G. Balachandran replies: The third stage of India's nuclear power programme envisages the use of thorium, which India has in abundance, and plutonium, which is a man-made metal not available in nature.
Plutonium is obtained from the reprocessing of spent nuclear fuel from nuclear power reactors using either natural uranium or low enriched uranium (LEU). Light Water Reactors (LWRs) use LEU.