India has a unique position in the world, in terms of availability of nuclear fuel resource. It has a limited resource of uranium but a large resource of thorium. The beach sands of Kerala and Orissa have rich reserves of monazite, which contains about 8 – 10% thorium. Thorium can be used to produce nuclear energy, but not directly due to its physics characteristics. It has to be converted to233U in a nuclear reactor, before it can be used as fuel. 233U provides better physics characteristics in comparison to the other fissile 235U and 239Pu. A Three-Stage Indian Nuclear Power Programme has been devised to utilise the available resources efficiently and in a sustainable manner. Work on thorium has been carried out right from the inception of our nuclear programme. Studies have been carried out on all aspects of thorium fuel cycle – mining and extraction, fuel fabrication, utilisation in different reactor systems, evaluation of its various properties and irradiation behaviour, reprocessing and recycling.