Why India Waited 70 Years for THIS Nuclear Reactor?

On the morning of December 26, 2004, about 150 contract workers were busy on a secret project in Kalpakkam, Tamil Nadu. Right by the sea, they’d dug a pit about 17 meters deep and were pouring concrete into it. They were laying the foundation for India’s most unique nuclear site. But nobody had a clue that a massive earthquake was happening out in the ocean. That earthquake set off a huge tsunami rushing straight toward the Tamil Nadu coast. At the nuclear site in Kalpakkam, the supervisor, seeing what was coming, told the workers…

They also give a warning, and soon tsunami waves crash through the compound wall, flooding the whole site. Most people manage to get out, but one worker dies, and water seeps into the foundation of the nuclear facility. This was where India’s prototype fast breeder reactor was being built, and a natural disaster flooded its base. But time goes on, wounds heal, and the place is rebuilt. Then, 22 years after the accident, this very spot makes history. On the night of April 6, 2026, at 8:25, this fast breeder reactor reached its first criticality.

The Prototype Fast Breeder Reactor (PFBR) at PFBR has successfully gone critical for the first time, meaning it’s sustained a nuclear chain reaction. This is a big milestone. The Department of Atomic Energy announced that India has now moved into the second phase of its three-stage nuclear power program. This three-stage plan was originally designed decades ago by a physicist.

The scientist who laid the foundation was Dr. Homi Jehangir Bhabha. For a developing country like India, it has never been easy. India’s nuclear program is full of accidents, explosions, and comebacks. Hello, I’m Ayush Yadav, and in today’s video, we’ll learn about India’s Prototype Fast Breeder Reactor (PFBR) and Dr. Homi Bhabha’s three-stage nuclear plan. We’ll also understand how significant it is for India to enter the second stage of this nuclear plan and what it really means. On May 18, 1974, India in Rajasthan…

India conducted its first nuclear explosion in Pokhran. It was on Buddha Purnima, and this underground test was named “Smiling Buddha.” India called it a peaceful nuclear explosion. But it was actually a demonstration of weapons capability and an unprecedented show of India’s strength. After this operation, a famous message went around: “The Buddha has smiled.” However, this test wiped the smiles off many countries’ faces. The plutonium used in this blast came from the CIRUS reactor, which was a research reactor supplied by Canada.

The heavy water used in the research was supplied by the US. Both these transfers were made under the Peaceful Use Agreement. So, the nuclear blast at Pokhran was a big deal for these countries. After this test, Canada’s Secretary of External Affairs, basically their foreign minister, announced in their Parliament that they were suspending the ongoing nuclear collaboration with India. The US used to supply fuel for the nuclear power reactors in Tarapur and Rajasthan in India, but…

After that, they canceled all the shipments coming here and pulled back completely. About 30 years before this blast, the US had dropped nuclear bombs on Hiroshima and Nagasaki. That’s how World War II ended, and the nuclear arms race among the world’s powerful countries began. India had just gained independence and was rebuilding itself from scratch. Meanwhile, India had to manage its growing electricity demand on one hand and secure its position in the rapidly changing geopolitical landscape on the other.

The goal was to keep things secure. Both of these paths required a lot of nuclear research. Under peaceful agreements, these Western powers didn’t really have a problem with India using nuclear energy to generate electricity. But the idea of India making its own nuclear bomb was a big worry for them. When India demonstrated its nuclear weapons capability in 1974, these countries got really tense. After that, the main reactor builders and nuclear fuel suppliers basically formed a club among themselves and…

It was called the Nuclear Suppliers Group, or NSG. Between 1975 and 1978, several meetings took place in London, and the NSG guidelines were formed. These countries planned to keep strict control over nuclear technology and fuel supply, which put India in a tough spot, basically choking it. India’s geopolitical situation made their boycott even harder to deal with. To understand how delicate the situation was, keep in mind that uranium is the main fuel for nuclear technology, and India only has about one or two percent of the world’s uranium reserves.

