Advanced plant in south of country capable of producing more fuel than it consumes
India’s first prototype fast breeder reactor (PFBR) at Kalpakkam has achieved first criticality, marking a “defining step” on the country’s civil nuclear journey, prime minister Narendra Modi said.
Criticality is the stage at which the nuclear reaction becomes self-sustaining.
The PFBR is a 500 MW sodium-cooled plant that is being commissioned at the same site as the Madras nuclear power station in Kokkilamedu, near Kalpakkam, in Tamil Nadu state, southern India.
It is designed to produce more fuel than it uses and has been under development since the early 2000s with construction beginning in October 2004. Fuel loading began in March 2024. A date for commercial operation has not been set.
The International Atomic Energy Agency (IAEA) says FBRs are a versatile and flexible technology that promises to create or “breed” more fuel by converting nuclear waste into fissile material.
The technology relies upon a closed fuel cycle, which means that spent fuel is reprocessed after its initial use in a reactor. Instead of sending the spent fuel into storage and eventually long-term disposal, the materials are reused, in particular the fertile material.
India’s PFBR has been designed and developed by the Indira Gandhi Centre for Atomic Research, a research and development institution under the country’s Department of Atomic Energy (DAE).
Paving Way For Thorium Reactors
The DAE said in a statement that the reactor is designed to enable “India to extract greater energy from its limited uranium reserves, while paving the way for large-scale deployment of thorium-based reactors”.
Modi said India had taken a defining step in its civil nuclear journey, advancing the second stage of its nuclear programme.
“The indigenously designed and built Prototype Fast Breeder Reactor at Kalpakkam has attained criticality,” he said on social media network X.
“This advanced reactor, capable of producing more fuel than it consumes, reflects the depth of our scientific capability and the strength of our engineering enterprise.
“It is a decisive step towards harnessing our vast thorium reserves in the third stage of the programme.”
India’s three-stage nuclear power programme is a long-term plan that involves the use of three different types of reactors to produce energy.
The first stage involves uranium-fuelled pressurised heavy water reactors (PHWRs) that produce plutonium. The second stage involves using the plutonium to create thorium-plutonium fuel for sodium-cooled fast reactors, which are then reprocessed to recover materials. The third and final stage involves using the recovered materials to create a closed thorium-232/uranium-233 (U-233) fuel cycle for advanced PHWRs.
The use of thorium as a fertile material in a nuclear reactor leads to the production of U-233. The very fissile nature of U-233 allows thorium to improve the reuse of reprocessed uranium in PHWRs and/or plutonium in light-water reactors.
A Key Feature Of ‘Stage Three’
The programme is necessary because India has abundant thorium reserves but little uranium, and the use of a thorium fuel cycle in the third stage is a key feature of the programme.
According to the IAEA’s reactor database, India has 21 commercial plants in operation and eight under construction. In 2024 its reactor fleet produced a 3.3% share of electricity generation.
India wants to build new nuclear plants to meet rising energy demand from a growing economy, provide baseload, low-carbon electricity to complement intermittent renewables and reduce its reliance on coal.
State-owned Nuclear Power Corporation Of India Ltd said recently that India plans to add 18 more nuclear reactors to its national energy mix by 2031-32, bringing the total nuclear power capacity of the country to more than 22 GW, up from about 7.4 GW today.
According to the IAEA, fast breeder technology was developed in the 1960s with demonstration and prototype reactors operating in a number of countries, including China, France, Germany, India, Japan, Russia, the UK and the US.
The IAEA says there are 12 experimental fast reactors and six commercial size prototypes with outputs from 250 to 1,200 MW that have been constructed or are in operation.
Russia operates the most powerful commercial FBR, the BN-800 at Beloyarsk, a site which also houses the BN-600 commercial FBR.
