A Conventionally Powered Aircraft Carrier Refuels in a Few Hours. Refueling a Nuclear Nimitz-Class Carrier Takes 3 to 5 Years and Requires Cutting Holes Through the Decks to Reach the Reactors. USS John C. Stennis Is Finishing Hers 14 Months Late.

A Conventionally Powered Aircraft Carrier Refuels in a Few Hours. Refueling a Nuclear Nimitz-Class Carrier Takes 3 to 5 Years and Requires Cutting Holes Through the Decks to Reach the Reactors. USS John C. Stennis Is Finishing Hers 14 Months Late.

Newport News does every carrier refueling, and it starts by pumping a million gallons of seawater out of the drydock. Both reactors are shut down and cooled, then crews cut through the decks above them — because the reactors sit deep inside a ship that was assembled around them. Spent cores come out, fresh enriched uranium goes in, the primary piping is replaced, and then the holes get closed. Along the way, 250 miles of pipe and 1,800 miles of …