Chennai, Nov 20 (IANS): India's atomic power company Nuclear Power Corporation of India Ltd has breached its target of restarting a unit at Kudankulam on November 19 and has now fixed revised target as December 25, 2015.

According to sources, the commissioning of the second unit is expected to happen at the end of 2016.

The start up process for second unit's approach to criticality is expected to happen during the first quarter of 2016-2017, the NPCIL said on Thursday.

According to Power System Operation Corporation Ltd (POSCO), the first 1,000 MW nuclear power unit at Kudankulam was expected to restart in December 2015.

The unit has breached several restart deadlines after it was shut down for annual maintenance in June 2015 for 60 days.

Anti-nuclear power activists said NPCIL loses around Rs.8 crore per day due to shut down of Kudankulam unit.

The NPCIL at an outlay of Rs.17,000 crore is setting up two 1,000 MW Russian reactors at Kudankulam in Tirunelveli district, 650 kms from Chennai.

The first unit attained criticality, which is the beginning of the fission process, in July 2013.

Subsequently it was connected to the southern grid in October 2013.

However, commercial power generation in the unit began on December 31, 2014.

Operating at full capacity the unit supplies power to Tamil Nadu (562.50 MW), Puducherry (33.50 MW), Kerala (133 MW), Karnataka (221 MW) and Andhra Pradesh (50 MW).