The controversy-hit Koodankulam Nuclear Power Project (KKNPP) will start its initial production of 400 MW electricity within 20 days, Union Minister V Narayanasamy said on Sunday.
"Yesterday, they started the criticality. The production of electricity will be started in next 20 days," Narayanasamy said.
He said initially 400 mega watts of electricity will be generated from the plant.
"After another 15 days, the production of 1,000 MW of electricity will be started," the Minister said.
The country's first 1,000 MW pressurised water reactor had last night attained criticality, setting the stage for power generation.
"All parameters are working well and everything is safe in the plant," said Narayanasamy, Minister of State in the Prime Minister's Office.
He said the allegations raised by non-government organisations over the safety of the plant are "not borne out of any truth".
"Scientists had said there were no security threats. There are seven layers of security system. The plant is very safe," the Minister added.
The project in Tamil Nadu's Tirunelveli district was hit by delays since December last following protests by locals raising safety concerns.
It was given a go-ahead by the Supreme Court in May.