jim hardy said:
well more exactly , ... sufficient to heat HALF the water in a 'typical' pool BY 140 deg...
Boiling away 1760 lbs/hr would be around 20 tons a day, which is hardly a dent in that 1500 ton inventory.
So if the pool was not pretty low on water it got more heat from someplace.
Conversely if it got no more heat, it musta been pretty low?
i don't know which is the truth, but assumed at the time it was low on water.
Again, that was an assumption but it did fit with the 'gamma backscatter' idea as cause of high radiation readings around building, and with high radiation readings from helicopters..loss of water = loss of shielding above spent fuel.
But i wasn't there. And there's surely other possibilities.
That one could unravel.
What's your thoughts?
Well. First, look at the facts: There's a 1400 m
3 pool of water with 0.5 MW of decay heat from spent fuel in it and its cooling has failed. 5 days later the operator informs its safety regulatory agency that due to the failed cooling, steam plumes are being emitted from the pool. The safety agency informs the public that this is the operator's estimate of the situation.
Next, there's the impeccable assumption: The laws of physics were not suspended in the pool.
Then follows the inescapable conclusion: What passed in this case as information from the operator to the agency, and from the agency to the public, was not information, not even false information. It was nonsense. Had it only been false information, that would be understandable. But no, for a statement to be possibly false, it must be implied that it can be possibly a true description of reality. Otherwise the statement is just so much nonsense -- and as your math has shown you, what was reported by the operator and sent on to the public by the agency was postulating a physical impossibility had occurred. All such statements are alike, they express nothing, they are all nonsense.
Imagine the operator had reported some other physical impossibility, e.g 'that gravity had reversed over the plant and was emptying the pool', and the safety agency reported this on to the public, the nonsensical nature of it all would have been clear to many people. It takes more knowledge to realize that a 1400 cubic meter pool of water cannot possibly be steaming plumes due to failed cooling after having been heated with 0.5 MW for a couple of days. The unsuspecting and ill-informed public would be excused in not 'getting it'. For Tepco the operator, and for NISA the agency, there is no excuse, and only a few credible explanations, none of which are flattering, and this is not the place to express them.
The fact remains, that what we were told about the situation in the pool did not make sense.
OK, so back to your considerations. If I get it, you meant to be able to extract as a fact that the pool was boiling from the nonsense "White smoke was seen rising from the vicinity of Unit-3 <..>TEPCO estimates that failing to cool the SFP has resulted in evaporation of pool water, generating steam.", then you added the assumptions that either the pool had lost a lot of water for unknown reasons, or it had an unknown heat source, then you coupled it to the observation of high doserate measured above the building, and got a plausible case of exposed fuel in the pool. But that seems to me to have been assumption upon assumption upon nonsense, and no surprise then that it was all wrong.