India’s Prototype Fast Breeder Reactor and the Dual-use Dilemma

Across the world, states are increasingly shifting toward renewable and low-carbon energy sources as part of broader climate and energy security plans. In light of the global energy disruptions due to multiple active conflict theatres, the Indian government also seeks to make India self-reliant in energy production through nuclear means. Under this broader energy transition framework, on 6 April 2026, India’s 500 MWe Prototype Fast Breeder Reactor (PFBR) at Kalpakkam achieved first criticality. It marks the completion of the second stage of India’s three-stage civilian nuclear programme. However, while India claims it to be a key milestone in its journey toward sustainable energy production, New Delhi’s assessment is often debated with respect to technical and operational challenges. There is also significant concern regarding the dual-use capacity of FBR, which India can exploit to increase production of Plutonium-239 for nuclear weapons.

The PFBR, initiated in 2004, took more than two decades to reach first criticality and still remains outside full commercial operationalisation for power production. MV Ramana, a renowned Indian physicist, has suggested that fast breeder reactors are inherently erroneous. Some of the core technical characteristics of these reactors reduce their efficacy and performance.

The primary challenge with these types of reactors is the risk of liquid-sodium leakage. Liquid sodium reacts explosively with air and water, resulting in an intense fire, and can cause severe structural damage. Another major concern is the period required for complete operationalisation. Despite India’s growing capacity, its intention of developing a three-stage nuclear programme, i.e., the thorium-based reactor, remains a far-fetched aspiration, as they typically take three to four decades to develop after the full operationalisation of the commercial FBRs. Moreover, PFBRs can take decades to become fully operational, making energy production from these reactors extremely cost-intensive. India’s PFBR has already doubled its estimated cost, and even at its original cost, electricity produced from this reactor will cost 80 per cent more than the usual cost of electricity produced by common Pressurised Heavy Water Reactors. These factors indicate that India’s development of the PFBR is more of a prestige-driven endeavour rather than a need-driven civilian energy production imperative. India’s PFBR and expansion of unsafeguarded reactor facilities also raise concerns about whether the 2008 US-India civil nuclear agreement should continue in its current form. With India’s claim to being a net security provider disproved post-Marka-e-Haq and the strategic ambiguities surrounding dual-use PFBRs, Washington may find it necessary to reconsider the future framework of this arrangement.

India’s PFBR uses mixed oxide fuel, a blend of plutonium dioxide and uranium dioxide. During the fission reaction under a fast neutron spectrum, fertile uranium-238 is converted into fissionable plutonium-239, a material that is inherently dual-use and can be used in both civilian energy and weapons programmes. While officially framed as part of India’s three-stage nuclear energy programme, this pathway expands the country’s stockpile of separated plutonium under the guise of energy production and would further increase India’s estimated capacity of producing up to 2,686 nuclear weapons. These facts raise serious concerns regarding India’s growing accumulation of weapons-grade material within a civilian nuclear framework, adding to the region’s already pronounced strategic asymmetry.

According to SIPRI Yearbook data from the last few years, India already exceeds Pakistan in the number of nuclear weapons. According to some assessments, as compared to Pakistan, India possesses a total capacity of generating seventy times more fissile material output through its unsafeguarded civilian nuclear reactor facilities alone. Furthermore, the Indian Department of Atomic Energy’s (DAE) former chairman, Anil Kakodkar, during the 2005-2006 debate over the India-US civil nuclear deal and India’s nuclear separation plan, signalled that India will not accept safeguards on the PFBR “to maintain minimum credible deterrence.”

Pakistan has serious concerns regarding India’s aspirations for producing a huge amount of fissile material under the guise of civilian energy production. The reactors collectively hold the capacity to produce approximately 700 kilograms of weapon-grade plutonium, which is enough to produce 175 nuclear warheads annually. Ultimately, this addition of an unsafeguarded 500 MWe reactor further deepens India’s pronounced 39:1 asymmetry in regional civilian nuclear capacity. Consequently, over 35% of India’s civilian power reactors now remain outside IAEA safeguards. This significantly enhances India’s latent fissile material production capacity and contributes to the continued expansion and modernisation of its nuclear arsenal. The scale of this capability, developed outside IAEA safeguards, threatens strategic stability and transparency, while enhancing the potential military implications of ostensibly civilian nuclear infrastructure.

In conclusion, even when framed as civilian energy development, such nuclear advancements can carry significant strategic implications, affecting regional security and strategic stability. The 500 MWe PFBR allows India to produce a huge amount of fissile material, which poses a direct threat not only to Pakistan but also to the entire South Asian region. Until it is placed under strict IAEA safeguards, the Indian assertion that its PFBR is a purely civilian endeavour must not be taken at face value.

Raja Zark Ullah Khan is a research assistant at the Centre of Aerospace and Security Studies (CASS) Lahore. He can be reached at [email protected]