Context: Recently 'core loading' process began at the Kalpakkam Fast Breeder reactor which marks a critical milestone in the country's 3-stage nuclear power programme.

• This reactor, developed by BHAVINI, marks a significant step in India’s nuclear capabilities.

About Core Loading

• In a nuclear reactor, core loading is the process of loading nuclear fuel assemblies into the reactor core.

• The fuel assemblies comprise fuel rods that contain fissile material, such as enriched uranium or plutonium, which undergoes nuclear fission to produce heat.

• And a fast breeder reactor is a type of nuclear reactor that is designed to produce more fissile material (such as Plutonium-239) than it consumes during operation.

• It achieves this by using fast neutrons to convert non-fissile isotopes (such as Uranium-238) into fissile isotopes (such as Plutonium-239).

• This process is known as "breeding" because it creates more fissile material than is initially loaded into the reactor.

Capacity of PFBR in Tamil Nadu

• India’s prototype fast breeder reactor (PFBR) in Tamil Nadu has a capacity of 500 Megawatt electric (MWe).

• It was designed by the Indira Gandhi Centre for Atomic Research and constructed by BHAVINI.

• Short for Bharatiya Nabhikiya Vidyut Nigam Limited, BHAVINI was established in 2003 to build and operate the PFBR.

Significance

• PFBR is considered a precursor to future fast breeder reactors (FBRs).

• After the core loading is completed, the Kalpakkam PFBR reactor will undergo the first approach to criticality, leading to power generation.

• Once it becomes operational, India will be only the second country after Russia to have a commercial operating fast breeder reactor.

• The latest development symbolises India’s entry into the crucial second stage of the country’s three-stage nuclear programme.

India’s 3-Stage Nuclear Programme

• India's three-stage nuclear power programme was formulated by Dr Homi Bhabha to secure the country's long term energy independence.

• The ultimate focus of the programme is on enabling the thorium reserves of India to be utilised in meeting the country's energy requirements.

• Thorium is particularly attractive for India, as India has only around 1–2% of the global uranium reserves, but one of the largest shares of global thorium reserves at about 25% of the world's known thorium reserves.

• Thorium is found in the monazite sands of coastal regions of South India.

• Dr Homi Bhabha, therefore, devised a three-stage nuclear power programme to make the most of India's limited uranium reserves and abundant thorium reserves.

• Each stage of the programme has fuel cycle linkages.

• This means that spent fuel from one stage is reprocessed to obtain fuel for the next stage — there is little to no wastage.

• Ultimately, the goal is to generate nuclear power while ensuring long-term energy security.

• Stage 1 – Setting up Pressurized Heavy Water Reactors (PHWRs) that use natural uranium as fuel. (Currently operational)

• Stage 2 (Current Stage) – Introduce Fast Breeder Reactors (FBRs) like the Kalpakkam FBR.

• FBRs use Pu239 (extracted from spent fuel of PHWRs) to generate electricity.

• Surround the reactor core with a fertile material blanket (U238).

• Fast neutrons from the core convert U238 in the blanket to more Pu239, breeding new fuel.

• Stage 3 (Future Stage) – Utilize Thorium (abundant in India) for power generation.

• Thorium itself is not fissile, but can be converted to fissile Uranium-233 (U233) in FBRs.

About BHAVINI

• Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI) is a government company under the Department of Atomic Energy (DAE). 

• Established in 2003, its primary goal is to construct and operate Fast Breeder Reactors (FBRs) for electricity generation. 

• BHAVINI has built the 500 MWe Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, representing India’s energy security future with technology from the Indira Gandhi Center for Atomic Research (IGCAR).