Discuss the prospects and challenges of constructing a nuclear fusion reactor.

In a thermonuclear fusion reactor, lighter atoms like those of hydrogen fuse to produce slightly heavier atoms like that of helium. There is a reduction of mass when four hydrogen atom combine at a very high temperature to form helium which releases  pure energy by way of Einstein's famous formula E=mc2. This is similar to the fusion energy that drives the sun.                                     Advantages of such a energy source:               • Nuclear waste produced is negligible, unlike conventional nuclear reactor. Also it can loose its radio-activity within 50-100 year.               • Abundant raw material(i.e. Hydrogen) present on earth, making it a renewable energy for all practical purposes.               • Amount of energy received is enormous after the reactor reaches its criticality.               • Doesn’t take much space, unlike hydroelectricity or solar power.              Challenges that we face in building fusion power reactors:               • Holding Super-hot Plasma is very difficult: Using strong magnets, the weltering plasma must be held in place, made to swill around, beams collide, fuse and release tremendous energy as heat. To create plasma for fusion, the mixture of deuterium and tritium needs to be heated to temperatures 10 times hotter than the Sun's center.               • Extracting heat safely is difficult: The heat must be removed from the reaction to boil water, produce steam and turn a turbine to generate electricity.               • Difficult to obtain Commercial viability: The plasma at high temperature needs to be sustained for a long time to reach criticality and if commercial energy has to be obtained.               • Instabilities: One of the critical challenges in the Tokamak is the sudden appearance of plasma instabilities. We need to get experience and assess the probability of such disruptions and work out how we can manage them. Making plasma at higher and higher temperatures and sustaining it at that temperature for more and more time will provide insights on disruptions.               • Huge investments required: Due to the scale of the fusion power production and the technical challenges make it a very expensive project even for the developed countries.           Although the commercially viable fusion energy still at least a couple of decades ahead of us, several advances have been made in this regard. Recently in Jan 2022 China's Experimental Advanced Superconducting Tokamak (EAST) sustained the plasma at 70 million degrees Celsius for several minutes. Similarly in February 2022, the Joint European Torus (JET) fusion experiment in Oxfordshire, U.K., went critical and produced thermonuclear fusion. This marks significant steps in the direction of a much larger upcoming International Thermonuclear Experimental Reactor (ITER), a global experiment to generate 500 MW of power by fusing hydrogen atoms into helium atoms by 2035.


POSTED ON 11-02-2022 BY ADMIN
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