Nuclear Energy & India's Atomic Programme: Notes for UPSC & SSC
Fission and fusion, how a reactor works, Bhabha's three-stage plan, thorium, India's key reactors and institutions, and the Pokhran tests. Clearly explained.
60-second revision
Homi J. Bhabha: father of the Indian nuclear programme. AEC set up in 1948, Department of Atomic Energy in 1954.
Apsara (Trombay, 4 August 1956) was the first research reactor in Asia.
Tarapur (Maharashtra, 1969) was India's first nuclear power station.
Three stages: PHWRs on natural uranium, then fast breeders on plutonium, then thorium.
Thorium is fertile, not fissile; India has large thorium reserves in monazite sands.
Moderator slows neutrons; control rods (boron, cadmium) absorb them.
Pokhran-I: Smiling Buddha, 18 May 1974. Pokhran-II: Operation Shakti, 11 and 13 May 1998.
Power reactors use fission; fusion (the Sun's process) is experimental — India is an ITER member.
Fission and fusion
Nuclear fission: a heavy nucleus such as uranium-235 or plutonium-239 absorbs a neutron and splits into lighter nuclei, releasing energy and 2–3 more neutrons. Those neutrons split more nuclei — a chain reaction. Every nuclear power plant in operation uses fission.
Nuclear fusion: light nuclei (isotopes of hydrogen) join to form helium, releasing even more energy per kilogram. It powers the Sun and stars and the hydrogen bomb. Controlled fusion for electricity is still experimental.
ITER is an international experimental fusion reactor being built in France; India became a member in 2005 alongside the EU, USA, Russia, China, Japan and South Korea.
The energy comes from the small loss of mass, given by Einstein's E = mc².
Parts of a reactor
Part
Job
Common materials
Fuel
Undergoes fission
Natural or enriched uranium; plutonium (mixed oxide) in breeders
Moderator
Slows fast neutrons so they cause more fission
Heavy water, ordinary (light) water, graphite
Control rods
Absorb neutrons to control or stop the reaction
Boron, cadmium
Coolant
Carries heat away to make steam
Water, heavy water; liquid sodium in fast breeders
Shielding
Stops radiation escaping
Thick concrete, steel
Bhabha's three-stage programme
Stage
Reactor type
Fuel
Output
1
Pressurised Heavy Water Reactors (PHWR)
Natural uranium
Power + plutonium-239 in spent fuel
2
Fast Breeder Reactors (FBR)
Plutonium-based fuel
Power + more fissile material; thorium blanket bred into uranium-233
3
Thorium-based reactors
Thorium-232 with uranium-233
Long-term power from India's thorium
Why this plan? India has modest uranium but some of the world's largest thorium reserves, mainly in the monazite sands of the Kerala, Tamil Nadu and Odisha coasts. Thorium-232 is fertile, not fissile: it cannot sustain a chain reaction by itself and must first absorb neutrons and turn into fissile uranium-233. The Prototype Fast Breeder Reactor (PFBR, 500 MWe) at Kalpakkam, built by BHAVINI, is the flagship of stage 2.
Institutions and milestones
Year
Event
1945
Tata Institute of Fundamental Research founded by Homi Bhabha
1948
Atomic Energy Commission set up
1954
Department of Atomic Energy created; atomic energy establishment at Trombay
1956
Apsara, first research reactor in Asia, goes critical at Trombay (4 August)
1967
Trombay establishment renamed Bhabha Atomic Research Centre after Bhabha's death (1966)
1969
Tarapur, India's first nuclear power station, begins operation
1974
Pokhran-I, Smiling Buddha (18 May)
1998
Pokhran-II, Operation Shakti (11 and 13 May); 11 May is National Technology Day
2008
India–US civil nuclear agreement and Nuclear Suppliers Group waiver
NPCIL (Nuclear Power Corporation of India Ltd) operates the power reactors; BHAVINI builds fast breeders; AERB (Atomic Energy Regulatory Board) is the safety regulator; IGCAR at Kalpakkam does fast-reactor research.
Uranium Corporation of India Ltd mines uranium, notably at Jaduguda in Jharkhand.
India has not signed the NPT or the CTBT, calling them discriminatory.
