There has been some very good speculation in the threads here, based on the evidence we have so far, that the containment pools have cracked or are broken.
But all that means is that they will have to set up a flow of water, rather than just adding some water to 'top off" the system.
The spent fuel facility I worked at had cages that maintained fuel rod spacing. Almost as important, it had a fairly common Stortz hose connection on the outside of the building that could easily by connected to a firetruck or hydrantfrom a safe distance and behind shielding. I can’t believe a spent fuel water pit would not be equipped this way anywhere in the world! Something ain’t adding up again.
Good info on current status seems so hard to get