When the high rise concrete pump trucks get on site I will feel a lot better. They can pump water or concrete through same and the booms are remotely controlled with video. They can line the cabs with lead and coninuously pump water from the ocean into their hoppers.
If they had liquid nitrogen to dump on the exposed spent nuclear fuel, would that be a good thing.
One problem is the temperature (so cold that it would be dangerous for the workers -- could only be done with special equipment remotely controlled).
But unlike liquid hydrogen or liquid oxygen, it would not blow up and even if there is some sort of nuclear bombardment to change into other elements, it would not be dangerous (except for radioactive isotopes).
Getting Liquid Nitrogen there would be one problem (with enough volume). Having special equipment to spray such cold material is another (uncharted ground).
Even better is use a fire engine down at the beach to pump up the sea water and use the hopper on the cement truck to add in boron.
Radiation from the pool at Unit 4 will destroy a video camera in a matter of minutes.
When's that supposed to happen?