India is on the brink of completing its most advanced nuclear reactor, a significant milestone in the nation’s nuclear energy ambitions. The Prototype Fast Breeder Reactor (PFBR), situated in Kalpakkam, Tamil Nadu, has been given the green light by India’s atomic regulatory body to start loading nuclear fuel. This development ushers in a controlled chain reaction in what is considered India’s most sophisticated and complex nuclear reactor.
The PFBR, a 500MW liquid sodium-cooled reactor, has been in development for two decades. Concerns have been raised about the use of sodium, a hazardous material, as a coolant. However, the Atomic Energy Regulatory Board (AERB) has conducted thorough safety reviews and inspections, ensuring the reactor’s safety. Once operational, India will join Russia as one of the only two nations with commercially operating fast breeder reactors.
“This is a monumental achievement for India’s self-reliant atomic energy program,” stated Dinesh Kumar Shukla, chairman of the AERB, as reported by NDTV. He emphasized that the PFBR is an “inherently safe reactor.”
The PFBR is entirely domestically designed and constructed, involving over 200 Indian industries, aligning with the government’s self-reliance push. Despite the technological challenges and the necessity for indigenous solutions, the project has experienced delays and cost overruns, now amounting to ₹68,400m (£651.43m).
The Department of Atomic Energy (DAE) describes the PFBR as a third-generation reactor featuring passive safety systems, ensuring it can safely shut down during emergencies. It also utilizes spent fuel from India’s nuclear program, thereby reducing nuclear waste and the need for long-term geological disposal.
Even with its advanced features, the PFBR’s capital and operational costs are comparable to those of other nuclear and conventional power plants. The reactor’s approval is also a significant step toward India’s utilization of plutonium as a nuclear fuel and opens the door for future thorium use—a resource India has in abundance.
India’s limited uranium reserves make thorium a critical element for the country’s long-term energy security, with experts suggesting that thorium could provide energy for over 300 years. Mastering thorium-based technology is seen as essential for securing India’s energy future.
Fast breeder reactors like the PFBR are unique because they generate more fuel than they consume, creating a nearly inexhaustible energy source. The term “fast” refers to the high-energy neutrons used in these reactors. India already operates a Fast Breeder Test Reactor (FBTR) at the same location, which has been in operation for 39 years.
With the AERB’s approval, the PFBR can now proceed with fuel loading and initial low-power physics experiments, and it is expected to become fully operational within a few months. Initially, the PFBR will use Uranium-Plutonium Mixed Oxide (MOX) fuel. A surrounding uranium-238 “blanket” will produce additional fuel through a process known as nuclear transmutation, which is the breeding mechanism that defines these reactors.
In the future, thorium-232 may also be used as a blanket material, producing fissile uranium-233 through transmutation, which will play a crucial role in the third stage of India’s nuclear program. This stage is essential for exploiting India’s extensive thorium reserves.
Nuclear energy is considered a reliable and low-carbon source of electricity, contributing to reduced greenhouse gas emissions and helping to diversify the energy supply. However, safety and waste management concerns persist, and researchers are exploring new technologies to address these issues.
China recently revealed the world’s first “meltdown-proof” nuclear power plant, highlighting the global focus on advancing nuclear technology. Currently, nuclear energy constitutes only 3.11 percent of India’s total power generation, but the country has ambitious plans to increase this share to nearly 9 percent by 2047, with significant investments being made in nuclear technology.
During the presentation of India’s latest annual budget, Finance Minister Nirmala Sitharaman informed parliament that nuclear energy would become “a very significant part of the energy mix” for India’s growth. The government aims to expand the nation’s nuclear power capacity from 6,780MW to 22,480MW by 2031, which will involve constructing 18 new reactors with a combined capacity of 13.8GW of electricity. Following the PFBR, two additional fast breeder reactors are in the planning stages.