, they can be specifically interrupted. If such an interruption is provided several times and with mutually independent measures, a very high level of security can be achieved overall, since errors in individual steps can be caught by the functioning of other steps. It does not matter whether these errors result from a failure of components or systems ("technical error") or from human error (" operating error ", " human error ", or "organizational error") (or both). One speaks of a “ multi-level, forgiving security concept” .

Disposal issue

Generation of radioactive waste from the nuclear industry

Albert Gunter Herrmann and Helmut Rothemeyer , in a basic work on the safety of long-term landfills, consider the fundamental challenges of storing toxic chemical waste to be comparable to those of medium- and short-term radioactive waste, but note a discussion that is much less heated in the case of the former. Herrmann refers to the role of nature observation of long-term geological processes in the assessment of the various repository concepts. In a Swedish study for the German Federal Office for Radiation Protection in 2004, this nature observation was systematized on the basis of a consideration of natural and anthropogenic analogues . Natural analogues mean natural processes that correspond to those in a repository and its geological environment. By observing them, the processes taking place in the repository - such as the movement of radioactive substances through rock sediments - can be better understood and thus better forecast for long periods of time.

The planning and procedure for final disposal are the responsibility of each state; there are internationally binding basic requirements by the International Atomic Energy Agency (IAEA). There are repositories for low and medium level radioactive waste in many countries. B. in France, Great Britain, Spain, the Czech Republic and in the USA. In Germany, the Morsleben repository is in operation and the Konrad repository is under construction. A permanent repository for highly radioactive waste from the use of nuclear energy has not yet been established worldwide (2013).

Further development of security technology

The safety of nuclear power plants depends on how a nuclear power plant is designed, built and operated. Worldwide, the safety of nuclear power plants has increased significantly since their introduction in 1956 through experience and retrofitting. Since 1994, the amended Atomic Energy Act in Germany has also required that incidents that go beyond the design (core meltdown accidents) in the case of new nuclear power plants must be contained to such an extent that their effects are essentially limited to the power plant site and no serious measures are taken in the vicinity are necessary to limit risks (evacuations). The new Franco-German joint development " European Pressurized Water Reactor " (EPR) apparently meets these conditions. One such power plant is currently being built in Finland and one in France; the planned completion has been postponed several times.

Since May 2001, 11 countries have been working on further developed reactor concepts in a joint project under the leadership of the USA as part of the Generation IV International Forum for Advanced Nuclear Technology (GIF) . A total of 6 different reactor concepts are being pursued with the aim of increased safety and improved economic efficiency while at the same time improving fuel utilization and increased proliferation security. In addition, possibilities of nuclear hydrogen production are being investigated. Two of these concepts should be ready for construction for demonstration plants in 2015 and the remaining four in 2020. A commercial use could then take place maybe 10 years later.

Dealing with accidents

Particularly well-known and serious accidents due to spectacular reactor failures include the events of Windscale / Sellafield (1957) , Three Mile Island (Harrisburg, 1979) , Chernobyl (1986) and Fukushima-Daiichi (2011) . The serious accident at Kyshtym (Mayak, 1957) occurred in a reprocessing plant. Accidents with a lower level of exposure to radioactive material in the vicinity of medical nuclear technology, such as the Goiânia accident in 1987 or the nuclear accident in Samut Prakan , were classified as similarly serious.

Accidents when handling radioactive substances

Medical applications of nuclear energy, such as the cobalt cannon , whose radiation source 60 Co is obtained by neutron activation in nuclear reactors, also entail considerable dangers, on the basis of which, however, the associated technology was not called into question. Tragic cases are the Goiânia accident in 1987 or the nuclear accident of Samut Prakan in Thailand in 2000. In Goiânia , almost 93 g of highly radioactive cesium chloride from the cesium isotope 137 Cs was stolen by scrap dealers from a former clinic and distributed among friends and acquaintances by the thieves. Hundreds of people were z. Partly heavily radioactively contaminated, as a result at least four people verifiably died within a few weeks, further deaths are linked to the accident.

The International Atomic Energy Agency valued Goiânia similarly to the fire in the nuclear reactor at the Plutonium Windscale / Sellafield production facility in Great Britain , the meltdown in the cavern reactor in Lucens , Switzerland and in the Three Mile Island (Harrisburg) nuclear power plant on the International Rating Scale for nuclear events ( INES) with level 5 (of 7) as Serious Accident .

