Thorium as India’s Energy Hedge

Thorium is re‑emerging as a strategic lever in India’s quest for reliable, low‑carbon energy security, but policy, technology and institutional gaps must be closed quickly, if it is to move from promise to power plant.

Global Promise, Indian Legacy

Globally, thorium has long been seen as a safer, more abundant alternative to uranium. Experiments in the US and Europe in the 1950s-70s never translated into commercial-scale outputs because cheap uranium, light‑water reactor dominance and weapons‑linked fuel cycles drove investment elsewhere.

India was the notable outlier: Dr Homi Bhabha’s three‑stage nuclear programme was explicitly designed around its vast thorium reserves, using natural uranium and heavy water reactors in Stage‑1, fast breeder reactors in Stage‑2, and thorium‑fuelled systems in Stage‑3.

Yet, even in India, large-scale thorium deployment remains delayed. Parliamentary replies (2015) projected commercial thorium reactors 3-4 decades after sustained Fast Breeder Test Reactor (FBTR) achieve scale in the 2040s - implying 2070-2080 timelines. Today, Bhabha Atomic Research Centre’s (BARC) Advanced Heavy Water Reactor (AHWR) - deriving ~60 per cent of power from thorium - symbolises both technological readiness and the persistent “pilot-plant purgatory” trapping thorium development.

Why India’s Thorium Plans Slipped

India’s long‑term nuclear planning erred less in vision and more in sequencing, resourcing and political economy. The three‑stage strategy assumed: rapid scaling of heavy‑water reactors, timely fast breeder deployment and an industrial ecosystem capable of complex fuel fabrication - assumptions repeatedly undercut by sanctions, financing constraints and project delays. Public sector dominance under the Atomic Energy Act 1962 created a closed, cautious culture; innovation and scale were locked within a few PSUs and research centres, with little competitive pressure or global integration.

These lapses forced reliance on coal/imports longer than planned. While Pressurised Heavy Water Reactor (PHWR) (Stage‑1) capacity grew, Prototype Fast Breeder Reactor (PFBR) and thorium stages (Stage 2 & 3) lagged.

SHANTI Act: A Structural Reset of our Nuclear Framework

The Sustainable Harnessing and Advancement of Nuclear Energy for Transforming India (SHANTI) Act (Dec 2025) replaces the Atomic Energy Act 1962 + Civil Liability for Nuclear Damage Act 2010. It permits private Indian companies to build, own and operate reactors, and to participate in fuel fabrication, including conversion, refining and enrichment of Uranium‑235 up to a government‑defined threshold, while reserving “sensitive” activities for the state. The Act moves from a single statutory operator‑liability cap towards a graded liability framework, aligning more closely with international practice and improving project bankability.

Crucially, SHANTI allows patents for peaceful applications of atomic energy, subject to national‑security exclusions. This can attract capital and talent into reactor design, advanced materials and fuel‑cycle services. For thorium, this opens space for joint ventures and privately led demonstration projects in parallel with the three‑stage PSU‑dominated track, potentially compressing timelines and diversifying risk.

India’s Wider Energy Security Playbook

India’s thorium debate sits within a far broader diversification drive across renewables and non‑fossil sources. As of Dec 2024, the country had installed about 209 GW of renewable capacity, up from 180.8 GW a year earlier, with a record 28.6 GW added in 2024 alone. Solar led this surge, jumping from 73.3 GW to 97.9 GW in a single year, while wind climbed to about 48.2 GW.

Analysis suggests India could meet 2030 power demand without adding new coal capacity, if it achieves the 500 GW non‑fossil target (per updated Nationally Determined Contribution - NDC), backed by storage and grid upgrades. In 2025, the Union Cabinet announced that India had already crossed the 50 per cent non‑fossil share in total power capacity, achieving this Paris‑pledge milestone five years ahead of the 2030 deadline. This mix—solar, wind, hydro, nuclear and legacy thermal—underpins a geopolitical strategy of reducing import dependence on coal and gas exporters, leveraging climate finance, and positioning India as a manufacturing and green‑hydrogen hub.

COP, SDGs and the G7 Benchmarks

Under the 2030 NDC (at the COP 21, Paris, 2015), India committed to two things. Cutting emissions intensity per unit of GDP by 45 per cent from 2005 levels, and achieving 50 per cent of installed electricity capacity from non‑fossil sources by 2030. Both trajectories are ahead of the original Paris pledges: India had already reduced emissions intensity by about 33 per cent by 2019, and surpassed the earlier 40 per cent non‑fossil capacity target well before 2030.

By mid‑2025, the government reported breaching the more ambitious 50 per cent non‑fossil capacity mark five years ahead of schedule, effectively placing India about nine years ahead of its initial Paris commitments. Among G7 economies, most are moving strongly on coal phase‑out and renewables, but still over‑rely on gas and have an “ambition gap” in renewable capacity relative to a tripling target from 0.9 TW in 2022 to 2.7 TW in 2030; Japan is widely seen as the laggard, while the EU‑based members and the UK are comparatively stronger performers. India’s early over‑delivery on non‑fossil capacity thus contrasts with G7 systems that, despite higher per‑capita emissions and incomes, have not yet aligned gas use with net‑zero‑power timelines.

What India Still Needs to Do

First, India must decisively move thorium from laboratory to limited‑scale commercialisation by time‑bound commissioning of AHWR‑class reactors and integrating them into the 500 GW non‑fossil roadmap. This will require: realistic cost models, international cooperation on safety and materials, and using SHANTI’s private‑sector opening to attract private capital.

Second, coal’s share in power generation, though falling in capacity terms, remains high in actual generation. India needs aggressive grid expansion, storage, demand‑response and flexible gas‑plus‑storage solutions to backstop high solar and wind shares, without locking into long‑lived fossil assets.

Third, governance reforms—transparent project pipelines, faster land and transmission approvals, and clearer state‑centre burden‑sharing—will matter as much as technology in sustaining the current pace of renewables growth.

Policy message: India must treat thorium as a strategic hedge complementing, not replacing, the ongoing solar‑wind‑hydro build‑out, with SHANTI as the bridge between a closed nuclear past and a more competitive, secure energy future.

Views expressed are personal. The writer is Former Security Advisor, Ministry of Home Affairs, GoI