Helicopter photos confirm reactor No. 4 spent fuel pool has boiled dry (LA Times)

[jpak]

http://www.latimes.com/news/science/la-sci-japan-reactor-damage-20110318,0,6146639.story

<snip>

When finished, the line should provide power to valves and controllers at the plant and for the cooling pumps that feed water to the spent fuel pools on the roofs of reactor buildings Nos. 4, 5 and 6. The line probably will not provide any benefit for reactors Nos. 1, 2 and 3 because the cooling systems for those reactors are thought to have been damaged by the hydrogen explosions that destroyed the outer buildings and that may have cracked the containment vessel of reactor No. 2.

The helicopters also took new pictures of the spent fuel pools on the roofs of the reactor buildings and have apparently confirmed fears that the pool at reactor No. 4 has boiled dry. Although the company has been saying that the fuel rods in the pool have remained partially covered, Gregory Jaczko, chairman of the U.S. Nuclear Regulatory Commission on Wednesday said that the best information he had at that time indicated the pool was dry and emitting high levels of radiation.

The new pictures apparently show no smoke or steam rising from the pool.

The spent fuel pool is a particular source of concern because it contains at least 135 tons of fuel rods, more than is in any of the reactors. Moreover, the fuel rods are not inside a containment vessel. If they start burning, the ash will be released directly into the environment.

<more>

[aquart]

1. I'm guessing that is not good news.

[jpak]

2. It is not - and uncharted territory

n/t

[ReturnoftheDjedi]

3. if they cannot get water back on those rods quickly, they will meltdown and could explode.

[amandabeech]

4. Even this history major knows that this is really, really seriously bad.

Who's taking odds on when Tepco will admit this?

[SpoonFed]

16. two weeks after never...

you're kidding right?
have a look at this about the ethical meltdown within TEPCO,
http://thewordenreport.blogspot.com/2011/03/ethical-meltdown-in-japan-on-toxicity.html

[Hell Hath No Fury]

5. Just as I thought --

Getting power up will help with some of the reactors but others are too damaged for their pumps/valves to work properly. They can' keep pouring water on them indefinitely -- what is the end game for those reactors?

[BrightKnight]

6. The DoD does not have any RC helicopters!!! Where does the DARPA budget go? - n/t

[jpak]

8. The Navy has drone helicopter in late development (MQ-8 Fire Scout) but it has small payload

200 lbs

http://en.wikipedia.org/wiki/Northrop_Grumman_MQ-8_Fire_Scout

[BrightKnight]

11. How difficult could it be to retrofit a Chinook helicopter?

I have an RC helicopter on my coffee table now. I can imagine a number if situations where an unmanned heavy lift capability might be essential. You would think that such a system would have been developed during the cold war.

Radiation is preventing pilots from getting close enough to drop the water where it is needed. The water drops have been described as suicide missions. There has to be an engineering solution to the problem.

[BrightKnight]

12. Sending an A160 Hummingbird in would provide valuable information.

I hope that the electronics in most military systems a radiation shielded.

[xchrom]

7. recommend

[Dennis Donovan]

9. So, 1,2,3 will need maintenance to get the cooling systems back on line...

Who is going to do the necessary work?:shrug:

[Tx4obama]

10. Buildings #5 and #6 each have more spent fuel rods than #4

Rachel Maddow - total amount of Spent Nuclear Fuel Rods in the pools at Dai-ichi plant
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=439x666399

Maddow video: Spent Fuel Rods Graphs
http://www.msnbc.msn.com/id/26315908/ns/msnbc_tv-rachel_maddow_show/#42121003
And also listen carefully at the 1:20 minute mark where she says "there's even a larger common pool" outside of the six reactor buildings!

[FBaggins]

14. #5&6 haven't had the same troubles as #4.

They're too far away to have been damaged in the earlier explosions.

There were some pool temperatures published a day or so ago and their pools had warmed up, but it wasn't anywhere close to the problem at the other four. They should also have a better chance of benefiting from a restoration of power.

[sam kane]

13. Move along, the pres. says its all good. nt

[PamW]

15. I can't see how this can be true...

Helicopter photos confirm reactor No. 4 spent fuel pool has boiled dry (LA Times)
=======================================

As the article states, units 1, 2, and 3 had hydrogen explosions. Because
reactor 4 was shutdown at the time of the quake, there was no hydrogen generation
from a hot reactor, hence no hydrogen explosion in unit 4.

Therefore, unit 4 is the only one that still has a roof over the fuel
pool. Since there is still a roof on the building, a helicopter pilot can't
see the fuel pool..

Here's a picture that shows what a high flying helicopter pilot would see:

http://www.allvoices.com/contributed-news/8476626-tremendous-fire-blazing-after-explosion-at-fukushima-nuclear-plant-unit-4/image/75247570-nuclear-reactor

The walls and roof area around the spent fuel pool are intact. The holes in the
sides due to the blasts from the other plants are lower down on the building.

