In news– Scientists in the United States have, for the first time, achieved a net gain in energy from a nuclear fusion reaction.
What is fusion nuclear energy?
- Nuclear fusion is the process by which two light atomic nuclei combine to form a single heavier one while releasing massive amounts of energy.
- Fusion reactions take place in a state of matter called plasma — a hot, charged gas made of positive ions and free-moving electrons with unique properties distinct from solids, liquids or gases.
- The sun, along with all other stars, is powered by this reaction.
- To fuse in our sun, nuclei need to collide with each other at extremely high temperatures, around ten million degrees Celsius.
- The high temperature provides them with enough energy to overcome their mutual electrical repulsion.
- Once the nuclei come within a very close range of each other, the attractive nuclear force between them will outweigh the electrical repulsion and allow them to fuse.
- For this to happen, the nuclei must be confined within a small space to increase the chances of collision.
- In the sun, the extreme pressure produced by its immense gravity creates the conditions for fusion.
- Fusion is a different, but more powerful, way of harnessing the immense energy trapped in the nucleus of an atom. This is the process that makes the Sun and all other stars shine and radiate energy.
- Attempts to master the fusion process have been going on at least since the 1950s, but it is incredibly difficult and is still at an experimental stage.
Fusion still far from reality-
- Significant though the achievement is, it does little to bring the goal of producing electricity from fusion reactions any closer to reality.
- By all estimates, use of the fusion process for generating electricity at a commercial scale is still two to three decades away. The technology used in the US experiment might take even longer to get deployed.
- There are at least two different ways in which fusion reactions are being experimented with. These differ mainly in the way the input energy is supplied to create the extreme heat to enable fusion, but that also results in differences in design and capabilities.
- At the Lawrence Livermore facility, scientists use high-energy laser beams to achieve those temperatures, also called ‘inertial fusion’.
- At some other places, including the international collaborative project in southern France called ITER in which India is a partner, very strong magnetic fields are used for the same purpose.
- According to current timelines, the ITER project is expected to demonstrate the viability of a commercially scalable nuclear fusion reactor between 2035 and 2040.
- ITER, when operational, would become the biggest machine anywhere in the world, more complex than the Large Hadron Collider at CERN, or the LIGO project to detect gravitational waves. Right now, the ITER reactor is in the machine assembly phase.
- India joined the ITER project in 2005. The Institute for Plasma Research in Ahmedabad, a laboratory under the Department of Atomic Energy, is the lead institution from the Indian side participating in the project.
- As a member country, India is building several components of the ITER reactor, while also carrying out a number of experiments and R&D activities related to the project.
- ITER is an international nuclear fusion research and engineering megaproject aimed at creating energy by replicating, on Earth, the fusion processes of the Sun.
Fusion VS Fission technology-
- The nuclear energy currently in use across the world comes from the fission process, in which the nucleus of a heavier element is split into those of lighter elements in a controlled manner.
- A large amount of energy is released in both these processes, but substantially more in fusion than fission.
- For example, the fusion of two nuclei of a heavier isotope of hydrogen, called tritium, produces at least four times as much energy as the fission of a uranium atom which is the normal process of generating electricity in a nuclear reactor.
- Besides greater energy yield, fusion is also a carbon-free source of energy, and has negligible radiation risks.
- But fusion reactions happen only at very high temperatures, 10 times the temperature that exists at the core of the Sun, and creating such an extreme environment in a laboratory requires huge amounts of energy.
- So far, the energy released in such experimental fusion reactions have been lower than what is consumed to create the enabling high temperatures.
- At best, some of these reactions have produced ‘near break-even’ energies