Kalpakkam quick breeder reactor attains criticality

India’s first prototype fast-breeder reactor (PFBR) in Tamil Nadu’s Kalpakkam on Monday (April 6, 2026) got here one other step ahead in its civil nuclear journey because it attained criticality.

First criticality in a quick breeder reactor is the second when the nuclear chain response turns into self-sustaining. A breeder reactor is a nuclear reactor that produces extra fissile materials than it consumes. In a ‘quick’ breeder reactor, the neutrons aren’t slowed, permitting them to set off particular fission reactions.

The PFBR is a machine that produces extra nuclear gas than it consumes. Its core-loading occasion is being hailed as a “milestone” as a result of the operationalization of the PFBR will mark the beginning of stage II of India’s three-stage nuclear energy programme.

The PFBR in Kalpakkam is the first-of-its-kind nuclear reactor. to make use of plutonium-based blended oxide as gas and liquid sodium as coolant. It can additionally make the most of the spent gas of Pressurized Heavy Water Reactors, which type the mainstay of nuclear energy in India at current.

In a publish on Prime Minister Narendra Modi on Monday stated it is a proud second for the nation. At present, India takes a defining step in its civil nuclear journey, advancing the second stage of its nuclear programme,” he stated.

“The indigenously designed and constructed Prototype Quick Breeder Reactor at Kalpakkam has attained criticality,” he added.

Mr. Modi stated this superior reactor, able to producing extra gas than it consumes, displays the depth of Indian scientific functionality and the power of the nation’s engineering enterprise. “It’s a decisive step in direction of harnessing our huge thorium reserves within the third stage of the programme. A proud second for India. Congratulations to our scientists and engineers,” he stated.

The loading of gas on the Kalpakkam PFBR had began in October final yr.

(With inputs from PTI)