The fast breeder route

THE UNION CABINET'S nod to the proposal of the Department of Atomic Energy to set up a 500 MW Prototype Fast Breeder Reactor at Kalpakkam brings to fruition more than 25 years of research and development on fast breeder technology. The breeder reactor forms the second stage of India's nuclear power programme. Unlike a thermal (light and heavy water) nuclear reactor, a breeder reactor generates more fissile plutonium than it consumes in the process of generating energy. This happens when the plutonium used in the breeder fuel converts non-fissile uranium kept as blankets to the plutonium. The approval for the Rs.3,492-crore project marks a major milestone for the department, which went about mastering the technology with dedication. It is a vindication of India's capability to work on cutting edge technologies with little assistance from abroad. The highlight of the fast breeder programme is the mastery of a technology using indigenously prepared mixed carbide fuel in the smaller Fast Breeder Test Reactor commissioned in 1985. That was the first time a mixed carbide fuel had been used anywhere. The Prototype Fast Breeder Reactor will however use a mixed oxide fuel that is easier to fabricate and reprocess. The mixed oxide fuel packs more energy than the carbide fuel and that should have a direct bearing on the cost of power production.

The compulsion for India to look beyond thermal nuclear reactors arises from the limited availability of natural uranium and other resources within the country. The known resources of 60,000 tonnes of natural uranium deposits, with only 0.72 per cent being fissile uranium, can at most generate 12,000 MW over a 30-year period. Any further nuclear power production will be possible only with imported uranium or fast breeder reactors. Restrictions on importing uranium rule out the first option. The breeder reactor alternative looks attractive with its capability to amplify energy from natural uranium many fold by converting 70-80 per cent of non-fissile uranium to fissile plutonium. Moreover, the five lakh tonnes of thorium, nearly one third of the world's reserve, would help generate nearly 500,000 MW during the third stage and provide energy security for a long time. Although breeder reactors theoretically can produce more plutonium than they consume, the proposed PFBR will have a low breeding ratio of 1.1 to start with. The focus is not to optimise the breeding ratio but to produce power at a competitive cost. The cost per unit (kilowatt hour) in 2010 is projected to be Rs.3.25, making it competitive with other energy sources.

Even as India lays a bigger bet on its fast breeder programme, many advanced countries have lost interest in the technology. The reasons are not difficult to comprehend. The fast breeder was once considered the best energy source to meet growing electricity demand and to help conserve uranium resources. But energy demand has not grown as expected and conserving uranium is no longer a priority. More important factors that go against the fast breeder are its failure to be cost competitive with thermal nuclear reactors and the availability of cheaper alternative energy sources. The liquid sodium coolant, which burns on contact with air or water, presents a technical challenge. Accidents caused by liquid sodium leakage at the Monju reactor in Japan and the Superphenix in France swayed public opinion against the technology. Further, the United States, gripped by a fear of reprocessed plutonium falling into wrong hands, turned down the technology. India therefore needs to tread carefully, testing and refining its expertise in the challenging technology, and ensuring cost competitiveness.

Recommended for you