New Delhi

TheInternational Energy Agency (IEA) on Wednesday praised India and Prime Minister Narendra Modi on the successful achievement of the first criticality of the 500 MWe Prototype Fast Breeder Reactor (PFBR), calling it an important technological milestone. In a post on X, the global energy body lauded Indian scientists and engineers for the achievement, which comes after years of development.

The IEA said the reactor will use significantly less nuclear fuel compared to conventional reactors and would help pave the way for a "pathway towards a closed fuel cycle".

The remarks come after India’s PFBR at Kalpakkam attained first criticality on Monday, marking the start of a controlled nuclear fission chain reaction. Earlier, PM Modi had termed the achievement a “defining step” in India’s civil nuclear journey.

He also noted that it advances the second stage of the country’s three-stage nuclear programme.

"The indigenously designed and built Prototype Fast Breeder Reactor at Kalpakkam has attained criticality," the Prime Minister said in a post on X.

He added that the advanced reactor, capable of producing more fuel than it consumes, reflects the country’s scientific and engineering strength and is a decisive step towards harnessing vast thorium reserves in the third stage of the programme.