Dave,
I am "reading between the lines" plus my limited knowledge.
I am regsitered as a radiation worker and have performed "hot" work under a nuclear reactor in the core catcher space - generally used to store "hot" tooling and equipment.
I have found the Wiki site to be more up to date than most of the news sites - of course that may mean like me its more speculative.
Visit
www.world-nuclear-news.org/
but the website is a bit swampped at present.
The UN and IAEA have yet to licence a high level radiation dump anywhere in the world - so they store spent fuel rods (often for later reprocessing) in the cooling ponds - most older reactors have had to increace their ponds to accomodate this waste.
If the Fukiyama plant has a lot of "spent" fuel rods in the pond and have accidentally exposed these rods (perhaps because of the quake - or using the water on the reactor - I don't know) it would seem that an uncontained reaction has started there - this is very bad news indeed.
When CNN offhandedly announced that there was a fire in the storeage pond - my hair stood on end.
Such an offhand comment by reporters with no real knowledge of the import of such a statement.
It could of course just be an ordinary chemical fire but not likely.
If it is nuclear then there is no pressure containment and trying to cool it down is going to release a lot of Hydrogen - it is also going to be radiologically very hot and impossible to get close to.
This also possibly suggests why they were using the crane - to redistribute "stuff" in the pond.
The fact that they have evacuated #1 suggests radiation levels are now at an unsafe level - thus complicating matters. If they have to pull back and (horrors) evacuate the control rooms (most of the containment efforts will be remote from the control room) then it is likely all three reactors and their ponds will follow suit.
That scenario could be worse than Chernobyl.
I hope to hell they get this under control - its like watching a slow motion train wreck.
#1 is a 460MW unit 2,3&4 are 784MW units amongst the largest in the world - Japanese built to a GE design.
If the reactors had been properly scrammed the control rods and safety rods should have gone in - bringing the reaction to a near complete halt - the residual and decay heat does not need that much cooling - the reactor is only supposed to be at 290°C at the concommitant steam pressure.
Even in a worst case scenario the water without circulation should absorb this heat by boiling and venting - undesirable because of radioactive products in the steam - sure you have to restore cooling sooner or later but the amount of heat coming from these reactors suggests that at least portions of the core are still active.
Caveat - I know enough about the processes but nothing about the actual Fukiyama plant design also the information I am basing my speculation on (for that's what it is) could be wrong or simply misreported - so I could be unduly alarmist.
Please do not take anything I have written here as Gospel - I could be wrong - but I am very concerned.
Regards,
Ken
Update,
The pond fire has been extinguished and has been attributed to hydrogen (reaction between overheated pond water and zirconium - 100°c - its boiling - should be 40° ) - so its a chemical surface fire - that's a relief. Still leaves some unanswered questions ?? such as how has the hydrogen been stopped ? Did they get it cooled down etc. etc.
