Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[gmax137]

Apologies if this has already been asked & answered, but I'm wondering if the work in Unit 4 at the time of the earthquake (removing core barrel (??)) involves use of acetylene cutting torches, or other equipment involving tanks of flammable/explosive stuff? Wasn't it cold there in early March? -- maybe the construction crews had propane heaters inside? I can imagine that with the core offloaded, there could be a lot of non-seismic temporary stuff brought in for the work. Stuff prone to damage by the earthquake.

Or how about the turbine-generator cooling hydrogen system - does any of that pass through the reactor building? I wouldn't think so, but I have no experience at BWRs.

Just fishing for off the wall ideas here.

 

[SteveElbows]

I think that they move crane to take video of SFP or/and inside building from new point.

Yes. People said they had seen the crane around unit 4 at night, but as I mentioned in a previous post, times for spraying are published and its rare for these time to be at night. We do not consistently hear about temperatures they have measured in the pool, and have no way to know if they do this more than is mentioned in the press, but its quite probable that they are doing other things using the crane, possibly at night/early morning before sunrise.

 

[MadderDoc]

Looking at the righthand photo posted by MadderDoc above you can see that the buckled upper wall panels are putting strain on the wall and columns below. If the upper portion of the wall were to collapse and pull down the support columns below perhaps this would put additional strain on the fuel storage pool supporting structure. Maybe this is what the concern with unit 4 stability is...

Sorry the nameing of that photo file might've indicated to you that we are looking at the south wall where the fuel pool is. But, the photo is of the north wall.

 

[MadderDoc]

That photo is a wall that's on the opposite side of the building to the fuel pool.

Personally I don't know exactly what makes them afraid, except to say that in general the building is in poor condition. Perhaps they are worried by what they see when they look into the hole that is lower down on the south side of the building, or the lower holes on the east side,certainly I assume that there is much detail we cannot see from the few photos we have, and that's part of the reason I don't think we have learned very much from all these hours spent (over)studying photos.

Who them, they?

Perhaps it is not so much what we have learnt, but what we have unlearnt. Think if all we had were the written reports, no imagery, think of what fancy theories we could come up with, based on the limited evidence, :-) and think how many of those we so readily can sort away and dismiss, based on what we know from photos.

 

[whoswho69]

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e1.pdf
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e2.pdf
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e3.pdf
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e4.pdf
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e5.pdf
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e6.pdf
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e7.pdf
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e8.pdf
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e9.pdf
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e10.pdf
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e11.pdf
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e12.pdf
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e13.pdf

 

[SteveElbows]

Who them, they?

Perhaps it is not so much what we have learnt, but what we have unlearnt. Think if all we had were the written reports, no imagery, think of what fancy theories we could come up with, based on the limited evidence, :-) and think how many of those we so readily can sort away and dismiss, based on what we know from photos.

I am pleased we got something, images soon after the event were more plentiful than I had hoped. There has not been enough new material in last month to satisfy peoples curiosities or give us something to feed off, so attempts to come up with something new have become somewhat desperate in recent weeks.

Anyway it sounds like if everything has gone according to plan, workers have entered reactor 1 through the doors that were opened on Sunday:

Tokyo Electric Power Co. said the doors of the No. 1 reactor building connecting it to the adjacent turbine building at the crisis-hit Fukushima Daiichi nuclear power plant were opened Sunday, paving the way for the utility to proceed with efforts to stabilize the damaged reactor.

The move came after the government's Nuclear and Industrial Safety Agency gave the go-ahead, saying it has assessed that opening the double-entry doors at the troubled facility would not have adverse impact on the environment.

Tokyo Electric, also known as TEPCO, said it plans to have workers go inside the reactor building at around 4 a.m. Monday to measure the levels of radioactivity inside.

http://english.kyodonews.jp/news/2011/05/89826.html

 

[SteveElbows]

According to a press report, 'demolition robots' made by this company are going to be used at Fukushima:

http://www.brokk.com/

http://www.yomiuri.co.jp/dy/national/T110508002670.htm

[URL]http://krafttelerobotics.com/industries/nuclear/images/180r_large.jpg[/URL]

 

[SteveElbows]

Two of the links in that strange post of many links are actually interesting. Strontium 89 & 90 results, found in soil and sea (none detected in air).