Most of it was low-grade uranium, which is really hard to extract. In comparison, Canada and Australia had rich uranium ores. So, until that time and for the coming decades, India depended on other countries for the fuel needed in its reactors. After our nuclear tests, the sanctions created a crisis for the operation of India’s nuclear power reactors. But we never lacked visionary people here. Our scientists had already prepared a cheat code for this. Homi Jehangir Baba was a physicist studying at Cambridge.

[Music] When World War II happened, he came to India. Here, IISc Bangalore worked with C.V. Raman, and then after independence in 1948, India formed the Atomic Energy Commission, with Bhabha later becoming its founding chairman. It’s said that Dr. Bhabha understood India’s geology and geopolitical situation very well. There was very little uranium available, and the post-war geopolitical situation was quite delicate. But look at nature’s irony. There was a huge reserve of thorium in Indian territory, with plenty of thorium in Kerala and Tamil Nadu.

The monazite sand found along the coast was really tough. India had about 25% of the world’s thorium reserves. Back in the 1970s, when global powers cut off India’s uranium supply, we already had Bhabha’s master plan ready. Though Dr. Bhabha passed away in 1967, he had already laid out our vision for nuclear safety before that. In a conference in Delhi in 1954, Homi Bhabha argued that India’s long-term nuclear program should be based not on uranium, but on thorium. Because we have…

India’s thorium reserves were about ten times larger than the non-uranium reserves back then. This was our unique advantage. But there was a problem too. The challenge with thorium is that you can’t directly produce nuclear energy from it. Thorium is a fertile material. For a nuclear fission reaction, it has to be converted into a fissile material like uranium fuel. And that’s not an easy task. Keeping this in mind, India’s nuclear program was designed in three stages. The second of these…

We’ve now entered the stage of the prototype fast breeder reactor. So, why did this take decades to develop? And what kind of reactor is this? What exactly is it? What do “fissile” and “fertile” mean? And what are the three stages of our nuclear program? To understand all this, we’ll quickly go over some basic stuff about how nuclear energy is generated. We’ll keep it fun and simple so it makes sense. The foundation of nuclear power is based on splitting the heavy nucleus of an atom to trigger a chain reaction. You probably studied this back in school.

Every atom has a nucleus at its center made up of neutrons and protons. Some special heavy nuclei, like Uranium-235, are unstable. If a neutron hits one of these nuclei like a bullet, it becomes unstable and splits into two separate pieces. This splitting of one thing into two parts is called a fission reaction. When an unstable atom like Uranium-235 splits, it releases energy and also shoots out neutrons. These neutrons then go on to hit other Uranium atoms and break them apart too, and that’s how the whole process continues.

This cycle keeps repeating. It’s called a chain reaction. Now, if you can use the neutrons released from the fission of one nucleus to cause more fission in other nuclei, it becomes a self-sustaining chain reaction. If this chain reaction isn’t controlled, it can release so much energy at once that it causes a huge explosion. This is exactly how a nuclear bomb or atomic bomb works. But when it comes to generating energy, making electricity, it’s really important to tame this chain reaction—to slow it down and control it carefully.

It’s really important. So you can boil water in this heat again. The steam that comes out is used to spin the turbine in a controlled way, which then generates electricity. This is exactly how a nuclear energy reactor works. The only difference between a nuclear bomb and a nuclear reactor is control. Now, terms like fissile and fertile come into play here. A fissile isotope is one that’s ready for fission and can easily sustain its chain reaction with slow neutrons. Examples of this are Uranium-235, Plutonium-239, and Uranium-233.

On the other hand, fertile isotopes like Uranium-238 and Thorium-232 usually don’t reach the fission stage just from solar neutrons. But if you place this material around a reactor and it keeps absorbing fast neutrons, it turns into fissile material. Okay, that was a lot of names and numbers. So, the numbers you see, like U-235, refer to the heaviness of the nucleus. It’s the total number of neutrons and protons inside the nucleus, like everywhere in the world…

A uranium atom has 92 protons, but the number of neutrons can vary. Take uranium-235, for example; it has 143 neutrons. Uranium-238 has 146 neutrons. This difference in neutron count changes how they behave in a nuclear reactor. Both are uranium, but these are called different isotopes of uranium. Uranium-230 is a fertile isotope, while uranium-235 is a fissile isotope. Whether an isotope is fertile or fissile depends on how heavy its nucleus is.

