Spraying water into the spent fuel tanks "never tried before"...a "last-ditch effort"

[brooklynite]

http://www.ustream.tv/channel/nhk-world-tv

cheery

[tekisui]

1. It seems like it is only a matter of time, now. So sad.

[nadinbrzezinski]

2. Well now we will cover labor issues....

:-)

I mean we cannot scare the people.

[FreakinDJ]

3. They need water on those rods 1 way or the other

[KansDem]

4. Aren't these spent fuel rods suppose to remain submerged in water for some 8-10 years?

I thought I heard that today on either Maddow or Hartman.

If so, then do they really expect to re-create that condition by spraying water on them?

[Statistical]

5. They are spraying water to FILL the pond again.

They can't get close enough to pump some water in. Visualize trying to fill a swimming pool from the other side of the yard using high pressure hose.

[KansDem]

6. But won't the water turn instantly into steam?

:shrug:

They'll have to have one hell of a flow rate...

[Statistical]

7. Maybe. We will find out soon enough.

Spent fuel is hot but much "cooler" than fuel in a reactor. It has undergone a lot of nuclear decay so its thermal output is a tiny fraction of fuel in a reactor. Remember it took 5 days for the water to evaporate/boil out so that kinda gives you a ballpark idea of the difference in heat output between the fuel in the pond and the fuel in the reactor. A lot depends on how "old" the fuel is, fuel that is a year "old" (since being removed from reactor) is much cooler than fuel that is only a month old.

Also it looks like they are using helicopters to dump large amounts of water at once (like fire fighting helicopters).
Live feed: http://www.ustream.tv/channel/nhk-world-tv
At the time I posted this the narrator said the helicopter dumped 7.5 tons of water. So while they are calling it a spraying it may be more a language thing. I would call it a water dumping.

[KansDem]

8. Thanks for the info...

:hi:

[Gabi Hayes]

10. they said on CNN a few minutes ago that much of the spent fuel is VERY fresh.

pipin' hot from the oven

[Statistical]

12. Well that would be bad.

Newer fuel = more thermal output = more of the water will flash to steam = will take more water drops to refill the pond.
If the rate the fuel flashes water into steam is greater than the rate they got water in the pond they will be fighting a losing battle.

Lets hope they gain the upper hand.

[arcane1]

9. The subject line reminds me of the BP oil spill

:(

[GreenPartyVoter]

11. me too :^(