Sea: http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e5.pdf

Soil: http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110508e7.pdf

 

[Caniche]

I'm sure all those nice vids are of Fukushima SFP 4 . But you know what they say, seen one spent fuel pool,seen them all
And what a stroke of luck that none of those blasted rsj's or roof panels or concrete panels ended up in the pool,neat

 

[Caniche]

Tepco -"Units 4-6 ,outage due to regular inspection ." Well it's not a complete lie,but hmm

 

[Astronuc]

I think I got it:
Under normal conditions enriched boric acid H₃BO₃ probably is -even at its much higher price and limited availability- the boron compound of choice in a nuclear power plant: highest concentration B-10, lowest concentration of accompanying elements (only O and H) and high purity due to its multi-step synthesis. And indeed therefore less high-grade NaOH or other base is needed for pH-adjustment.
I assume the purity requirements of the cooling water are very stringent. If the water after refueling/maintenance has to be made boron-free again by ion-exchange, smaller quantities are advantageous, even if the materials are more expensive.

Boric acid is NOT normally used in a BWR - certainly not in the primary system - and not in the spent fuel pool. The spent fuel structure contains boron in boral or boraflex.

Soluble boron in a BWR is introduced only in the case of emergency.

Soluble boron is used routinely in PWRs, and some used enriched boric acid. Some fuel design use enriched boron in ZrB₂ coating on fuel pellets in some fraction of fuel rods.

 

[ernal_student]

And what a stroke of luck that none of those blasted rsj's or roof panels or concrete panels ended up in the pool

With due respect, I have been asking myself, too. I am only a lay person, so all I can do is ask.
I have seen the images of the destroyed roofs on 3 reactors, and if I remember correctly someone had written in this forum that the pools are normally uncovered or just have a plastic cover.
How is it possible that only a few small items have fallen into a pool in a building that has exploded? In one case, did not a machine fall into a pool (I think that had been written in this forum)? There are only very few pictures that have been shown, it seems. How can one trust the information?

 

[MiceAndMen]

The technicians at the plant are citing the instabilities of the structure as a whole as causing worry about the SFP stability. From what I was told by a reliable source in the media is that this is a considerable worry, getting some sort of reinforcement under the SFP is a priority. This was before the building began leaning over.

Hi Nancy, glad you registered and started posting here. To my mind you're somewhat of a celebrity since you're the only one publicly named so far by the Japanese nuclear industry on their "internet enemies list". If it was me, I would wear that proudly as a badge of honor. I've been critical of some of your analyses on your website, but nevertheless am still glad you decided to join the conversations here. More data is always good and you seem to have some sources. Bringing more info to light will be good going forward in light of the reduced flow of photos coming out of Japan.

Considering the culture of Japanese business I think it's not unusual that some of your sources want to remain anonymous. Anonymous sources of information, however, will generate a fair amount of pushback here. Until their information can be corroborated by other sources they will not be given much weight.

With that said, I also don't think too much can be read into the "leaning tower of Fukushima" evidence presented thus far. The structural integrity of the unit 4 reactor building is a concern considering all the spent fuel in its pool, absolutely, but I don't think grainy long-distance pictures can be relied upon for proof. If the remaining concrete structure on the south side of building 4 came crashing down, taking the SFP with it, that would certainly be a very bad thing. But as of right now I just don't see it happening. It would be nice right about now if we could get a new set of high-res photos taken of the buildings at the Dai-ichi plant. Unfortunately I don't see that happening in the near future, either.

 

[MiceAndMen]

In one case, did not a machine fall into a pool (I think that had been written in this forum)? There are only very few pictures that have been shown, it seems. How can one trust the information?

I think you are referring to the Fuel Handling Machine from Unit 3. It was speculated here for a long time that it had been blown up into the air and landed near the northwest corner of its building. Later on there were photos (from the T-Hawk drone?) that showed it partially in the Unit 3 SFP. The FHM from Unit 4 is still standing and visible in many photos.

If they showed pictures of the Unit 3 SFP and it looked as clean as those from Unit 4 then I think a whole lot of people would jump on the TEPCO conspiracy bandwagon, but what we've seen from the Unit 4 SFP videos isn't all that surprising IMO.

