Chennai, Aug 29: The second 1,000 MW unit of the Kudankulam Nuclear Power Project (KNPP) in Tamil Nadu was connected to the grid on Monday, said a senior official.

\"The second unit of KNPP was connected to the grid at 11.17 a.m. The unit is operating at 170 MW,\" R.S. Sundar, the site director at KNPP, told IANS over telephone from Kudankulam.

\"With this the atomic power generation of Nuclear Power Corp of India Ltd (NPCIL) on Monday crossed 5,000 MW. It was a twin milestone for us,\" S.K. Sharma, chairman and managing director, NPCIL, told IANS over phone from Mumbai.

He said the commercial operation of the second unit was expected to happen by the end of this year and the tariff for the power generated from this unit will be decided then.

The tariff for the power generated from the first unit is around Rs 3.90 per unit, Sharma said.

Meanwhile, the second unit will be operated for three or four days and then will disconnected from the grid for testing the parametres.

\"A week after that the unit will be reconnected with the grid and the power generation will be gradually increased to 50 per cent. After clearances from AERB (Atomic Energy Regulatory Board), the power generation will be increased in stages,\" Sundar said.

\"In three months time we expect the unit to start power generation to its full capacity,\" he added.

\"We will touch power generation of 280 MW by the end of the day. We will operate the plant at that level for four days and then disconnect the unit from the grid,\" H.N. Sahu, station director, told IANS over phone.

He said the unit had AERB permission to operate up to 50 per cent capacity.

\"On restarting the unit later, the power levels will be increased to 50 per cent. After that we have to get AERB\'s permission for increasing the power levels. In a couple of months, we hope to touch 100 per cent power levels,\" Sahu added.

The second unit went critical or started nuclear fission on July 10.

According to Sundar, the unit was operating at low power after it went critical.

India\'s atomic power plant operator NPCIL has built two similar 1,000 MW nuclear power plants at Kudankulam with Russian equipment.

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 began only on December 31, 2014.

The unit experienced regular breakdowns after that and finally got stabilised some months ago to generate at an average around 940 MW power daily.

It was the first pressurised water reactor of India.

Second nuclear power unit at Kudankulam connected to grid