Nuclear Programme of India: Three Stages and Reactors

India began work on atomic energy before it had a single power reactor, and the plan drawn up in the 1950s still governs what the country builds today. The reason is a simple matter of geology: India has modest reserves of uranium but among the largest reserves of thorium in the world, lying in the monazite sands of the Kerala and Odisha coasts. The programme was therefore designed to begin with uranium and end with thorium, in three linked stages.

How the programme was organised

The Atomic Energy Commission was set up in 1948 with Homi Jehangir Bhabha as its chairman, and the Department of Atomic Energy followed in 1954, placed directly under the Prime Minister so that it would not be tied to any one ministry. The Atomic Energy Act of 1962 gave the Union Government control over atomic minerals and the production of atomic energy. Bhabha, who had already founded the Tata Institute of Fundamental Research in 1945, is called the father of the Indian nuclear programme; the establishment he built at Trombay was renamed the Bhabha Atomic Research Centre in his memory after his death in 1966.

The three stage programme

• Stage one uses pressurised heavy water reactors burning natural uranium, with heavy water as both moderator and coolant. Besides electricity they produce plutonium 239 in the spent fuel.
• Stage two uses fast breeder reactors fuelled by that plutonium, with a blanket of thorium around the core. A breeder makes more fissile material than it consumes, and the thorium blanket is converted into uranium 233.
• Stage three burns the uranium 233 in thermal breeder reactors, and the Advanced Heavy Water Reactor is designed for this stage. Only at this point does the country run on its own thorium.

The Fast Breeder Test Reactor at Kalpakkam proved the second stage technology, and the Prototype Fast Breeder Reactor of 500 megawatts, built at the same place by BHAVINI, is the larger machine of that stage.

The research reactors and the power stations

Apsara, which went critical at Trombay on 4 August 1956, was the first nuclear research reactor in Asia. CIRUS followed in 1960 and Dhruva in 1985, both at Trombay. On the power side, the Tarapur Atomic Power Station in Maharashtra, commissioned in 1969 with American help, was the first nuclear power station in the country and uses boiling water reactors. The Rajasthan station at Rawatbhata, built with Canadian collaboration, introduced the pressurised heavy water reactor, the design that India then made its own and repeated at Kalpakkam in Tamil Nadu, Narora in Uttar Pradesh, Kakrapar in Gujarat and Kaiga in Karnataka. Kudankulam in Tamil Nadu is different: it uses Russian pressurised water reactors of the VVER type.

The tests and the international position

India carried out its first nuclear test at Pokhran in Rajasthan on 18 May 1974, under the name Smiling Buddha, and described it as a peaceful nuclear explosion. The second round of tests, five devices on 11 and 13 May 1998, was called Operation Shakti, and 11 May is observed every year as National Technology Day in memory of it. India has not signed the Nuclear Non-Proliferation Treaty or the Comprehensive Test Ban Treaty, holding that both are discriminatory. The civil nuclear agreement with the United States, followed by the waiver from the Nuclear Suppliers Group in 2008, allowed India to trade in nuclear fuel and technology while keeping its civilian reactors under the safeguards of the International Atomic Energy Agency and its strategic reactors outside them.

How a reactor works

In a fission reactor a heavy nucleus such as uranium 235 splits when it absorbs a neutron, releasing energy and more neutrons, and a moderator slows those neutrons so that the chain reaction continues. Heavy water, graphite and ordinary light water are the usual moderators; control rods of cadmium or boron absorb neutrons and hold the reaction steady; and a coolant, which may be heavy water, light water or liquid sodium in a fast reactor, carries the heat away to raise steam. A fast breeder has no moderator at all, because it needs fast neutrons to convert thorium 232 into uranium 233 and uranium 238 into plutonium 239.