Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[SteveElbows]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120912/0745_syasin.html Tepco is releasing 600 photographs taken from 11 March 2011 to 28 March 2011. "Because of bad coordination within the company, we were not able to fully grasp the photograph status and were late to release them. It is possible that more unreleased pictures are remaining, so we are checking in order to release them", they explain. Pictures showing accumulated water in power equipment rooms in unit 1 and unit 2 turbine buildings are included.

http://photo.tepco.co.jp/index-j.html [the 600 new pictures are in the links numbered (1) to (40)]

Thanks. I would probably have found some of the photos on this particular page of that collection to be the most interesting if they had been released much earlier. Some (mostly numbers 4 & 11) show that area between reactor 3 & 4 where rather radioactive debris was discovered in a survey, and it looks like these photos are from before they 'bulldozed' over that area/turned the debris into a more concise pile.

http://photo.tepco.co.jp/date/2012/201209-j/120911-31j.html

 

[zapperzero]

Some (mostly numbers 4 & 11) show that area between reactor 3 & 4 where rather radioactive debris was discovered in a survey

Speaking of which, what building is this, does anyone know? Sorry for asking, I know I should have no trouble identifying it, but my memory is acting up again.

http://photo.tepco.co.jp/library/20120911_31/120911_295.jpg

also, is the large pipe in the bottom-left corner a part of the venting system?

http://photo.tepco.co.jp/library/20120911_31/120911_289.jpg

 

[tsutsuji]

]27 August 2012 government-Tokyo Electric mid and long term response committee, technical development progress headquarters (8th meeting) ( http://www.meti.go.jp/earthquake/nuclear/20120827_02.html )

Document 2
http://www.meti.go.jp/earthquake/nuclear/pdf/120827/120827_02c.pdf Progress status of development of machinery and equipments to prepare fuel debris removal

https://www.physicsforums.com/showthread.php?p=4064974&posted=1#post4064974 Translation [installment 1: abstract]
https://www.physicsforums.com/showthread.php?p=4068601&posted=1#post4068601 Translation [installment 2: remote decontamination]
https://www.physicsforums.com/showthread.php?p=4069889&posted=1#post4069889 Translation [installment 3: PCV leakage points identification]

Translation [installment 4: PCV repairs]

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[tsutsuji]

Translation [installment 4: PCV repairs]

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[SteveElbows]

Speaking of which, what building is this, does anyone know? Sorry for asking, I know I should have no trouble identifying it, but my memory is acting up again.

http://photo.tepco.co.jp/library/20120911_31/120911_295.jpg

also, is the large pipe in the bottom-left corner a part of the venting system?

http://photo.tepco.co.jp/library/20120911_31/120911_289.jpg

I'm not sure what that building is for, but looking at the high quality aerial images from early on, its the building that is directly west of the shared reactor 3/4 stack tower.

The large pipe is the broken part of reactor 3 vent pipe that got plenty of attention at the time due to showing up so clearly on the same set of aerial photos.

Meanwhile I see they have now removed the reactor cap from the reactor 4 refuelling floor, just like they did with the containment cap:

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120913_03-e.pdf

And they have done a new visual study of reactor 3 pool, or at least the state of the debris that is around the pools surface.

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120913_02-e.pdf

 

[zapperzero]

I'm not sure what that building is for, but looking at the high quality aerial images from early on, its the building that is directly west of the shared reactor 3/4 stack tower.

EDIT: that would be the switching area, according to this:
http://files.abovetopsecret.com/images/member/f9037506eaef.gif

The large pipe is the broken part of reactor 3 vent pipe that got plenty of attention at the time due to showing up so clearly on the same set of aerial photos.

So, yes. thanks, I was not sure. What a clean break, by the way! The bolts sheared and the whole thing just fell off. I wonder how hot it is.

EVEN LATER EDIT: here's another big pipe segment:
http://photo.tepco.co.jp/library/20120911_40/120911_590.jpg

from here
http://photo.tepco.co.jp/date/2012/201209-j/120911-40j.html

SOME MORE PIXEL-HUNTING LATER:
would this
http://photo.tepco.co.jp/library/20120911_39/120911_522.jpg

be the very same switching area? There is debris on the floor, apparently concrete from Unit 3 blowing up.

 

[Rive]

Meanwhile I see they have now removed the reactor cap from the reactor 4 refuelling floor, just like they did with the containment cap:

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120913_03-e.pdf

I can be wrong but those big concrete pieces under the 'landed' cap looks like the top concrete shielding of the reactor well.

Ps.:

EVEN LATER EDIT: here's another big pipe segment:
http://photo.tepco.co.jp/library/20120911_40/120911_590.jpg

That will be a different pipe, not part of the venting system. You can see it's connections on this photo: http://photo.tepco.co.jp/library/20120911_40/120911_593.jpg

 

[a.ua.]

