Nuclear fuel rods fully exposed at Japan reactor - Jiji

[jpak]

http://www.reuters.com/article/2011/03/14/japan-quake-rods-idUSTKB00733720110314

(Reuters) - Nuclear fuel rods at a quake-stricken Japanese nuclear reactor are now fully exposed, Jiji news agency said, quoting the plant's operator, Tokyo Eletcric Power Co .

The report referred to the Fukushima Daiichi complex's No.2 reactor, where levels of water coolant around the reactor core had been reported as falling earlier in the day.

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[FBaggins]

1. And this is not one of the ones that has had an explosion, right?

n/t

[tama]

5. Right

Explosians at 1 and 3, this is 2.

[tekisui]

6. My understanding is that there have been 2 explosions. One at reactor #1

and one at reactor #3. I think you are correct in that there hasn't been an explosion at reactor #2, yet.

[Chichiri]

7. Right, #2 is the one whose building hasn't blown up yet

[xchrom]

2. Recommend

[Chichiri]

3. Okay, what does this mean?

I imagine it's not good, but what are they exposed to? The air in the reactor core? In the containment building? The outside air?

[tama]

8. They are cooled

by water. When they are exposed - no water to cool them - they heat up and start to melt.

[jpak]

9. The core needs to be cooled constantly - if it is not, the fuel rods heat up

If they get too hot, the cladding enclosing the uranium fuel fails releasing radioactivity.

If they get too hot, they melt

if enough fuel accumulates at the base of the reactor vessel, the fission chain reaction can be reestablished - and cannot be controlled

The temperatures rise and may melt/breach the reactor vessel.

large releases of radioactivity may result

[Name removed]

14. Deleted message

Sub-thread removed by moderator. Click here to review the message board rules.

[HereSince1628]

4. Let's hope they've cooled enough to prevent the usual time curve

to fuel rods slumping.

[FBaggins]

10. "The fuel rods on unit 2 have been fully exposed for the second time today"

http://abcnews.go.com/International/japan-earthquake-us-nuclear-commission-troubled-fukushima-reactors/story?id=13131123

[JohnWxy]

11. Jesus! that means they are in for a melt-down.

[FBaggins]

12. In for? They've had at least three (probably four) already. n/t

[NNadir]

13. So what?