New Delhi, March 23: India is set to induct Russian nuclear-powered submarine Nerpa in the first week of April making its navy only the sixth in the world with such a capability.

The Nerpa, to be re-christened the INS Chakra, is part of a hush-hush deal through which the Indian Navy has leased the submarine for 10 years. India also paid for the submarine to be built.

The submarine was handed over to the Indian Navy in January. In the first week of April, the navy is set to formally commission it into its fleet. The submarine would be based in Vishakhapatnam.

This is the second time the Indian Navy is taking a nuclear-powered submarine on lease from Russia. The first, also named the INS Chakra, was returned to Russia after its stint in India through the 1980s.

Russian news agency RIA Novosti estimated that the contract cost India more than $900 million. The deal included training of the crew. Nearly 100 sailors from the Indian Navy were based in Russia for training.

About 20 Russian sailors were killed in an accident on the Nerpa during trials in 2008. But a source in the Indian Navy said the submarine’s nuclear reactor was safe and that it had been sanitized.

The 8140-tonne submarine is said to be able to stay underwater for 100 days with a crew of 73. Since returning the first nuclear submarine it had leased, the Indian Navy lost its capability to operate such a vessel since the original crew had retired from service. The INS Chakra II is nuclear-powered but not nuclear-armed.