India must urgently accelerate thorium fuel adoption to secure long-term energy independence, reduce reliance on imported uranium, and achieve its 100 GW nuclear power target by 2047.

Thorium’s abundance in India, combined with its efficiency and safety advantages, makes it the most strategic option for the country’s nuclear future.

India’s nuclear program has traditionally been structured in three sequential stages. The first stage involves Pressurised Heavy Water Reactors (PHWRs) using natural uranium.

The second stage deploys Fast Breeder Reactors (FBRs) that generate plutonium from Stage 1 fuel.

The third stage envisions thorium-based reactors, leveraging India’s vast thorium reserves. However, the global uranium supply deficit now demands that thorium be introduced earlier into the cycle.

PHWRs, which are expected to account for nearly half of India’s targeted 100 gigawatts-electric nuclear capacity by 2047, offer significant fuel flexibility. These reactors can be adapted to run on a blend of thorium and High-Assay Low-Enriched Uranium (HALEU) without altering their external design. This adaptation would fast-track India’s entry into the third stage of its nuclear program, bypassing delays inherent in the sequential approach.

Thorium is fertile rather than fissile, meaning it cannot sustain a chain reaction alone. It must be paired with fissile drivers such as uranium or plutonium. Recycling thorium alongside these fuels dramatically increases energy potential, up to 70 to 100 times compared to a once-through uranium cycle. This recycling advantage ensures that India’s nuclear resources are maximised for centuries.

India currently imports more than 70% of its uranium, leaving its nuclear program vulnerable to geopolitical supply risks.

In contrast, thorium is abundantly available in domestic coastal and riverine sands, particularly monazite deposits. India holds nearly 25% of the world’s thorium reserves but less than 2% of global uranium. Transitioning to thorium would transform India from a dependent energy importer into a self-reliant nuclear powerhouse.

Thorium-based fuel cycles also produce significantly lower volumes of long-lived radioactive waste. This reduces the burden of waste management and enhances environmental safety. Furthermore, thorium fuels are highly resistant to nuclear proliferation, strengthening India’s global non-proliferation credentials.

India has already made progress in this direction. In April 2026, the Prototype Fast Breeder Reactor at Kalpakkam achieved first criticality. This reactor uses a thorium blanket around its core, bombarding thorium with neutrons to produce Uranium-233, the fissile fuel required for Stage 3 reactors. This milestone demonstrates the feasibility of thorium integration into India’s nuclear program.

Policy reforms have also paved the way for private sector participation. The SHANTI Act of 2025 permits private companies to engage in nuclear operations and fuel management. Major domestic firms such as TATA Power, Reliance, and JSW Energy have bid to finance and build Bharat Small Reactors. This private involvement will accelerate deployment and innovation in thorium-based technologies.

Global uranium resources are under increasing pressure, with supply constraints already visible in the market. Recycling technologies and thorium adoption are essential to ensure India’s nuclear expansion does not stall due to fuel shortages.

Strategic investments in thorium research, reactor adaptation, and private sector collaboration must be prioritised to safeguard India’s energy future.

The government is strongly advised to integrate thorium into PHWRs immediately, expand thorium recycling capabilities, and accelerate the deployment of thorium-based reactors.

This will ensure that India achieves its nuclear capacity targets while securing energy independence, environmental safety, and technological leadership in the global nuclear sector.

IDN (With Agency Inputs0