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Thursday, June 06, 2013

Nuclear Fusion Power Plants To Meet India's Electricity Requirements

"the fusion power plant has to be realized by 2050 so that it can reduce the carbon emission considerably and also makes an impact on the long-term Indian energy scenario."

India's electricity consumption, by 2100, is expected to touch 2600 GWe, an increase of more than a 1000 per cent from the present installed capacity of around 258 GWe. Depleting reserves of known sources of fossil fuels, & the ecological damage associated with its use renders unsustainable, present approach in meeting any future energy requirements. Keeping this in mind, India, from the very outset set about addressing this challenge - developing a 3-stage nuclear fission power programme that would eventually help the country make use of its vast reserves of fertile Thorium to generate electricity. Fission power, with all its benefits, however, raises some of its own unique challenges, namely ensuring safe disposal of radioactive by-products of the fission process. Given that India's present-day per capita consumption of electricity is just around 5.8 per cent of that of the developed world, there is an urgent need to ensure ramping up & sustaining availability.

Nuclear-Fusion-Power-Generation-India-Roadmap-R

Yet another form of transformation is Nuclear Fusion - the process which the Sun undergoes to release the enormous amount of energy, a fraction of which eventually reaches Earth3. Unlike fission, however, Nuclear Fusion produces no harmful radioactive Steady-State-Superconducting-Tokamak-SST-1-India-Nuclear-Fusion-Rproducts - Helium, that is generated, is clean. For a given amount of fuel, the energy released during fusion is around a million times more than that released in a conventional chemical combustion process. It essentially means that, hypothetically, a mass of coal, if it were capable of undergoing nuclear reaction, would have been able to release around a million times more energy than it currently releases. Alternately, a kilogram of coal, if it could be be made to undergo fusion, would release as much energy as one can get by burning a million kilograms of the same coal. Either way one looks at it, nuclear fusion holds a very promising prospect of satisfying India's burgeoning hunger for energy, without the associated drawbacks we face with todays fuels.

The Gujarat-based Institute for Plasma Research [IPR] has been at the forefront of researching application of Nuclear fusion for power generation in India. Starting with the Aditya Tokamak6 [Fusion Reactor] that it developed & has been operating since the 1980s, it recently completed building its successor, the Steady-state Superconducting Tokamak [SST-1]. In addition, India is also a partner member in the ambitious International Thermonuclear Experimental Reactor [ITER] project underway in France, contributing 10% of the hardware sub-systems needed to build it.

Nuclear-Fusion-Power-Plant-Schematic-Diagram-R

This interesting paper, authored by Scientists at the IPR1, lays out the roadmap for India to develop a practical fusion reactor for generating electricity commercially. It is estimated that the cost of electricity generated in such reactors would be around Rs. 5-10 per kW-h. The paper lists out, broadly, some of the challenges that need to be addressed & technologies that need to be developed if the use of this process is to be realised on a commercial scale - the Indian Fusion Power Plant [IFPP].

via www.iaea.org

The primary challenge, in ensuring commercial viability, lies in sustaining a controlled Nuclear fusion [confinement] for hours on end. Presently the Aditya Tokamak can sustain confinement for fractions of second. The SST-1 has been built to ensure confinement forTokamak-Cross-Section-R 1000 seconds. Internationally, the Tore Supra Tokamak in France has reported confinement for 390 seconds. The ITER aims to attain confinement of 1000 seconds, generating 500 MW electricity power during that period & consuming no more than a 0.5 gram mixture of Deuterium-Tritium, in the process. Yet another major technological challenge that needs to be solved is the development of material that don't turn radioactive very easily [low activation property]. This is because, while the fusion process itself produces no radioactive elements, it liberates a vast number of neutrons, which strike the material used to build the reactor, with the potential to irradiate it4.

Clearly, there is still some way to go. Not surprisingly, proponents of this technology in India have put forth fusion as a solution for our energy needs, starting only the second half of this century. However, once built, India would have in its possession a limitless source of clean energy, fuel for which [Deuterium] can be sourced from sea-water2. Estimates suggest, given the present pace of research, 5% of India's energy requirements can be met with Nuclear fusion by 2100, the number rising to 10% if it receives greater impetus from its backers, the Government of India [GoI]. Needless to say, funding & support for research in this field is of paramount importance in ensuring a safe, energy secure future for India5.

via www.iaea.org

Notes/Extra tidbits:

1 = the Tokamak that is planned to be built following the completion of the SST-1, the SST-2, is also referred to as the DEMO reactor.

2 = Deuterium, the heavier isotope of Hydrogen, is an atom in the compound 'Heavy Water', that is present in a concentration of 1 part in 6000 in sea water, that can meet demands for estimated millions of years. Tritium, on the other hand, can be bred from Lithium, another widely available element.

3 = Dissatisfied with the fact that the Earth receives only about a hundred millionth of the the actual energy generated by the Sun, Freeman Dyson proposed a solution.

4 = One can nearly completely eliminate this problem by going the 'Aneutronic Fusion' route like the Deuterium-Helium-3 reactions, proton-Boron reactions that produce very little free neutrons. Those, however, poses its own set of challenges, especially the condition under which such fusion is carried, far more extreme than the, already extreme enough, conventional fusion reactions. The focus of India's research appears to be mastering this conventional Deuterium-Tritium [D-T] cycle.

5 = While the process of fusion occurring at temperatures matching that in the Sun is a universally accepted view, the concept of 'Cold Fusion' is one that has never been quite wholly disapproved. In fact, following the announcement of the results of the original experiment on Cold Fusion in the U.S, the Bhabha Atomic Research Centre [B.A.R.C.] in India has been one of the few institutes who claimed that they were able to replicate the results of the experiment. As a result, India allocated a fair bit of resource into researching it. In fact, the work done in India features quite prominently in the pro-Cold Fusion [now referred to as Low Energy Nuclear Reactions (LENR)] circuit.

This is an interesting video interview in which the leading figures of Cold Fusion research in India - one-time Director of BARC, the late Dr. PK Iyengar & Dr. M Srinivasan, speak of their work in understanding the Cold Fusion process & why they believe their study is valid in proving the theory.

6 = Given that one needs to supply an enormous amount of energy to initiate fusion, for a fusion reaction to have generated net power, it is essential that confinement of at least 1 second be achieved. Thus, the 'Aditya' Tokamak is a net consumer of electricity, a fact that should change when the SST-1 is put into action.

Godspeed

Related: Nuclear Energy & Technology: many myths, some debunking