Uranium is a very dense, radioactive metallic element, naturally occurring in rocks, soil and the ocean.
Before it can be used in a reactor for electricity generation, uranium must undergo a series of processes to turn it into useable fuel. First, the fuel is formed into pellets. These fuel pellets are placed inside long metal tubes, which are assembled in "bundles" to become the fuel assemblies inserted in the core of the reactor. Each individual fuel pellet has the generation capacity equal to one ton of coal.
In a nuclear reactor, the uranium fuel is assembled in such a way that a controlled fission chain reaction can be achieved. The heat created by splitting the atoms is then used to make steam, which spins a turbine to drive a generator, producing electricity.
A nuclear fuel assembly is made up of small pellets of uranium