Nuclear energy is produced by fissioning the atoms of minerals such as uranium, thorium, radium, lithium, etc. India possesses the world's largest reserves of monazite, the principal source of thorium and some reserves of uranium. 

1. URANIUM = Uranium contains about 0.7% of the isotope U-235 which on fissioning releases enormous amount of energy. Its principal isotope U-238 can be transmitted to plutonium which also is fissionable.
 Uranium occurs in Archaean crystalline schists and pre-Cambrian metamorphosed slates and phyllites in Bihar and some parts of the Himalayas and in pegmatites of Bihar, Rajasthan and Andhra Pradesh. The deposits of monazite sands along the Kerala coast are a more reliable source of uranium.
 Uranium also occurs in association with copper sulphides and iron oxides. Compounds of uranium commonly occurs in the copper belt of Bihar and in the Aravallis in Rajasthan. The Ilmenite beach sands in Palghat and Quilon districts in Kerala and in Kanya Kumari district of Tamilnadu contain a small amount of uranium oxide. Pitchblende containing uranium occurs in many areas in the mica mines of Gaya (Bihar), Nellore (Andhra Pradesh), Udaipur and Jaipur
(Rajasthan). 
The production of uranium at present is confined to the mines at Jaduguda in Singhbhum district (Bihar). 

2. THORIUM= Neatron reaction on ordinary thorium gives U-233, a fissionable isotope and releases huge amount of energy. Thorium is obtained from monazite which contains upto 10% of thoria and 0.3% of urania. The Ilmenite beach sands of Palaghat and Quilon districts in Kerala contain the world's richest monazite deposits. It occurs in the beach sands of Visakhapatnam too.

 DEVELOPMENT OF NUCLEAR ENERGY = Dr. Homi Bhabha was the pioneer of the nuclear programnme in India. He stressed the need of establishing the Tata Institute of Fundamental Reserarch in 1944. The Atomic Energy Commission was incorporated 1948. The Atomic Energy Institute was setup at Trombay in 1954. which was later renamed as the Bhabha Atomic Research Centre in 1967. Dr. Bhabha was succeeded by Dr. Vikram Sarabhai who prepared a long term up programme of atomic energy and space research. This centre has so far set 6 nuclear reactors in the country. The nuclear programme of India has three phases of development. 

     (1)  The first phase (1948-1956)-APSARA reactor was set up at Trombay (Maharashtra) 
    (2)  The second phase (1956-1966)-Various technological facilities were developed. 
    (3)  The third phase (Since 1966)-Atomic power stations were set up and various projects were taken up.
 
      In 1956, a beginning was made when APSARA, the first research reactor attained criticality. India's first nuclear power station (440 MW) set up at Tarapur near Mumbai started power generation in October 1969. The second plant with an installed capacity of 440 MW, was erected at Rawatbhata near Kota (Rajasthan). 
     The third plant came up at Kalpakkam (Tamilnadu) and the fourth one at Naraura (Uttar Pradesh). Plants at Kaiga (Karnataka) and Kakrapar (Gujarat) have also been commissioned.
      To meet the fuel and heavy water requirements of the power reactors, a nuclear fuel complex was set up at Hyderabad and heavy water plants at Vadodara (Gujarat), Rawatbhata (Rajasthan), Talcher (Orissa), Tuticorin (Tamilnadu) and Thal (Maharashtra). Heavy water plants are also being set up at Manuguru (Andhra Pradesh) and Hazira (Gujarat). 

RESEARCH AND DEVELOPMENT = Research and development activities include the establishment of VECC at Calcutta, High altitude laboratory at Gulmarg (J and K), Nuclear research laboratory at Srinagar (J and K), Seismic centre at Gauri Bidnor (Karnataka), High Technology Centre at Indore (M.P.), Indira Gandhi Atomic Research Centre (IGÇAR) at Kalpakkam (Tamilnadu) and Nuclear fuel centre at Hyderabad (Andhra Pradesh). Besides these, radio isotops are being produced of BARC.