For better or for worse, when we hear the word 'nuclear', we automatically associate it with nuclear weapons. The sheer shock of 'little boy' and 'fat man', the two nuclear bombs dropped on Hiroshima and Nagasaki, had been that far-reaching.
But as many claim, destruction and creation are two sides of the same coin. So, Nuclear armageddon aside, nuclear energy can also become a beacon of hope for humanity, especially against the backdrop of climate change. Nuclear fusion reactors have further entrenched the belief that nuclear energy is indeed the future of clean power.
Put simply, nuclear fission, the predominant process of generating nuclear energy, splits an atom into two or more smaller ones, typically by shooting a rogue neutron (released from a radioactive atom like Uranium) at it literally at lightning speed. Nuclear fusion, on the other hand, is the process of fusing two smaller atoms to create a larger one. Typically, nuclear fusion involves combining isotopes of hydrogen—deuterium and tritium — to form helium, a larger nucleus. It is also the process of energy generation in stars like the sun.
During both the fission and fusion processes, an enormous amount of energy is released. However, the amount of energy released during the fusion process is much larger and safer compared to nuclear fission.
Another important argument against nuclear fission is the release of highly radioactive byproducts into the environment which may take hundreds or even thousands of years to decay. In other words, if not managed appropriately, they pose long-term risks to human life.
Nuclear fusion, on the other hand, does not pose such risks and can produce vast quantities of clean energy. That being said, nuclear fusion is even more significant for scientists because energy generation in this process does not come with risks of radioactive contamination. For this reason, nuclear fusion is often called the 'holy grail' of clean energy.
Unfortunately, achieving nuclear fusion has long evaded scientists, until last December when the US National Ignition Facility at the Lawrence Livermore National Laboratory (LLNL) announced a significant breakthrough in nuclear fusion.
On 13 December 2022, the US Department of Energy announced that researchers had finally succeeded in extracting more energy from the process than they had put into it, after decades of attempts. Previously on 5 December, scientists exposed a tiny cylinder containing a pellet of frozen deuterium and tritium to 2.05 megajoules of energy.
The pellet was squeezed, producing high temperatures and pressures that fused the hydrogen inside of it. The fusing atomic nuclei produced 3.15 megajoules of energy in a brief explosion that lasted a fraction of a billionth of a second, which is roughly 50% more energy than was originally used to heat the pellet.
The ignition was put out in an instant, yet its impact will live on. Scientific breakeven, or net energy gain, has been the long-term goal of fusion research. And in this breakthrough, more energy is gained than the energy given as the original input. The US Energy Secretary Jennifer Granholm described the achievement as "one of the most spectacular scientific triumphs of the 21st century" at a press conference in Washington.
However, they have only produced a tiny quantity of energy in this experiment, hardly enough to boil a few kettles. But it is nevertheless a significant step forward towards making fusion-powered future a reality.
Moreover, this experiment demonstrates that the science behind fusion is valid. However, it still has to be replicated, and polished, and the energy it produces will need to be greatly increased before scientists can even consider scaling it up.
The expense of this endeavour has been in the billions of dollars; fusion is expensive. But overcoming these obstacles will undoubtedly be greatly aided by the prospect of a clean energy source.
However, many of these difficulties are not specific to the NIF, and fusion labs and companies all over the world are working to overcome them. Additionally, commercial companies in the US and the UK have developed new superconducting magnets that could help develop smaller, more potent reactors.
Elon Musk, the billionaire CEO of Tesla, expresses his admiration of the research, but with one important caveat: the cost. Regarding fusion research, he tweeted, "It's cool and for sure can and should be done, but I suspect its best case will be more costly than wind and solar."
Ambrogio Fasoli, a fusion physicist at the Swiss Federal Institute of Technology in Lausanne, says, "It looks like science fiction, but they did it, and it's fantastic what they've done." It's difficult to predict whether or when this work will result in a new energy source in the future. However, fusion researchers believe that when the technology is ready, it will be a fantastic tool for humanity.
The fusion reaction has produced the first net energy gain in human history. It is a critical step on the way to clean energy, even if more research – a lot more research – is required to make the technology repeatable, scalable and more effective.