INS Arihant submarine's N-reactor goes critical

India reached a major military and technological milestone on Saturday when the nuclear reactor on board submarine INS Arihant went critical, launching the country into a select league of nations which can develop nuclear-powered submarines.

The 80 MWe nuclear reactor on-board the submarine will start producing nuclear energy to propel the 104 meters long 6,000-tonne submarine. Being constructed at a military shipyard in Visakhapatnam, the first indigenous submarine would go for sea trial after the monsoon and may be inducted into the service by 2015.

When inducted, the INS Arihant will complete India’s nuclear triad giving New Delhi a second strike capability from land, air and sea in case of a nuclear attack.

Describing it as a very important milestone in the nation’s journey towards self reliance in critical areas, Defence Minister A K Antony said the submarine will be the pride of the Navy when it joins the fleet.A dedicated team of naval engineers and scientists from the Defence Research and Development Organisation and a secret unit from the Bhabha Atomic Research Centre worked tirelessly on the project for close to three decades. Miniaturising the nuclear reactor was a big technological challenge.

It remained one of India’s top secret military projects till 2009 when Prime Minister Manmohan Singh decided to announce its successful development to the world. But non-functioning of the nuclear reactor for over three years caused some concerns of late.
Ending all speculations, INS Arihant’s nuclear reactor attained criticality early on Saturday morning, said an official. Capable of remaining underwater for a month, the nuclear submarine also has a diesel back up for emergency situations in the deep sea.

The Navy, meanwhile, has begun operating a 12,000-tonne Akula class Russian
nuclear-powered submarine, INS Chakra.

It has an arsenal of conventional weapons and can remain under water for 100 days.
Though there is no official admission, sources said development of Arihant had cost about Rs 7,000 crore. Only five nations–the USA, the UK, Russia, France and China– currently operate nuclear submarine.

But when the submarine was launched in July 2009, many systems and components were not in place. The circular design of the submarine’s interior panel made the job more complicated. “More than 150 systems have to work simultaneously for the submarine to operate,” sources said.

At the moment, the N-submarine has 125 K-15 short range ballistic missiles with a 1-tonne nuclear warhead, which can hit the target at a distance of 700 km. Eventually they will be replaced by 3,500 km range submarine launched ballistic missiles, which are currently under development. Construction has begun for the second nuclear-submarine.