a material or a body of material which reflects incident radiation. In nuclear reactor technology, this term is usually restricted to designate a part of a reactor placed adjacent to the core for the purpose of returning some of the escaping neutrons back into the core by scattering collisions.
Sketch of core showing the general disposition, lattice, form, pitch and dimensions of core, reflector, location, shapes and dimensions of control elements, experimental and/or irradiation positions.