Jan 02, 2008: The U.S. decision to equip its next class of cruisers with nuclear power was driven largely by the rising cost of oil. Equipping a warship with a nuclear power plant increases cost by about $800 million. But with the expected growth of oil prices, the additional cost of a nuclear power plant is expected to pay for itself over the thirty year life of a warship.
Other than that, it's pretty much a wash. A nuclear power plant is much larger than an oil fueled one. While you eliminate the need for space to store oil, that just about takes care of the greater space requirements for the nuclear plant. OK, you don't have to spend all that time refueling at sea. But then there's the problems attendant with battle damage to a ship with a nuclear reactor on board. No one's had to face that one yet, but it's only a matter of time.
Another problem is getting qualified crew for the nuclear power plant. The nuclear subs have long had a problem with that, because the subs tend to be away from home, and out of touch with families, longer than the nuclear aircraft carriers. But even these carriers have to pay higher and higher bonuses to get, and retain, the sailors who can maintain and operate a nuclear plant. The latest generation of navy nuclear plants are built to eliminate some of these personnel problems (being easier to operate and maintain), but you still need quality sailors to look after these expensive, and potentially dangerous, machines.
But with nuclear cruisers, there is another benefit. It will be possible to have a carrier task force that is entirely nuclear powered (one carrier, two cruisers and one nuclear attack sub). Such a force could move at high speed for long distances, giving the force enormous strategic mobility, covering over 1,200 kilometers a day, thus able to reach anywhere on the high seas within two weeks.