Fukushima Fukushima: Unit 2 Discharge - Why Differs from Units 1 & 3?

[zapperzero]

True enough, but the debris is still there crying for an explanation.

It looks like plastic sheeting. Maybe that's just what it is. It would have been used, I believe, for most any kind of maintenance activity in that area. The boots tell the same story - work in progress, abandoned because of the quake, or simply because it was the weekend.

 

[SteveElbows]

It looks like plastic sheeting. Maybe that's just what it is. It would have been used, I believe, for most any kind of maintenance activity in that area. The boots tell the same story - work in progress, abandoned because of the quake, or simply because it was the weekend.

Yeah, and we don't actually know the exact time that humans were on the refuelling floor for the very last time before that reactor went seriously wrong. In theory they may have been there on occasions after the earthquake, official narratives are not detailed about stuff that is not considered central to the decline of each reactor or measures taken to try to control the situation. For all we know they may have been dealing with the consequences of sloshing of the spent fuel pool for some time, although I know of no reports that point strongly in that direction, just giving an example of events that would be overshadowed by later dramatic events.

 

[MadderDoc]

It looks like plastic sheeting. Maybe that's just what it is. It would have been used, I believe, for most any kind of maintenance activity in that area. The boots tell the same story - work in progress, abandoned because of the quake, or simply because it was the weekend.

Fair enough, zapperzero. We do know from the operation log that maintenance work of the overhead crane was ongoing; from the Quince photos it can clearly be seen that the crane has been parked over the reactor cap, and a ladder has been improvised at its east end to gain access to the operator booth of the crane, from which there is access to the rest of the crane. Also some ropes can be seen hanging from the ceiling to the floor at each end of the beams of the crane, plausibly for hoisting stuff up and down.

And there is the very technical, albeit temporary looking machinery that has been planted on the middle of the reactor cap.

During its tour Quince stares into a sort of controlled route to the work area under the crane, and this route leads straight to the area with the funny boots, at the edge of the reactor cap.

Right at the entry to this route can be seen big plastic bags, plausibly for unloading personal plastic coveralls etcetera before exiting the work area.

So, the irregular debris strewn along the red fence could well be wrapped up waste material produced during the maintenance work, left there by the maintenance workers for later waste disposal.

 

[MadderDoc]

Not too much can be gleaned from the scaled version of this image, looking towards an entry to the torus room in unit 2, which we have been discussing:

One could well get the impression that the place just needs a good clean up, and a lick of paint.

However, there may be more to it. Looking at the original photo, at:
http://photo.tepco.co.jp/library/120314/120314_05.JPG

Is that door still on its hinges?

 

[SteveElbows]

Nothing in that photo really suggests its not on its hinges, or have I missed something?

The vent on the wall above the door was of slightly more interest to me.

 

[MadderDoc]

Nothing in that photo really suggests its not on its hinges, or have I missed something?

The vent on the wall above the door was of slightly more interest to me.

I'd expect the signs on the door to be on the outside, but if the door is on its hinges, this door would be left-hinged, opening out from the torus room, and the signs we can see on this door would be meant to be seen only from inside of the torus room. The corresponding door in unit 3 is right-hinged. and would open inward towards the torus room. Perhaps this could explain why the door in unit 3 came to bulge out jammed shut, while the door in unit 2 was merely slammed open.

The tilting of the vent (if that's what interests you?) could be a design feature, such as to not blow air into the corner, but rather into the room. A similar tilt can be seen with the corresponding vent in unit 3 in the high res photo at:
http://photo.tepco.co.jp/library/120314/120314_10.JPG

 

[jim hardy]

Well the fellow is wearing respirator, full plastic pc's and using a survey meter with long handle to see what's the field on far side of doorway before he goes through it.

Did they go beyond the door, anyone know?

Most of you know this, but for possible benefit of others -
He's dressed for an area that's highly contaminated with transferables ( stuff that'll rub off on your clothes), not just radiation from stuff inside pipes..

 

[SteveElbows]

I'd expect the signs on the door to be on the outside, but if the door is on its hinges, this door would be left-hinged, opening out from the torus room, and the signs we can see on this door would be meant to be seen only from inside of the torus room. The corresponding door in unit 3 is right-hinged. and would open inward towards the torus room. Perhaps this could explain why the door in unit 3 came to bulge out jammed shut, while the door in unit 2 was merely slammed open.

