AP Chem: What is happening on a molecular scale when equilibrium is established?

Although the diagram is not shown, i know that the convection is heated by a the core.

This is what i found “nuclear fuel is material used in nuclear power stations to produce heat to power turbines. heat is created when nuclear fuel undergoes nuclear fission. most nuclear fuels contain heavy fissile actinide elements that are capable of undergoing and sustaining nuclear fission.” i hope this you for what your looking for. can you plz mark me brainliest?

What are the statements?