10.12.21 Protecting the climate with nuclear power? Author: Christian Buck • Credits: IMAGO / Xinhua • Reading time: 8 min.

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At the end of the year, three of the six remaining German nuclear power plants will be shut down: Brokdorf, Grohnde and Gundremmingen C. The Emsland, Isar 2 and Neckarwestheim 2 reactors will follow them twelve months later. But while Germany is phasing out nuclear power, more and more countries across the world are showing an interest in it as a carbon-free source of electricity. The new generation of reactors promises increased safety, a reliable supply of electricity in the long term and, in some cases, even a solution to the ultimate storage problem.

In October of this year, an unusual document was published that attracted a lot of attention. “Germany has not (…) exploited all the possibilities available to it,” read an open letter signed by cognitive psychologist Steven Pinker, climate researcher James Hansen, former editor of German newspaper Die Zeit Theo Sommer, and Finnish Green politician Tea Törmänen, among others. “The elephant in the room is the fact that Germany is increasing the carbon emissions of its energy system by phasing out nuclear power at the very point in time when decarbonizing the electricity industry is the main strategy for establishing an energy system with net-zero emissions.”

The signatories call on Germany to make changes. “You could still achieve your 2030 climate targets. You could change course and reset your priorities so that the phase-out of coal comes before the phase-out of nuclear power. The only thing that is needed is an emergency climate ordinance amending the Atomic Energy Act to bring back into effect the extension of the working lives of the nuclear power plants from 2030 to 2036, which was agreed in 2010.”

France invests in nuclear energy

Emmanuel Macron, The president of France

Can nuclear power protect the climate? Something that here in Germany is only spoken about behind closed doors has become a central topic for debate in other parts of Europe. Many EU member states are investing in nuclear power with the aim of reducing their CO2 emissions. One of these is France, which already operates 56 reactors and has plans to build six more. “We are relying on nuclear power for our future energy needs and for the future of the environment,” says French president Emmanuel Macron.

Other European countries want to join the nuclear club, with Poland being the most prominent example. More than 70 percent of its energy comes from coal. If the EU is to meet its climate targets, Poland needs to find new carbon-free energy sources. This is why Germany’s eastern neighbor has already put four potential sites for new reactors on its shortlist: Lubiatowo-Kopalino, Zarnowiec, Patnow, and Belchatow. The first new power plants are likely come on stream in 2033 at the earliest.

Other countries, in particular Austria and Luxembourg, are strongly opposed to any further expansion of nuclear energy. But they are in an increasingly isolated position, because more and more European states are reconsidering their approach to nuclear power. The EU is also planning to set a new course over the decades to come and this will have a major impact on the future of nuclear energy. The European Commission taxonomy system will identify the investments that are climate-friendly and, therefore, eligible for funding. If nuclear energy is officially included in this category, billions of euros could be made available for the expansion of the industry and for research in areas such as small modular reactors (SMRs). The supporters of these mini power plants say that they will provide a safe, decentralized, carbon-free supply of electricity.

New reactor concepts increase safety

Opponents of nuclear power often refer to the safety risks involved in the industry and cite the nuclear accidents in the USA (Three Mile Island), the Soviet Union (Chernobyl), and Japan (Fukushima). By contrast, its supporters, such as safety expert Rafael Macián Juan from the Technical University of Munich, highlight the small number of incidents over recent decades.

In addition, the technology has been under constant development. One example of the progress made is the European pressurized reactor (EPR), which belongs to generation 3+. Two reactors of this type have been in operation in China for some years and three others are under construction in Finland, France, and the United Kingdom. “The EPR is an improved version of familiar German and French reactors,” says Dr. Walter Tromm, expert in nuclear safety research at the Karlsruhe Institute of Technology (KIT). “Under the reactor pressure vessel is a core catcher that, like a sump, can trap molten core material and cool it until it solidifies. The AP 1000 reactor from Westinghouse is another evolutionary development of existing concepts. It can contain a core meltdown in the pressure vessel, which allows it to be cooled from the outside in the event of an incident.”

However, the new reactors have major problems to overcome in practice. For example, the commissioning of the Finnish EPR was subject to considerable delays and rocketing construction costs. The power plant is currently expected to come online in the summer of 2022. The situation with the British EPR has been similar. According to the latest reports, it will begin generating electricity in 2026. Even in France, the home of the EPR, the new reactor being built in Flamanville has been plagued with delays and cost increases. The plant is now likely to come into operation in 2023 at the earliest, rather than in 2012 as originally planned. “We are currently lacking experience in reactor construction in Europe,” explains Tromm. “Countries such as China and South Korea are ahead of us in this respect.”

