A Review of Thorium-Fueled Molten Salt Reactors for Achieving India’s Net-Zero 2070 Goal

Abstract: With its growing energy needs and abundant thorium reserves, India is in a suitable position to implement emerging nuclear technologies. One such technology is the Molten Salt Reactor (MSR), which has proven theoretical advantages over Pressurized Heavy Water Reactors (PHWRs) across domains such as safety, efficiency, and waste management. With around 13% of the world’s thorium reserves, the switch to MSRs provides India with a trade advantage as well, reducing its reliance on imported uranium. This review, using data from peer-reviewed literature, nuclear agencies, and government reports, provides a detailed comparative study between MSRs and PHWRs across five crucial domains: fuel use, reactor design and safety, waste management, engineering challenges, and economic viability. Results show that for the Indian context, MSRs have some major long-term advantages, including fuel burnup rates above 200 GWd/tHM and better use of local resources like thorium. However, major hurdles such as high capital costs, limited industrial and commercial readiness, and a lack of experience with new MSR technologies make the implementation of MSRs in India at this time exceedingly unfeasible. Therefore, the review considers Small Modular Reactors (SMRs), which are smaller, factory-built units that are quicker to build, easier to license, and fit well with India’s manufacturing systems. While MSRs remain a promising long-term option, SMRs may be a more realistic and affordable way for India to move toward its clean energy and net-zero 2070 goals.