India's Atomic Energy Regulatory Board (AERB) has granted clearance for the first pouring of structural concrete for units 3 and 4 at the Kudankulam NPP in Tamil Nadu.

The two Russian-built VVER-1000 pressurised water reactors are repeat designs of units 1 and 2 with improvements based on commissioning and operational experience feedback, according to AERB. Kudankulam 1 began commercial operation in December 2014, and in April, India signed an agreement provisionally accepting Kudankulam 2 from Russia marking the reactor's entry into commercial service.

Excavation of the main plant area has already been completed, ready for construction of the new units to begin. First concrete is now expected in late June or early July. The general contractor is Atomstroyexport, and the general designer is Atomenergoproekt. Both companies are part of ASE Group, itself a subsidiary of state nuclear corporation Rosatom. Russia and India earlier in June signed a framework agreement enabling construction of the third stage of the plant (units 5 and 6). The agreement includes an inter-governmental credit protocol for implementation of the project.