Science & Technology
Nuclear Technology and Energy
GS Paper III
Nuclear Technology and Energy — Quick Revision
One-page UPSC revision of nuclear technology: fission basics, reactor types, three-stage programme, CLNDA, the 2008 waiver, fusion and radioisotopes.
SyllabusGS III · Infrastructure: energy; science and technology — developments and their applications in everyday life
A last-week revision sheet for nuclear technology. Most questions hinge on function words: slows, absorbs, cools, breeds.
Reactor Basics
| Term | Meaning |
|---|---|
| Fission | Splitting a heavy nucleus (U-235, Pu-239, U-233) |
| Chain reaction | Neutrons from one fission cause further fissions |
| Critical | Chain reaction exactly self-sustaining |
| Moderator | Slows neutrons — heavy water, light water, graphite |
| Control rods | Absorb neutrons — boron, cadmium, hafnium |
| Coolant | Removes heat — water, heavy water, liquid sodium, gas |
| Enrichment | Raising the share of U-235 above its natural ~0.7% |
| Fertile | U-238 and Th-232 — become fissile after absorbing a neutron |
Reactor Types in India
| Type | Fuel | Moderator / coolant | Where |
|---|---|---|---|
| BWR | Enriched U | Light water | Tarapur 1 and 2 (1969) |
| PHWR | Natural U | Heavy water | Most of the fleet; Kakrapar-3 (700 MWe) |
| VVER (PWR) | Enriched U | Light water | Kudankulam |
| Fast breeder | Pu–U mixed oxide | None / liquid sodium | FBTR (1985), PFBR (Kalpakkam) |
Three Stages
| Stage | Reactor | Fuel | Output |
|---|---|---|---|
| 1 | PHWR | Natural uranium | Power + Pu-239 |
| 2 | Fast breeder | Pu-239 | Power + more Pu-239; U-233 from thorium blanket |
| 3 | Thorium reactors (e.g. AHWR design) | Th-232 + U-233 | Power from thorium |
High-yield facts
- Thorium source: monazite beach sands (Kerala, Tamil Nadu, Odisha, Andhra Pradesh).
- PFBR (500 MWe) core loading began March 2024; built and run by BHAVINI.
- CLNDA 2010 — operator liability ₹1,500 crore; Section 17(b) — right of recourse against suppliers.
- AERB (1983) was created by executive order, not by a separate statute.
- Budget 2025-26 — Nuclear Energy Mission (₹20,000 crore for SMRs), 100 GW by 2047.
Timeline
| Year | Event |
|---|---|
| 1948 | Atomic Energy Commission |
| 1954 | Department of Atomic Energy |
| 1962 | Atomic Energy Act |
| 1969 | Tarapur — first nuclear power station |
| May 1974 | Pokhran-I |
| 1983 | AERB constituted |
| May 1998 | Pokhran-II |
| 2005 | India joins ITER |
| September 2008 | NSG waiver; India–US civil nuclear agreement concluded later that year |
| 2010 | CLNDA |
| 2016 | India ratifies the Convention on Supplementary Compensation |
Radioisotopes and Uses
| Isotope | Use |
|---|---|
| Cobalt-60 | Cancer radiotherapy; food irradiation; sterilising medical products |
| Iodine-131 | Thyroid diagnosis and treatment |
| Technetium-99m | Diagnostic imaging |
| Carbon-14 | Dating organic remains |
Traps
Watch these
- Thorium is fertile, not fissile.
- Control rods absorb; moderators slow.
- Fast breeders have no moderator.
- India is outside the NPT and CTBT; the 2008 NSG decision was a waiver, not membership.
Related Topics
- Nuclear Energy: Reactors and India’s Three-Stage Programme
- Nuclear Technology — practice questions
- Nuclear Technology and Energy — overview
- Mineral and Energy Resources
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