During a recent dinner party an exceptionally lively debate erupted between several of my friends. I was astounded at the fervour the debate sparked in people I had till then considered cool and imperturbable. I was doubly astounded because they were getting wound up over the nuclear power issue. When last was anyone in a huff about nuclear power? Like armed warheads, intimidating terminology was being discharged across my dinner table and it was for self-defence, not diplomatic reasons that I refused be drawn into the fracas.

I was not aware of the controversial nature of this topic and did not want to be caught up in the fallout. The anti-corner considered all things nuclear to be no less than mankind’s ultimate creations of abomination, our betrayal of nature. In vain the pro- corner tried clarifying the distinctions between nuclear fusion and nuclear fission. Although I camouflaged my ignorance by the occasional sagacious nod, I must admit that after a bottle or so of very good Shiraz, nuclear fusion had become complete confusion. Thinking about the discussion the next day I decided it was time for me to investigate. We are at the dawn of a new century, during which we will face and hopefully endure an inescapable energy crisis. Mankind’s energy needs are escalating exponentially and we find ourselves increasingly dependant on electricity in almost every aspect of our lives from transport and medicine to communications and security. Man(un)kind has up till now principally generated energy from burning old plants, otherwise known as fossil fuels. This is a primitive and wasteful process which is has horrible repercussions, and could very well spell nothing less than the end of all forms of life on Earth. The application of Einstein’s E=mc² equation however enabled us to utilise nuclear fission, a previously unknown source of energy.

Using nuclear fission we could now extract about ten million times more energy from the same amount of mass. Fission is a method of releasing energy by splitting atomic nuclei. I wrestled with the word until I realised that both it and the word fissure are derived from the same Latin word for cleave. An atom’s nucleus is made up of the atomic particles protons (positive charge) and neutrons (no charge) which are held together by exceptionally strong nuclear forces. If a nucleus is split, these forces are released as vast amounts of energy.

The nucleus’s particles are flung apart and may then bash into and split the nuclei of neighbouring atoms. These may then do the same and this is a process known as a nuclear chain reaction. An uncontrolled nuclear chain reaction is essentially an atomic explosion. If controlled however, the energy can be released slowly and converted into useable power. Almost everything we perceive with our senses is made up of atoms. These are the fundamental building blocks of the 100 or so elements represented by the periodic table. The first and lightest element is hydrogen and it has for its nucleus one proton and one neutron around which zooms one negatively charged electron. At the other end of the periodic table are the heavy elements with over 100 protons and 100 neutrons in their nuclei.

These elements, such as uranium and plutonium, tend to be unstable and subsequently easier to split. That is why they are used as fuel in nuclear reactors.

What Happens To The Radioactive Waste?

Unfortunately they also emit radioactivity and remain doing so for tens of thousands of years after being viable as fuel. This radioactive waste could be regarded at the Achilles heal of the nuclear industry, and it is the most common argument used by anti-nuclear activists. Almost all of the world’s spent fuel is kept on site where it was generated, typically in spent fuel pools. The only reactors that don’t do so are those who do reprocessing, which is in fact a constructive solution. Disposing of spent fuel is a political rather than a technical problem. The nuclear industry knows exactly what to do with it, but in many countries the politicians are dragging their feet with the identification of deep level repositories, mainly because it is not really a pressing problem. All countries with nuclear energy are responsible for the safe management of their own wastes. Finland, America and Sweden are well progressed in engineering deep geological repositories for the safe, long-term storage of their spent fuel wastes. Compared with the huge atmospheric emissions from fossil-fuel energy, nuclear wastes exist in small, highly manageable amounts that can be stored without harm to people or the environment (for instance, one kilogram of uranium in the PBMR fuel has a greater energy output than 430 tons of the best coal)! Nuclear is, in fact, the only energy-producing sector that captures and accounts for all its wastes.

Even conventional reactors have relatively small quantities of spent fuel compared to, for instance, coal. To put this in perspective: the US has 104 nuclear reactors. If all the spent fuel generated in those reactors would be stacked on a soccer field, it would be 3 meters high! And lastly, unlike some chemical wastes – which are persistent – the radioactivity of nuclear waste steadily declines over time by natural decay of the radioisotopes.

