The main difference between conventional submarines and nuclear ones is the power generation system. Nuclear submarines employ nuclear reactors that either generate electricity that powers electric motors connected to the propeller shaft or rely on the reactor heat to produce steam to drive steam turbines. Submarine reactors typically use highly enriched fuel to deliver a large amount of energy.
The nuclear reactor also supplies energy to the submarine’s other subsystems. Such as, for maintenance of air quality, fresh water production by distilling salt water from the ocean, temperature regulation, etcetera. At present, all naval nuclear reactors have diesel generators as a backup.
N-subs have considerable advantages over ‘conventional’ (typically diesel-electric) ones. Nuclear propulsion, being independent of air, frees the submarine from the need to surface frequently, as is necessary for ‘conventional’ submarines. The large amount of power generated by a nuclear reactor allow n-subs to operate at high speed for long. The current generation of n-subs never need to be refueled in their 25-year life span.
The US launched the USS Nautilus, the first nuclear submarine in 1954. Nautilus could circle the world underwater for up to four months without resurfacing.
India’s just-launched 6,000 tonne n-sub Arihant, puts it in a select club with access to this deadly weapon of mass destruction. The US, Russia, France, Britain and China are the others in the group.
The 367-foot underwater killer made with Russian help will be operational after trials lasting three to five years. It will carry missiles with a range of about 450 miles. It will be able to accurately fire nuclear warheads at will. Fittingly, Arihant means destroyer of enemies.
Fortunately for the hawks, India already possesses the ability to ‘Arihant’ its enemies with fighter aircraft and missiles capable of carrying nuclear warheads. If all goes well, Arihant will give India underwater ballistic missile capabilities that, we hope, will turn out to be useless. I mean, never used.