UPSC CSE Prelims
Question 86
To meet its rapidly growing energy demand, some opine that India should pursue research and development on thorium as the future fuel of nuclear energy. In this context, what advantage does thorium hold over uranium?
- Thorium is far more abundant in nature than uranium.
- On the basis of per unit mass of mined mineral, thorium can generate more energy compared to natural uranium.
- Thorium produces less harmful waste compared to uranium.
Which of the statements given above is/are correct?
View correct answer and explanation
Correct answer: D
Correct Option: D
Explanation: Thorium is relatively abundant and its fuel cycle is presented as having possible efficiency and waste-management advantages, but it requires breeding into fissile U-233.
Statement/Item-wise Analysis:
1: Correct - Thorium is more abundant in Earth’s crust than uranium.
2: Correct - In suitable advanced breeder/fuel-cycle assumptions, a thorium resource can yield more usable energy than natural-uranium once-through use.
3: Correct - Thorium-based cycles can reduce some long-lived transuranic waste, though still generate radioactive waste.
Option-wise Analysis:
A: Incorrect - omits correct items 2, 3.
B: Incorrect - omits correct item 1.
C: Incorrect - omits correct item 2.
D: Correct - includes exactly the valid statements/items and excludes the invalid ones.
Review Note: Thorium is fertile, not directly fissile; energy/yield and waste comparisons depend on reactor and fuel-cycle assumptions.