Defence minister Rajnath Singh is set to commission India’s second nuclear-powered ballistic missile submarine, INS Arighat or S-3, in the presence of top officers including Navy chief Admiral Dinesh Tripathi at a quiet event in Visakhapatnam on Thursday, according to people aware of the matter. India will now have two SSBNs – INS Arihant and INS Arighat -- patrolling the …