It's the second 1,000MW pressurised water reactor that went critical.
The second unit of Kudankulam nuclear power project became critical as it started nuclear fission on Sunday at 8:56 p.m., according to officials of Nuclear Power Corporation of India Ltd (NPCIL).
This is the second 1,000 MW pressurised water reactor to go critical in India, almost exactly 3 years after Kudankulam's first unit went critical in July 2013.
Commercial generation is slated to start in four to six months after further tests are conducted and after the unit has been connected to the Southern power grid.
When Kudankulam's second unit finally starts power generation to its full capacity, Tamil Nadu, India's eleventh largest state, will hit 2,440MW of total nuclear power capacity.
Photo by Petr Pavlicek/IAEA