It also informed Parliament that five sites -- which would have total 28 nuclear reactors -- have been accorded 'in principle' approval by the central government.
Jitendra Singh, minister of state for personnel, public grievances and pensions and prime minister's office (PMO), told Rajya Sabha on Thursday through a written answer that "at present, there are nine nuclear power reactors at various stages of construction" that are targeted for completion by 2024-25.
"In addition, 12 more nuclear power reactors have been accorded administrative approval and financial sanction by the government in June 2017," he added.
Singh handles the DAE, which comes under the PMO.
"Thus, 21 nuclear power reactors, with an installed capacity of 15,700 MW are under implementation, envisaged for progressive completion by the year 2031," he added.
Gujarat, Rajasthan and Haryana each has two reactors under construction currently. Tamil Nadu has three reactors under construction, according to Singh.
Each of the five states -- Haryana, Rajasthan, Karnataka, Madhya Pradesh and Tamil Nadu -- have been accorded administrative approval and financial sanction to establish two nuclear reactors, Singh told Rajya Sabha.
Jaitapur in Maharashtra, Kovvada in Andhra Pradesh, Chhaya Mithi Virdi in Gujarat, Haripur in West Bengal and Bhimpur in Madhya Pradesh are the five sites that have been accorded 'in principle' approval to establish nuclear reactors, Singh stated.
In response to another question in Rajya Sabha, Singh stated that during 2014-15 and 2015-16, two nuclear power plants -- Kudankulam units 1 and 2 -- were commissioned and commenced commercial operation.
"There are presently no proposals for accord of administrative approval and financial sanction of nuclear power projects pending with the government," he added.