I think the more important observation is that even with a perfect hit you'd be adding 7.5 tonnes of water which would raise the water level by only 15 cm when the fuel assemblies are over 4m tall.

So dropping water from helicopters is just useless.

So, in what may be my last act of "advising", I'll advise you to cut the jargon. -- My old PhD advisor, to me, 26/2/11