INS Arihant undergoes sea acceptance trials

In a major step towards achieving allround ability to launch nuclear payload from air, land and water, a miniature 83 MWe pressurised water reactor (PWR), was fitted into INS Arihant and trials were conducted.The PWR is fuelled by highly-enriched uranium, which was developed with the help of Russians. The submarine was launched into the water last year and began its ‘sea acceptance trials’ (SAT) earlier this year wherein it was taken out of the harbour to conduct crucial trials.

“The nuclear reactor was fitted into the submarine for the first time some time back. Since it is the first time that India has built a miniature nuclear reactor for moving platform, it has to be tested when the submarine undergoes various kinds of motion like rolling and pitching,” sources said.

The challenge for Bhabha Atomic Research Centre was to make a compact reactor to fit into the 10-m diameter hull of INS Arihant (literally meaning slayer of enemies). The enriched uranium for the reactor comes from the Rare Materials Project, an undertaking of the Department of Atomic Energy, situated at Ratnahallai, near Mysore. With INS Arihant, India has become the sixth country after the US, Russia, China, France and Britain to have succeeded in constructing a nuclear submarine.

At the end of the trial Arihant will be given a nuclear regulatory authority certification before it could be deployed in the open oceans.As India has a policy of ‘no first use’ of nuclear weapons, a robust and survivable retaliatory strike capability is dependent on this nuclear-powered submarine. This makes Arihant a shot in the arm for India’s nuclear triad. With its ability to remain submerged in the waters for infinite time, Arihant with its stealth can remain undetected by the army and can fire its nuclear-tipped missiles from under the sea.


Arihant will be armed with 12 nuclear-tipped submarine launched missile K-15 with a range of 750 km. Plans are afoot to equip it with four K-4 Submarine Launched Ballistic Missiles (SLBMs) with a range of 3,500 km later. Presently, the K-4 is under-development.

With Indian Navy’s submarine fleet down to 14, a major overhaul is the need of the hour especially when compared to neighbouring China that is known to operate 8-10 nuclear powered submarines and 50-60 conventional ones.