Nuclear waste becomes a raw material

Dr. Sören Kliem, Head of the reactor safety department at the Helmholtz-Zentrum Dresden-Rossendorf

Alongside the improved design of the third generation of reactors, experts are also investigating completely new types of nuclear power plants. Some of these fourth generation reactors would be able to use uranium 238 or thorium, which are in plentiful supply. This would mean that enough nuclear raw materials would be available for the foreseeable future. The new reactors could also burn nuclear waste and therefore significantly reduce the disposal problem. “The waste would become a raw material,” says Dr. Sören Kliem, who heads the reactor safety department at the Helmholtz-Zentrum Dresden-Rossendorf. “The end products from the reactors would only have to be stored for around 1,000 years instead of 300,000.”

Other types of generation 4 reactors produce highly efficient process heat as well as electricity. “They could make this heat available to the chemical industry, for example, for the production of synthetic fuels,” explains Kliem. He believes that the new reactors are much safer than those from the third generation. In addition, they do not produce materials that can be used to make nuclear weapons.

However, there are as yet no commercial reactors of this kind connected to the grid, and many of the ideas still have to demonstrate their viability in practice. But research is underway throughout the world; the members of the Generation IV International Forum (GIF) include 13 countries and the European Atomic Energy Community (Euratom), which have come together to coordinate their research and development activities. Germany is indirectly involved via Euratom.

Mini reactors from the production line

Dr. Walter Tromm, Expert in nuclear safety research at the Karlsruhe Institute of Technology (KIT)

Small modular reactors (SMRs), some of which are fourth generation systems, can provide a decentralized supply of energy. With an electrical power output of a few hundred megawatts, they are not only much smaller than conventional nuclear power plants, which generally produce around 1,500 megawatts per block, but are also manufactured under controlled conditions in a factory and simply assembled on site.

This could allow costly problems on construction sites to be avoided and would also bring safety benefits. “The factory production process and the relatively high numbers of reactors being manufactured would allow practical experience to be fed directly back into improvements in the design,” says Tromm. “This would make it possible to introduce development cycles like those in the aircraft industry where the products are constantly being improved.” The small size of SMRs and their solid construction will allow meltdowns to be contained inside the reactor. “If an SMR that has failed is underground, it can simply be flooded with water,” explains Tromm.

Many companies are currently competing for the leading positions in the SMR market. They include the Danish start-up Seaborg Technologies, the long-established British company Rolls Royce, Rosatom from Russia, and NuScale from the USA. The young industry is receiving considerable research funding from the governments of the USA, Canada, and the United Kingdom. “This is the government of Canada ensuring that we have every tool possible in our toolbox to reach net-zero carbon emissions by 2050 and address the existential crisis of climate change,” says Seamus O’Regan, Canada’s minister for natural resources, who estimates that the global SMR market will be worth up to 300 billion dollars by 2040.

Competition for nuclear fusion

Energy can be produced from nuclear fusion as well as fission, as the sun demonstrates on a daily basis. In addition to the international ITER consortium, individual countries all over the world, such as the United Kingdom and China, are carrying out research in this field. If you believe the promises of researchers, politicians, and entrepreneurs, nuclear fusion represents an almost inexhaustible source of energy. Its critics prefer to highlight the slow pace of progress in this area. The ITER research reactor, for example, will begin producing a small amount of surplus energy only in the mid-2030s.

If the speed of development does not increase, commercial reactors are not likely to come on stream until the middle of the century. However, start-ups such as First Light Fusion in Oxford are also working in the field of nuclear fusion. The company aims to start a nuclear reaction by means of collisions, rather than surrounding the fuel with a magnetic field, as is the case with ITER. It intends to have built its first fusion power plant by the 2030s.

The role that nuclear fission and fusion will be playing in the German energy sector by that time remains unclear. According to experts, the decision to phase out nuclear power would be very difficult to reverse. “The three power plants that are being shut down in December are definitely irrecoverable, because they have no more fuel elements and their approvals have expired,” says Kliem. “From a technical perspective, there would have been no problem in continuing to operate these three reactors and the remaining three that will be running until the end of 2022, because they are among the safest in the world.” This situation is unlikely to change; there will be no return to the extension of the reactors’ working lives agreed in 2010 and the wishes of the authors of the open letter will not be fulfilled.


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