NEW DELHI: India holds the world’s largest identified thorium resources, according to the latest U.S. Geological Survey compilation, a position that has long underpinned New Delhi’s interest in using the metal as part of its nuclear energy program. The USGS’s February 2026 thorium summary lists India with 850,000 tons of identified thorium resources, ahead of Brazil at 630,000 tons and Australia and the United States at 600,000 tons each, based on worldwide identified totals.
Thorium is most commonly found in the mineral monazite, typically recovered from heavy mineral sands, where it is often treated as a byproduct because commercial demand remains limited. India’s thorium-bearing deposits are concentrated in coastal placer sands and associated heavy mineral deposits. International nuclear references, including the World Nuclear Association, also cite India’s “reasonably assured” thorium resources at about 319,000 tonnes, reflecting a narrower accounting category than broader identified resource estimates used in other datasets.
India’s interest in thorium is linked to the fact that thorium-232 is a fertile material that can be converted in a reactor into uranium-233, a fissile isotope that can sustain a chain reaction. Unlike uranium-235 or plutonium-239, thorium itself does not readily undergo fission in conventional reactor designs, so thorium-based fuel cycles generally depend on a starter supply of fissile material and a fuel cycle capable of handling irradiated materials. India has for decades described a staged nuclear power program that ultimately seeks to use thorium in advanced reactor systems.
Resource base and fuel cycle realities
While thorium’s abundance in India is well documented, global use remains limited and the material is not widely separated during mineral processing. The USGS notes that monazite is primarily produced for rare earth elements, with only a small fraction of byproduct thorium recovered and consumed. India’s thorium pathway is therefore tied not only to geology but also to industrial capacity for fuel fabrication and, where pursued, chemical processing of irradiated fuel. International summaries also note estimates by India’s Atomic Minerals Directorate that large monazite inventories could contain substantial thorium content.
India’s nuclear sector has carried out research on thorium-related fuels and systems alongside its broader power program. The World Nuclear Association describes India’s Kalpakkam Mini (KAMINI) reactor at the Indira Gandhi Centre for Atomic Research as operating on uranium-233 fuel, an unusual capability internationally. Such activities are distinct from commercial electricity generation at scale and sit within a larger civil nuclear framework that includes multiple reactor types and fuel supply arrangements. India’s overall nuclear generating capacity and expansion plans are driven by a broader mix of technologies and imported and domestic fuel streams.
Proliferation risk and safeguards considerations
Thorium is sometimes presented as inherently proliferation proof, but international safeguards practice does not treat thorium fuel cycles as risk-free. Uranium-233, the fissile material bred from thorium-232, is recognized in safeguards frameworks as a material that requires control and accounting. At the same time, some thorium fuel cycles produce uranium-232 as an impurity, whose decay products emit strong gamma radiation that complicates handling and can add a barrier to diversion in certain circumstances. Those technical features can affect how materials are managed, but they do not remove the need for safeguards.
The proliferation and security profile of any thorium-based system depends on how fuel is fabricated, irradiated, stored, transported and, where applicable, chemically processed after use. International nuclear references have noted that thorium fuel cycles can introduce measurement and verification challenges, particularly when materials are recycled or separated, because uranium-233 and associated isotopes must be tracked through complex processes. As with other nuclear materials, oversight relies on transparent accounting, inspections, and facility design and operating practices aligned with applicable safeguards arrangements.
India’s thorium endowment is widely regarded as one of the largest in the world, and its scale is reflected in multiple international compilations that use different definitions of resources. The distinction between broad identified resources and narrower assured categories is important in comparing totals and assessing what is economically and technically recoverable. Thorium’s role in energy supply is also bounded by engineering realities: thorium is not a ready-to-burn fuel in standard reactors and requires fissile support and specialized fuel cycle capabilities to produce and use uranium-233. – By Content Syndication Services.