Arihant, which is 110-metre-long and weighing 6,000 tonne, is powered by an 83 MW pressurised light water nuclear reactor, as per a media report.
The vessel was built under Advanced Technology Vessel Project at the Ship Building Centre, Visakhapatnam. Navy Chief of Staff Admiral Sunil Lamba had formally commissioned the ship into the naval fleet.
Nuclear tipped ballistic missiles or Ship Submersible Ballistic Nuclears (SSBNs) can be carried in the ship. The SSBNs are capable of concealing themselves undetected for months together in the sea depths and provide India with the capability to strike back after a N-attack from another nation.
Apart from India, only five countries in the world such as the United States, United Kingdom, France, Russia and China have developed nuclear-armed submarines so far.
The advantage of sea-based nukes, especially submarines, is that they are harder to track and destroy as compared to land and air launch platforms.