Correct Option
The correct option is Kerala.
Explanation
Thorium is a fertile radioactive material essential for the third stage of India’s three-stage nuclear power programme. It is primarily extracted from Monazite sands, which are beach placer deposits containing rare earth elements and thorium.
Detailed Analysis
- Geographical Distribution: Monazite sands are found along the coastal tracts of India. The most significant deposits are located in the coastal stretches of Kerala, Tamil Nadu, Andhra Pradesh, and Odisha.
- Kerala's Significance: The monazite sands of the Kerala coast (specifically the Chavara deposits in Kollam district) are world-renowned for their high grade. These sands contain a very high percentage of Thorium Oxide (ThO2), typically ranging from 8% to 10%, making them the richest deposits in terms of quality.
- Resource vs. Grade: According to recent data from the Atomic Minerals Directorate (AMD), in terms of total tonnage of monazite resources, Andhra Pradesh leads, followed by Tamil Nadu and Odisha. However, in the context of standard geography textbooks and general studies, Kerala is the primary answer due to the exceptionally high concentration of thorium in its sands and its historical status as the main source of monazite mining in India.
Key Takeaway
Thorium is obtained from Monazite sands. While Andhra Pradesh has the largest volume of resources, Kerala is traditionally cited for having the richest reserves due to the high thorium content in its coastal sands.