First i want to thank you for a great idea of lowering big areas filled with nuclear stuff.
Another good idea is to make using this turbines power first before other sources like reserve steam engines.
But i have problem with your heater/turbine setups on heavy load. i tried 750deg branch on heavy load >95%) and it have unexplainable problem with lack of steam on some turbines and reactor cooling to 970deg.
Math was this. I used reactors connected in long line, 2 in a row, all connected together with heat pipes around.
Ending row (on each side): 1 reactor 120MW - 2 heaters + 1 pump - 1 turbine
Main row (on each side):
1 reactor 160MW - 3 heaters + 1 pump - 1 turbine
3 main rows:
3 reactors - 3*(3 heaters + 1 pump) - (1+2+2) turbines
Math seems almost perfect.