The new technology proposed by the Pebble Bed Modular Reactor (PBMR) developed in SA will reduce the amount of radioactive waste substantially, and proposes using graphite to contain the waste for hundreds of years. However, it is widely perceived to be a problem, one which is compounded by the fact that the waste is erroneously believed to provide viable fuel for bombs. This is not true.

If all necessary safety precautions are observed reactors are totally safe, but man is only human. The Chernobyl disaster was entirely preventable and the PBMR bears as much resemblance to Chernabyl as a Tiger Moth airplane does to a rocket ship. This information puts a whole new perspective to the spent fuel issue.

There are currently 435 nuclear reactors in 31 countries. While we desperately need the energy they create there are vocal, emotional and generally uninformed people trying to get them shut down. I have carefully looked at the proposed alternatives and quite frankly not one is in the least feasible. Hmm… there is perhaps one possibility. It is not, however, seen as an answer by the anti-nuclear group, which only further demonstrates their lack of understanding. This possibility is the holy grail of energy production: nuclear fusion. While fission split nuclei, fusion actually fuses them. When the nuclei of two atoms are forced together they undergo an elemental transmutation.

This is precisely what the alchemists of old tried to do. This process, like fission, releases enormous, uncontrollable amounts of energy. Unlike fission however, instead of using heavy, radioactive elements for fuel, fusion uses the lightest, most abundant element in the universe, hydrogen. The small amount of radioactive waste it produces breaks down within a few decades. If this sounds too good to be true, rest assured, it is. Scientists understand and can explain the process perfectly and it undoubtedly works, after all it is the way stars generate their energy.

The technical challenges however have stumped us and a working reactor has remained ‘just around the corner’ for decades. Governments are spending fabulous amounts of money in the hopes of seeing this ideal become a reality, the latest being an EU backed body of British scientists. They are also funding a reactor that will be built in France by 2016 that will use “hot fusion” instead of lasers, contained by superconducting magnets. An EU/US collaberation has built a 20km tunnel in a disused iron mine (which is ideal because of its strong magnetic fields) in northern Michigan. It is now widely believed that the reality of a working fusion generator is finally about forty years away.

No, really! Excluding some miracle breakthrough, scientists predict one should be up and running sometime after 2050. Before scoffing, consider the challenges of perfecting it and the fact that it’s the ideal solution!

You thought splitting an atom was difficult?

To get the nuclei of atoms to fuse you first have to get rid of the pesky little electrons buzzing about. Nuclei are comprised of neutrons (no charge) and protons (positive charge) which give them an overall positive charge. As you may know, like charges repel each other - think of magnets. This electrostatic repulsion is called the Coulomb barrier, and is suspected to be the reason why the archetypal scientist is bald. No, only kidding!

Fusion takes place in the stars because inside them exists both extremely high temperatures and pressures. Although on earth we are unable to recreate these pressures, we are able to create even higher temperatures. So we take hydrogen gas and heat it up to several times the temperature of the sun’s core. At this temperature it is no longer a gas but plasma – electrons no longer remain with their nuclei, but roam around freely.Magnetic fields are used to contain the super heated plasma. Once the Coulomb barrier is overcome and two hydrogen nuclei can be forced together, they will transmute into helium shedding their excess energy in the process, much of which will heat the plasma further, ensuring a chain reaction of fusing nuclei. Cold fusion differs from hot fusion in that it uses lasers.

This is the ultimate energy dream. The greatest advantage over other forms of nuclear fuel is that cold fusion will not produce any more radiation than we are already bathed in all the time - something called background radiation. The generators too should also be infinitesimally smaller than those of today, in fact not much larger than a loaf of bread.

Consider how our lives will change for the better when we have clean, cheap fuel! Now, at least I can tell my fusions from my fissions and am more prepared for the next dinner party! If it takes forty years, or if it remains just around the corner, we must pursue it at all costs. It appears to be all that stands between us and the next great extinction.