Opinion: Unlocking n-powered future

Thorium-based systems will be a game-changer in decarbonising energy sector, especially when India aims to treble n-power generation capacity by 2030

Published Date – 15 May 2024, 11:59 PM




By Rudra Prasad Pradhan, Kalyani Yeola

Kerala is famous for its languid beauty, laidback lifestyle and stunning beaches. But it’s what lies beneath that has the country’s nuclear industry excited. The State is also home to a massive amount of thorium, which India’s nuclear scientists see as the prospective mineral to help fuel an indigenous nuclear power programme. Indeed, India has the largest thorium deposits in the world, with the golden beaches of Odisha in eastern India also home to the prized mineral. Together, Kerala and Odisha account for over 70 per cent of India’s thorium.


The reason for the fuss is understandable: Department of Atomic Energy (DoAE) scientists consider thorium as a “practically inexhaustible energy source” which will not emit greenhouse gases. India’s first home-built prototype fast breeder reactor, the 500-megawatt Kalpakkam nuclear plant in Tamil Nadu, which has undergone successful tests, offers a glimpse of how thorium can help power the nation. Thorium itself is not enough. It needs to be converted to Uranium-233 in a reactor before it can be used as fuel. The Kalpakkam reactor demonstrated that this conversion is possible.

Energy Security

As of 2014, the DoAE claimed to have “established 11.93 million tonnes of in situ resources of monazite (thorium-bearing mineral)” in six States. These reserves contain about 1.07 million tonnes of thorium. Prime Minister Narendra Modi recently visited the Kalpakkam power plant to witness the “commencement of core loading”. The plant’s successful core-loading is a benchmark development to achieve India’s sustainable nuclear energy security. Once operational, the plant will mark the critical second stage in India’s three-stage nuclear power programme. Following the core loading process, the Kalpakkam reactor will undergo its first approach to criticality, leading to power generation.

Given India’s patchy uranium reserves and the Nuclear Supply Group’s substantial multilateral export control regime on the supply of nuclear materials, equipment and technology, policymakers have, for some time, been working on a long-term goal of utilising indigenously available thorium.

A Trigger

While thorium is no magic metal or a nuclear fuel by and in itself, it can, however, be used to create such a fuel. Researchers agree that Thorium-232, “the only naturally occurring isotope of thorium, is considered ‘fertile’ for fission”. But it needs a “driver”, such as uranium and plutonium, to “trigger and maintain a chain reaction”. When sufficiently irradiated, Thorium-232 undergoes a series of nuclear reactions. This leads to forming Uranium-233 which can then be “split” to release energy to power a nuclear reactor.

In a June 2019 statement in Parliament, the government said the DoAE “planned the use of large deposits of thorium available in the country as a long-term option”. But this decision was not entirely new. It was part of an old plan that tied in with DoAE scientists and officials’ previously laid out three-stage nuclear power programme.

If India can use its thorium, it will be free from dependence on the uncertain uranium supply chain regime. In simpler terms, the three-stage nuclear power programme aimed to multiply the “domestically available” fissile resource through the use of natural uranium in Pressurised Heavy Water Reactors (PHWRs), followed by the use of plutonium obtained from the spent fuel of PHWRs in Fast Breeder Reactors. “Large-scale use of thorium” will follow, making use of Uranium-233 that will be “bred” in reactors.

Global Race

Five years ago, the government took steps “towards technology development and demonstration” to ultimately put in place a “mature technology” so that thorium utilisation was “available in time”. While domestic energy self-sufficiency was the goal, India is also caught up in a thorium-related global race that underscores the geopolitics surrounding this ‘power’ metal.

In June 2023, China took steps to issue an “operating permit” for an “experimental molten salt thorium nuclear reactor”. This reactor, located in the Gobi Desert, will be put through tests in the next few years. The US, UK and Japan are said to have shown enthusiasm for research in the application of thorium in nuclear power.

Part of the Indian determination to pursue an indigenous course on nuclear energy was the lack of any significant movement by the US on commercially providing nuclear reactors. This may have stemmed from past US governmental and suppliers’ “anxieties” even after the July 2005 civil nuclear agreement that did not bear much fruit insofar as India was concerned. Mutual US-India trust and confidence appeared to have been restored in 2023 when the Biden administration sought to “tangibly consummating” the accord “by completing the negotiations for nuclear reactor sales to India”. This could give an impetus to India-US collaboration in nuclear energy in general and “development of next generation small modular reactor technologies in a collaborative mode” in particular. At the same time, a potential deal between India and France, for the construction of six new large European Pressurised Reactors at Jaitapur in Maharashtra, has not been “concluded”.

Negotiations between the French supplier, Electricite de France, unexpectedly stalled because of “unresolved problems”, including liability. This relates to payments in the event of an accident. India’s nuclear cooperation with Canada dates back several years. A bilateral agreement was signed between the DoAE and Canada’s Cameco in 2015 in which Cameco would supply 3220.50 tonnes of “uranium concentrate” under a long-term contract through 2020 for India to meet its energy needs. While the governments agreed in February 2018 to “expand the ongoing mutually-beneficial civil nuclear cooperation”, there has been little tangible progress on the ground. As recently as March, it was revealed that Russia’s state-owned atomic energy company, Rosatom, was in negotiations with India for a “possible supply of technology” for small modular reactors which can be constructed in about four years and rely on comparatively less water consumption.

Self-sufficiency

The slowdown in partnership commitments of Western nuclear powers prompted the government to make “sustained efforts” in “different areas of thorium fuel cycle” which was aligned with the tom-tommed “self-sufficiency” in critical and sensitive areas. The DoAE’s efforts are directed at enlarging the current thorium-related research and development work and activities to a bigger scale and towards the development of technologies. However, the commercial utilisation of thorium on a “significant scale can begin only when abundant supplies of either Uranium-233 or Plutonium resources are available”.

Indian researchers and scientists agree that it will take decades before the commercial establishment of the Fast Breeder Reactor (FBR) stage is achieved. But some other say it is “possible to considerably advance” the thorium stage if certain technical processes are deployed before the DoAE takes steps to “enter” the FBR stage on a big scale.

Notwithstanding the delay, thorium-based systems will be a game-changer in decarbonising India’s energy sector, especially when it aims to treble its nuclear power generation capacity by 2030 to “meet the twin goals of energy security and sustainable development”.

While India has taken major steps in thorium-related research and is a recognised partner in most fora under the International Atomic Energy Agency (IAEA), it remains an outsider in other “multilateral collectives” that focus on thorium-based systems. India can, however, push for thorium-based systems and fuel cycle on a faster track if it can leverage its R&D and non-proliferation credentials as part of international forums.

Rudra Prasad Pradhan Kalyani Yeola

(Rudra Prasad Pradhan is Professor and Kalyani Yeola is a Senior Research Fellow, at the Department of Humanities and Social Sciences, BITS, Pilani, Goa Campus. 360info)