Thorium — Global Thorium Reserves: Where the Ore Is

Thorium — Global Thorium Reserves: Where the Ore Is

Overview

One of thorium's most compelling attributes as an energy resource is its geographic distribution. Unlike uranium — which is concentrated in a relatively small number of countries (Kazakhstan, Canada, Australia, Namibia, Russia, and Niger dominate production) — thorium is broadly distributed across the globe, with significant reserves on every inhabited continent.

Thorium in the Earth's Crust

The IAEA estimates that the Earth's upper continental crust contains an average of 10.5 parts per million (ppm) of thorium, compared to approximately 3 ppm for uranium. This means:

• Thorium is approximately three to four times more abundant than uranium by mass
• Thorium is present in measurable quantities in virtually all granite and many other rock types
• Even ordinary soil and beach sand contains trace quantities of thorium
• The challenge is not finding thorium but finding it in high enough concentrations to make extraction economically worthwhile

The Monazite Mineral: The Primary Source

The primary commercial source of thorium is monazite*** — a rare earth element phosphate mineral with the general formula (Ce,La,Nd,Th,Y)PO₄. Monazite concentrates thorium because thorium's +4 oxidation state allows it to substitute for the REE's +3 positions with charge compensation. Monazite is found primarily in:

• Placer deposits*** (coastal beach sands): Concentrated by wave action and density sorting; the richest deposits are in India, Brazil, Australia, and the southeastern United States
• Granitic intrusions*** and associated pegmatites
• Carbonatite*** igneous rocks

Detailed Reserve Assessment by Country

India (~25–30% of world reserves)

India holds the world's largest thorium reserves, concentrated in coastal monazite sand deposits primarily in:

• Kerala State (southwest coast)
• Tamil Nadu (southeast coast)
• Andhra Pradesh (east coast)
• Odisha (east coast)

India's vast thorium resources are the primary strategic driver of its ambitious three-stage nuclear program, with Stage 3 specifically designed to exploit the thorium cycle. India's reserves have been estimated at up to 11.93 million tonnes of thorium, though more conservative estimates are in the 846,000 tonne range for reasonably assured resources (RAR).

Brazil (~17% of world reserves)

Brazil has extensive monazite deposits, particularly in:

• Minas Gerais state (inland; granitic intrusions)
• Bahia state
• The Brazilian coast

Brazil was historically the world's largest monazite exporter and has been an active participant in thorium energy research.

Australia (~16% of world reserves)

Australia's thorium reserves are associated with:

• Olympic Dam (South Australia) — a massive underground deposit of uranium, copper, gold, silver, and rare earth elements that also contains thorium
• Various Western Australian mineral sand deposits
• Northern Territory carbonatites

United States (~16% of world reserves)

The United States has substantial thorium reserves, concentrated in:

• Idaho and Montana (large carbonatite-related deposits)
• North Carolina (placer deposits)
• California (Mountain Pass rare earth deposit)
• Florida (coastal mineral sands)

The Thorium Energy Alliance estimates enough thorium in the United States to power the entire country at its current energy consumption level for over 1,000 years.

The Rare Earth Mining Byproduct Opportunity

An underappreciated dimension of the global thorium resource base: vast quantities of thorium already exist in processing facilities and storage sites as a byproduct of rare earth element extraction.

Because monazite is the primary ore for both thorium and heavy rare earth elements, every tonne of REEs extracted from monazite produces a corresponding quantity of thorium as an unavoidable byproduct. Currently, this thorium:

• Is separated from the REEs as part of the processing
• Must be handled as radioactive waste (requiring licensed disposal)
• Represents a significant liability for REE processing companies
• Is stored at various sites in the US, Malaysia, Australia, and elsewhere

If thorium reactors were commercially developed, this material — already extracted, already separated, currently a liability — would immediately become a highly valuable fuel resource.