Unit 2 of India’s Kudankulam NPP in Tamil Nadu achieved first criticality on 10 July after completion of all statutory and regulatory requirements and receipt of clearance from the Atomic Energy Regulatory Board (AERB, the Nuclear Power Corporation of India Limited (NPCIL) said in a statement. Russian and AERB experts were part of a team which supervised the process.

NPCIL said during the first stage of operation the 917MWe VVER-1000 plant will be synchronised to the local grid with about 400MWe of power “within 30 to 45 days from the date of criticality”. Then, after completion of procedural and regulatory requirements, power will be gradually increased in several steps. Construction of unit 2 was completed in July 2015, and it was loaded with its first fuel in May 2016. Construction of the Kudankulam units began in 2002. Kudankulam 1 achieved first criticality in mid-2013 and entered commercial operation in December 2014.

The units are being built under an agreement between India and Russia signed in 1988. The two AES-92 VVER-1000 reactors were supplied by Russia's Atomstroyexport under a Russian-financed contract. They have been built by NPCIL and also commissioned and operated by NPCIL under IAEA safeguards, with supervision from Russian specialists. Enriched uranium fuel for the entire life of the plant is to be supplied by Russia.

Russian state nuclear corporation Rosatom’s representative in India, Natalia Kudryashova, told Sputnik that it usually it takes one month to become operational after the unit becomes critical “but in this case it may take longer as the regulatory body wants 200% assurance, plus it is a new project for our Indian colleagues, although they have been already operating unit 1 successfully”. She added that the NPP Director expects commercial operation to begin in four months.

Two further AES-92 VVER-1000s are planned for construction at Kudankulam, with longer-term plans for up to 12 Russian reactors. Earlier this year Russian President Vladimir Putin said negotiations for Kudankulam 3 and 4 were at an advanced stage.