OK, so I added a second row of boilers round the outside of the square...if I wanted better cooling I should replace those with water source blocks instead? And would the same work for the fuel cores, Place water source blocks above them and it should provide better cooling than air without reducing neutron production?
As for water production, i'm using liquid transfer nodes, which have pretty prodigious throughput, plus i'm routing the water from my condensers back into the system. My concern with that would be more that I can't remember if it's possible to overfill a fluiduct to the point of breaking it rather than not having enough water at any point XD