In India, both Kakrapar-1 and -2 units are loaded with 500 kg of thorium fuel in order to improve their operation when newly-started. Kakrapar-1 was the first reactor in the world to use thorium, rather than depleted uranium, to achieve power flattening across the reactor core. In 1995, Kakrapar-1 achieved about 300 days of full power operation and Kakrapar-2 about 100 days utilising thorium fuel. The use of thorium-based fuel was planned in Kaiga-1 and -2 and Rajasthan-3 and -4 (Rawatbhata) reactors.

With about six times more thorium than uranium, India has made utilisation of thorium for large-scale energy production a major goal in its nuclear power program, utilising a three-stage concept:

-Pressurised Heavy Water Reactors (PHWRs, elsewhere known as CANDUs) fuelled by natural uranium, plus light water reactors, produce plutonium.

-Fast Breeder Reactors (FBRs) use this plutonium-based fuel to breed U-233 from thorium. The blanket around the core will have uranium as well as thorium, so that further plutonium (ideally high-fissile Pu) is produced as well as the U-233.

-Advanced Heavy Water Reactors burn the U-233 and this plutonium with thorium, getting about 75% of their power from the thorium.

Source: World Nuclear Association