EDIT: that would be the switching area, according to this:
http://files.abovetopsecret.com/images/member/f9037506eaef.gif

LATER EDIT: are you sure it is not the entrance corridor to unit 3? Because otherwise, what blew up in there?

It traces of tsunami.

 

[zapperzero]

It traces of tsunami.

No it is not, there is no silt. But upon looking more carefully, it appears that junk from the explosion hit it pretty hard. Some of it made it inside.

 

[westfield]

<snip>

So, yes. thanks, I was not sure. What a clean break, by the way! The bolts sheared and the whole thing just fell off. I wonder how hot it is.
.

I'm not 100% sure but it's likely that the joints in the vent pipe are not bolted together as such, the joints have to allow for expansion so it's more like a "slip joint" hence the clean seperation.

EVEN LATER EDIT: here's another big pipe segment:
http://photo.tepco.co.jp/library/20120911_40/120911_590.jpg

from here
http://photo.tepco.co.jp/date/2012/201209-j/120911-40j.html

.

Is that pipe the vertical stack that was attached to the exterior NW corner of [STRIKE]U3 [/STRIKE] U4 perhaps (edit cheers Steve, I should have checked)

SOME MORE PIXEL-HUNTING LATER:
would this
http://photo.tepco.co.jp/library/20120911_39/120911_522.jpg

be the very same switching area? There is debris on the floor, apparently concrete from Unit 3 blowing up.

EDIT : I'm having a bad day - my mistake - answer should have been no, different building - that interior shot is the Units 1 & 2 UHV switch building. Up on the hill west of Units 1 & 2
impacted by U3 explosion.

 

[SteveElbows]

Is that pipe the vertical stack that was attached to the exterior NW corner of U3 perhaps

Yes, but reactor 4 not reactor 3.

 

[westfield]

No it is not, there is no silt. But upon looking more carefully, it appears that junk from the explosion hit it pretty hard. Some of it made it inside.

No visible tsunami damage to that building. The corner that is opened up is actually closer to unit 4. The images are not the best but it seems there might be more displaced cladding post U4 explosion.


After Tsunami, then after U3 explosion , finally after U4 explosion

 

[zapperzero]

No visible tsunami damage to that building. The corner that is opened up is actually closer to unit 4. The images are not the best but it seems there might be more displaced cladding post U4 explosion.

Yep. Thanks. You are of course referring to the concrete "cladding" of the switching building, yes?

 

[westfield]

Yep. Thanks. You are of course referring to the concrete "cladding" of the switching building, yes?

I was looking at the sheet steel cladding that's come off that U3 & 4 HV switch building and is laying on the ground around it. The images are not great but I thought there may be more of the wall cladding laying around after the U4 explosion vs before. Difficult to say either way...looking for something more interesting in that bunch of unreleased images now.

 

[westfield]

Unit 2 transformer yard - oil level is a little on the low side

 

[tsutsuji]

]27 August 2012 government-Tokyo Electric mid and long term response committee, technical development progress headquarters (8th meeting) ( http://www.meti.go.jp/earthquake/nuclear/20120827_02.html )

Document 2
http://www.meti.go.jp/earthquake/nuclear/pdf/120827/120827_02c.pdf Progress status of development of machinery and equipments to prepare fuel debris removal

https://www.physicsforums.com/showthread.php?p=4064974&posted=1#post4064974 Translation [installment 1: abstract]
https://www.physicsforums.com/showthread.php?p=4068601&posted=1#post4068601 Translation [installment 2: remote decontamination]
https://www.physicsforums.com/showthread.php?p=4069889&posted=1#post4069889 Translation [installment 3: PCV leakage points identification]
https://www.physicsforums.com/showthread.php?p=4071111&posted=1#post4071111 Translation [installment 4: PCV repairs]

Translation [installment 5: surveys inside PCV]

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[tsutsuji]

Translation [installment 5: surveys inside PCV]

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[tsutsuji]

Translation [installment 5: surveys inside PCV]

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[tsutsuji]

]27 August 2012 government-Tokyo Electric mid and long term response committee, technical development progress headquarters (8th meeting) ( http://www.meti.go.jp/earthquake/nuclear/20120827_02.html )

Document 2
http://www.meti.go.jp/earthquake/nuclear/pdf/120827/120827_02c.pdf Progress status of development of machinery and equipments to prepare fuel debris removal

https://www.physicsforums.com/showthread.php?p=4064974&posted=1#post4064974 Translation [installment 1: abstract]
https://www.physicsforums.com/showthread.php?p=4068601&posted=1#post4068601 Translation [installment 2: remote decontamination]
https://www.physicsforums.com/showthread.php?p=4069889&posted=1#post4069889 Translation [installment 3: PCV leakage points identification]
https://www.physicsforums.com/showthread.php?p=4071111&posted=1#post4071111 Translation [installment 4: PCV repairs]
https://www.physicsforums.com/showthread.php?p=4073726&posted=1#post4073726 Translation [installment 5: surveys inside PCV]

Translation [installment 6: RPV/PCV integrity assessment]

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[tsutsuji]

Translation [installment 6: RPV/PCV integrity assessment]

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[tsutsuji]

Translation [installment 6: RPV/PCV integrity assessment]

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[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120914/1345_chusuiryo.html On 13 September Tepco said the injection rate problem had been solved, but the injection rate declined again on 14 September (a 10% decline at unit 1 from 09:00 PM on 13 September to 01:00 AM on 14 September, and a decline from 01:00 AM to 07:00 AM at unit 2). In both caes the needed rates were secured. As a countermeasure, Tepco is increasing the injection rates. Tepco suspects foreign bodies are remaining in the pipes.