 

[ernal_student]

I think you are referring to the Fuel Handling Machine from Unit 3. It was speculated here for a long time that it had been blown up into the air and landed near the northwest corner of its building. Later on there were photos (from the T-Hawk drone?) that showed it partially in the Unit 3 SFP. The FHM from Unit 4 is still standing and visible in many photos.

If they showed pictures of the Unit 3 SFP and it looked as clean as those from Unit 4 then I think a whole lot of people would jump on the TEPCO conspiracy bandwagon, but what we've seen from the Unit 4 SFP videos isn't all that surprising IMO.

I understand. So I have confused reactor 3 and reactor 4, sorry.

 

[ranchorelexo]

New temps for reactor 3.

http://www.tepco.co.jp/nu/fukushima-np/f1/images/032_1F3_05090600.pdf

 

[Jorge Stolfi]

Yes. We appear to have seen enough fuel racks to hold the recorded number of assemblies in the pool. Here is a rough lineout of the stacking in the pool, as much as can be gleaned from the two released videos.

How do you get the distance to the back wall? Could there be a wider gap there?

I cannot make out the far edge of the racks (beyond the fallen stair). Shouldn't there be a broader metal "lip" all around the rack (as there is on the near side)? Perhaps there is some large dark piece of debris over the fuel, just beyond the stairs?

Is the water in that part of the pool murkier than the rest (as if there were more bubbles there)? Or is it just that things are farther away in that direction?

 

[coolin'_down]

Thank you all for so much for this site and for all the information. I'm not a scientist but I've been listening to the briefings given by Tepco and NISA trying to keep track of the situations at Fukushima NPP. Though the situation is still very worrying and the many crude approaches taken by Tepco is surprising, I had never been alarmed enough to warrant posting in this site. To get to the point. Tepco just annouced that they will be putting Hydrazine into the spent fuel pool (I think in #1) to counter corrosion, but I read on wikipedia that Hydrazine is also used as rocket fuel! Is Hydrozine usually used in NPP?

 

[Jorge Stolfi]

And what a stroke of luck that none of those blasted rsj's or roof panels or concrete panels ended up in the pool,neat

In unit 4 the fuel-handling machine was parked over the spent-fuel pool when the explosion happened. Perhaps it caught most of the roof debris that would have otherwise fallen into the pool.

There is a video taken by a T-Hawk that peeks into one of the service floor "new windows" on the East side of Unit 4, looking at the yellow drywell cap parked near the opposite wall. Given the extension of the damage to walls and roof, there seems to be surprisingly little concrete rubble on the service floor.

The wall panels were blasted outwards, so it is no wonder that none is to be found inside. As for the roof,
someone suggestde that it may have been lifted by the explosion largely as a single unbroken sheet, which then fell down diagonally over the north end of the building, slicing through the northernmost row of roof girders and contributing to the damage of the north wall.

 

[rowmag]

Here's what Google Translate gives for the headers

Let me make a stab at improving a little on Google Translate (corrections welcome):

1. Temperature of Water Nozzle N4B
2. RPV base head (upper part)
3. RPV body flange
4.Temperature of lower part of pressure vessel
5. RPV stud-bolt temperature
6. RPV body flange (temperature of lower part)
7. Relief safety valve 2-71D Leakage
8. Relief safety valve 2-71F Leakage
9. Main steam isolation valve 2-86A Leak-off
10. D/W HVH return temperature
11. RPV bellows seal
12. S/C Pool water temperature A
13. S/C Pool water temperature B

 

[MiceAndMen]

In unit 4 the fuel-handling machine was parked over the spent-fuel pool when the explosion happened. Perhaps it caught most of the roof debris that would have otherwise fallen into the pool.

There is a video taken by a T-Hawk that peeks into one of the service floor "new windows" on the East side of Unit 4, looking at the yellow drywell cap parked near the opposite wall. Given the extension of the damage to walls and roof, there seems to be surprisingly little concrete rubble on the service floor.

The wall panels were blasted outwards, so it is no wonder that none is to be found inside. As for the roof,
someone suggestde that it may have been lifted by the explosion largely as a single unbroken sheet, which then fell down diagonally over the north end of the building, slicing through the northernmost row of roof girders and contributing to the damage of the north wall.