You don’t need to remember names, addresses, or Aadhar card numbers, or what exactly 235 means. Just know this: fissile fuel can be used right away to run nuclear reactors. Fertile fuel, on the other hand, needs to be activated first. Then it converts into fissile fuel. Only after that can reactors run on it and generate energy. From this simple concept, you get the idea of what a fission chain reaction is, what fertile and fissile materials are, and how the whole process is sustained. This is the core of Dr. Homi Bhabha’s vision and India’s three-stage nuclear plan.

You’ll understand it. In 1954, there was a conference going on in Delhi about the development of atomic energy for peaceful purposes. Homi Jehangir Baba was talking about generating electricity using nuclear energy. He brought up a geopolitical cheat sheet that takes advantage of India’s unique geology. Along India’s coastal areas, especially in Kerala, Tamil Nadu, and Odisha, there’s black and brown beach sand spread out. This sand contains a mineral called monazite, and from monazite, thorium can be extracted. The thorium that comes from this monazite is the isotope thorium-232.

Compared to the rest of the world, India has a huge amount of Thorium-232 in its soil. That’s why Bhabha said India’s long-term nuclear vision should focus on thorium, not uranium. The only problem is that Thorium-232 isn’t fissile—it can’t undergo fission right away. But it’s fertile, meaning it can’t sustain a chain reaction on its own. However, if it absorbs fast neutrons, it changes form through a series of reactions over many decades and turns into Uranium-233, which is fissile.

It’s about isotopes. We have a lot of fertile thorium available. But turning all that thorium into fissile uranium is a tough challenge. And we’re not just talking small quantities here. Whatever we do has to consider India’s population and growing energy needs. [Music] A large amount of fertile material needs to be converted into fissile material. That’s why India’s nuclear program is designed in stages [Music], and each stage takes decades. You can’t start the next stage properly until the previous one is fully completed. Why is that, you ask?

You’ll understand as we go along. After independence, India’s first stage was the natural uranium and pressurized heavy water reactor, called PHWR. Natural uranium is mostly U-238, about 99.3%, which is fertile, and only about 0.7% is U-235, which is fissile. India didn’t have uranium enrichment technology back then. To extract energy from this natural uranium, Canada had designed CANDU reactors. Bhabha chose the PHWR design for India, which was inspired by these Canadian CANDU reactors. PHWR stands for Pressurized Heavy Water Reactor, and they are…

In the operation, a special kind of water called heavy water (D2O) is used as a moderator and coolant. So basically, in stage one, what happens in the PHWR? The small amount of fissile U-235 that we extract or that comes from here and there is used to start a fission chain reaction. This releases energy, which is then converted into electricity. Also, inside this reactor, the fertile U-238 absorbs the neutrons released during these reactions. You might be thinking that uranium-238 is useless, but it’s not.

Quietly absorbing neutrons, it took a different path through a separate reaction. And after uranium-238 absorbs neutrons, it eventually produces plutonium-239. This is a really useful thing that will come in handy later. Plutonium-239 is where stage two begins. Stage one reactors weren’t just generating energy; they were also producing plutonium-239 as a byproduct of the fuel they used, which can be used as fuel itself. In the first stage, India proved its ability in reactor design and fuel management.

We were getting stronger. But we were still dependent on uranium-based reactors from outside. We didn’t really have any other option. But keep in mind, ultimately we wanted to move to thorium-based reactors. The fast breeder reactors come into play in the second stage. These fast breeder reactors show the reality of what we actually have in the first stage. And the third stage is all about the dream of thorium. The second stage acts like a bridge between them. And in these reactors, the plutonium fuel from the first stage is used, kind of like the fuel.

Fast breeder reactors are really amazing, guys. They don’t just generate electricity, but they also produce new fuel. If you break down the name, it clears up a lot. “Breeder” literally means “one that produces.” It’s called a breeder reactor because it produces fissile fuel from fertile fuel like thorium. How does it work? The answer lies in the first word: fast. The neutrons in it are fast neutrons.

