India is planning to use thorium as a nuclear fuel to generate power as importing Uranium-233 has been hit by global sanctions imposed against certain countries and because the India-US nuclear agreement has not gone forward.
Technologies for fabrication of thoria-based fuel pellets, carrying Uranium-233, have been established at the Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, near Chennai. Studies have also been carried out to use thorium in different types of reactors with regard to fuel management, reactor control and fuel utilisation.
“Thorium Oxide (Thoria) pellets contained in bundles are used in the initial cores of operating Pressurised Heavy Water Reactors (PHWRs) and valuable experience has been generated in operation and re-use of this irradiated thorium fuel. The irradiated thoria pins of research reactors have been reprocessed to obtain Uranium-233,” said a senior official of the Department of Atomic Energy on condition of anonymity.
The recovered Uranium-233 has been fabricated as fuel for the 30kW (thermal) KAMINI reactor at IGCAR.
“IGCAR is involved in development of indigenous technology towards Fast Breeder Reactors with closed fuel cycle facility. A 500MW prototype Fast Breeder Reactor is in an advanced stage of construction by BHAVINI,” the officer said.
“A critical facility for the Advanced Heavy Water Reactor was commissioned at Bhabha Atomic Research Centre (BARC) and is used for carrying out experiments to further validate the physics design features of Advanced Heavy Water Reactor (AHWR),” said the official.
BARC has designed an Advanced Heavy Water Reactor (AHWR) of 300 MW capacity. This reactor using thorium-based fuel will serve as a technology demonstrator not only for the thorium fuel cycle technologies but also for several advanced passive safety features.
“In order to facilitate an early scrutiny of the innovative features of the design from the safety considerations, a pre-licensing design safety appraisal of the reactor has been completed by the Atomic Energy Regulatory Board,” the official said.
The DAE is pursuing research and development in line with the Indian three stage nuclear power programme to produce more nuclear energy.
Three-stage nuclear power programme, which is based on a closed nuclear fuel cycle, has been chalked out to use Thorium as a viable and sustainable option at the inception of India’s nuclear power programme.
“On account of the physical characteristics of Thorium, it is not possible to build a nuclear reactor using Thorium alone. It has to be converted to Uranium-233 in a reactor before it can be used as fuel,” the officer said.
Thorium is available in the monazite sands on the east and west coasts of India and in some places in Bihar. But the largest concentration of monazite sand is on the Kerala coast. Over 15,200 tonnes of uranium are estimated to be contained in monazite sands.
The known reserves of thorium in India are estimated to be between 4,57,000 and 5,08,000 tonnes. Kerala, Jharkhand, Bihar, Tamil Nadu and Rajasthan are the main producers.