Nuclear subs are a "money no object" technology, as our supposed insurance policy against Soviet invasion and/or armageddon, it's whatever it takes.
That technology is so expensive, so far from economically viable, that only two countries (US & France) are even using it for aircraft carriers, despite its potential huge advantages over oil (stay at sea for years at a time without refuelling, no need for vulnerable supply ships etc.)
That technology is so expensive, so far from economically viable, that only two countries (US & France) are even using it for aircraft carriers, despite its potential huge advantages over oil (stay at sea for years at a time without refuelling, no need for vulnerable supply ships etc.)