The vessel with a maximum speed of 30 knots, can go up to 600 meters deep in water and has an endurance of 100 days with a crew of 73.

Vishakhapatnam: After a gap of two decades, India is all set to join the elite club of nations having nuclear-powered submarines with the induction of the Russian-origin 'Nerpa' into the Navy tomorrow.

Defence Minister A K Antony will formally commission the Akula II class Nerpa rechristened INS Chakra into the Navy at the Ship Building Complex here, Defence Ministry officials said here.

India has earlier leased and operated Charlie Class Russian nuclear submarine from 1988 for training its personnel on such submarines.

With INS Chakra and the indigenous INS Arihant expected to start operational patrols soon, India will soon have two nuclear submarines guarding its vast maritime boundaries.

The Nerpa has been taken on lease from Russia for ten years and would provide Navy the opportunity to train and operate such nuclear-powered vessels.

"Our crews will get the experience of operating under water for several months at a go as unlike the conventional diesel electric submarines, which have to come to surface at regular intervals, nuclear submarines can remain under water for months," Navy officials said.

India had signed a deal with Russia in 2004 worth over USD 900 million for leasing the submarine.

It was expected to be inducted a couple of years earlier, but after an accident in 2008, in which scores of Russian sailors died during trials, the delivery schedule was changed.

Indian Navy crews have already been imparted training for operating the submarine in Russia.A crew of over 70 people including around 30 officers is required to operate the INS Chakra.

The heart of the submarine is its nuclear reactor which has been made by Russia.Its displacement is around 8,140 tonnes.With a maximum speed of 30 knots, the vessel can go up to 600 meters in water and has an endurance of 100 days with a crew of 73.

The vessel is armed with four 533mm torpedo tubes and four 650 mm torpedo tubes.

The indigenously built Arihant is also expected to join the naval fleet soon as DRDO chief V K Saraswat recently said that "it is in advanced stages.It will be ready for operations in next few months".

India is also working to develop arsenal for Arihant as it has already carried out more than 10 test launches of the K-15 missile (also known as Sagarika) in the Bay of Bengal.

The nuclear-capable ballistic missile is said to have a range of over 700 kms and the premier research agency plans to increase its strike range in the near future.

The Nerpa was handed over to the Indian Navy after the completion of trials in December last year.

PTI