Only 4 kilograms of uranium are required to power nuclear submarines for 30 years without refueling. The reactors used in nuclear submarines are based on highly enriched uranium (HEU), which contains 90% or more uranium-235. This enriched uranium can produce a large amount of energy in small quantities.
4-5 kilograms of enriched uranium can power a nuclear submarine for several decades, as nuclear fission reactions produce a tremendous amount of energy. The energy produced by the fission of one kilogram of uranium-235 is equivalent to approximately 24,000,000 kilowatt-hours.
The efficient use of fuel in nuclear reactors and the design of the reactor itself eliminate the need for frequent fuel replacements. Nuclear submarines do not require fuel replacements for 20-30 years, which is a significant technological advantage for their long-term missions.
This is why nuclear submarines have greater autonomy than conventional diesel-electric submarines.
Why aren’t we planning for SMR use in Australia?
