India’s PFBR Hits Criticality: 500 MWe Milestone, 2nd After Russia, Thorium Unlocks Energy Security

India’s 500 MWe Prototype Fast Breeder Reactor at Kalpakkam achieved criticality on April 6, 2026, at 8:25 PM, advancing to Stage II of its three-stage nuclear program. Only Russia previously operated a commercial fast breeder, following US and French failures despite billions invested. The milestone targets vast thorium reserves for sustained energy security and lower import reliance.