With the PFBR’s first criticality, India’s three-stage nuclear vision moves from doctrine to deployment, reshaping its geopolitical calculus. The successful first criticality of India’s 500 MWe Prototype Fast Breeder Reactor (PFBR) at Kalpakkam is much more than a technical milestone; it is a decisive step in India’s three stage nuclear programme. This indigenous, sodium cooled fast breeder reactor bridges the gap between our current uranium based nuclear fleet and the long-t