SHASHWAT GUPTA RAY
At a time when energy crisis is brewing across the country, the 500 MWe (MegaWatt electrical) Prototype Fast Breeder Re actor (PFBR) at Kalpakkam nuclear power plant going critical is a big achievement as it will not only help in producing vast source of fissionable nuclear fuel for our nuclear power pro gramme, but also strength en our national security, Goa-based veteran nuclear scientist Bimalendu Dey said. In a landmark achieve ment for India’s nuclear energy programme, the 500 MWe PFBR successful ly attained first criticality (start of controlled fission chain reaction) on April 6, marking a historic step in providing long-term ener gy security and advancing indigenous nuclear tech nology capabilities. India is now only the second nation (after Russia) to operate a commercial-scale Fast Breeder Reactor (FBR). Former Associate Chief Engineer (Operation), Nu clear Power Corporation of India Limited (NPCIL), De partment of Atomic Energy (DAE), Mumbai, Dey was part of the first batch of scientists selected by Gov ernment of India in setting up nuclear power plants in India. He was associated with this plant at Kalpakkam from 2010 to 2013, when he wrote the Commis sioning Procedures (CPs) for all conventional sys tems of PFBR. CPs are the first steps for start of commission activities of various systems of the total plant. “The PFBR marks the move to Stage-2, where plutoni um (produced from Stage-1) is used as fuel, moving closer to utilising India’s vast thorium reserves. This will help in ending our dependency on Uranium, which is a well known critical source to generate nuclear power, but is not available in India abundantly,” Dey said. PFBR is the first indigenously designed fast breeder reactor in India. It is estimated that India’s Uranium re source is only about 50,000 tonnes. Presently most of our operating nuclear power stations used uranium a fuel. There is always urgent need for fuel and India has to de pend on imported fuel. “India has about 1.07 million tonnes of in-situ Thorium reserves. This non fissionable element can be convert ed to U233 a fissionable nuclear fuel in PFBR. With this, India can have sufficient fissile material stock. With the achievement of first criticality, India moves closer to re alising the full potential of its three-stage nuclear power programme,” he said. The Fast breeder (FBR) technology forms the vital bridge between the current fleet of pressurized heavy wa ter reactors and the future deployment of thorium-based reactors, leveraging the country’s abundant thorium re sources for long-term clean energy generation. The FBRs are a key to India’s long-term nuclear strate gy. Unlike conventional thermal reactors, the PFBR uses Uranium-Plutonium Mixed Oxide (MOX) fuel. The core of PFBR is surrounded by a blanket of Uranium-238. Fast neutrons convert fertile Uranium-238 into fissile Plutonium-239, enabling the reactor to produce more fuel than it consumes. The reactor is designed to eventually use Thorium-232 in the blanket. Through transmutation, Tho rium-232 will be converted into Uranium-233, which will fuel the third stage of India’s nuclear power programme. “This unique capability significantly enhances the utili sation of nuclear fuel resources and enables the country to extract far greater energy from its limited uranium re serves while also preparing for large-scale use of thorium in the future,” Dey said. Paying tribute to father of India’s atomic energy pro gramme, Dr Homi Jahangir Bhabha, the veteran nuclear scientist said that during initial period in 1953, foresaw the need for developing FBR for higher utilising of Urani um to over 75%. “Uranium contained 0.7% as U 235 and rest 99.3 %is U 238. So about 0.7% of natural uranium get utilised (U 235).The remaining about 97% of U238 which is non-fis sionable by slow neutrons, can be converted to Plutonium (PU 233), a fissionable fuel in FBR/PFBR,” he said. Speaking about the attainment of third and final stage of nuclear power generation, Dey said that the Kalpakkam nuclear power complex will transition to using abundant thorium reserves to achieve long-term energy independ ence, when it moves into the third stage of its nuclear power programme. “This final stage involves powering reactors with Urani um-233, which is bred from Thorium-232 during the sec ond stage (FBR) now active at Kalpakkam,” he said.
