Nuclear Reactor Components

Reactor: Those components which, together, support the controlled fission process and the generation of steam for the purpose of producing power. Components include the reactor core, reactor vessel, control rods and reactor coolant system. Fuel Cladding: The long zirconium metal tubes in which the fuel pellets are stacked. The fuel cladding along with the fuel pellets are referred to as 'fuel rods.' The fuel cladding serves as the first and primary fission product barrier. Fuel Assembly: An array of fuel rods (plus guide thimbles and an instrument tube) held together by grid assemblies. There are many fuel assemblies in the core. Also referred to as a 'fuel bundle'. Core: The reactor core is comprised of the fuel assemblies and the structural materials which together serve to promote the fission process. Reactor Coolant: The water which serves to remove the heat energy from the core. Typically, water is referred to as 'reactor coolant' only when it is located within a reactor coolant system.