You imply you have working knowledge of real nuclear piles? Am I correct on this? Anyways, next question!
Off-Topic:
Of course. Technically, for breeders IRL, you guys have the right description that it turns back into fuel. However, the fuel is actually Plutonium, not Uranium. Also, reactors can be cooled by water as the fuel bundles in a reactor is supposed to be done so. However, the water (rather it is heavy or light water) would be radioactive and would be at a high temperature at high pressure (so that it can remain in a liquid state).
http://en.wikipedia.org/wiki/CANDU_reactor (uses heavy water for coolant, natural uranium as fuel)
http://en.wikipedia.org/wiki/Pressurized_water_reactor (uses light water for coolant, enriched uranium as fuel)
http://en.wikipedia.org/wiki/Boiling_water_reactor (uses light water for coolant, enriched uranium as fuel)
On-Topic: Thanks for the help.
P.S. Perhaps the things i listed could be used in a future update.