If you apply a redstone signal to the steam grate, it stops letting out steam.no reactors that can irradiate the area. The issue is more trying to build a large enough seup that i can run the HP-turbine off off a HTGR setup. What i have seen thusfar is i will need to make 4-5 PBR setups and feed 4-5 heat exchanges. each exchange can do 4-5 boilers. so provided i can keep up with the water (shouldn't be an issue) then i should be able to get it running and keep it running.
Is there on/off valves for the steam line by any chance? i would assume there is but i have not found them thus far in my searches through the book or NEI