The tilting of the vent (if that's what interests you?) could be a design feature, such as to not blow air into the corner, but rather into the room. A similar tilt can be seen with the corresponding vent in unit 3 in the high res photo at:
http://photo.tepco.co.jp/library/120314/120314_10.JPG

Thanks for the info about the vent, makes sense.

As for the door, it does not surprise me to see signs on the inside of the door. The building seems pretty heavily labelled everywhere. And there are signs in other photos that the triangular rooms at this level are labelled MB, and the very edge of a letter B may just be visible on the sign on that door.

 

[SteveElbows]

Did they go beyond the door, anyone know?

Yeah according to TEPCOs report they went through that door and took 2 more photos, one of the stairs ( http://photo.tepco.co.jp/library/120314/120314_06.JPG )and then one of the suppression chamber ( http://photo.tepco.co.jp/library/120314/120314_07.JPG ).

This report shows how the photos relate to the locations:

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120314_01-e.pdf

 

[jim hardy]

Thanks Steve.
( http://photo.tepco.co.jp/library/120314/120314_07.JPG ).

Is that insulation or the actual pressure vessel?

Any observations on the red stain ? It looks to surround an irregular shape resembling a crack.
Insulation cracked wouldn't be a surprise.

 

[MadderDoc]

Yeah according to TEPCOs report they went through that door and took 2 more photos, one of the stairs ( http://photo.tepco.co.jp/library/120314/120314_06.JPG )and then one of the suppression chamber ( http://photo.tepco.co.jp/library/120314/120314_07.JPG ).

This report shows how the photos relate to the locations:

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120314_01-e.pdf

Thank you. Referring to the new images you link to, taken from through a doorway to the torus room (according to the handout that would be a door from the NE side of the torus):
120314_06.JPG has EXIF time 12:11:58, and
120314_07.JPG has EXIF time 12:12:11.

Then this photo, at:
http://photo.tepco.co.jp/library/120315/120315_01.jpg
would seem have been taken from through the very same doorway of the torus room: it has EXIF time 12:12:18.
But, this photo has been published as coming from the NW side of the torus room? So from which side of the torus have these photos actually been taken?

Also I am not quite sure what is up in this third photo.

 

[MadderDoc]

Thanks Steve.
( http://photo.tepco.co.jp/library/120314/120314_07.JPG ).

Is that insulation or the actual pressure vessel?

Any observations on the red stain ? It looks to surround an irregular shape resembling a crack.
Insulation cracked wouldn't be a surprise.

I certainly see it as the actual painted metal surface of the torus, or suppression chamber. Is a torus insulated? Never thought they would be, but I am just an amateur in those matters.

The red stain looks to me as if it is coming from dripping from further above, or perhaps from a leak higher up on the torus. It does not seem to me to originate from the irregular shape resembling a crack. That shape could be more innocently, a rusty weld.

 

[tsutsuji]

Thanks Steve.
( http://photo.tepco.co.jp/library/120314/120314_07.JPG ).

Is that insulation or the actual pressure vessel?

Any observations on the red stain ? It looks to surround an irregular shape resembling a crack.
Insulation cracked wouldn't be a surprise.

This picture is captioned as followed by http://www.yomiuri.co.jp/science/news/20120314-OYT1T01074.htm

Whitish dust has deposited on red brownish paint, but some part was soaked by water. This is how the suppression chamber is looking, a part of the PCV, a 34 m diameter donut. On the right hand side, a different silver-colored pipe can be seen (Picture taken by Tepco)

The caption of the other picture ( http://photo.tepco.co.jp/library/120314/120314_04.JPG ) is the following:

Unit 2's suppression chamber photographed for the first time since the accident. On the right hand and far side, the suppression chamber can be seen. On the left and closer side a different silver-colored pipe can be seen. (Picture taken by Tepco)

[Do you think the whitish "dust" can be salt ?]

 

[SteveElbows]

Yes I was just going to say that as far as I know the torus is red, something stained this part of the torus white, and then something else washed off part of the white stain.

The photo from the other door shows the torus looking quite red, but the lighting isn't good so I wouldn't like to stretch this comparison too far.

I not know about the possible wrong location of that other photo, I haven't thought about it much but mis-labelling is always possible. I suspect that down is to the right of the photo, and that the 'floor' that can be seen in this direction is actually the water which has reached that level of the torus room (the same water we see in the stairwells). This water can hardly be seen but if you follow the wall downwards then it becomes visible to the eye.

