BackgroundNuclear fusion
Nuclear fusion makes life on earth possible: it is the source of energy of the sun and the stars. During nuclear fusion, light atomic nuclei melt together to form heavier ones, whereby a small amount of mass is converted into an huge amount of energy. Ever since the scientific world realised for the first time what the reason was for the huge amounts of energy emitted by the sun, it has been its dream to learn to harness that energy source on earth.
Nuclear fusion seems to be one of the most attractive long-term energy options, in particular because the fuel is cheap and abundantly available to everybody, and because of the highly favourable safety and environmental properties.
Nuclear fusion occurs at very high temperatures (tens to hundreds of millions of degrees Celsius). At these temperatures, matter no longer exists in solid, liquid and gaseous form, which we are all familiar with; instead, atoms fall apart into separate nuclei and electrons. The high temperature also gives atomic nuclei enough speed to collide with another, despite the fact that their positive charge makes them repel one another. In this process, heavier nuclei are created and huge amounts of energy are released.
Before we will be able to generate electricity in a commercially responsible manner using nuclear fusion, the huge scientific challenge lies in controlling that extremely hot plasma. No material can withstand these temperatures; the plasma must therefore be ‘confined’ in a magnetic field, at a sufficient distance from the reactor wall. Significant scientific and technological progress has been made in fusion research during the past decade. Researchers have successfully controlled the plasma and made it produce a large amount of energy for a short period of time (several seconds). This has led to a strong increase in the plausibility of nuclear fusion as a source of large-scale and clean energy production.
The research requires huge investments and the use of many scientists, and is therefore performed in large-scale international partnerships. Recently, an international coalition decided to built ITER (Latin for ‘the path’): a large, new test reactor in Cadarache in Southern France. ITER is supposed to prove the technical feasibility of fusion energy as a source of energy by generating a long-term burning plasma. The development of ITER signals the crossover from fundamental research to the development of technology. Additional material-research will be performed parallel to the experiments in ITER. Subsequently, an initial prototype of a commercial fusion power station should be built. If the research progresses successfully, it should be possible within a period of 30–35 years to demonstrate that large-scale generation of fusion energy is technically possible and economically feasible, and has attractive safety and environmental characteristics.
