India's Three-Stage Nuclear Power Programme for Energy Security
The Department of Atomic Energy (DAE) is promoting indigenous thorium-based technologies to ensure long-term energy security and achieve self-reliance in the nuclear fuel cycle, recognizing India's limited uranium resources and vast thorium reserves. The Three-Stage Nuclear Power Programme is designed to optimally utilize limited uranium resources while exploiting large thorium reserves for sustainable long-term energy security through a closed fuel cycle approach where spent fuel from one stage provides fissile material for the next stage.
Current Programme Status and Infrastructure
DAE has developed expertise in reactor design, manufacturing, construction, and front-end and back-end fuel cycle technologies for Pressurised Heavy Water Reactors (PHWRs) deployed in the first stage. Plutonium extracted from spent fuel from domestic PHWRs serves as fuel for the second stage, with Bhabha Atomic Research Centre (BARC) successfully developing indigenous capabilities and implementing back-end fuel cycle technologies including fuel fabrication. Operational back-end fuel cycle plants are currently functioning at Tarapur and Kalpakkam, while the Integrated Nuclear Recycle Plant (INRP) at Tarapur and the Fast Reactor Fuel Cycle Facility (FRFCF) at Kalpakkam are under construction for reprocessing and waste management of spent fuel from PHWRs and Fast Breeder Reactors (FBRs) respectively.
Critical Milestone Achieved
The Prototype Fast Breeder Reactor (PFBR) achieved its first criticality on April 6, 2026, marking India's formal entry into the second stage of the nuclear power programme, representing a significant advancement in the country's nuclear energy capabilities.
Thorium Utilization and Third Stage Development
The third stage envisages using U-233 bred from Th-232 as fuel, with the Department undertaking sustained research and development for thorium utilization. Thorium Oxide (Thoria) pellets have been used in the initial cores of operating PHWRs, and Thoria-based fuels have been irradiated in BARC research reactors. The irradiated Thoria pins have been reprocessed to obtain uranium-233, which has been fabricated as fuel for the Kalpakkam Mini Reactor (KAMINI) reactor at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam.
Future Roadmap and Technology Development
The programme aims to multiply domestically available fissile resources through natural uranium utilization in PHWRs, followed by plutonium from PHWR spent fuel in FBRs. Large-scale thorium utilization will follow using fissile uranium-233 bred from thorium in breeder reactors fueled by plutonium, but only after adequate installed capacity of FBRs has been achieved. Research and development efforts are underway for thorium utilization technologies, with Molten Salt Reactor (MSR) envisaged as a suitable technology for long-term sustainable thorium utilization. DAE is developing MSR technology to demonstrate efficient thorium utilization, with ongoing R&D on special materials development and qualification, molten fluoride salt chemistry, and component development for molten salt demonstration reactor. These efforts aim to ensure mature thorium technologies are available before large-scale deployment, strengthening India's long-term energy security, fuel sustainability, and self-reliance in nuclear energy.