It's good to see someone who want to do the work themselves and only wants guiding.

So have you looked into how much energy 1000kg of coal will release?

Hint Look up heat of combustion and ask again if unsure.

Right so that gives us the amount of energy we want to produce from our Uranium.

A nuclear reaction results in a loss of total mass which is the source of its energy.

Did you know this?

If you google around you will find that U235 produces a loss of 0.2 atomic mass units (AMU) per mole of U235.

Einstein helps us find out how much energy this represents.

Can you calculate this?

(Hint you should end up with about 200MeV)

However in the real world about 175MeV is spent as kinetic energy for the fission products so is unavailable - you should ask your teacher whether you need to allow for this.

So all that remains is to find out how many moles you need to develop the coal energy.

Let us know how you get on.