Thorium the Fuel of the Future to Revitalize Nuclear Power Generation

Abstract

After disasters like Kyshtym, Windscale, Fukushima, Chernobyl etc., nuclear energy carried a dreaded stigma. The cost of nuclear power generation in the conventional way is on the rise, and so there is a resurgence in nuclear technology using thorium as fuel. There is a great pressure from international community to reduce carbon emission. So many countries are looking for a path to generate energy that is distinctly different but pays off in the long run. More abundantly available in India than uranium, thorium is cheaper, safer, and greener. The key difference between thorium and other nuclear fuels like uranium and plutonium is that it cannot sustain a chain reaction of its own, yet it can produce fissile material, if neutrons are provided from an external source. On the other hand, uranium and plutonium can sustain a chain reaction of its own. Although there are lot of benefits in using thorium as a primary source, but extracting its latent energy in a cost-effective manner is difficult. Thanks to extensive research work done in various research laboratories and we have now reached the end of the tunnel. When thorium-232 is bombarded by neutrons, a subatomic particle, from a fissile fuel like uranium or plutonium, it can be converted into U-233.The process creates energy and once the process starts it sustains of its own turning more thorium-232 nearby into the same nuclear fuel. This route to generate energy is very attractive to India because India has meager reserves of uranium, whereas the known reserves of Indian thorium bearing mineral monazite is about 12.47Mt (against the world reserve of 16 Mt) which contains about 1 Mt of thorium dioxide., and if it is utilised it can meet the energy requirement of India during the next century and beyond. India has a three-stage nuclear power programme and is making inroads on its fast breeder reactors that would enable India to make use of its thorium reserve fully. This philosophy would greatly reduce our dependence on other countries, as importing uranium has been hit by global sanctions. Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam has developed technologies of making thoria based fuel pallets. India Government in December 2016 accorded in principle to locate at Tarapur Advanced Heavy Water Reactor of 300 MW capacity, designed by BARC, which would use thorium-based fuel. India is likely to make a significant push in power generation by thorium fuel cycle and hopes to make 65% of its power requirement from thorium.