Complex sentence: Two Westinghouse A4W nuclear reactors are used for propulsion (the ship is capable of steaming more than three million miles before refueling) turning 4 five-bladed screws that weigh each, driving the ship at speeds over.
Split into simpler sentences: Two Westinghouse A4W nuclear reactors are used for propulsion, this means that the ship is capable of steaming more than three million miles before refuelling. The ship has 4 five-bladed propellers that weigh each and can drive the ship at speeds over.