Russia and India have signed a framework agreement enabling construction of the ’third stage’ of the Kudankulam nuclear power plant, including an intergovernmental credit protocol for implementation of the project.

The documents were signed yesterday at the 18th Annual Russian-Indian Summit, held alongside the St Petersburg International Economic Forum, by Valery Limarenko, president ASE Group, and Sri Sharma, chairman and managing director of the Nuclear Power Corporation of India Ltd (NPCIL).

The agreement, which was signed in the presence of Russian President Vladimir Putin and Indian Prime Minister Narendra Modi, covers construction of units 5 and 6 according to Russian nuclear reactor design. Russian nuclear power corporation Rosatom said the agreement and protocol are required to start construction of the units, specifying as they do the “obligations of the two sides, costs and other important conditions of their cooperation”.

According to a Rosatom statement, Limarenko said: “Extremely important documents have been signed that have been the focus of intensive joint work in recent months.” He added: “All the formalities have been carried out now in order to finally launch the project to construct two new power units at Kudankulam using Russian technologies”. The project has now entered the “practical phase”, he added.

Kudankulam, in Tamil Nadu, is home to two VVER-1000s supplied by the ASE Group, which is Rosatom’s engineering subsidiary and includes Atomstroyexport and Atomenergoproekt.

Kudankulam 1 entered commercial operation in December 2014, while in April this year NPCIL signed an agreement provisionally accepting Kudankulam unit 2 from its Russian suppliers and thus marking the unit’s entry into commercial operation. Two further VVER-1000 units — Kudankulam 3 and 4 — are to be built at the site in the second construction phase. Pouring of first concrete for units 3 and 4 is planned for the end of June, Rosatom said yesterday.

Cooperation between India and Russia to build the Kudankulam plant has its origins in an inter-governmental agreement signed in 1988 by the then Indian Prime Minister Rajiv Gandhi and Soviet Union leader Mikhail Gorbachov. First concrete for unit 1 was poured in March 2002, with that for unit 2 following four months later. The units were originally scheduled to begin commercial operation in December 2007 and December 2008 respectively.

Although unit 1 was completed in March 2011, its commissioning was delayed due to protests and legal action following the accident at Japan’s Fukushima Daiichi plant the same month. Plant owner Nuclear Power Corporation of India Limited announced in July 2013 that the unit had achieved first criticality. It was connected to the grid in October that year. Unit 2 — India’s 22nd nuclear power reactor — achieved first criticality in July last year.