Dunping water on something 3 or 4 thosuands degree hpot will usually just instantly turn that water to steam

If one actually could somehow emerse the containment vessel or cooling ponds with water... the sudden shock to the hot hot metal and concrete containment structures would cause them to crack wide open.

Also you can;t put water into a containment vessel if it is full of 1000 lbs per square inces of pressure with a 500 lbs pressure hose.

You have to take away the pressure, Problem is that valves can get stuck closed when pressure is high.

so many problems

Do you really thing ANY pipes are intact after the 4 huge explosions that tore up the containment buildings?
http://www.youtube.com/watch?v=T_N-wNFSGyQ

yeah right, the pipes are just fine.