Here's a breakdown:

* Uranium pellets: These are small, cylindrical pieces of enriched uranium dioxide, the fuel source for nuclear reactors.

* Fuel rods: These are long, hollow metal tubes (usually made of zirconium alloy) that contain the uranium pellets stacked end-to-end.

* Fuel assemblies: Multiple fuel rods are bundled together to form a fuel assembly.

So, while "container" might be technically accurate, "fuel rods" is the more specific and commonly used term.