The Story So Far
- The Prototype Fast Breeder Reactor (PFBR) at Kalpakkam reaching criticality is an important milestone, but it is only the beginning of a long process.
- After this stage, the reactor is tested carefully over months to ensure safe and reliable functioning.
What is Criticality?
- A reactor becomes critical when a self-sustaining chain reaction begins inside it.
- In simple terms, each nuclear reaction produces enough neutrons to continue the process without external input.
- Engineers control this process using fuel design, temperature, and neutron flow, ensuring stability.
- However, this stage is only about technical stability, not economic or commercial success.
How do Fast Breeder Reactors (FBRs) Work?
- Most of India’s current reactors are Pressurised Heavy Water Reactors (PHWRs), which use natural uranium.
- These reactors are inefficient because only about 1% of the fuel is actually used.
- Fast Breeder Reactors are different because they create more fuel than they consume.
- They use plutonium as fuel and surround it with depleted uranium, which gets converted into new plutonium.
- This makes FBRs far more efficient, with around 10% or higher fuel utilisation.
What is India’s Three-Stage Nuclear Programme?
- India’s nuclear strategy, designed by Homi Bhabha, aims to ensure long-term energy security.
- In the first stage, PHWRs use uranium to produce plutonium and electricity.
- In the second stage, FBRs use this plutonium to generate more fuel and power.
- In the final stage, reactors will use thorium, which India has in large quantities.
- FBRs act as the bridge that connects current resources to a future based on thorium.
Why are FBRs Challenging?
- FBRs are technologically complex, especially because they use liquid sodium as coolant, which is highly reactive.
- Even a small leak can be dangerous, so the system requires extreme precision and safety standards.
- Globally, many countries have struggled, as seen in Japan and France, where projects faced failures or shutdowns.
- While FBRs are technically possible, they are still expensive and not fully economically proven.
- They also require strong institutions and a culture of transparency and safety, which cannot be compromised.
How has India pursued FBRs?
- India has continued investing in FBRs because they are key to energy independence and long-term planning.
- The nuclear sector is largely controlled by the government, which allows policy continuity over decades.
- However, this insulation has also reduced accountability and public scrutiny.
- The PFBR project reflects this, with costs rising from ₹3,500 crore to ₹6,800 crore and repeated delays.
- The larger challenge is not just building reactors, but also developing fuel reprocessing and supporting infrastructure.
What next for the PFBR?
- The reactor will now be tested at low power to study its real-world performance and safety behaviour.
- Based on these tests, engineers will gradually increase its output and refine operational systems.
- Before becoming fully operational, it must receive approval from the Atomic Energy Regulatory Board.
- At that stage, it will begin generating electricity for the grid in a stable and sustained manner.
- At the same time, India will move ahead with future breeder reactors and fuel cycle facilities.
Conclusion
- Fast Breeder Reactors represent India’s effort to move towards long-term energy security and self-reliance. However, their success will depend not just on technology, but also on honest evaluation, strong regulation, and careful use of public resources.
