The division and fusion of nuclear energy is finite

Nuclear Fusion - The Better Nuclear Power?

Nuclear fusion instead of nuclear fission. Above all, those countries that rely heavily on nuclear power today - countries like China, France and Russia - believe in this formula. The difference is as follows: A nuclear power plant generates its energy by splitting heavy uranium nuclei. A fusion reactor, on the other hand, is supposed to fuse light hydrogen into helium. And that would have several advantages over uranium fission.

On the one hand, the fuels for the fusion would be practically inexhaustible - in contrast to uranium. On the other hand, a disaster like that of a nuclear power plant is impossible, namely a fusion reactor would have stored far too little energy. And it wouldn't create long-lived nuclear waste. So you don't need a repository.

But all of these advantages are offset by a major negative: So far, no one has succeeded in building a fusion reactor. The technology is extremely demanding. The first realistic attempt is ITER - the largest experimental reactor of all time.

New source of energy

It all started in November 1991. At that time, Europe's fusion researchers could still cheer from the heart. With the JET test reactor in England, the physicists managed to fuse hydrogen into helium in a controlled manner for the first time, if only for two seconds. The way seemed free for a new, almost inexhaustible source of energy. The researchers set about building the blueprints for a new, even larger reactor, the ITER.

The huge experiment should definitely show that one can generate energy with fusion on a large scale. Specifically, ITER should be able to produce ten times more energy than you put into it. "A acid test for the suitability of the fusion principle," says Hartmut Zohm, fusion researcher at the Max Planck Institute for Plasma Physics in Garching near Munich.

The model for ITER is the sun

The sun produces almost infinite amounts of energy

In 2005, the European Union, together with Japan, South Korea, China, Russia, India and the USA, decided to build ITER in southern France. It consists of a huge, hoop-shaped vacuum chamber in which huge magnets hold a mixture of hydrogen. This gas is to be heated to a 150 million degree hot plasma - hot enough that the hydrogen nuclei can fuse to form helium and release energy. The system should cost five billion euros, and it should be ready in 2018.

But already in 2008 there were increasing signs that neither time nor budget can be kept. The reactor will probably not be fully operational until 2026 at the earliest. In addition, ITER is likely to be almost three times more expensive and cost up to 15 billion euros instead of five billion.

There are many reasons for this: Firstly, the raw material prices for those special steels and metals that are needed for ITER have risen sharply. "Second, the reactor was initially designed with a relatively sharp pen," believes Zohm. In the meantime it has been discovered that the technology is more complicated in detail and therefore costs more.

Bureaucratic friction losses

The 150 million degree hot plasma must not touch the inner walls of the reactor, otherwise it would cool down and make fusion impossible. That is why it is locked in such or similar extremely strong magnetic cages

Third, there is a problem with management: the seven partners are spread all over the world, which makes the organization a rather sluggish affair. Each of the partners would like to employ their own industries as much as possible. As a result, however, one and the same component is not built in inexpensive mass production by one company, but by several companies from different countries. Zohm: "This creates friction losses that are reflected in additional costs."

In the meantime, the management has been replaced and the project structure has been streamlined. The EU, which as host for ITER bears almost half the costs, has to divert the missing money from other research programs and from unused funds from its budget.

In any case, the merger critics feel confirmed. "From a scientific point of view, it is certainly an exciting challenge to master nuclear fusion," says Greenpeace atomic expert Heinz Smital. "But you shouldn't pretend you're doing something for the energy supply!" After all, ITER is just a highly complex scientific experiment and not a functional prototype for a power plant.

That is why Smital is calling for the megaproject to be stopped immediately and for the billions to be invested instead in expanding renewable energies, for example in huge solar power plants in the Sahara.

Author: Frank Grotel├╝schen
Editing: Judith Hartl / Nicole Scherschun