nowaysj wrote:Correct me if I'm wrong, but the cooling system in the plant failed because outside power was cut, and then the generators failed for the cooling system, and then the batteries died. Is that the extent of your fail safe for a facility that can rain down radioactive material for hundreds of miles? That sounds like the fail safe for a renegade rave. .
Yes, the cooling system was certainly not made to survive these circumstances. It is still unclear why it failed. It could be the external (diesel) powered generators were damaged because of the tsunami. Others were apparently damaged during the several explosions that ensued later.
The system is designed in a way that should the cooling system (pumps) fail, the cores should remain submerged for something up to 8 hours I believe. It took the engineers longer than 8 Hours to get fresh water pumping back into the reactors though, causing several of the rods to become exposed which caused massive overheating (not melting as far as I know). Absence of clean freshwater (de-mineralized) forced them to use Seawater which is less effective. => Steam => Venting => current situation .
If you look at the schematics of the installation, it does in fact resemble an inflated balloon. Getting water in such a structure (with steam, heat and pressure taken in account) is not evident.
Mistakes were made, undoubtedly, but this facility is over 30 years old mind you. Anyway, it looks like whatever the outcome will be, it will be retired anyway as it is already damaged beyond repair...