More power for India

India aims for 100 GW of nuclear power by 2047, about ten times what it runs today. Getting there takes reactors India can build quickly, run safely and fuel with its own thorium.

Learn more
about thorium

One Plant Three Buildings

Qark One is a single reactor of about 300 MWe. Scroll through the plant: turbine hall, reactor building and control building, each with one job.

Concept render of a Qark One plant in cutaway: turbine hall on the left, reactor building in the centre, control building on the right Turbine hall Reactor building Control building
Concept render

Overview

The whole plant

About 300 MWe of firm, carbon-free power from one reactor, on a compact site.

1 / 3

Turbine hall

Steam from the reactor drives a turbine-generator, the same kind of machine that runs in any thermal power station.

2 / 3

Reactor building

The reactor sits beneath a pool of about 8,000 m³ of water, held high in the building to cool the core by gravity alone.

3 / 3

Control building

Operators run the plant from a control room in its own building, beside the electrical and instrumentation systems.

Concept render of a factory hall where large reactor components are fabricated
Concept render

Made in India

Qark One is designed around components that Indian industry can fabricate in its own workshops and deliver to site for assembly. India’s heavy-engineering firms have been making reactor components for decades.

Learn more
about building in India
Concept render of an underground reactor building with deep pools of water
Concept render

Safe by Gravity

If the plant loses all power, Qark One needs no pumps, no diesel and no operators to stay safe. Water flows down from the pool by gravity, natural circulation carries the heat away, and the core stays cool for 72 hours with no action at all.

Grace period
72 hours without power or operator action
Water pool
About 8,000 m³, fed by gravity
Circulation
Natural, with no primary pumps
Shutdown
Two independent systems
Learn more
about passive safety

Refuelled While Running

Qark One burns thorium oxide mixed with high-assay low-enriched uranium (HALEU), packed into 54-pin clusters. Fresh fuel goes in from the top while the reactor keeps running, so the plant never has to shut down just to refuel.

Fuel
(Th–HALEU)O₂, 54-pin clusters
Fuel channels
452, vertical
Refuelling
On power, from the top
Learn more
about Qark One
Concept render of a reactor vessel in cutaway with the core glowing at its base
Concept render

Drawn in Detail

The general arrangement for Qark One, drawn from published data for the AHWR-300 LEU, the thorium reactor designed by India’s Bhabha Atomic Research Centre.

General arrangement drawing QE-GA-001 for Qark One: reactor block section, core lattice plan, coolant channel detail, parts list and principal data

Principal data

Concept status. Indicative arrangement from published AHWR-300 LEU data; dimensions approximate, not for construction.

View the
full drawing
Reference design
AHWR-300 LEU (BARC, published data)
Thermal / electric
920 MWth / ≈300 MWe
Coolant
Boiling light water, natural circulation
Moderator
Heavy water (D₂O), low pressure and temperature
Fuel
(Th–HALEU)O₂, 54-pin clusters
Fuel channels
452 vertical, 225 mm square pitch
Main heat transport
7 MPa, 285 °C coolant outlet
Refuelling
On power, top entry
Shutdown
SDS-1 shut-off rods, SDS-2 liquid poison
Passive cooling
72 h grace period, ≈8,000 m³ gravity-driven water pool

India’s Own Fuel

India holds one of the world’s largest reserves of thorium, much of it in the monazite sands along its coast. Since the 1950s, its three-stage nuclear programme has aimed to make thorium its main fuel.

Waves breaking on a sand beach below coastal cliffs

  1. Stage 1

    Pressurised heavy-water reactors

    Natural uranium fuels India’s working fleet and produces plutonium.

  2. Stage 2

    Fast breeder reactors

    Plutonium-fuelled reactors breed more fissile material and can turn thorium into uranium-233.

  3. Stage 3

    Thorium reactors

    Thorium and uranium-233 become the fuel for the long term.

Qark One is designed to put thorium to work now, with HALEU as its driver fuel, rather than waiting for stage three.

Learn more
about thorium

Work With Qark Energy