With a physical progress completed upto 99.66 per cent, the 1,000 MW first unit is expected to be commissioned next month, NPCIL website said.
Earlier, NPCIL expected it to be commissioned by this month.
NPCIL is building two 1,000 MW VVER nuclear power units with Russian collaboration at Kudankulam in Tirunelveli district of Tamil Nadu.
The Supreme Court had on May 6 cleared hurdles in commissioning of the controversial plant, saying that the safety and security requirements have been taken care of and the project would benefit larger public interest.