Once again, science and intellect win out over agenda-biased knee-jerk responses.

Try again... better luck next time.

PamW

[SpoonFed]

17. denier needs reality check

go look at the satellite photos and aerial imagery,
2 or three sides of reactor 4 at Daiichi are gone, the 4 side has nice
big chunks out of it.

Quit your irrational disbelief.

[PamW]

18. Spoon fed is the right name for you.

or three sides of reactor 4 at Daiichi are gone, the 4 side has nice
big chunks out of it.
===============================

I have seen the pictures. Evidently you don't know where the fuel pool
is. The fuel pool is up near the top where the structure is intact - no
hole in the roof and the sides are intact there also.

As a scientist, I object when people who don't know what they are
talking about, and don't know the design; say nonsensical things.

I'm not a "denier" - so much for your unsubstantiated ad hominem fallacy.

In order to minimize radiation, the helicopters had to stay rather high.
Get a piece of paper and draw the sight lines from helicopter through the
holes and into the building. You will find that the areas that can be
seen from those heights are below the location of the fuel pool.

Next time, try to do some analysis instead of a knee-jerk response.

PamW

[Wilms]

19. Fact Check: Aerial view of #4.

http://www.latimes.com/health/la-sci-quake-radiation-workers-20110318,0,5659183.story

[SpoonFed]

20. next time, how about

...you just take a look at the current photos for the thing.

I've seen another recent foto where there is fire and
black smoke coming from the pool area also.

[jpak]

21. Is someone having a meltdown?

:D

[jpak]

22. deny this

[FBaggins]

23. "Visual inspection of Unit 4’s pool showed water in the pool"

From wtmusic's OP -

"Spraying of spent fuel pools at Units 3 and 4 is still underway. Visual inspection of Unit 4’s pool showed water in the pool, and so efforts have been temporarily focused upon Unit 3. While efforts at using helicopters to dump water onto the pools had been largely unsuccessful , army firetrucks used in putting out aircraft fires have been employed with some success. The elite Tokyo Hyper Rescue component of the Tokyo fire department has arrived on scene and is conducting missions of roughly two hours in length, during which they spray the pools for 7-8 minutes, wait for steam to dissipate, and spray again.

http://mitnse.com/

My assumptions -

Sounds like the leak (or what I assume is a leak) is part-way up the pool wall. The fuel is only partially submerged (so that "visual" check had better be from quite some distance away), so when the spray hits the exposed parts you get steam... but it dissipates because the pool itself isn't boiling (or isn't boiling substantially).

BTW - That link contains another link to updated radiation readings all around the local area).

[jpak]

24. I wonder if that is because there may be spent MOX fuel in No. 3?

:shrug:

[FBaggins]

25. There isn't any spent MOX fuel in the pool at #3.

Though that wasn't an unreasonable assumption.

I think they may have just learned their lesson about focusing on just one big problem while smaller problems grow into big ones. (which isn't to say that I don't think that they're giving it their best effort). If they've removed the imminent threat at #4, maybe it's best to bring #3 up to some comfort level before moving on. Maybe they'll also be able to judge how far #4 is leaking while they do it.

#3 was the first unit (I think in the country) to receive MOX and it was around last Fall. They wouldn't have refueled since then, so there wouldn't be any spent MOX yet to put in the pool.

Though again, spent reactor fuel has plutonium in it anyway. I'm pretty sure that's either where the plutonium in the MOX came from, or where they planned to get it from in the future.

[GliderGuider]

26. They need to send an intern down into that freakin' pool with a freakin' ruler.

[FBaggins]

27. That's about what happened at Chernobyl.

(Just going from memory... no gurantee of accuracy)

They didn't know what the water level was in a given pool and expressed concern. Some junior engineer slipped out and checked. He said the level was three feet above the rods... and died a very short time later from exposure.

I prefer to think he was a hero than an idiot who thought "why not just look?".

[oldhippie]

28. Pam, is there a difference in the "spent" fuel pool and the regular .....

.... fuel pool? They keep calling it the "spent" fuel pool. I was assuming that was an uncovered pool somewhere where they put spent fuel roods for storage and wasn't covered by a containment building. I can imagine that they could see that from an aircraft. Am I not understanding this correctly? I for one, appreciate your take on stuff.

[SpoonFed]

29. apology?

I'd guess not.

[jpak]

30. lol

science marches on!

[FBaggins]

31. Was your post earlier today an apology to Pam?

"Charles said that if the spent fuel pools at reactors 3 and 4 should be emptied of water, the dose rates on the site would be so high that it would be extremely difficult to work there. But that doesn't seem to be the case, contrary to some reports on Wednesday, he said."

Oops... My mistake. It was banana's OP... But you seemed to accept it.