 

[etudiant]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120914/1345_chusuiryo.html On 13 September Tepco said the injection rate problem had been solved, but the injection rate declined again on 14 September (a 10% decline at unit 1 from 09:00 PM on 13 September to 01:00 AM on 14 September, and a decline from 01:00 AM to 07:00 AM at unit 2). In both caes the needed rates were secured. As a countermeasure, Tepco is increasing the injection rates. Tepco suspects foreign bodies are remaining in the pipes.

Guess it is not easy to put in a strainer just before the pipes enter the reactor when everything is seriously contaminated.

 

[tsutsuji]

]27 August 2012 government-Tokyo Electric mid and long term response committee, technical development progress headquarters (8th meeting) ( http://www.meti.go.jp/earthquake/nuclear/20120827_02.html )

Document 2
http://www.meti.go.jp/earthquake/nuclear/pdf/120827/120827_02c.pdf Progress status of development of machinery and equipments to prepare fuel debris removal

https://www.physicsforums.com/showthread.php?p=4064974&posted=1#post4064974 Translation [installment 1: abstract]
https://www.physicsforums.com/showthread.php?p=4068601&posted=1#post4068601 Translation [installment 2: remote decontamination]
https://www.physicsforums.com/showthread.php?p=4069889&posted=1#post4069889 Translation [installment 3: PCV leakage points identification]
https://www.physicsforums.com/showthread.php?p=4071111&posted=1#post4071111 Translation [installment 4: PCV repairs]
https://www.physicsforums.com/showthread.php?p=4073726&posted=1#post4073726 Translation [installment 5: surveys inside PCV]
https://www.physicsforums.com/showthread.php?p=4076720&posted=1#post4076720 Translation [installment 6: RPV/PCV integrity assessment]

Translation [installment 7: open competitive biddings]

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[tsutsuji]

Translation [installment 7: open competitive biddings]

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[tsutsuji]

Translation [installment 7: open competitive biddings]

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[tsutsuji]

Additional information about the long term research and development effort is included in the presentations from the 7 August "workshop on machinery and equipments toward the decommissioning of Fukushima Daiichi NPP" held in Koriyama city: http://www.meti.go.jp/earthquake/nuclear/20120810_01.html

http://www.meti.go.jp/earthquake/nuclear/pdf/120810/120810_01b.pdf Program
http://www.meti.go.jp/earthquake/nuclear/pdf/120810/120810_01c.pdf Presentation (1) Middle and long term roadmap and research and development
http://www.meti.go.jp/earthquake/nuclear/pdf/120810/120810_01d.pdf Presentation (2) Fukushima Daiichi general situation
http://www.meti.go.jp/earthquake/nuclear/pdf/120810/120810_01e.pdf Presentation (3) Practical use of technical catalogue public appeal results
Session 1:
http://www.meti.go.jp/earthquake/nuclear/pdf/120810/120810_01f.pdf Development of remote decontamination techniques inside buildings
Session 2:
http://www.meti.go.jp/earthquake/nuclear/pdf/120810/120810_01g.pdf Development of PCV leakage points identification techniques
http://www.meti.go.jp/earthquake/nuclear/pdf/120810/120810_01h.pdf Development of PCV repair techniques
http://www.meti.go.jp/earthquake/nuclear/pdf/120810/120810_01j.pdf Development of PCV internal survey techniques

 

[SteveElbows]

If anyone wants a closer look at 'routine' reactor cap removal, they've posted images and video of the removal process from one of the reactors at the other Fukushima nuclear plant:

http://photo.tepco.co.jp/en/date/2012/201209-e/120914-01e.html

 

[Azby]

Interesting paper describing the use of muons to image the core of Fukushima Daiichi Reactor #1:

Cosmic Ray Radiography of the Damaged Cores of the Fukushima Reactors.
Konstantin Borozdin, et al.; Physical Review Letters, September 12, 2012

http://arxiv.org/pdf/1209.2761v1.pdf

The paper describes simulations, and concludes that it is feasible.

Azby

 

[zapperzero]

The paper describes simulations, and concludes that it is feasible.

The simulations they did were about imaging an in-vessel melt. I wonder if/how this would work with the core being dug into the concrete at the bottom of the drywell, as simulations show it probably is.