With the recent launch of Chandrayaan-2, India has taken a giant leap in its space programme by trying the reach the south pole of the moon. In its latest project, the Indian Space Research Organisation (ISRO) is now trying to tackle the Sun.
Obviously, missions to the Sun are very tricky – its surface temperature is 15 million degrees Celsius! But India is participating in an experimental project in southern France to create a mini Sun on Earth to harness energy.
Which project is this? The ITER (International Thermonuclear Experimental Reactors) Project will be the most expensive science undertaking ever, with 35 different countries participating in the venture. It is estimated to cost Euro 20 million. India is covering 10% of the cost. In today’s world, where countries are often at war with each other, this is truly a global venture. A real example of how science, and an aim for the greater good of humanity at large, can unite people!
What are they building? Called a tokamak, it is an experimental machine that aims to harness the energy released through fusion, a carbon-free source of clean energy based on the science that powers our Sun and other stars. This energy is stored as heat in the walls of the reactor or chamber where the fusion reaction takes place, and it is hoped that this energy will then be able to be converted into electrical energy.
What is India contributing to this project? India is contributing to one of the most significant parts to the project – the world’s largest refrigerator, or cryostat. This will house the massive reactor where the fusion reaction will take place.
What is ‘fusion’? The process by which two atoms of hydrogen combine or ‘fuse’ together to form an atom of Helium. This process releases energy. Conditions necessary for fusion are very high temperatures, and a lot of pressure to hold the atoms together for the fusion reaction to take place. The Sun and the stars have the force of gravity creating the pressure. On Earth, we need to create fusion reactors that can maintain the appropriate conditions for the reaction. This has proved to be very difficult.
The tokamak uses a very strong magnetic field to create the pressure to power the process in the reactor. The first tokamak was developed by the Soviets back in the 1960s, but nuclear fusion has been very hard to put into practise. The ITER reactor is going to be the largest ever – on completion it will be about 28,000 tons – that’s roughly the weight of 4666 adult elephants!! It will have an incredible ten million parts that will be assembled on site. It will hopefully produce upto 500 megawatts of energy.
How is power made today? Today’s power plants mostly burn fuel to release heat, which is then converted into mechanical and then electrical energy. Many power plants use fossil fuels as the raw materials. There are also nuclear power plants that use a process called nuclear ‘fission’ to produce energy.
What is nuclear ‘fission’? Nuclear power plants use the process of ‘fission’, where atoms of a weakly radioactive substance called uranium are split apart. This process releases energy which converts water in the fission reactor into steam, which is then used to generate electrical energy.
Why continue to pursue the development of a fusion reactor if it is so hard? To generate energy through a clean source – the raw materials deuterium, lithium and tritium are very widely available, and no carbon dioxide is released during the fusion process. In addition, the ITER says that fusion can generate much more energy than other power plants can. For example, it can generate 4 times the energy generated by nuclear fission, the process used in current nuclear reactors, and nearly 4 million times the energy released by traditional power plants that burn fossil fuels! The waste materials are also much safer than the radioactive waste of nuclear fission plants.
Where does the project stand today? In November 2017, the project was halfway done, and experiments should begin in 2025.
Written by: Pereena Lamba and Sunaina Murthy