Many have come to regard nuclear fusion, rather than nuclear fission, as the energy source of the future, but there are several problems remaining to be ironed out before fusion reactors can be widely installed.
Research by electronic engineer Goretti Sevillano from the University of the Basque Country (UPV/EHU) has examined ways of potentially solving some of these issues. If it can be achieved, there are considerable advantages to obtaining energy by fusion, in which lightweight atoms are joined, as opposed to fission, whereby the nuclei of heavy atoms are split.
"In fission reactions there is a risk of explosion, but not in fusion, so nothing like what took place in Chernobyl or Fukushima would ever happen," explained Sevillano. "What is more, the waste generated in fission has a very long life and is radioactive; but this is not the case in fusion. Likewise, the fuels are more accessible. Uranium or plutonium is used in fission, and its access is not so widespread; but in fusion, helium or tritium, which can be obtained from water or earth, is used."
The ITER project, a large-scale collaborative experiment currently under construction in southern France, is one example of where the work carried out by Sevillano could be put to use. ITER is aiming to establish the viability of nuclear fusion as an energy source by building a Tokamak reactor, a device which uses a magnetic field in a torus, or donut-shape, to contain plasma.
For fusion to take place, the materials necessary must be turned into plasma, which has to then be spatially confined in order to produce and harness nuclear power. The systems of control required are complex.
"To develop Tokamaks, many of the plasma's parameters must be controlled, as well as the whole device itself; the currents that are going to be used, the voltage, the intensity, etc. Until all these things are controlled, it will not be possible to use these machines to produce marketable energy," noted Sevillano.
"Control of the parameters is necessary to obtain the maximum energy possible from the plasma, and the amount of this energy that can be extracted is calculated on the basis of the current: the greatest amount of current possible has to be maintained during the longest time possible," she continued. "That is why these parameters have to be controlled by means of the control, in turn, of the numerous coils and voltages within the structure."
Sevillano embedded a code known as ASTRA, which is used to simulate reactions in a Tokamak, into MATLAB (high-level computing software) to enable the development of specialised control mechanisms for the reactors. This is just part of a long and complex process, however, as 'First Plasma' at ITER is not expected to be achieved until 2020.