The corrupt Japanese Nuclear Industry takes us all for fools. Let me make the math real simple for the nuclear scientific morons. You have a melted core inside an RPV. You are injecting tons of water every hour. The water level is not measurable and radioactive water is appearing all over the lower recesses of the facility. Now we just add, melted core to leaking water, and you come up with the conclusion that there are serious holes in the RPV. In fact it is impossible for an entire core to melt and for the RPV to remain intact in a BWR. That is acknowledged in many studies. So the bottom line is they are injecting water not even knowing where the bulk of the melted core (called corium) actually is located right now. All smoke and mirrors. They just assume the concrete floor of a building that just had its earthquake motion rating exceeded which also experienced massive vertical and horizontal ground displacement, is still 100 % intact. With no cracks.
It’s water. We actually know how to keep water from leaching into the environment. It may be a hard job, but it is emminently doable. Impermeable membranes, set into, and if necessary below the foundation, then you collect the water, purify it, and recirculate it.
It’s the same job normally done by the reactor vessel. If the vessel isn’t water-tight, make the next barrier water-tight.
Might not even have to do that. If there are simply cracks in the substructure, you just have to provide a lower-resistance path for the water, like through an active pumping system. Collect the water before it reaches the cracks, then throw in sealant, and you might cut off all the leakage, or 99.9% of it.
Still don’t know what has made the vessel leak. Could be melts, but it also could be broken pipes that enter and exist the containment.
Nice thing is that they are able to collect more data now that things are stable, and the data is helping them understand the problem, which will lead to better solutions.