Thorium project

• Project description
• Project objectives
• Project technical notes
• Project outcomes
• Project outputs
• Presentations
• Contact the project team
• Onshore Energy Security Program links

Project description

Thorium is an alternative to conventional nuclear fuels, such as uranium and plutonium and offers the following advantages:

• Almost all natural thorium is usable in a reactor compared with 0.7% of natural uranium;
• the residue material from thorium-fuelled reactors is difficult to reprocess into weapons-grade material; and
• unlike uranium, thorium requires a source of neutrons to start and maintain a nuclear fission reaction, which is the process of splitting atoms to release large amounts of energy.

While there is considerable development work required before the thorium fuel cycle can be commercialised, there is renewed interest in thorium fuel because less radioactive residue is produced and there is potential to re-use some of the radioactive by-products generated by conventional uranium-fuelled nuclear reactors. Currently, thorium fuels are used to varying degrees in some research reactors in India and Russia. Tests are being undertaken in Russia on the use of thorium fuel in conventional nuclear reactors and they may gain regulatory approval for its use within 10 years while India is in process of developing a thorium fuelled Advanced Heavy Water Reactor.

Exploration for thorium to date has been minimal and there are no comprehensive records of resources, mainly because of a lack of large-scale commercial demand. Most of the known thorium resources in Australia are in the monazite component of heavy mineral sand deposits, which are mined for ilmenite, rutile, leucoxene and zircon. This project has undertaken a review of Australia’s thorium resources and the geochemical processes controlling the distribution of the element in the earth’s crust. As part of this review Geoscience Australia has upgraded Australia’s thorium resource database and will provide a summarised report on thorium resources in the publication, Australia's Identified Mineral Resources 2008.

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Project objectives

• An improved understanding of the status and distribution of Australia’s thorium resources for use in the determination of government policy and industry investment decisions.
• A better understanding of the geochemistry of the thorium cycle in the Earth’s crust.
• Development of recommendations outlining whether an expanded Thorium Project is required.

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Project technical notes

A general understanding of the crustal distribution of thorium in Australia can be gained from Geoscience Australia’s OZCHEM dataset which has information on 56,000 samples of rocks, drill hole samples and regolith which have been analysed for thorium. Figure 1 shows the distribution of the 56,000 sample sites and where samples returned an analytical result of 50ppm or greater thorium content.

The display of thorium distribution in Figure 1 is limited to those geological provinces in which Geoscience Australia has carried out surveys in the past. Most of the geological provinces that have not been sampled and analysed for thorium are sedimentary basins with limited geochemical sampling. This existing data will soon be supplemented by data from Geoscience Australia’s Baseline Geochemical Survey which will obtain geochemical analyses for 60+ elements, including Thorium, at an average density of one site for around 5,000 square kilometres throughout Australia.

Figure 1 Distribution of geochemical samples which have been analysed for thorium (source Geoscience Australia’s OZCHEM database)

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Project outcomes

• An enhanced understanding of the status and distribution of Australia’s thorium resources for use in determining government policy and industry investment decisions and their potential for an alternative nuclear fuel source.
• A decision on whether a more comprehensive Thorium Project is required.

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Project outputs

• Upgraded the thorium resource database and provide a summarised report on thorium resources in the publication, Australia's Identified Mineral Resources 2008.

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Presentations

• Australia’s thorium resources – current developments, likely overseas demand by Yanis Miezitis [PDF 350kb]
• Resources and geology of Australia's thorium deposits by Miezitis, Y., Mernagh, T.P. and Lambert, I.B., Technical Meeting on "thorium based fuel cycle for Pressurized Heavy Water-cooled Reactors, Light Water Reactors and High Temperature Gas-cooled Reactors, International Atomic Energy Agency, 22-25 October 2007, Istanbul, Turkey [PDF 1.2MB]

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Contact the project team

Thorium project email: thorium@ga.gov.au

Onshore Energy Security Program links

• Onshore Energy Security Program
• Geothermal Energy Project
• National Geochemical Survey of Australia
• Thorium Project
• Uranium Systems Project
• Gawler–Curnamona Project
• Mount Isa–Georgetown Project
• Northern Territory Project
• Northern Western Australia Project