Joachim Radkau emphasizes that the anti-nuclear and environmental movement was by no means based on incisive disasters, but rather on local initiatives and local interest groups. According to Radkau, individual health is an essential driver.

Reactor accidents and process errors

A study published in 2012 at the Max Planck Institute for Chemistry assesses the risk on the basis of previous experience with accidents and not on the basis of estimated values. The study comes to the conclusion that a major accident can be expected every 10–20 years. According to the Mainz team, there is a risk of contamination of more than 40 kilobecquerels per square meter in Western Europe, where the reactor density is very high, on average once every 50 years. In a global comparison, the citizens of densely populated southwest Germany bear the highest risk of radioactive contamination due to the numerous nuclear power plants on the borders of France, Belgium and Germany.

According to statistics from the Swiss Paul Scherrer Institute (PSI) for nuclear and reactor research, the number of immediate fatalities from known nuclear accidents in OECD countries for the period from 1969 to 2000 per gigawatt year is “zero”. In comparison, the above-mentioned PSI study lists 0.13 deaths / GW year for coal-fired power plants in OECD countries, and also as "zero" for hydropower plants in the EU15. The study lists only the Chernobyl disaster (the Soviet Union was not part of the OECD at the time) for deaths due to long-term effects from nuclear power plants and estimates this at around 10,000 to 100,000 deaths, which to this day can be directly attributed to the long-term effects of Chernobyl. (See also the list of accidents in nuclear facilities , which deals only with cases of radioactivity leakage). For hydropower plants in non-OECD countries, it lists 13.77 fatalities / GWyear (cynically, the majority stems from another major disaster; the rupture of 62 dams in China around the Banqiao Dam in 1975 with an assumed 26,000 immediate deaths).

The underlying study (Hirschberg et al. (1998): Severe accidents in the energy sector ) by the Paul Scherrer Institute cited above deals with nuclear power plants (pp. 137–182) mainly with the estimated costs incurred for any possible damage limitation worst possible fictitious accident scenarios in nuclear power plants with the highest safety standards (which in the study are also described as rarely fulfilled in western countries). This at the maximum distance from human settlements, not with a single nuclear power plant or the actual effects of such a catastrophe, such as concrete deaths or the extent of environmental damage; The results can therefore also be interpreted in such a way that “less” can be done in the case of nuclear power plant accidents, despite the considerable burden and damage.

Regardless of this, the meltdown at Three Mile Island and its containment, which ultimately proceeded lightly, confirmed the effectiveness of the security concept there with staggered barriers and multiple facilities to protect these barriers. In Chernobyl there was an uncontrolled increase in output due to serious violations of the applicable safety regulations and the design-related properties of the graphite-moderated nuclear reactor of the type RBMK -1000 without containment, which led to the reactor exploding.

Effects of accidents

Robert Peter Gale believes the health risks from the Fukushima nuclear disaster are relatively low. He justifies this, among other things, with the fact that the prognoses made by him as a senior physician in 1986 after the Chernobyl disaster on the number of cancer cases and disabilities in newborns (which are also mentioned in the Scherrer study) turned out to be too high in 1988. Compared to the psychological consequences, the consequences of the radiation of the Chernobyl disaster on human health were far less drastic.

He says about the Fukushima accidents:

"The most serious long-term consequences of a nuclear accident are usually not medical, but political, economic and psychological in nature."

So far there have been two deaths in the vicinity of the power plant disaster, which were caused by the tsunami and not the radiation effect. The much more serious impact had the necessary evacuation of tens of thousands of people from the wider area.

Ethics of Catastrophic Risk Management

An elephant in the room is an English metaphor for a risk or danger that is very well present during a conversation, but which is ignored by everyone present. Niklas Möller and Per Wikman-Svahn cite the concept of the black elephant in the 2011 Fukushima nuclear disaster , a risk or danger that was known before a disaster but was deliberately ignored.

You contrast this with Nassim Nicholas Taleb's concept of a black swan, cited on the basis of the financial crises . A black swan is a serious event that was beyond any expectation, but is relatively easy to interpret and understand in retrospect.

