High time now that DAE commissions the long delayed FBTR.
In 1974, the country was excluded from the Nuclear Non-Proliferation Treaty for acquiring nuclear weapons capability, and during the next three decades in isolation, when it was viewed as a nuclear pariah, the country developed a three-stage nuclear program based on a closed-fuel cycle, where spent fuel of one stage is reprocessed to produce fuel for the next stage.
The first step of the three-stage program involves building indigenously engineered PHWRs fueled by natural uranium (U). “Natural uranium contains only 0.7% of U-235, which undergoes fission to release energy (200 Mev/atom). The remaining 99.3% comprises U-238, which is not fissile, however, it is converted in the nuclear reactor to fissile element Plutonium-239 [Pu-239]. In the fission process, among other fission products, a small quantity of Pu-239 is formed by transmutation of U-238,” NPCIL explained. The country’s first 220-MW PHWR at Rajasthan 1, completed in 1973, was based on CANDU (Canada Deuterium Uranium) technology, but India relied on domestic designs for the others after Canadian assistance was withdrawn in 1974, even as the second Rajasthan unit was under construction. In 1981, it completed Rajasthan 2, and went on to complete Madras 1 and 2 between 1984 and 1986 using a standardized 220-MW PHWR design. Kaiga 1 and 2, and Rajasthan 3 and 4, which came online around 2000, incorporated improvements to the design.
The nuclear program’s second stage comprises fast breeder reactors (FBRs), which are fueled by mixed oxide of U-238 and Pu-239, recovered by reprocessing of the spent fuel from the first stage. Once the program has established enough inventory of Pu-239, the fast reactors will use
Thorium-232 to breed U-233, NPCIL said. The country currently has plans to build two prototype FBRs at Kalpakkam in Tamil Nadu, a site that already hosts a 500-MW fast breeder test reactor. In September 2018, the Department of Atomic Energy announced that the test reactor—which was originally expected to be commissioned in 2012 and has suffered several delays—is expected to achieve criticality in 2019
(That deadline was also missed). In the third stage, using wholly indigenous technology, the country will use advanced heavy-water reactors fueled with U-233 obtained from the irradiation of
thorium in PHWRs and fast reactors.