Anyway they were in quite a rush when taking those photos due to the radiation, and the video from the reactor 2 mission suffered from lack of focus/plastic bag issues, so I don't think I will be able to piece much more together from the available footage, but I will watch the dreadful video again just in case.

 

[SteveElbows]

[Do you think the whitish "dust" can be salt ?]

Thanks again for the very helpful translations.

Salt seems like a possibility for sure, though I am not good at chemistry so I cannot comment on what other substances it could be.

 

[MadderDoc]

<..>
[Do you think the whitish "dust" can be salt ?]

Ah :-). Finally a question on my homefield. If you mean salt = NaCl, then no, it is clear if you zoom that the "dust" once dried up can well be wetted, but is not that easily washed away. If it were just NaCl, then it would, due to its high solubility. If you mean salt = ionic compounds, then yes, likely the "dust" would in the main be a mixture of dried up, relatively insoluble salts. E.g. Carbonates, oxides, mixed hydroxides. Think Calgon.

 

[jim hardy]

Boric acid leaks leave white crystals. I don't know about sea salt.

 

[NUCENG]

Yes I was just going to say that as far as I know the torus is red, something stained this part of the torus white, and then something else washed off part of the white stain.

The photo from the other door shows the torus looking quite red, but the lighting isn't good so I wouldn't like to stretch this comparison too far.

I not know about the possible wrong location of that other photo, I haven't thought about it much but mis-labelling is always possible. I suspect that down is to the right of the photo, and that the 'floor' that can be seen in this direction is actually the water which has reached that level of the torus room (the same water we see in the stairwells). This water can hardly be seen but if you follow the wall downwards then it becomes visible to the eye.

Anyway they were in quite a rush when taking those photos due to the radiation, and the video from the reactor 2 mission suffered from lack of focus/plastic bag issues, so I don't think I will be able to piece much more together from the available footage, but I will watch the dreadful video again just in case.

No guarantee that the Japanese use the same paint scheme or coatings we use in US BWRs, but US BWR torus coatings I have seen are white. Consider the possibility that the paint/coatings could have been flaked off or affected by high torus temperatures and possible mechanical/hydraulic vibration during the accident.(SRV venting RPV to torus or boiling in the torus Or steam release from a torus containment failure into the torus room.) Rust Red may be what is left and the white sections are areas where the coating is still intact.

The silver piping in the first picture could be banded insulation on steam exhaust piping from HPCI or RCIC to the Torus.

The picture in the corner room is of the stair up to the "Mezzanine Level" The basement level would have the RHR and Core Spray Pumps. There would also be a RHR heat exchanger standing vertically from the basement to the mezzanine level, but I don't see it in that picture. The two pictures of the starwells show that the basement level of the corner rooms are partially flooded.

 

[tsutsuji]

I tried to google some other suppression chamber pictures, and here is what I found:

http://net-news-jp.img.jugem.jp/20110327_2044919.jpg This from a 27 March 2011 blog entry at http://net-news-jp.jugem.jp/?eid=1438 . It looks like the construction work of a suppression chamber at Fukushima Daiichi or a similar plant. The caption on the screen says "unit 2: on the 15th there was an explosion/damage at the suppression chamber", so I guess this picture was provided by a television program as part of an explanation about the trouble at unit 2. The outer color is the same reddish-brown.

http://www.dailymotion.com/video/xpgy9x_yyyyyyyy-yyyyyyyyyyyyyyyyyyyy_news This is a television program explaining Tepcos' inspections to unit 2 and unit 3 suppression chambers on 14 March 2012. They have a nice 3D computer graphic showing the catwalk surrounding the torus and the accumulated water below. At 2:57, Junichi Matsumoto is saying "for example we may have a robot make a round trip on the catwalk so that we grasp the whole situation".

http://www.tepco.co.jp/fukushima1-np/b42112-j.html Visit of Ookuma and Futaba town officials at Fukushima Daiichi unit 1. Suppression chamber is seen in the bottom left picture.

http://www.tepco.co.jp/fukushima1-np/b13110-j.html Fukushima Daiichi unit 1 suppression chamber: bottom left

http://www.gengikyo.jp/topics/20011119a05.htm bottom left : a red colored suppression chamber at Shimane NPP

 

[MadderDoc]

I tried to google some other suppression chamber pictures, and here is what I found: <..>

