Sodium coolants are liquid metals used in some nuclear reactors to transfer heat away from the reactor core. They are effective because they have a high thermal conductivity and can operate at high temperatures without becoming gaseous. This property allows for efficient heat exchange, making sodium coolants suitable for fast breeder reactors, which generate more fuel than they consume. One of the main advantages of sodium coolants is their ability to remain liquid at high temperatures, which enhances reactor safety and efficiency. However, sodium is highly reactive with water and air, requiring careful handling and specific design considerations in systems like the Sodium-cooled fast reactor (SFR).