Indigenous nuclear sub ‘Arihant’ quietly commissioned: reports

India quietly commissioned into service its first indigenous nuclear submarine, the INS Arihant, in August this year and the vessel has been operational since then, The Times of India reported today citing sources.

With its induction, India has completed the first step towards setting up a nuclear triad, ie nuclear capability by land, sea and air.

The daily said that according to the same sources, despite being inducted, the Arihant is "not yet fully ready" to be deployed for "deterrent patrols". The report added that the ministry of defence and the Indian Navy have refused to comment on the matter.

INS Arihant is India's first nuclear-powered ballistic missile submarine. While India has leased nuclear submarines from Russia before, Arihant is the first such vessel built indigenously.

According to reports, the vessel will be armed with K-15 missiles, which can carry nuclear warheads to a range of 750 km, and with K-4 missiles, which have a longer range.

In April this year, news agency IANS had reported that the K-4 ballistic missile was test-fired secretly from the Arihant in March year. The report added that the Defence Research and Development Organisation (DRDO) refused to officially comment on the matter.

The report said that the K-4 missile had a range of 3,500 km, adding that the Arihant has four vertical launch tubes, which can carry 12 K-15 missiles or four larger K-4 missiles.

The Arihant, which weighs in at 6,000 tonnes, is powered by a 83Mw pressurised water reactor, which as reported earlier has been built with considerable assistance from the Russians, who are said to have helped scientists at the Bhabha Atomic Research Centre in miniaturising the reactor to fit into the 10-metre diameter hull of the nuclear submarine. The reactor went critical in 2013.

The Rare Materials Project of the Department of Atomic Energy in Ratnahalli, Mysore, supplied the highly enriched uranium, while the submarine itself was built in a completely enclosed dry dock at the Shipbuilding Centre in Vishakapatnam.

Private Indian enterprises also played a role in the design and development of the vessel.

At the time of the submarine's launch in 2009, engineering major Larsen & Toubro (L&T) had said in a release that it had played a critical role in building the submarine.

As reported earlier, based on the design provided by the Indian Navy and DRDO, L&T's submarine design centre carried out detailed engineering, using the latest 3D modelling and product data management software, said a press release.

According to media reports, Tata Power built the control systems for the submarine, while the systems for the steam turbine integrated with the reactor are supplied by Walchandnagar Industries.