How nuclear-powered submarines actually work

USS Virginia returns to the shipyard after its first voyage in open seas, July 30, 2004.
US Navy
The Australian government has just declared an historic defence agreement with the US and UK.
The deal will see a new fleet of nuclear-powered submarines patrol Australian waters.
Nuclear-powered subs can operate at sea for longer, spend more time submerged, and sail at higher speeds than conventionally powered subs.
See more stories on Insider's business page.
The Australian government has just dec