Nuclear fusion: Fortune favours the bold

For optimists, nuclear fusion is, quite literally, the stuff that stars are made of, whereas for pessimists (some would say realists) it is rather more the stuff that science fiction is made up of.

The latter may well be why it is impossible to find long-term projections of what nuclear fusion’s contribution to man’s energy needs may be, even in the very long-term.  Simply put, nobody knows if it will ‘pan-out’ in the end and certainly not when.

All the more surprising then, you might say, that seven members representing 34 countries (European Union, United States, Russian Federation, People’s Republic of China, India, South Korea and Japan) came together in 2007 to build the International Thermonuclear Experimental Reactor (ITER).

Based in, Cadarache, southern France, and at an estimated cost of €12.8bn, this is no elementary school science-project and easily ranks as the single most expensive international scientific project to date.

More specifically, and if successful, the new reactor will use deuterium (which can be distilled from any water) and tritium (a residue of the fusion process itself) to fuel a magnetically contained reaction which in effect forces atoms of those two elements together, in the process creating an innocuous substance, helium, and releasing immense amounts of energy. 

But there is a trick to the above which we have forgotten to mention. The ionized gas must first be stored in a specially designed containment vessel and heated to approximately 150 million degrees Centigrade. 

To be more exact, that equates to roughly 10 times the temperature at our Sun’s core. More amazingly even, such a feat actually seems feasible.

To be had in account, ITER will not be a fully functional power station nor does it aim to be. Rather, if the experiment succeeds then such a station, now simply designated as “DEMO”, will be built towards 2033.       

So what is ITER’s goal? Frankly, it is nothing short of modern alchemy. In a less prosaic manner, there are really two related objectives.

Firstly, to create 10 times more power output than is required to start and maintain the reaction. Secondly, and perhaps far more useful, developing the technologies, materials and processes necessary to give humanity access to a limitless supply of energy, with little contamination and in a safe manner.

According to ITER recent advances in containing the plasma have reduced the projected cost of electricity from so-called Tokamak (something like the Russian acronym for ‘containment chambers with doughnut shapes’) reactors by a factor of two, to a value that is only about 50% more than the projected cost of electricity from advanced light-water reactors and just 25% more than coal (although 100% more than that of natural gas).

All of the above on current technology and without taking into account the lower environmental foot-print and far greater safety when compared to some of those other competing technologies. .

The latter is true because what radioactive residue nuclear fusion creates has a low ‘half-life’, of less than a century.

Furthermore, if power were ever to be cut to the installation then the reaction would cease and literally cool-off in a matter of seconds.

Will it work? There is obviously no guarantee that it will, quite the opposite probably. In fact, there are rival projects pursuing alternative paths, such as the Wendelstein 7-X Stellerator at Germany’s Max Planck institute or the Japanese Large Helical Device. 

Simply put, those machines employ far more complex designs, with the containment vessel looking like something akin to a twisting coil. That design is meant to try and compensate for the almost supernaturally complex forces which trying to magnetically contain plasma at such temperature unleashes and that some believe will ultimately stymie the ITER research team.  

Nonetheless, while the entire undertaking does indeed sound nothing short of fanciful, the theories from which the idea spawns are the same ones that fuelled the advent of the nuclear age, back in the early 20^th century.

Hence, a warning to cynics, those theories revolutionized almost every field of human endeavour since and probably sounded just as fanciful back then as nuclear fusion does now. 

And while the recent tragedy at Fukushima has led many, at least for now, to rue the day that nuclear technology came into our lives, the fact seems to be that it does offer a very important and economically feasible alternative to other highly contaminating energy sources, not to mention what would happen if the key to its fusion variant is found.

Thus, even were ITER not to be a resounding success, it is not at all unlikely that it would result in new technologies and knowledge that could mark an important new step forward on this quest.

Astronomically ambitious and daring nuclear fusion indeed is, but certainly worth the gamble.