The first pouring of structural concrete for two more Russian-built VVER-1000 reactors at India’s Kudankulam nuclear power plant in Tamil Nadu took place on 29 June after the Atomic Energy Regulatory Board (AERB) granted a permit to Nuclear Power Corporation of India (NPCIL) to start construction of Kudankulam 3&4. Excavation of the main plant area has already been completed. First concrete marks the start of the second phase of the Kudankulam project. Kudankulam already hosts two operating VVER reactors which entered commercial operation in December 2014 and April 2017. They were built as part of an inter-governmental agreement signed between Moscow and New Delhi in 1998.

The general contractor for Kudankulam 3&4 is Russia’s Atomstroyexport, and the general designer is Atomenergoproekt – both companies are part of ASE Group, the engineering subsidiary of Russian state nuclear corporation Rosatom. ASE Group president Valery Limarenko noted in a statement that the Russia-Indian "strategic vision" on cooperation in the peaceful uses of atomic energy that envisages construction of at least 12 new Russian-designed power units in India by 2020.

The new units will be a "repeat design" of Kudankulam 1&2, with "improvements" based on feedback from commissioning and operational experience from the first units, AERB said. Russia and India earlier in June signed a framework agreement enabling construction of the third stage of the plant, comprising the construction of Kudankulam units 5&6. The agreement includes an inter-governmental credit protocol for implementation of the project.