Nuclear submarines operate on nuclear reactors that provide the immense power necessary for long-duration underwater voyages. Unlike conventional submarines that rely on diesel fuel, nuclear-powered subs use highly enriched uranium as fuel, which allows them to operate for many years without needing to refuel. The refueling process involves replacing the spent fuel rods within the reactor with fresh ones, a complex and highly controlled procedure conducted in specialized facilities. Typically, nuclear submarines only require refueling once every 20 to 30 years, depending on the reactor design and operational usage. This long interval is a major strategic advantage, enabling submarines to remain submerged and undetected for extended periods during missions. Refueling is not performed at sea but in dockyards equipped with extensive nuclear safety measures to handle radioactive materials safely. Besides refueling, nuclear submarines undergo regular maintenance and checks to ensure their propulsion systems function optimally. Advanced safety protocols and crew training are essential to managing the nuclear reactors onboard, minimizing risks and ensuring safe operation. The ability of nuclear submarines to operate without frequent refueling is pivotal for military strategy, allowing for greater stealth, endurance, and operational range. This capability is made possible by sophisticated nuclear engineering and strict adherence to safety standards, reflecting the high level of technological expertise invested in naval nuclear propulsion.