reactor core

The reactor core is the central part of a nuclear reactor where nuclear fission occurs, generating energy. It contains the fuel, which is typically uranium dioxide pellets encased in cladding tubes made of materials like zirconium alloy. This cladding acts as the first barrier to prevent radioactive fission products from escaping.12

The core also includes a coolant, such as water or liquid sodium, to carry away the heat produced by fission. In many reactors, a moderator, like water or graphite, is also present. The moderator's role is to slow down fast neutrons, making them more likely to cause further fission and sustain a chain reaction. The energy generated in the core is the basis for nuclear power systems.134