Möller and Wikman-Svahn warn to include the potential for catastrophic consequences more openly in planning and provision. In Japan, despite the risk of an earthquake and tsunami, the nuclear facilities had not been renounced. "Avoiding earthquake zones, for example, is a reiteration of the principle of inherently safe design. If we still decide to place a nuclear power plant in an earthquake zone, making sure that we are not dependent on functioning diesel generators to avoid a loss of coolant accident is an application of the principle of safe fail. The uncertainty reduction entailed by a holistic extension of the two fundamental safety principles, means that black swans are less likely to turn into catastrophes since we place our world in a more stable position, which is more apt to also handle the unexpected "(, German: “Avoiding earthquake zones would be an appeal to inherent safety. If we do decide to build a nuclear power plant in an earthquake zone, resilience is important, ensuring that we do not have to rely on working diesel gensets to avoid the cooling failures. The holistic application of the two security concepts means that black swans are less likely to become disasters because we put our world in a more stable position that is more capable of mastering the unexpected ”)

Comparison with the safety of other energy sources

Several studies have been carried out to compare the health risks of generating energy from nuclear and other energy sources. The most significant evaluation factor here is the number of victims per amount of energy generated (deaths per terawatt hour, t / TWh). The numbers from different studies differ by orders of magnitude because different criteria are used. The main reasons that lead to the differences are

  • Consideration of the long-term consequences of nuclear accidents
  • Calculation method of the long-term effects of small radiation doses, e.g. B. the linear no-threshold model (LNT). The LNT model is an assessment of the health consequences with the assumption that the risk increases linearly with the radiation dose, i. H. an arbitrarily small dose has an effect and the duration of exposure is not relevant (a large exposure for a short time is no more dangerous than a small dose for a long time). Many studies show that the LNT model is a pessimistic overestimation, as living beings have protective mechanisms against small doses of radiation that are no longer effective at large doses.
  • Taking into account the accidents and health consequences of coal and uranium mining
  • Consider the effects of air pollution on oil and coal
  • Period of study (most energy sources have seen major safety improvements in the last few decades, so it is incorrect to consider different sources over different time periods). Difference whether the study summarizes the historical data or a projection of the risk from power plants in operation.
  • World regions taken into account. The inclusion of China plays a crucial role in hydropower and coal, for example.
  • Taking into account the accidents in Chernobyl (up to 9,000 deaths according to long-term effects according to the LNT model according to WHO, up to 33,000 deaths according to the LNT model for the entire northern hemisphere according to the TORCH study) and at the Banqiao Dam (170,000–235,000 deaths in 1975 ) without discussing whether such accidents would be realistic with today's systems

The figures and results from several sources are listed and commented on below.

Forbes

The magazine Forbes presented the following results from the year 2012, the data from the World Health Organization , the Centers for Disease Control and Prevention and the National Academy of Sciences originate:

  • Coal: 170 t / TWh (China: 280t / TWh, USA: 15t / TWh; especially lung cancer)
  • Oil: 36 t / TWh
  • Solar: 0.44 t / TWh (mainly due to roof construction accidents)
  • Water: 1.4 t / TWh (mainly Banqiao accident, 1975)
  • Wind: 0.15 t / TWh
  • Nuclear energy: 0.09 t / TWh (including mining and based on the overestimation of the LNT model)

New Scientist

New Scientist magazine , cited by Greenpeace as a pessimistic example of the danger posed by nuclear energy, published the following figures:

  • Coal: 2.8–32.7 t / TWh
  • Water: 1.0–1.6 t / TWh (and up to 54.7 t / TWh with the Banqiao accident)
  • Natural gas: 0.3–1.6 t / TWh
  • Nuclear energy: 0.2–1.2 t / TWh (long-term effects of Chernobyl according to the LNT model, mining not taken into account)

Greenpeace

Greenpeace denies most of the studies on the subject with an article from 2011. In particular, the IEA study from 2008 is criticized. According to the IEA study, nuclear energy is significantly safer than coal, oil, natural gas and, above all, liquid gas . Greenpeace's criticisms are:

  • The IEA does not take into account the accidents from non- OECD countries, so Chernobyl is not taken into account. The IEA comments on this (p. 296) that only the direct consequences of accidents are taken into account here and not the long-term consequences, which would result in much more pessimistic figures for coal, especially in China (not OECD). In addition, the accidents in Banqiao, which include 235,000 deaths from the use of hydropower, are also not counted when selecting the OECD countries.
  • The study does not take into account the consequences of uranium mining. However, the figures cited by Greenpeace come from a study by the IEA from 2002, which cites data on uranium mining from a source from 1995 (Dones et al., 1995). According to UNSCEAR, safety in uranium mining has been greatly improved over the past few decades , primarily through increased ventilation to prevent radon accumulation.

