What is a Meltdown?

Normal operation Steel cap Pressure reactor vessel Steam out - Steam out Electricity - Concrete containment Turbine Generator Normal water level structure Fuel rods - Water in Heat Exchanger Condenser Control rods Recirculation pump dund - Condensed water in Sea water Wet well Torus Concrete containment wall The meltdown process If the cooling system which pumps water into the pressure reactor vessel fails, water levels pellets of uranium oxide which can drop and expose fuel rods that are made of a Zirconium At around 2,000 C, the The meltdown is trapped by the containment chamber, another layer of protection, which is surrounded by another thick In a worst-case scenario, fuel can melt through both the containment chamber and The reactor becomes ever Zirconium can melts, exposing hotter because of the fission process, if it's still occurring, and because of the radioactivity of the fission products. It then melts through the bottom of the vessel. concrete containment wall, releasing radioactivity. will also melt by 3,000 C. concrete structure. metal can containing enriched uranium oxide.