Japan: What will pouring water do?

i believe the pouring water is to resist the more radiation to happen. like cooling it off so the more heat doesnt get produced.

The only explanation I can have is to keep it in cooling mode. Keeping it cool will allow it not to overheat. If so my thinking it will be way too much of a waste.

As many has confirmed, pouring water helps maintain the temperature to prevent the plants from further heating up...

Basically to prevent explosion from overheating. I think without the cooling system, they have to manually adjust it, otherwise the next explosion will send radiation all over the world.

I am also not expert in nuclear technology but I thought I would express my views on this. Nuclear reactor consists of a solid R.C.C. structure fully packed with equally strong R.C.C. dome roof. This structure houses the reactor inside and cooled by cooling system. Inside this reactor there is another strong vessel may be of R.C.C. or steel I am not aware. This vessel houses the radioactive rods which is used as fuel for the reactor which is to be protected to avoid the radiation from radio active material entering into the atmosphere. Now when the cooling system of the reactor fails, being a closed container, the temperature inside will rise. By spraying water you can cool the outside structure which will eventually pass the cooling to the inside of the reactor. This is what I feel about the issue.