Thank you indeed. Also, in the Fukushima 1985 movie, at (about at the 4:00 mark), there is a brief section with a top down view of the torus during construction. To a chemist under the circumstances, that reddish color whispers: Pb3O4 pigment :)

 

[NUCENG]

I tried to google some other suppression chamber pictures, and here is what I found:

http://net-news-jp.img.jugem.jp/20110327_2044919.jpg This from a 27 March 2011 blog entry at http://net-news-jp.jugem.jp/?eid=1438 . It looks like the construction work of a suppression chamber at Fukushima Daiichi or a similar plant. The caption on the screen says "unit 2: on the 15th there was an explosion/damage at the suppression chamber", so I guess this picture was provided by a television program as part of an explanation about the trouble at unit 2. The outer color is the same reddish-brown.

http://www.dailymotion.com/video/xpgy9x_yyyyyyyy-yyyyyyyyyyyyyyyyyyyy_news This is a television program explaining Tepcos' inspections to unit 2 and unit 3 suppression chambers on 14 March 2012. They have a nice 3D computer graphic showing the catwalk surrounding the torus and the accumulated water below. At 2:57, Junichi Matsumoto is saying "for example we may have a robot make a round trip on the catwalk so that we grasp the whole situation".

http://www.tepco.co.jp/fukushima1-np/b42112-j.html Visit of Ookuma and Futaba town officials at Fukushima Daiichi unit 1. Suppression chamber is seen in the bottom left picture.

http://www.tepco.co.jp/fukushima1-np/b13110-j.html Fukushima Daiichi unit 1 suppression chamber: bottom left

http://www.gengikyo.jp/topics/20011119a05.htm bottom left : a red colored suppression chamber at Shimane NPP

OK I'm convinced on the color. In that bottom left picture in the background you can see the silver insulated pipe labeled HPCI. So give me partial credit please.

 

[jim hardy]

you folks are amazing.

that's Synergy - the whole is greater than the sum of its parts !

 

[westfield]

Thank you. Referring to the new images you link to, taken from through a doorway to the torus room (according to the handout that would be a door from the NE side of the torus):
120314_06.JPG has EXIF time 12:11:58, and
120314_07.JPG has EXIF time 12:12:11.

Then this photo, at:
http://photo.tepco.co.jp/library/120315/120315_01.jpg
would seem have been taken from through the very same doorway of the torus room: it has EXIF time 12:12:18.
But, this photo has been published as coming from the NW side of the torus room? So from which side of the torus have these photos actually been taken?

Also I am not quite sure what is up in this third photo.

As Steve indicated it seems to go this way (edit: doesn't it? Some of the pipe brackets seem quite funky in that alignmnent but dripmarks in the paint and other stains seemed to confirm the correct orientation) - very visible "tide marks" on what seems to be the S\C and the two pipes on the left. The white substance really has coated the torus with considerable consistancy. Could it be something has condensed on hotter parts like the outside of the torus? Looking at other items in that image seem to show very little dust\whiteness while torus is well coated except where it's damp. Could it be an oxidisation of the paint of the torus?

I have no idea if it's related but the white substance also reminds me of the white substance that appears on many surfaces over at RB 4 refuelling floor level. Like here which seems to be linked to the steam that was coming of the sfp and reactor void early on. Note the containment cap is coated mainly on the side adjacent to the reactor void where there was lots of steam happening.

 

[Rive]

...

...

I don't know about the others, but for this picture left/bottom corner, on the two shiny insulated pipes that's serious Al corrosion.

Ps.: I could not spot such corrosion on the SFP videos, but now I'm a bit worried about those racks.

 

[westfield]

I don't know about the others, but for this picture left/bottom corner, on the two shiny insulated pipes that's serious Al corrosion.

Ps.: I could not spot such corrosion on the SFP videos, but now I'm a bit worried about those racks.

The appearance of the two pipes is odd isn't it - Is it corrosion or is it the same sort of white substance that has adhered to the torus?
Again, could heat\steam be a factor in creating the white substance on the two pipes or causing it to build up on the pipes?

Re debris on SFP racks - It's got to be at least plausable that most of it is concrete dust & other debris from the substantial demolition work going on over the top of RB4 SFP and reactor void lately. I know the SFP has some floaty covers on it but that sort of dust will get anywhere and everywhere.

 

[SteveElbows]

I have no idea if it's related but the white substance also reminds me of the white substance that appears on many surfaces over at RB 4 refuelling floor level. Like here which seems to be linked to the steam that was coming of the sfp and reactor void early on. Note the containment cap is coated mainly on the side adjacent to the reactor void where there was lots of steam happening.

