As India opens up its nuclear power sector to private sector participation and eyes a stake in the export market, the need to expedite the fabrication of an Indian Light Water Reactor (LWR) has been flagged as a priority within the nuclear establishment, The Indian Express has learnt.
To this effect, there is a concerted push by the Department of Atomic Energy to speed up work on the 900 MWe (megawatt electric) LWR project — design work on this had started in 2015.
Having an indigenous LWR, alongside the existing fleet of pressurised heavy water reactors (PHWR), is expected to boost India’s leverage in dealing with foreign vendors to secure better terms in imports, officials said.
Significantly, LWRs constitute the bulk of the international reactor market, and without integrating Indian companies into the global supply chain, making a breakthrough in the export segment is likely to be difficult.
This is also the backdrop to the Sustainable Harnessing and Advancement of Nuclear Energy for Transforming India Act, 2025, passed in the winter session of Parliament, which opens up the possibility of more imported LWR-based nuclear projects of the kind being set up by the Russians in Kudankulam.
The legal changes are seen within the establishment as necessary to tap the dominant global LWR ecosystem, even as India retains its core strengths in other reactor types.
India’s civil nuclear programme has deep expertise in manufacturing heavy water reactors from 220 MWe PHWRs to the new 700 MWe units. Based on heavy water (deuterium) and natural uranium, PHWRs are a technology that India’s nuclear establishment has mastered. However, these are increasingly out of sync with LWRs, which now dominate the global market.
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Why LWR push
Light Water Reactors form a mainstay of the global n-program; these use light water, enriched uranium, and have simpler design, lower construction cost, economies of scale, and high thermal efficiency.
LWRs currently account for over 85% of the civil nuclear reactor capacity in the world.
There are at least three reasons for this trend: LWRs entail simpler design and engineering compared to heavy water reactors given that they use normal water as both coolant and moderator and so have some degree of overlap with the technology used by regular thermal power units (coal-fired and gas-based power plants); they typically entail lower construction cost on account of economies of scale, given that LWRs make up most of the installed nuclear capacity; these reactors are seen as being more thermal efficient.
While LWRs use normal water, they need enriched uranium as fuel. Given that access to enriched uranium is not a constraint in much of the western world, LWRs are used extensively by US, Russia and France and now form the backbone of most international reactor fleets.
PHWRs, by contrast, are prized for fuel flexibility and the ability to operate on natural uranium, an advantage in India’s resource-constrained context but a relative handicap in export markets shaped and dominated by LWR technology.
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The import of LWRs at higher cost raises two important issues: one, that these new projects should not come at the expense of indigenous reactor design and PHWR production capacities; and two, that higher capital expenditure also results in higher tariffs, which must be absorbed in Indian market conditions.
The setting up of nuclear reactors at the Jaitapur site in Maharashtra has been in limbo because of high tariff concerns, alongside liability issues earlier flagged by French atomic power major Areva and its own financial troubles. The liability concerns have been addressed in the new nuclear amendments.
India’s time-tested strength in PHWR technology and a renewed focus on fuel manufacturing, given its vast thorium resources, are being seen as a combination worth prioritising. In this context, proactively moving towards becoming a major supplier of PHWRs fuelled with a mix of thorium and imported low-enriched uranium has been cited by experts as an area of immense potential.
This is particularly relevant as nuclear energy is set to be critical to economic growth across a significant segment of emerging economies — the UAE, Bangladesh, Saudi Arabia and Turkey have signalled their intent to embrace nuclear power in a big way.
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India’s domestic programme focused on the eventual harnessing of thorium is designed for a specific national context characterised by modest uranium resources and vast thorium reserves. The use of thorium along with low-enriched uranium in the current generation of Indian reactors could significantly ease existing barriers to scaling up nuclear power.
From this perspective, PHWRs are seen as especially attractive — potentially more so than LWRs. India could, therefore, move forward to emerge as a major nuclear supplier of PHWRs fuelled with a mix of thorium and imported low-enriched uranium, sources said.
This comes at a time when India is also hoping to pitch itself as a credible destination to manufacture nuclear reactors, especially small modular reactors (SMRs) with capacities between 30 MWe and 300 MWe, cost-effectively and at scale.
Beijing, too, is working on an ambitious plan to seize global leadership in the SMR space. Like India, China sees SMRs as a tool of diplomatic outreach in the Global South and as a sector it could disrupt, much as it has done in the electric vehicle industry.
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