Officials say the water trucks sprayed about 60 tons of water, so far, on reactor 3 at the Fukushima Daiichi nuclear plant.

That isn’t going to be enough:  Each spent fuel pool can hold up to 2000 tons of water, so you can see it’s going to take a lot of water (there are 6 reactors and several spent fuel pools).

Another problem is that even if they get outside power hooked to the plant, most of the power panels, and cooling pumps, have been destroyed by the tsunami.  So they are now working to fix that problem as well.