When you run reactor and turbines on a long term energy loss on start is insignificant, i mean really. Turbines actually stops after steam input is empty, whatever it written in wiki (Nuclear Control Advanced Information Panel approved). I think wiki means that turbine stays in "machine processing Enabled" (in fact like all machines without machine controller installed or recent structural changes made) state that swiches by soft hammer and doesn't have effect on its inner process directly. I mean that all system depends on steam, steam depends on LHE, reactor activity and finally redstone signal in reactor redstone port.
P. S.: Actually LHE has its own startup penalty that is about 3 times longer than turbines.
P. P. S.: Turbines doesn't use up rotor durability when out of steam.
And there is no need to store steam anywhere, because steam-dist.water is close cycle system without any loss (almost). Only must have dist water buffer in LHE side input for insurance. Actually i thought this way about cseam buffer too, but it proved its useless in first minute.