The Nuclear Submarine

 

Michio Kaku

Enriched uranium, containing a higher concentration of the fissile isotope uranium-235 (typically 3-5% for reactors), is a highly efficient fuel for nuclear submarines.

A mere 5 kilograms can power a submarine for 30 years without refueling due to the immense energy released during nuclear fission.

In a nuclear reactor, uranium-235 atoms split when struck by neutrons, releasing energy, additional neutrons, and fission products.

This chain reaction sustains itself, generating consistent heat to produce steam, which drives turbines for propulsion and electricity.

The compact nature of nuclear reactors, combined with uranium’s high energy density (about 1 million times greater than fossil fuels), allows submarines to operate for decades without refueling.

A 5 kg core, enriched to optimize fission, can sustain a reactor producing 10-20 megawatts, sufficient for a submarine’s needs.

This eliminates the need for frequent refueling, unlike diesel-electric submarines, enabling extended missions, stealth, and global reach.

The reactor’s sealed design and long-lived fuel reduce logistical demands, though strict safety and non-proliferation measures are critical due to the radioactive materials involved.

This efficiency revolutionized naval operations, making nuclear submarines a cornerstone of modern fleets.