India has reached a significant milestone in its long-term energy independence ambitions after a next-generation reactor at Kalpakkam (a nuclear research complex on India's southeastern coast) achieved criticality on 7 April — the point at which a nuclear chain reaction becomes self-sustaining. The reactor converts thorium, a naturally occurring metal far more abundant in India than uranium and considered safer to handle, into usable fuel through particle bombardment; India holds the world's largest thorium reserves, giving it a strategic incentive to master the technology. The Department of Atomic Energy will now conduct intensive tests over several months before scaling up to larger reactors, with the government targeting commercial deployment on the national grid between 2030 and 2040.