Greenpeace concludes that nuclear energy is the most dangerous source of energy.

Nuclear Engineering and Technology

A study from the journal Nuclear Engineering and Technology by Lee et al compares the risk of nuclear, wind, and photovoltaics, but with a small number of factors. In summary, the following amounts of health risk are given:

  • Solar: 2.8 · 10 −7 / TWh (especially cancer risk due to cadmium and tellurium poisoning in the event of fire)
  • Wind: 5.9 · 10 −8 / TWh (mainly due to a break in the rotor blade)
  • Nuclear energy: 1.1 · 10 −9 / TWh

Next big future

An article from the blog Next Big Future from 2008 represents a large collection of sources on the subject, with the result:

  • Coal: 161 t / TWh (data from WHO )
  • Oil: 36 t / TWh
  • Solar: 0.44 t / TWh
  • Water: 1.4 t / TWh (including Banqiao)
  • Wind: 0.15 t / TWh (from the production of steel and concrete)
  • Nuclear energy: 0.04 t / TWh (including 4000 deaths in the accident in Chernobyl)

The author comments on the figures that there are no more reactors in the world that are as dangerous as the one from Chernobyl. The eight remaining RBMK reactors in operation worldwide (all in Russia) have a containment building and work with a lower vapor bubble coefficient than those in Chernobyl, all other reactors currently in operation (2015) work with negative vapor bubble coefficients ( light water reactors ) or slightly positive ( heavy water reactors ) ), so that a core meltdown in operation is not possible.

In an article from 2011, the author corrects the estimate for the health hazard of Chinese coal-fired power plants, so that the global average drops to 100 t / TWh.

Scientific American

In 2007, the magazine Scientific American analyzed the radiation exposure of coal-fired power plants and nuclear power plants with the result that it is about 10-100 times higher in coal-fired power plants. The reason for this is the proportions of thorium and uranium in the ashes: Although the radioactivity from nuclear waste is of course greater than that in the ashes, as commented in the Cern Journal, it may be shielded in solid form and due to the small amounts in the nuclear facilities, which is at the emitted ashes is impossible. There is also increased radiation exposure in coal mining.

The amount of radioactivity from the ashes is heavily dependent on the filters installed and the negative health effects of the ashes from coal-fired power plants are for the most part not caused by the radioactive pollution.

Heal study

The Health and Environment Alliance (Heal) estimates over 18,000 premature deaths per year in Europe in 2017 due to coal-fired power plants, 2,700 of them in Germany.

See also

literature

  • Günter Kessler, Anke Veser, Franz-Hermann Schlueter, Wolfgang Raskob, Claudia Landman, Jürgen Päsler-Sauer: Safety of light water reactors . Springer-Vieweg 2012, ISBN 978-3-642-28380-2
  • S. Hirschberg et al .: Severe Accidents in the Energy Sector. Paul Scherrer Institute, Villigen 1998, OCLC 59384513 , p. 241f.

