"The synchronisation of Unit 1 of the Kudankulam Nuclear Power Plant was done at 2.45 am. It is generating 75 MWe," KNPP Site Director R S Sundar told PTI.
The synchronisation coincides with Prime Minister Manmohan Singh's two-day visit to Russia.
In a bid to overcome legal hitches that have held up a deal on two new plants at the Kudankulam nuclear power complex over liability provisions, Dr Singh and President Vladimir Putin on Monday pledged to "resolve all outstanding issues" related to the project.
Russia is opposing the application of liability clauses under a new Indian law. Unit 1 had already attained criticality on July 13.
Atomic Energy Regulatory Board had in August given its nod to increase the power generation by 50 per cent up to 500 MW.
Nuclear Power Corporation of India Ltd is constructing two 1,000 MW units at KNPP jointly with Russia at Kudankulam in Tiruneveli district, some 650 km from Chennai.
The unit attained criticality in July this year after much delay, following protests against the project by anti-nuclear activists in areas around the complex, citing safety reasons.
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