IN THE 8th century, the Pallava kings who ruled southern India made Mamallapuram their main port on the Bay of Bengal. They had caves and temples carved from the granite hills behind the town, which is still a centre of pilgrimage. These structures are also inspiration for scientists working at the Indira Gandhi Centre for Atomic Research, whose stacks are visible from Mamallapuram. “If our ancestors could build temples that last 13 centuries, it should not be beyond us to build a reactor that lasts 60 years,” says Baldev Raj, director of the IGCAR.
Raj’s temple of the future, which is now being built, is a 500-megawatt, sodium-cooled, fast breeder reactor, which generates not only electricity but plutonium too. Many countries – the US, UK, France and Japan among them – have toyed with commercial-scale fast breeders, but their programmes have either crashed or been halted. Only Russia has run a large fast breeder for any length of time. Yet India is determined to follow this apparently risky route as a key step towards long-term self-sufficiency in energy.
The average Indian is electricity poor, consuming just 600 kilowatt-hours a year, enough to keep a fridge running. By comparison, average consumption in wealthy OECD nations is 10,000 kilowatt-hours a year. Yet even if every Indian used just half that amount, by 2050 the country would need 10 times as much generating capacity as it has now. One way to fill that gap is to use coal, but though India has plenty of it, the coal is mostly of poor quality, so burning it would push up pollution and global warming.
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Oil and gas are in short supply, so India is looking elsewhere. It has small stocks of uranium and about a quarter of the world’s supply of thorium, which is rarely used in reactors because it is not fissile – that is, its nucleus does not readily “split” to release energy. Yet India’s nuclear vision is to use these reserves to keep its power lines humming for centuries. The IGCAR is one of the nerve centres of this programme. Built on the sandy coastline beside the fishing village of Kalpakkam in Tamil Nadu, it has the feel of a university campus. Some 1200 scientists work in white, stately buildings and strange-shaped industrial units surrounded by casuarina trees.
Here is everything you would expect to see in a nuclear research centre. A huge team of materials scientists study creep, fatigue and corrosion, and create new materials. There is a particle accelerator that bombards materials with protons to simulate neutron damage, and labs devoted to studying sodium and giant robots. Elsewhere engineers bend huge metal components to make sure they outperform their safety specifications and test model structures in earthquake simulations.
The vision these people are pursuing comes in three stages, each using a different type of reactor. The first stage is well under way: India has 12 water-moderated reactors burning natural uranium. Neutrons flying around in these reactors not only induce uranium-235 to split and release energy, but also convert non-fissile uranium-238 into fissile plutonium-239 (see Diagram).
“If our ancestors can build temples that last 13 centuries, it should not be beyond us to build a reactor that lasts 60 years”
This plutonium will be recycled for use in the second stage – the Kalpakkam fast breeder – which will work in a different way from the existing power reactors. In water-moderated reactors, water slows neutrons down. But fast reactors like their neutrons “fast”, or energetic, so the water coolant is replaced with liquid sodium, which does not slow down the neutrons. One of the controversial quirks of these reactors is that by surrounding the core with a “blanket” of uranium-238, it is possible to create more plutonium than is used as fuel.
The final stage is to reclaim this plutonium and use it in an advanced water-moderated reactor, which is still at the design stage. The plutonium would be added to uranium-233, another fissile form of uranium, and thorium-232, which is transformed into more uranium-233. This is later separated from the spent fuel and recycled. By repeated recycling India should squeeze out far more energy from its uranium than if it had just been burnt once. The supplies should last for more than two centuries, says Raj.
This is a colossal endeavour, but India should have the resources to carry it out. While the nuclear industry has been fighting for its life in the US and Europe, in India it has thrived. This has happened largely out of necessity. India has been shunned by other nuclear countries since 1974 when it exploded its first nuclear bomb. Since then, it has updated and built its own reactors, starting from an old Canadian water-moderated design. As well as the 12 in operation, another six are being built.
India is self-reliant in other areas too. It cannot buy uranium from abroad or import nuclear technology so it has developed expertise in fuel processing and reprocessing. Kalpakkam is home to two experimental reactors – a small fast breeder and a reactor called KAMINI, which is the world’s only working plant fuelled by uranium-233. The relatively small fuel loads for both plants are produced in India.
More reactors, more radioactive waste – in Europe and the US campaign groups would be marching in the streets. But in India there seems to be no national voice against civil nuclear power. Protest focuses mainly on safety issues around individual plants and uranium mines. Still, some critics ask why India is going nuclear at all when it has plenty of potential sites for miniature hydroelectric plants, wind and solar power. “Reactors are basically meeting the needs of cities,” replies Raj. “But whether a big grid is suitable for rural areas, I think the natural answer is no.” He sees small-scale plants and renewables as a priority for improving quality of life in rural areas.
His view is echoed even by organisations that promote sustainable development, such as the New Delhi-based non-governmental research organisation The Energy and Resources Institute (TERI). India’s electricity needs are such that “it makes sense to move in the nuclear direction”, says Pradeep Dadhich, an energy expert at TERI. But the government has also identified 80,000 villages that are unlikely ever to be connected to the grid, so India’s power sources must always be mixed, he says.
For all that, opting for fast breeders is a bold move. The first commercial fast reactor, called Fermi 1, was built at Lagoona Beach, near Detroit in the US. It closed after only three years when a blocked sodium cooling circuit caused the core to overheat and melt. The US abandoned the technology for good in the mid-1990s when uranium prices fell and the government decided that having reprocessing plants round the world turning out plutonium was a bad idea.
In 1986, France switched on the biggest-ever fast breeder, the 1200-megawatt Superphenix, but that was plagued by sodium leaks and was closed down 12 years later in what the nuclear industry insists was a “political decision”. Monju, a Japanese fast reactor, suffered a sodium leak and fire in 1995 – a year after starting up. Plant managers tried to hush up, and the reactor has been closed down ever since.
Raj is aware of all this. “We have studied the strengths and weaknesses of all the international designs,” he says. “Our reactor incorporates the best design features internationally.” Pipes carrying sodium, for example, will be surrounded by inert nitrogen to reduce the risk of sodium fires, and the team has devised sensitive detectors to pick up sodium leaks within seconds.
Nevertheless, bad luck has already hit the reactor from an unexpected direction. The tsunami that swept across the Indian Ocean in December tragically killed five people at IGCAR. The reactor’s foundation – a 100-metre square raft of concrete – was submerged under 7 metres of mud and water. It now looks as though a second raft will have to be built on top of this contaminated structure before the reactor can be built. Discussions are under way on whether the site needs better sea defences.
Despite the unfortunate record of fast breeders up to now, international opinion seems to be swinging back towards them. Governments of 10 countries, including the US, UK, France, Canada and Japan, have identified these reactors as candidates for making nuclear power more “sustainable”. Fast breeders can be configured to burn up radioactive isotopes, which could reduce amounts of long-lived radioactive waste. They can also be run at temperatures high enough to “crack” water and produce hydrogen – to supply the coming hydrogen economy. If these attitudes prevail and India’s programme succeeds, the country could find itself not so much a nuclear pariah as an atomic guru.
“Despite the unfortunate record of fast breeders up to now, international opinion seems to be swinging back towards them”