

Figure \(\PageIndex\): The containment structure of the Millstone Nuclear Power Plant.

Any nuclear reactor that produces power via the fission of uranium (U-235) or plutonium (Pu-239) by bombardment with neutrons must have at least five components: nuclear fuel consisting of fissionable material, a nuclear moderator, reactor coolant, control rods, and a shield/containment system. Chain reactions of fissionable materials can be controlled and sustained without an explosion in a nuclear reactor.
