I read this morning that the expended fuel rods at Fukushima are stored in a pool above the reactor core. If the reactor has a meltdown, the pool is damaged and will leak, exposing the fuel rods to air, which will cause them to heat up and release far more radiation into the atmosphere than could a mere meltdown.
Currently the Japanese government is planning to keep the spent fuel rods cool by dumping water from helicopters. This was done to put out the fire at Chernobyl, but I recall that at least one pilot died from radiation exposure.
Another way, as shown in the above sketchup image, would be to use tower cranes to position water hoses into the damaged pool. I show both stationary and mobile tower cranes. If Google Sketchup Warehouse has the proper dimensions for the equipment and buildings, this technique appears workable.
I think the flow rate from hoses directed by a fleet of tower cranes would be considerably higher than that provided by helicopters taking turns. Moreover, with the aid of teleoperation, the hose spray could be directed toward the areas with the worst damage and highest levels of heating, whereas dumping water from helicopters might be hit-or-miss in regard to its targeting. Also, hoses from tower cranes could provide an adjustable flow rate, whereas helicopter dumping entails the risk of a transient temperature shock causing an explosion when the rods heat up excessively between dumpings and then are abruptly cooled during the dumpings.
(NOTE: It is beyond the scope of this blog to discuss why it appears that GE deliberately designed Japanese nuclear power plants to be doomsday devices.)