In the underwater SFP video, I think the metal staircase is from the fuel handling machine. It looks like a complete set of stairs with a handrail, not like it was separated from something else. The vertical distance seems to be appropriate for accessing some parts of the FHM.

 

[Jorge Stolfi]

Here is a rough lineout of the stacking in the pool, as much as can be gleaned from the two released videos.

The "round thing" may be an enclosure within the SFP that holds a fuel transportation cask while loading and unloading. That would be another version of the square concrete enclosure visible in the far left corner of the SFP in the photo of an unidentified japanese reactor (Unit #5?) attached.

Some blueprints/drawings (said to fit Unit #1) show a separate "cask-loading pool" between the equipment pool and the elevator shaft. Presumably in Units #2--#4 that separate pool was replaced by a smaller enclosure within the SFP.

 

[Jorge Stolfi]

Yes. We appear to have seen enough fuel racks to hold the recorded number of assemblies in the pool. Here is a rough lineout of the stacking in the pool, as much as can be gleaned from the two released videos.

Your sketch shows 30*(7+7+12+12+10)+40 = 1480 slots for fuel assemblies; perhaps there are another 60 in the blind corner at right. On the other hand, some slots seem to be empty.

Yet a previous post claims that there were (548 in-use + 1331 spent + 202 new) = 2081 assemblies in the pool. If that number is correct, then we are missing 500 to 600 assemblies. Seems a bit too much for roundoff error...

 

[ernal_student]

named so far by the Japanese nuclear industry on their "internet enemies list".

Where can one see such a list (of one person?)

 

[MadderDoc]

Your sketch shows 30*(7+7+12+12+10)+40 = 1480 slots for fuel assemblies; perhaps there are another 60 in the blind corner at right. On the other hand, some slots seem to be empty.

Yet a previous post claims that there were (548 in-use + 1331 spent + 202 new) = 2081 assemblies in the pool. If that number is correct, then we are missing 500 to 600 assemblies. Seems a bit too much for roundoff error...

Yes indeed. I was going with the figure 1331 assemblies in storage, by March 2011, according to this source.
http://progressivelever.com/2011/03/22/more-on-spent-fuel-pools-at-fukushima/

 

[yakiniku]

New temps for reactor 3.

http://www.tepco.co.jp/nu/fukushima-np/f1/images/032_1F3_05090600.pdf

Do we have corresponding information regarding the pressures and radiation levels in reactor 3?

Would someone be able to comment at what temperature would things become a concern? The values look high but what is considered 'okay', 'normal' or 'abnormal'?

 

[AntonL]

Your sketch shows 30*(7+7+12+12+10)+40 = 1480 slots for fuel assemblies; perhaps there are another 60 in the blind corner at right. On the other hand, some slots seem to be empty.

Yet a previous post claims that there were (548 in-use + 1331 spent + 202 new) = 2081 assemblies in the pool. If that number is correct, then we are missing 500 to 600 assemblies. Seems a bit too much for roundoff error...

it is 1331+202 = 1533 fuel rods
548 in use is included in 1331

 

[Jorge Stolfi]

Yes indeed. I was going with the figure 1331 assemblies in storage, by March 2011, according to this source.
http://progressivelever.com/2011/03/22/more-on-spent-fuel-pools-at-fukushima/

OK, so the 1331 figure includes both in-use and spent. But what about the new assemblies? Several sources give "1331 + 204 new = 1535", e.g.

http://www.ken-zo.com/wp-content/uploads/METI Japan-challenges_full.pdf

It is quite possible that they got it wrong too. But google finds >20,000 hits for Fukushima Daiichi 1535...

 

[MiceAndMen]

Where can one see such a list (of one person?)

A Japanese news story from 27 April says TEPCO doesn't like what Nancy has on her website.
http://www.asahi.com/english/TKY201104260122.html

This is like Sony trying to blame the Anonymous hackers for their own incompetence. Sony was running unpatched web servers without a firewall. Solution? Blame someone else.
http://www.reuters.com/article/2011/05/04/sony-idUSN0422224820110504
http://consumerist.com/2011/05/secu...re-was-obsolete-months-before-psn-breach.html

If Nancy made TEPCO angry then she must be doing something right. That's why I support what she's trying to do on her website even though I disagree with a lot of her analysis and conclusions. I hope she sticks around here as we all try to learn from each other and piece together what has happened, and what is happening at the Dai-ichi plant.

