New Delhi, August 10
Inching closer to developing a nuclear triad, India today formally announced that the nuclear reactor on its 6,000 tonne submarine INS Arihant has gone ‘critical’, a significant landmark. The indigenously built Arihant (slayer of enemies) will dive into sea in a couple of weeks.

That the reactor could be formally declared critical anytime was first reported by The Tribune in its columns on July 29. The vessel, once commissioned about 18 months from now, will complete the third and last leg of the nuclear triad, which means attaining the capability to fire nuclear missiles from land, air and sea.

A nuclear submarine is militarily considered to be one of the most potent second-strike platforms for retaliation to a nuclear strike. India has a no-first use nuclear policy.

During the Cold War, the US and the USSR kept their submarines on deterrence patrols — ready to fire within seconds of a nuclear strike by the adversary. Unlike conventional vessels, a nuclear-powered submarine does not need to surface for up to nearly two months in contrast to conventional submarines.

Prime Minister Manmohan Singh and Defence Minister AK Antony have welcomed the development

Sources explained that the “reactor went critical” meant that it was now generating power. Its potential will be increased progressively.

It is still not coupled with the engine and propulsion, but the most important milestone has been achieved.

As much as 80MW of power will be generated from its pressurised water reactor (PWR). The PWR was developed by the Bhabha Atomic Research Centre with assistance from a Russian design team.

It uses enriched uranium as fuel and light water as coolant and moderator.

The submarine, that has nearly 60 per cent local content, will now start making shallow dives. Then it will undertake deeper dives for longer periods. From there on, the vessel will be gradually loaded with weapons and missiles and with each addition all parameters will be tested before the next load is added.

“For two months or so each test will be conducted underwater. This will include the Submarine Launched Ballistic Missile (SLBM)”, official sources said. New Delhi has done 10 underwater launches of the SLBM’s code named ‘B05’ using a submerged pontoon to mimic a submarine. It can travel to 700 kms while the bigger variant, so far known as ‘K-4’, can hit targets 3,500 kms away and will finally be installed on the Arihant and also the next two follow-on submarines of the same class.

India will join the select band of countries like the US, the UK, France, and China who have such a technology and prowess.

The submarine has been developed jointly by the Indian Navy, Bhabha Atomic Research Centre (BARC) and the Defence Research and Development Organisation (DRDO) at the naval dockyard in Visakhapatnam and has cost Rs 15,000 crore to develop. Russian designers have assisted in building the vessel.