Hi Arnie -
re steam tables;
one wonders if reactor 1 is intentionally kept at pressure so steam will be more dense hence provide better cooling.

Unit 2 they could be keeping above saturation on purpose so that the steam exiting will be dry, hence carrying along no little iodine friends as it leaves. As nasty as 2's basement is that's what i'd do in their shoes.

Lastly the seawater they put into unit 4's pool - where did they get it? From their intake? That seawater had iodine in it from unit 2 like 10^4 Bq/cc.. That could be source of quite a bit of iodine in 4's pool, even at 100::1 dilution. I would think a pool criticality would have steam cleaned the pool and left it in disarray.

Your observations and ideas are refreshing. Take this as constructive questioning not being argumentative.

and if you have any insights as to the orange flashes at beginning instant of units 1&3 explosions please share them!
Orange is color of salt flame and by timelines i've seen they had not yet started seawater into spent fuel pools at time of those explosions. So how'd salt, not being a gas, get mixed in with the hydrogen?

old jim