India’s own
nuclear fuel
Thorium is about three times as abundant as uranium in the Earth’s crust, and India holds one of the largest reserves in the world. Qark One is designed to start using it now.
Monazite sands along India’s coast hold much of its thorium.
Why thorium
Thorium-232 cannot sustain a chain reaction on its own. When it absorbs a neutron it becomes, after a short decay chain, uranium-233, which can. A reactor fuelled with thorium therefore breeds much of its own fuel as it runs.
Thorium dioxide melts at a higher temperature than uranium dioxide and conducts heat better, and a thorium fuel cycle produces far less plutonium and other long-lived heavy elements than a uranium one.
And India has plenty of it. Thorium is one of the few energy resources the country holds in abundance, which is why its nuclear programme has pointed towards it for seventy years.
India’s three-stage programme
Since the 1950s, India’s nuclear programme has planned a path in three stages, each making the fuel for the next and ending with thorium.
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Stage 1
Pressurised heavy-water reactors
Natural uranium fuels India’s working fleet and produces plutonium.
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Stage 2
Fast breeder reactors
Plutonium-fuelled reactors breed more fissile material and can turn thorium into uranium-233.
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Stage 3
Thorium reactors
Thorium and uranium-233 become the fuel for the long term.
Where Qark One fits: it is designed to put thorium to work now, using high-assay low-enriched uranium as the driver fuel, rather than waiting for the third stage.
Qark One’s fuel
(Th–HALEU)O₂: thorium dioxide mixed with uranium dioxide enriched to between 5 and 20 percent uranium-235.
The uranium drives the chain reaction from the first day, while the thorium breeds uranium-233 that is burned where it forms. Each fuel cluster holds 54 pins in three rings of 12, 18 and 24 around a central water tube, and clusters are changed from the top while the reactor runs.
Where we are
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Now
Concept design
General arrangement QE-GA-001 (rev A) sets out the reactor block, the core lattice and the principal data for Qark One.
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Next
Basic design and safety analysis
Fuel, core physics, thermal-hydraulics and the passive safety systems are worked up in detail and checked against India’s safety codes.
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Then
Regulatory engagement
We plan to engage India’s Atomic Energy Regulatory Board early, well before applying to build a first unit.
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Then
The first plant
Site selection, construction and commissioning of the first Qark One. No site has been announced yet.