Im pretty sure that cream coloured stuff at reactor 4 is from the spraying of anti-scatter material that they did. They had two different sorts of this substance, the greenish version which we saw sprayed at lower levels, but when they did the reactor buildings they used the cream version.

 

[westfield]

Im pretty sure that cream coloured stuff at reactor 4 is from the spraying of anti-scatter material that they did. They had two different sorts of this substance, the greenish version which we saw sprayed at lower levels, but when they did the reactor buildings they used the cream version.

They would spray that stuff into the SFP and reactor void but not the top of the containment cap there?

 

[MadderDoc]

The appearance of the two pipes is odd isn't it - Is it corrosion or is it the same sort of white substance that has adhered to the torus?

Like Rive, I too perceive the stuff on the two shiny tubes as corrosion of aluminium, but of course I can't be sure based on just that photo. Edit: It would make sense to me if it is corrosion as well as deposition of the same sort, as that seen at the torus tide-lines.

Again, could heat\steam be a factor in creating the white substance on the two pipes or causing it to build up on the pipes?

I am not sure where you're at, temperature and humidity are factors in many chemical and physical processes indeed!

Re debris on SFP racks - It's got to be at least plausable that most of it is concrete dust & other debris from the substantial demolition work going on over the top of RB4 SFP and reactor void lately. <..>.

OT alert. Certainly there must be cement dust present in the pool, but that it should constitute most of the debris we've seen developing in SFP4 I don't think is plausible. I see numerous top tie plates which have grown a layer of debris of such magnitude that no detail whatsoever of the tie plate is visible -- and next close to them I see the position number coupons of the racks, which in no instance I've spotted anywhere in the videos have been obscured by any such debris.

Back on topic, the grey stuff on the Unit 2 torus. I imagine dust, and for example cement dust from time to time has settled on the torus, and likewise that steam and humidity must have been present from time to time to partly dissolve some of the cement dust, only to re-precipitate it while drying up running downwards along the side of the torus. That would over time build up to a matte layer on the surface, similar to what people experience in hard water areas.

 

[SteveElbows]

They would spray that stuff into the SFP and reactor void but not the top of the containment cap there?

No. This was stuff that was sprayed liberally all over the buildings. There were some videos of it, and at the time it could also be seen on the TEPCO webcam. It was quite a long time ago now, but I remember it happening because I wasn't sure it if there would be any negative impact from spraying such substances all over everything.

They wouldn't deliberately want such stuff to go in the fuel pool or the reactor well, it was supposed to stop radioactive dust from being blown off the buildings etc.

Anyway there is no really obvious pathway that I can think of for lots of this stuff getting into reactor 2 torus room, and plenty of other candidates for what the white stains are caused by.

Meanwhile part 1 of the new borescope probe mission into reactor 2 drywell is due to happen in the coming hours, although the measurement of radiation isn't due to happen till the day after, and I am not sure how long it will take them to publish the results.

 

[westfield]

<snip?


I am not sure where you're at, temperature and humidity are factors in many chemical and physical processes indeed!

<snip>

Back on topic, the grey stuff on the Unit 2 torus. I imagine dust, and for example cement dust from time to time has settled on the torus, and likewise that steam and humidity must have been present from time to time to partly dissolve some of the cement dust, only to re-precipitate it while drying up running downwards along the side of the torus. That would over time build up to a matte layer on the surface, similar to what people experience in hard water areas.

Well I was thinking along the same lines of some sort of deposition that came out of steam and condensed on the torus and the two pipes, but not cement dust, wouldn't that be streaky and inconsistant? I was wondering about salt or some other chemical in the water.

Alternatively in the case of the torus I was thinking of the possibility of oxidised "red lead" paint cause by heat inside the torus.

All heat related as you say.


I was curious as to how consistent the "coating" seems to be on the surface of the torus. It apprears to be a very evenly distributed deposit.

Leading on from that I'm pondering if there were high ambient temps in the torus room or just within the torus and if there are any clues in the images that might indicate the scale of the theorized RB2 S\C failure.

Was it a small leak from a valve\minor gasket in a flange or was it a massive failure of the torus? This is what I'm curious about in RB 2 ( along with the did it dry vent or not question)

So a question I have is - is there any likely substance in the water TEPCO used in the emergency that could leave the whitish deposits deposited via steam?