Web links

Individual evidence

  1. ↑ Outline History of Nuclear Energy, World Nuclear Association (as of 2010)
  2. ↑ a b c d e f g h i Kahlert, Joachim (1988): Die Energiepolitik der DDR. Defects management between nuclear power and lignite. Bd. 92. Bonn: Verlag Neue Gesellschaft
  3. ↑ Federal Office for Radiation Protection: Monitoring of emissions from nuclear power plants ( Memento from January 17, 2012 in the Internet Archive ) (pdf)
  4. ↑ a b c Introduction to electrical energy technology, Friedhelm Noack, Hanser Verlag, 2003 - 344 pages
  5. ↑ Formation of secondary phases in deep geological disposal of research reactor fuel elements - structure and phase analysis Neumann, A.2012, Forschungszentrum Jülich GmbH Central Library, Verlag, ISBN 978-3-89336-822-8 , publications of the Forschungszentrum Jülich series Energy & Environment 329 (2012)
  6. ^ A b c Long-term safe landfills: situation, principles, implementation Albert Gunter Herrmann, Helmut Rothemeyer Springer DE, 1998 - 474 pages
  7. ↑ a b c d e f g h Rise and Crisis of the German Nuclear Industry. 1945-1975. Replaced Alternatives in Nuclear Technology and the Origin of the Nuclear Controversy. Rowohlt, Reinbek 1983, ISBN 3-499-17756-0 .
  8. ↑ Panos Konstantin: Practical book energy industry: Energy conversion, transport and procurement , p. 295.
  9. ↑ Mark Hibbs, Decommissioning costs for German Pebble Bed Reactor escalating, NUCLEONICS WEEK, Vol. 43, no. 27, p. 7 (July 2002)
  10. ↑ http://www.wmsym.org/archives/2000/pdf/36/36-5.pdf
  11. ↑ The planning work was already carried out parallel to the commissioning of the smaller AVR pebble bed reactor in Jülich, which had the negative consequence that the operating experience of the AVR could hardly be incorporated into the THTR concept.
  12. ↑ Rainer Moormann : Air ingress and graphite burning in HTRs: A survey of analytical examinations Performed with the code REACT / THERMIX, Jülich Research Center, Report Jül-3062 (1992)
  13. ^ R. Moormann: Phenomenology of Graphite Burning in Air Ingress Accidents of HTRs , Science and Technology of Nuclear Installations, Volume 2011 (2011), Article ID 589747, 13 pages, http://www.hindawi.com/journals/stni/ 2011/589747 / ref /
  14. ↑ FAZ Gesellschaft March 22, 2011 Environmental historian Joachim Radkau "Disasters give the final kick"
  15. ↑ Nuclear crisis "Some things remain puzzling" Japan has long been more risk-conscious about earthquakes than about nuclear energy. By Elisabeth von Thadden March 17, 2011 Source DIE ZEIT, March 17, 2011 No. 12
  16. ↑ see also article atomic moratorium
  17. ↑ Society for Reactor Safety - Second interim report on the safety assessment of the Greifswald nuclear power plant, blocks 1–4 (WWER-440 / W-230)
  18. ^ Felix Christian Matthes - Electricity Industry and German Unity: A Case Study on the Transformation of the Electricity Industry in East Germany
  19. ↑ Process-oriented evaluation of natural and anthropogenic analogues and their evaluation as a trust-building element in safety assessments for facilities for the final storage of radioactive waste ( Memento of the original from December 19, 2014 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Bertil Grundfelt (Kemakta Konsult AB), John Smellie (Conterra AB), Stockholm, July 9, 2004, study on behalf of the FEDERAL OFFICE FOR RADIATION PROTECTION (BfS) @1@ 2Template: Webachiv / IABot / www.bfs.de
  20. ^ INES - The International Nuclear and Radiological Event Scale. (pdf; 193 kB) International Atomic Energy Agency , August 1, 2008, p. 3 , accessed on March 14, 2011 (English).
  21. ↑ Joachim Radkau, The era of ecology. A world story. Beck, Munich 2011, ISBN 978-3-406-61372-2 .
  22. ↑ http://www.kulturwest.de/literatur/detailseite/artikel/die-umweltbewegung-hat-ihren-ursprung-nicht-in-katastrophen/ »THE ENVIRONMENTAL MOVEMENT DIDN'T ORIGIN IN DISASTERS« The book currently: Der Bielefelder In his voluminous new work, historian Joachim Radkau takes on the »era of ecology«. A conversation from an unexpectedly current occasion. INTERVIEW: ANDREJ KLAHN
  23. ↑ The nuclear disaster is more likely than expected Western Europe carries the world's highest risk of radioactive contamination from serious reactor accidents, press release of the Max Planck Institute for Chemistry, Mainz May 22, 2012.
