Nuclear fusion research

Nuclear fusion research

Bringing the starfire down to earth

The detailed and exciting presentation on the technology of nuclear fusion was the focus of the cooperation event with the Deutsches Museum. Hartmut Zohm's presentation can be found on the Catholic Academy's YouTube channel (see link below). A brief introduction to the topic and socio-ethical assessments are intended to help categorise it.


The technology

The development of fusion technology as an energy source is a historically unique long-term project: After beginnings in the middle of the 20th century with relatively short-term expectations of success, commercial availability is now hoped for by 2050. We are therefore already a long way down the road. It is a Promethean project at the limits of technical controllability that aims to bring starfire to Earth and thus solve the energy problem in a comprehensive manner.

Nuclear fusion is the counterpart to nuclear fission: instead of splitting a heavy nuclide such as uranium, light atomic nuclei are fused together, which can release even more energy. The sun is a shining example of this: A huge fusion reactor has been raging inside it for billions of years. Modelled on the sun, the primordial fire, fusion power plants are designed to fuse hydrogen nuclei into helium. This produces immeasurable amounts of energy - without greenhouse gases and without long-lasting radioactive waste. Chain reactions as in nuclear fission are ruled out by natural law. The use of energy density is impressive: one gram of hydrogen isotopes of deuterium and tritium provides an amount of energy that would otherwise require tonnes of coal to be burned. Nuclear fusion could realise the dream of clean, low-risk and virtually unlimited energy.


The state of affairs

With all this in mind, nuclear fusion is by no means at the stage of mere basic research or even Science Fiction:


The resource situation is essentially unproblematic, as the fusion fuels deuterium and tritium are available in abundance or can be easily obtained. Overall, however, nuclear fusion is a highly complex process, and integrating its elements into a functioning whole is a challenge for the pioneers of physics. One of the world's leading pioneers is Hartmut Zohm. He is particularly committed to the DEMO project, a demonstration power plant as a possible successor to ITER, which should produce enough tritium for a self-sustaining fuel cycle. The further development of fusion technology requires physicists who enjoy creative tinkering with the complex interplay of very different processes. Above all, we need progress in the development of materials.

Courageous investors are also needed. The nuclear fusion research reactor in France has so far been a financial disaster. Instead of the originally estimated costs of 5 billion euros, there is now talk of 15 billion. But overall, the collaboration between private and public research is giving new impetus to development: quite a few billionaires, such as Elon Musk, sense the potential of a commercially viable fusion power plant and are prepared to invest large sums to accelerate development. A race for priority and pioneering profits has begun.

According to Hartmut Zohm, nuclear fusion is the "only reliable source of energy to supplement renewables in the long term", as stated in an article in the Süddeutsche Zeitung on 13 July 2022. It is true that nuclear fusion will come too late to support the goal of climate neutrality by 2045, to which Germany and the EU have committed themselves. But it is foreseeable that we will still need a substantial supplement to renewable energies in order to secure the base load supply. Nuclear fusion could be an important alternative to coal worldwide, particularly in China and India.


Nuclear fusion - what speaks against it

Nevertheless, all this raises a whole series of fundamental ethical questions:

  1. Is it legitimate to invest billions of taxpayers' money in a project that we do not know whether it will succeed? Due to the high investment costs of an estimated five to six billion dollars per power plant, these are very capital-intensive and, according to current estimates, not competitive in liberalised markets for the time being.
  2. Would the centralisation of energy supply associated with the commercial introduction of fusion reactors be socially and environmentally sustainable?
  3. Whether fusion reactors will really be inherently safe has neither been proven nor disproven. Tritium is extremely mobile and difficult to control in the event of a release.
  4. Although the problem of radioactive waste is much smaller than with nuclear fission, both in terms of volume and the time factor (maximum 100 years), it also exists with nuclear fusion.
  5. How can the risks of technical accidents and sabotage that release the radioactive and chemotoxic inventory of the power plants be assessed? To be able to assess this more precisely, we would need to know more about the design of the future power plants, which has not yet been finalised.
  6. The military use of nuclear fusion as a hydrogen bomb represents a high risk. Tritium is of particular importance for the further development of nuclear arsenals because it is used in various advanced nuclear weapon designs. It poses a significant proliferation risk in the operation of fusion reactors.
  7. The question of public acceptance remains unanswered: will nuclear fusion be perceived as a "back door" for the return of nuclear energy after the end of nuclear fission-based power plants? A broad, open-ended public dialogue is needed.


Nuclear fusion - what speaks in favour of it

These concerns, which must be carefully weighed up, are countered by reasons in favour of investing in the research and development of nuclear fusion.

  1. The global hunger for energy will continue to rise in the foreseeable future and could double by the middle of the century; it is foreseeable that it can only be satisfied with renewable energies with great difficulty and ecosocial and economic ambivalence.
  2. The goal of freeing ourselves from fossil dependencies is so ethically urgent due to climate change that we should perhaps accelerate the research and development process instead of hesitating. Perhaps we need a Manhattan Project for nuclear fusion? Was it ethically negligent that we did not invest much earlier and more intensively in research into nuclear fusion?
  3. Of course, this must not be at the expense of promoting renewable energy sources, but it could and should complementary to do this. Nuclear fusion would be suitable for the uniform base load in urban centres, but hardly for rural regions and for countries in the Global South. The idea that nuclear fusion and renewable energies are mutually exclusive alternatives is a misconception.
  4. Overall, the risk of breeding weapons-grade fissile materials is rather lower with a pure fusion reactor than with a fission reactor. International cooperation on ITER is also a peace project that should be continued.
  5. We should not ignore the immense quantitative potential of nuclear fusion. It represents a qualitative leap in energy generation which, compared to chemical energy generation through combustion, is comparable to the leap from driving to flying. This, too, was not a short-term success, but it has significantly advanced the development of mankind and is now indispensable.

Weighing up

If we carefully weigh up the arguments in favour and against, in my view there is no stalemate, but rather the ethical task of learning from the critical objections for a development of nuclear fusion that is as low-risk as possible, economically feasible and complementary to the promotion of renewable energies. Mankind's dream of modelling the fusion power plant on the sun and bringing the fire of the stars to earth is not just a dream. Science Fiction more. It can become a reality in less than a generation.