Containment Vessel
Reactor Vessel
Steam Line
Support Trunnion
Steam Generator
Riser
Nuclear Core
Conduction
Heat is transferred from the primary coolant through the walls of the tubes in the steam generator, heating the water (secondary coolant) inside them to turn it to steam.
Energy from nuclear reaction heats the primary reactor coolant causing it to rise by convection and natural buoyancy through the riser, much like a chimney effect.
Convection
Colder (denser) primary coolant "falls" to bottom of reactor pressure vessel, cycle continues.
Gravity
