FUSION BREAKTHROUGH
The Future of Power
For decades, scientists have pumped more energy into experimental fusion reactors than the total new energy created in the process. This setback has made nuclear fission — not fusion — the default preference in the pursuit of limitless, zero-carbon power, despite its health and safety risks. However, the new development emerging from the California-based Lawrence Livermore National Laboratory has changed the situation now with their historic breakthrough. Scientists at this facility have, for the first time, produced more energy in a nuclear fusion reaction than was used to ignite it, something called net energy gain. It is seen as a big step forward in the decades-old endeavour to master a technology that is considered the most dependable source of energy in the future.
Announcing this historic achievement, US Energy Secretary Jennifer Granholm said, “Simply put, this is one of the most impressive scientific feats of the 21st century … It is the first time it has ever been done in a laboratory anywhere in the world,” adding further that researchers have been working on the technology for more than 60 years.
The Experiment
· The experiment forced a minuscule amount of hydrogen into a peppercorn-sized capsule, for which scientists used a powerful 192-beam laser that could generate 100 million degrees Celsius of heat.
· Using powerful lasers to focus enormous energy on a miniature capsule, scientists started a reaction that produced about 1.5 times more energy than was contained in the light used to produce it.
· Under the pressure of these forces, the capsule started imploding on itself and leading to the fusion of hydrogen atoms and the release of energy.
· The fusion energy released by the implosion was more than that put in by the laser, a massive achievement given that, just a few years ago, the NIF laser could only get out about a thousandth of the energy it put in.
· This process is also called ‘Inertial Fusion’. At some other places, including the international collaborative project in southern France called ITER (International Thermonuclear Experimental Reactor), very strong magnetic fields are used for the same purpose.
Future prospects
· Attempts to master the fusion process have been going on at least since the 1950s, but it is incredibly difficult and is still in an experimental stage.
· The nuclear energy currently in use across the world comes from the fission process.
· Besides greater energy yield, fusion is also a carbon-free source of energy, and has negligible radiation risks.
· Though the achievement is significant, it does little to bring the goal of producing electricity from fusion reactions any closer to reality.
· By all estimates, the use of the fusion process for generating electricity at a commercial scale is still 3-2 decades away.
· The technology used in the US experiment might take even longer to get deployed.
Basics of Fusion
· Nuclear fusion is defined as the combining of several small nuclei into one large nucleus with the subsequent release of huge amounts of energy.
· It is the opposite reaction of fission, where heavy isotopes are split apart.
· Fusion, a form of nuclear energy generated when light-weight atoms fuse, is the process at work in every star’s core, releasing an enormous amount of energy.
· Fusion reactions take place in a state of matter called plasma. Plasma is a hot, charged gas made of positive ions and free-moving electrons that has unique properties distinct from solids, liquids and gases.
· It is a different, but more powerful, way of harnessing the immense energy trapped in the nucleus of an atom.
· In fusion, nuclei of two lighter elements are made to fuse to form the nucleus of a heavier atom.
· A large amount of energy is released in both these processes, but substantially more in fusion than fission.
· This is the process that makes the Sun and all other stars shine and radiate energy.
Advantages of Nuclear Fusion
Abundant Energy: Fusing atoms together in a controlled way releases nearly four million times more energy than a chemical reaction such as the burning of coal, oil or gas, and four times as much as nuclear fission reactions (at equal mass). It has the potential to provide the kind of base-load energy needed to provide electricity to cities and industries. Harnessing fusion, the process that powers the Sun, could provide a limitless, clean energy source.
Sustainability: Fusion fuels are widely available and nearly inexhaustible. Deuterium can be distilled from all forms of water, while tritium will be produced during the fusion reaction as fusion neutrons interact with lithium.
No CO2: Fusion doesn’t emit harmful toxins like carbon dioxide or other greenhouse gases into the atmosphere. Its major by-product is helium: an inert, non-toxic gas.
No long-lived Radioactive Waste: Nuclear fusion reactors produce no high activity, long-lived nuclear waste.
Limited Risk of Proliferation: Fusion doesn’t employ fissile materials like uranium and plutonium (Radioactive tritium is neither a fissile nor a fissionable material).
No Risk of Meltdown: It is difficult enough to reach and maintain the precise conditions necessary for fusion—if any disturbance occurs, the plasma cools within seconds and the reaction stops.
Other international initiatives
International Thermonuclear Experimental Reactor (ITER) Assembly: It aims to build the world’s largest tokamak to prove the feasibility of fusion as a large-scale and carbon-free source of energy. The ITER members include China, the European Union, India, Japan, South Korea, Russia and the United States.
China’s Artificial Sun: The Experimental Advanced Superconducting Tokamak (EAST) device designed by China replicates the nuclear fusion process carried out by the Sun.
Conclusion
Potentially, this fusion breakthrough is a step toward harnessing the process that fires the sun to generate carbon-free electricity. Now that it has succeeded in fusing two light hydrogen atoms to make one heavier helium atom releasing large amount of energy, it is one of the most significant scientific challenges ever tackled by humanity. However, here a million-dollar question is: “Will the nuclear fusion technology ever move out of the LLNL and become available for industrial use?”
It sure can and would, only if the developed world’s governments permit – as a prototype fusion power plant could be available by the 2030s. Pakistan needs clean air and carbon-free environment more urgently than any other country. And given the country’s wherewithal to master nuclear fission technology at the Kahuta Research Laboratories (KRL), it appears to have the required capacity to go for nuclear fusion as well.
The writer is a member of staff.