The indigenous nuclear submarine, INS Arihant’s heart began throbbing on Saturday. To be more specific, its nuclear reactor went ‘critical’, thus began generating power, which can now propel the submarine.
The reactor that will burn low enriched Uranium-235 (LEU) fuel in its core, to energise the boiler that will, in turn, create combustion, and will create steam to turn the turbine which will in turn move the propellers (screws, in navy lingo) that will move the sub, radically changing the strategic scenario of at least the South Asian region, if not beyond.
This reactor of the Arihant is reportedly a ‘pressurised light water’ variety, generating about 80 MW of power.
The ‘light water,’ as opposed to radioactive heavy water (deuterium oxide), is easier to handle, and in turn more accessible at sea. The LEU of 20-25 per cent enriched fuel rods were prepared at the Rare Materials Project (RMP) based in Mysore. They were in the making for more than two decades as the gas-based centrifuge technology was not easy to muster.
So Saturday’s achievement of ‘criticality’ aboard Arihant sent two messages to the world. One, India now has a functioning nuclear submarine of its own, and two, it will no longer need anyone to supply LEU to power Tarapore or even Kudankolam electricity generating reactors.
In nuclear parlance, enriching U-235 to five per cent level is more difficult than enriching to 20 per cent or 95 per cent. An important element of a nuclear reactor is its containment chamber, usually made of steel. Arihant’s chamber too is made of special steel that hermetically seals the reactor.
The last documented nuclear reactor meltdown on a sub is that of a Russian variety that took place in 1961. Ever since, the nuclear submarines have become more technologically advanced and better designed.
The crew that will man Arihant are being trained on the INS Chakra, the nuclear powered submarine that the country has leased from Russia.
But the INS Arihant’s emergence changes the strategic scenario of the region drastically as it completes the nuclear triad in terms of the country’s ability to create a ‘minimum credible nuclear deterrent.’
Till now, the Indian strategic forces had the ability to deliver nuclear second strike from the air or by ballistic missiles, which could in turn be targetted for defensive or counter-strike purposes.
But with a nuclear submarine, whose location will always be unknown and a matter speculation, the deterrent becomes a real, clear and a present danger.