Why is it in the News?

In a major boost to their time-tested partnership, India and Russia recently signed some "very important" agreements related to the construction of the future power-generating units of the Kudankulam nuclear power plant.

About the Kudankulam Nuclear Power Project:

• The Kudankulam Nuclear Power Project is India's largest nuclear power plant situated in the Tirunelveli district of Tamil Nadu.
• It is being developed by the Nuclear Power Corporation of India (NPCIL) in collaboration with Russia's Rosatom State Atomic Energy Corporation.
  • The construction began in March 2002.
• Since February 2016, the first power unit of the Kudankulam NPP has been steadily operating at its design capacity of 1,000 MW.
  • The plant is expected to start operating at full capacity in 2027.
• Water-Water Energy Reactor: The Kudankulam Nuclear Power Project employs VVER (Water-Water Energy Reactor) technology, a pressurized water reactor design developed in the former Soviet Union, known for its safety and reliability.
• Power Generation Capacity: The current power generation capacity is 2×1,000 MWe VVER, expected to significantly increase with the construction of four additional reactors, estimated at ?89,470 crore.
• All units are subject to International Atomic Energy Agency (IAEA) safety analysis, except the Kalpakkam nuclear plant, reserved for strategic use under the India-US Nuclear Agreement.

What is the 3-Stage Nuclear Programme of India?

• India's nuclear program is structured into three stages, strategically designed to harness the extensive Thorium deposits within the country, constituting approximately 25% of the world's total reserves.
• This focus on Thorium is crucial as India possesses limited Uranium reserves, accounting for about 2% of the global uranium reserves.
• 1st Stage: The initial stage employs Pressurized Heavy Water Reactors that operate on natural uranium, consisting of 99.3% U-238 and 0.7% U-235.
  • The fissile U-235 triggers a chain reaction, while the non-fissile U-238 transforms into Pu-239 as a byproduct (spent fuel).
  • This Pu-239 is subsequently utilized in the Fast Breeder Reactors in the 2nd stage.
• 2nd Stage: Fast Breeder Reactors primarily rely on Plutonium, utilizing a combination of Plutonium-239 from the 1st stage and the abundant U-238 found on Earth to generate additional Plutonium inside the reactor.
  • As U-238 does not initiate a chain reaction, the reactors are termed Breeder reactors.
  • To maximize the chances of neutron interaction with U-238, these reactors, known as Fast Breeder Reactors, omit a moderator to slow down neutrons.
  • Once Plutonium-239 is fully consumed, Thorium is introduced to convert it into U-233, to be used in the 3rd stage.
• 3rd Stage: Thermal Breeder Reactors utilize U-233 produced in the 2nd stage, incorporating thorium-232.
  • Notably, Thorium is non-radioactive and non-fissile. Since these reactors also generate U-233 from Thorium-232, they are classified as breeder reactors.
  • India's significant reserves of thorium, particularly in the form of monazite sand, emphasize the critical role of the 3rd stage in India's nuclear energy portfolio.