  24. ↑ St. Hirschberger, P. Burgherr, G. Spiekerman, E. Cazzoli, J. Vitazek, L. CHeng: "Comparative Assessment of Severe Accidents in the Chinese Energy Sector" (PDF; 1.6 MB), PSI report no. 03-04, Paul Scherer Institute, March 2003, ISSN  1019-0643
  25. ↑ a b c The Real Danger , by Robert Peter Gale, Spiegel April 4, 2011 Debate
  26. ↑ Robert Gale: The threshold that puts everyone in danger . The American doctor Robert Gale takes stock of his Chernobyl mission in Moscow. Der Spiegel April 18, 1988.
  27. ↑ a b c d Niklas Möller & Per Wikman-Svahn (2011): Black Elephants and Black Swans of Nuclear Safety, Ethics, Policy & Environment, 14: 3, 273-278, doi : 10.1080 / 21550085.2011.605853
  28. ↑ Nassim Nicholas Taleb: The Black Swan: The Power of Highly Unlikely Events . Hanser Wirtschaft , 2008, ISBN 978-3-446-41568-3 . (Original: The Black Swan: The Impact of the Highly Improbable (Penguin, ISBN 978-0-14-103459-1 , February 2008))
  29. ↑ M. Tubiana, LE Feinendegen, C. Yang, JM Kaminski: The linear no-threshold relationship is inconsistent with radiation biologic and experimental data. In: Radiology. Volume 251, number 1, April 2009, pp. 13-22, doi : 10.1148 / radiol.2511080671 , PMID 19332842 , PMC 2663584 (free full text).
  30. ↑ The 2007 Recommendations of the International Commission on Radiological Protection , International Commission on Radiological Protection , Retrieved on July 31, 2015
  31. ^ Health Impacts, Chernobyl Accident Appendix 2 , World Nuclear Association, 2009. Retrieved July 31, 2015.
  32. ↑ Health effects of the chernobyl accident and special healthcare program , World Health Organization , 2006
  33. ↑ How Deadly Is Your Kilowatt? We Rank The Killer Energy Sources , Forbes, 2012
  34. ^ Deaths and energy technologies , Greenpeace, 2011, accessed July 30, 2015
  35. ↑ Fossil fuels are far deadlier than nuclear power , New Scientist, 2011 Retrieved on July 30, 2015
  36. ^ Deaths and energy technologies , Greenpeace, 2011, accessed July 30, 2015
  37. ↑ [ http://www.iea.org/publications/freepublications/publication/etp2008.pdf Energy Technology Perspective, IEA , 2008, accessed July 30, 2015
  38. ↑ Comparing Nuclear Accident Risks with Those from Other Energy Sources ( Memento of the original from September 24, 2015 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , OECD, 2010 @1@ 2Template: Webachiv / IABot / www.oecd-nea.org
  39. ↑ Environmental and health impacts of electricity generation ( Memento of the original from September 24, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , IEA, 2002 @1@ 2Template: Webachiv / IABot / www.ieahydro.org
  40. ↑ Effects of ionizing radiation , UNSCEAR , 2006]
  41. ^ Integrated societal risk assessment framework for nuclear power and renewable energy sources , Nuclear Engineering and Technology, 2015
  42. ↑ Deaths per TWh for all energy sources: Rooftop solar power is actually more dangerous than Chernobyl ( Memento of the original from January 20, 2016 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , nextBIG future, 2008 @1@ 2Template: Webachiv / IABot / nextbigfuture.com
  43. ↑ Ambient (outdoor) air quality and health , World Health Organization , 2014, accessed July 31, 2015
  44. ↑ Deaths per TWH by energy source ( Memento of the original from July 24, 2015 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , The Next Big Future, 2011. Retrieved July 31, 2015 @1@ 2Template: Webachiv / IABot / nextbigfuture.com
  45. ^ Coal Ash Is More Radioactive than Nuclear Waste , Scientific American, 2007. Retrieved July 31, 2015
  46. ↑ Coal ash is NOT more radioactive than nuclear waste ( Memento of the original dated August 27, 2009 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , CEJournal, 2008, Retrieved August 27, 2015 @1@ 2Template: Webachiv / IABot / www.cejournal.net
  47. ↑ How do coal-fired power plants damage our health? ( Memento of the original from December 9, 2016 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , Health and Environment Alliance (Heal), 2017 @1@ 2Template: Webachiv / IABot / www.env-health.org