Usually, in any energy reactor, we understand that moderators are used to control the chain reaction. They slow down the neutrons a bit so that too many neutrons don’t cause an uncontrollable chain reaction. Otherwise, it could lead to an explosion, basically turning it into a bomb. But in a fast breeder reactor, there are no moderators inside to slow down the neutrons. Instead, around the plutonium core, there’s a shell of fertile material like thorium or depleted uranium.

There’s a layer that’s wrapped with a blanket around it. So when fast neutrons come out and hit this fertile shell, they turn it into fissile material. If all this sounds confusing, think of the fast breeder reactor like a stove. Imagine a regular nuclear reactor like the stove in your village—normal. You put dry wood in it, it burns, leaves ash behind, and produces energy. But in the end, ash is what remains. Just like that, our old…

Conventional nuclear reactors use fissile fuels like plutonium. They generate energy and leave behind waste. But we have a lot of thorium, which is also a fissile fuel. Think of it like wet wood—you can’t just light it on fire directly. But it’s still useful wood. Now imagine a magic stove where you put in 1 kg of premium dry wood, and it creates fire. Around this stove, you layer the wet wood fuel. The heat coming from this stove then…

It’s turning the wet wood lying around into premium dry wood by drying it out. This magical stove not only gives us fire but also prepares premium dry wood for future fires. That’s exactly what our fast breeder reactor does. Here, the wet wood is like the thorium lying in bulk—it doesn’t burn easily on its own. In other words, you can’t get a direct reaction from it just like that. But if it’s activated with fast neutrons, this same wood will become high-quality fissile fuel tomorrow. This is the Indian nuclear program.

The ultimate goal of the second stage is to convert the fertile fuel we have into fresh fissile fuel using a fast breeder reactor. Once we have gathered enough fissile fuel, we will move on to the third stage. The vision for the third stage is to use nuclear reactors like advanced heavy water reactors or molten salt designs. That’s for the future. These will mainly run on Uranium-233, which we breed from thorium in the second stage. According to the Department of Atomic Energy.

This third stage will be entirely based on the effective use of thorium and a self-sustaining closed fuel cycle. Basically, everything will run on its own. And when you reach this third stage, the long geopolitical arc that Bhabha started will be complete. It means you’ve started from a point where the world is ready to make deals with you. You had uranium and heavy water reactors, and now you’re shifting towards producing your own fuel for your reactors so that no nuclear supplier groups—these cartels—can easily choke you off. Because you have…

If you have your own raw material, you can base it on that. It’s the same thing. Anyway, that’s the vision. Now let’s get back to reality. Making nuclear energy is actually as easy as making a stove. What all goes into it, bro? But the truth is, the whole process is packed with really tough physics and complex engineering. Right now, we’ve built a prototype fast breeder reactor. Prototype means an initial working model. Making this PFBR is like reaching the peak of nuclear engineering, like touching the summit. So far.

Only Russia operates commercial-scale fast breeder reactors. Countries like the US, Germany, France, and Japan have already shut down their programs. At the Kalpakkam Nuclear Complex in Tamil Nadu, Indian engineers faced some seriously daunting technical challenges. That’s how we got here. The toughest challenge for this PFBR was choosing the right coolant for the reactor. Normal reactors use water, but water slows down neutrons. For a breeder reactor, you need fast neutrons, so that’s why…

When it’s activated, [music] you can’t use water because it would slow things down. That’s why sodium was chosen as the coolant. In India’s PFBR, around 1750 tons of liquid sodium is used. Friends, sodium is actually a soft solid metal. You can cut it with a knife. But above 98 degrees Celsius, sodium turns into a liquid. And in the PFBR, this sodium circulates at about 547 degrees Celsius. Now, on one hand, sodium is an excellent heat conductor, right? Exactly what you need for a coolant.

But from a chemistry perspective, this is a dangerous situation. In chemistry class, sodium is notorious for being super reactive. If you throw a piece of sodium into water like that, it’s going to explode. Okay, water isn’t actually used in our PFBR. But this liquid sodium at 500 degrees Celsius—if it comes into contact with air, it’ll catch fire instantly. That will release some really toxic gases and stuff. A disaster. To handle sodium’s fiery nature, the PFBR is designed as a pool-type reactor.

