Submarine nuclear power plants

A submarine nuclear power plant, also known as a nuclear propulsion system, works on the same fundamental principles as a nuclear power plant on land, but it is designed to provide propulsion for a submarine rather than electricity for a grid.

Here’s an overview of how a submarine nuclear power plant works

Nuclear Reactor: The heart of a submarine’s nuclear power plant is a nuclear reactor. It typically uses enriched uranium or plutonium as fuel. The reactor core contains fuel rods made of these materials.

Fission Reaction: Inside the reactor core, a controlled nuclear fission reaction takes place. During fission, the nucleus of an atom is split into two smaller nuclei, releasing a significant amount of energy in the form of heat. This heat is the source of power for the submarine.

Heat Transfer: The heat generated by the nuclear fission reactions is used to heat a coolant, which is usually a high-pressure, high-temperature water or a liquid metal like sodium or lead. This heated coolant flows through a series of pipes and passes near the reactor core.

Steam Generation: In a pressurized water reactor (PWR), which is commonly used in submarine nuclear power plants, the hot coolant is used to heat a secondary loop of water, which is kept at lower pressure. This secondary water loop turns into high-pressure steam due to the heat it absorbs from the primary loop.

Steam Turbines: The high-pressure steam generated in the secondary loop is directed to a steam turbine. The force of the high-speed steam against the turbine blades causes the turbine to spin.

Power Generation: The spinning steam turbine is mechanically connected to a generator, which converts the mechanical energy into electrical energy. This electrical power is used to operate the submarine’s propulsion system, electrical systems, and other equipment.

Cooling: After passing through the steam turbine, the steam is condensed back into water using a cooling system, usually seawater or a separate cooling loop. This condensed water is then returned to the secondary loop to be reheated by the primary loop.

Control Systems: Sophisticated control systems are in place to manage the nuclear reactions, maintain the desired reactor temperature and power level, and ensure the safety of the reactor and crew. 

Why do we use Nuclear Power

The key advantage of a submarine nuclear power plant is its ability to generate a large amount of power with a small amount of fuel, allowing submarines to operate underwater for extended periods without the need to surface frequently for refueling. Additionally, nuclear power plants produce very low emissions, making them ideal for submarines that need to remain stealthy and undetected while submerged.


Nuclear Safety

Safety measures, redundancy, and rigorous training for the crew are crucial aspects of operating a submarine with a nuclear power plant to ensure the safety of the vessel and its crew, as well as to prevent any accidental release of radioactive materials.

Members of the engineering team on a nuclear submarine, commonly called ‘Back Afties’ due to the where there watch keeping positions are onboard, Back Aft.