Where is the spent fuel that was stored above the Fukugawa reactors?

[kristopher]

This blog also has http://uvdiv.blogspot.com/ a good set of graphics and you can see that storage for spent fuel looks to be extremely vulnerable to the damage done by the hydrogen explosion.


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After the blast we have to ask what happened to the spent fuel in temporary storage above the reactors don't we? According to another DU post, as of March 2010 there were 3450 fuel assemblies stored in the reactor buildings where the pools are above the reactors. According to the post between reactors 1, 2 and 3 there are probably about 200 tons of spent fuel that are at risk.

This is the risk without consideration of the possible effects of the explosion.

Safety of Spent Nuclear Storage Pools: from 2006 report requested by Congress
The study provided a probabilistic risk assessment that identified severe accident scenarios and estimated their consequences. The analysis determined, for a given set of fuel characteristics, how much time would be required to boil off enough water to allow the fuel rods to reach temperatures sufficient to initiate a zirconium cladding fire.

... For cases where active cooling (but not the coolant) has been lost, the thermal-hydraulic analyses suggested that operators would have about 100 hours (more than four days) to act before the fuel was uncovered sufficiently through boiling of cooling water in the pool to allow the fuel rods to ignite. This time was characterized as an “underestimate” given the simplifications assumed for the loss-of-pool-coolant scenario.

The overall conclusion of the study was that the risk of a spent fuel pool accident leading to a zirconium cladding fire was low despite the large consequences because the predicted frequency of such accidents was very low. The study also concluded, however, that the consequences of a zirconium cladding fire in a spent fuel pool could be serious and, that once the fuel was uncovered, it might take only a few hours for the most recently discharged spent fuel rods to ignite.


http://www.nap.edu/openbook.php?record_id=11263&page=44

[drm604]

1. Good question. n/t

[doc03]

2. If there was a even real China Syndrome situation there do you

really think (any) government would level with us about it?

[Mnemosyne]

3. Excellent question. K&R n/t

[flamingdem]

4. Right at the top where experts fear it is letting off steam

This was on a twitter search I did and it was stated by a Dr. Alvarez

[kristopher]

5. Judging by the photo of #3 above

the claim it is all still at the top of the building (exposed or not) is not a given at all.

[flamingdem]

6. Yes, in fact you're probably right about that! nt

[kristopher]

7. Interesting lack of response to this post by those who promote nuclear. nt

[kristopher]

8. Satellite photos show spent fuel pools damaged.

Some good information from the EE forum by snagglepuss. Posted first here: http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x278949

Thanks Snagglepuss.

Guardian's US environmental correspondent Suzanne Goldenberg reports:

Anti-nuclear campaigners are drawing attention to some important technical aspects about the explosions at the Japanese nuclear reactor. It's an especially welcome intervention given the lack of information coming from the Japanese nuclear authorities

First, they are warning about a secondary risk of explosion and radiation link from the spent fuel pools which are located just above the reactors. That means they are outside the steel casing encirclinng the reactors, but inside the containment structures that were damaged in the explosions

Robert Alvarez, a senior policy expert at the institute of Policy Studies, said satellite pictures of the Fukushima plant showed evidence of damage to the spent fuel pool. "There is clear evidence that the fuel cask cranes that haul spent fuels to and from the reactor to the pool both fell. They are gone," he said. "There appears to be copious amounts of steam pouring of the area where the pools is located."

He said there was no evidence of fire but described the situation as "worrisome".

"What we don't know is whether or not explosions or the quake or the tsuanmi or a combination of things might have damaged support structures or compromised the pool," Alvarez said. ...

http://www.guardian.co.uk/world/blog/2011/mar/14/japan-tsunami-nuclear-alert-live