The whole reactor core, primary pump, heat exchangers, and all that are sitting in a big stainless steel pool filled with liquid sodium. The idea is, if something goes wrong, this huge pool of sodium will take a long time to heat up. That buys enough time to do an emergency shutdown and get things under control. But it also means every single weld in this pool has to be flawless. Because if even a tiny bit of radioactive sodium leaks out, it’s a huge problem. There are plenty of critical situations like this.

With that in mind, we built the PFBR, our fast breeder reactor. Because with great power comes great responsibility. Work on the PFBR has been going on in Kalpakkam for almost twenty years now. When the project kicked off back in 2004, we thought it’d be done by 2010. But at first, we didn’t get much help from outside—no support at all—and since this tech was totally new, things got tricky. Critics kept brushing it off, saying, “Hey, why is it taking so long?” and the budget just kept going up.

Yeah, all the big countries have already shut it down. So why are these Indians still trying to build it? But yesterday, the scientists and engineers at the plant were solid folks too. They were wondering, how long is this mess gonna take to fix? If not today, then maybe tomorrow. Sorry about that. The silence around this project was finally broken in March 2024, when they started loading the reactor core. They did it in three steps — control rods first, then blanket assemblies, and last the mixed oxide fuel. All of that goes inside. And now, on April 6, 2026, this PFPR has…

We’ve hit first criticality—that’s when a nuclear reactor can keep a chain reaction going by itself. With this milestone, India has officially moved into stage two of its 70-year nuclear plan. We’ve just entered a new chapter, folks—beyond the stars, with even more to discover and plenty of excitement ahead. One thing the usual media isn’t really pointing out about this project is that during this first criticality, the PFBR’s blanket—the outer shell containing fertile material—is made of fertile Uranium-238.

They use natural uranium and depleted fuel here. Thorium hasn’t been used yet. Our end goal definitely includes adding a thorium blanket to the design. That’s our long-term plan and what we’re aiming for. But for now, thorium isn’t part of the PFBR. And remember, don’t go around saying we’ve made thorium-based fissile fuel—that’s not true yet. This fast breeder reactor’s second stage will run for decades, and once enough fissile fuel is built up…

We need to get a whole team of FBRs ready, like an army of them. Once that’s set, large-scale thorium use will kick off, and that’s when we’ll hit stage three. Some estimates say full thorium rollout won’t start until after 2070. Only time will tell—it might take longer, who knows. And if we’re still around, we’ll keep you updated, you know how it goes. Also, no one can say our videos only come out once in a blue moon anymore—look, we’re working on being consistent. You guys asked about PFBR in the last video’s comments.

Alright, we’ve covered that. If you’ve got any questions or want to know more, just drop a comment and we’ll try to get back to you. If you liked the video, please share it with your friends. If it was alright, a like would be cool too. There’s also a hype button—check that out. By the way, about 50-60%, maybe even 90% of you watching haven’t subscribed yet. You’re an important viewer, so please hit subscribe and stick around—we’re growing fast here. Some pretty niche jokes too. Anyway, January 24, 1966…

Dr. Homi Bhabha died in a plane crash. The official investigation said it was due to a navigation mistake or miscommunication. But later, some theories popped up suggesting foreign countries sabotaged the plane to slow down India’s nuclear program. We’ve seen how nations like the US openly go after nuclear scientists from other developing countries. So, there’s no concrete evidence that foreign forces were behind Bhabha’s death. Still, given how agencies like the CIA work, it’s definitely worth considering.

It doesn’t even sound like some wild conspiracy theory. Whether it was an accident or planned, I’m not sure. But man, just look at this guy’s legacy. It’s because of the grit and hard work of people like Homi Bhabha that, in this crazy, cutthroat world of geopolitics, India’s energy and defense are pretty solid. But how many of these folks do we actually remember? Maybe if we ever shake off all the fakes and cheap tricksters, we’ll finally give real respect to the true builders and caretakers of this country. Until then, we’ll just have to settle for their stories. The next video will cover another story.