Nuclear Technology and Energy — Practice Questions
UPSC Prelims-pattern practice questions on nuclear technology with explanations — fission and fusion, thorium, ITER, radioisotopes, nuclear timeline.
Questions
These are original UPSC-pattern practice questions. Attempt each one before revealing the answer.
Consider the following statements:
- Nuclear fission releases energy by splitting heavy nuclei into lighter ones.
- Nuclear fusion requires temperatures of the order of millions of degrees Celsius.
- Most commercial nuclear power plants operating today generate electricity through fusion.
Which of the statements given above is/are correct?
Solution
Statements 1 and 2 are correct — fusion needs temperatures of the order of 100 million °C. Statement 3 is incorrect — every commercial nuclear power plant today uses fission. Fusion has not yet produced commercial electricity; ITER is an experiment.
Answer: B
The principal source of thorium in India is
Solution
Monazite, found in the beach sands of Kerala, Tamil Nadu, Odisha and Andhra Pradesh. Bauxite is the ore of aluminium; pitchblende (uraninite) is an ore of uranium; chromite is the ore of chromium.
Answer: B
Consider the following statements about ITER:
- It is being built in France.
- India is one of its members.
- It is based on inertial confinement, in which lasers compress a fuel pellet.
Which of the statements given above is/are correct?
Solution
Statements 1 and 2 are correct — ITER is at Cadarache, France, and India has been a member since 2005. Statement 3 is incorrect — ITER is a tokamak using magnetic confinement. Laser-driven inertial confinement is the approach of the US National Ignition Facility.
Answer: A
Consider the following pairs of radioisotopes and their uses:
- Cobalt-60 — cancer radiotherapy
- Iodine-131 — treatment of thyroid disorders
- Carbon-14 — dating of organic remains
- Uranium-238 — irradiation of food to prevent sprouting
How many of the pairs given above are correctly matched?
Solution
Pairs 1, 2 and 3 are correct. Pair 4 is wrong — food irradiation generally uses gamma rays from cobalt-60 (or electron beams and X-rays), not uranium-238. Three pairs are correct.
Answer: C
Arrange the following events in chronological order:
- Commercial operation of Tarapur Atomic Power Station
- Pokhran-I nuclear test
- Waiver granted to India by the Nuclear Suppliers Group
- Enactment of the Civil Liability for Nuclear Damage Act
Select the correct answer using the code given below.
Solution
Tarapur — 1969; Pokhran-I — May 1974; NSG waiver — September 2008; CLNDA — 2010. The order is 1-2-3-4.
Answer: D
Can nuclear energy play a significant role in India’s transition to net zero by 2070? Critically examine.
Solution
Introduction: India has pledged net-zero emissions by 2070. Solar and wind are growing fast but are variable; nuclear power offers low-carbon, round-the-clock baseload. Budget 2025-26 set a target of 100 GW of nuclear capacity by 2047.
Body:
- Case for: near-zero operational emissions; high capacity factors; small land footprint per unit of energy; complements renewables in grid stability; SMRs can replace retiring coal units; indigenous PHWR technology and fleet-mode construction.
- Constraints: high capital cost and long gestation; uranium import dependence; supplier liability concerns (CLNDA Section 17(b)); public safety concerns after Fukushima; waste management; limited regulatory independence; state monopoly until legal reforms take effect.
- Enablers: Nuclear Energy Mission for SMRs; proposed amendments to the Atomic Energy Act and CLNDA; progress towards the second stage with the PFBR; international fuel supply since the 2008 waiver.
Conclusion: Nuclear energy can be a significant complement to renewables rather than a substitute for them — provided cost, regulation and public trust are addressed alongside capacity expansion.