According to the Union Government, India plans to build more nuclear power plants to increase the production of clean energy. The government has recently approved five new sites for nuclear power plants and given the financial go-ahead to build 10 700-MW pressurised heavy water reactors.

 

India’s nuclear-power programme

  • The three-stage nuclear programme is developed with the aim of utilising the vast Thorium reserves in India (about 25% of the world)
  • Besides India has limited availability of Uranium reserves (about 2% of the world’s uranium reserves)
  • First Stage —
      • Pressurised Heavy Water Reactors are based on natural uranium that contains 99.3% U-238 and 0.7% U-235.
      • U-235 being fissile sets up the chain reaction and U-238 being non-fissile gets converted to Pu-239 as a byproduct (spent fuel) which is in turn used in the Fast Breeder Reactors in the second stage.
  • Second Stage —
      • Fast Breeder Reactors are primarily based on Plutonium.
      • Further the breeder reactors use mix of Plutonium-239 produced in the first stage and U-238 that is abundantly found on earth to produce Plutonium inside the reactor.
        • Note that U-238 is not fissile material and thus cannot set up chain reaction.
      • Since the amount of Plutonium produced inside the reactor is more than that initially used, it is called Breeder reactor.
      • In order to increase the probability of neutron hitting U-238, these reactors do not use a moderator to slow down neutrons and thus they are called Fast Breeder Reactors.
      • Once the Plutonium-239 is completely used, Thorium is introduced in the reactor to convert it into U-233 that will be used in third stage.
  • Third Stage —
    • Thermal Breeder Reactors uses U-233 that is produced in the second stage using thorium-232.
      • Thorium is also not radioactive and thus not fissile.
      • Since these reactors also produce U-233 out of Thorium-232 they are called breeder reactors.
      • India has abundant thorium reserves in the form of monazite sand, and therefore the third stage is critical for India’s nuclear energy basket.