Not really The pipes fill up with coolant (visually seem full) and drain completely when I turn off the reactor. I have fluid ejectors in the LHEs so they shouldnt store it?
All of those items (pipes, LHEs) hold some fluid. Though they are ejecting fluid, it is not instantaneous, and they have to take an action to remove the heat. So Let's say you have 14 pipes holding 500mb fluid each (waiting to be used) and 14 LHE's holding 1000 fluid each. you would need at least 21 buckets of fluid to keep the pipes filled. I often put 36-40 buckets of coolant into a reactor to keep it filled for 14 LHEs, and I will see 4 buckets, more or less, in the primary tank after that.
Is there anyone who knows a good MOX Fluid reactor design? I would really like to utilize both types of Fuel in my Fluid reactors .
Keep in mind MOX works just like uranium but with 1/2 the life, at 0 heat. Therefore you could just sub it in when you wanted. If I can fix the MOX reactor you showed for fluid, I'll let you know... but it's a HUGE balancing act, you have to get Net 0 heat loss or gain.
IF you had something like Nuclear Control, you could pull a part when it reaches 7500 and add it back at 7000 to keep high efficiencies... but I don't have nuclear control