 

[fluutekies]

it is 1331+202 = 1533 fuel rods
548 in use is included in 1331

That are my figures:

1331 used + 204 unused = 1535 assemblies in SFP4

http://www.iaea.org/newscenter/news/tsunamiupdate01.html
[Fukushima Nuclear Accident Update (22 March 2011, 18:00 UTC)]

 

[MiceAndMen]

Yes. We appear to have seen enough fuel racks to hold the recorded number of assemblies in the pool. Here is a rough lineout of the stacking in the pool, as much as can be gleaned from the two released videos.

Your diagram is very good. The similarity to the Oyster Creek SFP blueprint drawings is amazing, right down to the circular "fuel cask drop" in the corner. At least that's what I think it is.

The 2-level spent fuel rack stacking theory is also dead now, thank goodness.

 

[fluutekies]

Fukushima Daiichi Nuclear Power Station First Floor of Turbine Building of Unit 1, May 6th, 2011)

 

[MadderDoc]

How do you get the distance to the back wall? Could there be a wider gap there?

I have not made any real attempt to assess the distance from the racks to the walls at the far end and to the sides. There might well be a wider gap.

I cannot make out the far edge of the racks (beyond the fallen stair). Shouldn't there be a broader metal "lip" all around the rack (as there is on the near side)?

Some close ups of racks show very clearly that a broad lip (with the stamped numbers) is affixed to only one side of the rack.

Perhaps there is some large dark piece of debris over the fuel, just beyond the stairs?
Is the water in that part of the pool murkier than the rest (as if there were more bubbles there)? Or is it just that things are farther away in that direction?

The water is somewhat murky, but working through the videos, my impression was that the murkiness is well-mixed. Naturally, it'll affect the most distant views the most. Some debris might well be hiding there, but no more fuel racks, I think.

 

[|Fred]

named so far by the Japanese nuclear industry on their "internet enemies list". ../...A Japanese news story from 27 April says TEPCO doesn't like what Nancy has on her website.

You may be putting word into the article "TEPCO suspects the blueprint is one of its internal documents, if proven to be genuine,the document is subject to the restrictions imposed under its regulations on nuclear materials protection."

 

[GJBRKS]

One question regarding the SFP #4 video:

There are bubbles rising in the water... where do they come from? Or rather, what's in a SFP that could produce air bubbles?

If there is a leak in the SFP , bubbles could be formed by cracks in the pool where water leaves and air enters.

My assumption is that the SFP has a leak , and the bubbles could be the symptom

 

[I_P]

I have not made any real attempt to assess the distance from the racks to the walls at the far end and to the sides. There might well be a wider gap.



Some close ups of racks show very clearly that a broad lip (with the stamped numbers) is affixed to only one side of the rack.



The water is somewhat murky, but working through the videos, my impression was that the murkiness is well-mixed. Naturally, it'll affect the most distant views the most. Some debris might well be hiding there, but no more fuel racks, I think.

I get 1480 based on your drawing (including the 4x10 rack) so there would be 2 sets of 30 missing - the ones that would fit in the lower right of your drawing below the control blades. There are two smaller cylindrical objects standing near the large cylinder to its right. What is up with the empty slots shown at the end of the video to the right of the rack of 40?

 

[Curium]

what is quite interesting, is that the melted-looking hole in the roof grid, severely bent/twisted / heat-damaged looking beams, etc are right over spent fuel pool. It is undeniable that beams next to spent fuel pool have some very specific look not replicated anywhere else.

Gundersen made an update to his previous hypothesis about SFP #3.

(1) The orange flash in the video was the Stored Fuel Pool in Unit 3 exploding, because is so localized to the area of the SFP, and because its shape is channeled vertically upward
(2) The fact that the explosion expands outward somewhat to the right, but not to the left, also supports that hypothesis based on the structure of the plant
(3) If the contents of the fuel pool were lifted upward, this cannot have been only an external hydrogen explosion, something exploded in the pool itself
(4) Some other people (not Gundersen himself) suggested that since plutonium melts at a higher temperature than uranium, plutonium could have accumulated in a mass at the bottom of the pool
(5) This could cause a prompt, but "moderated" criticality

Contentions 1, 2, and 3 seem correct on the basis of the evidence. New question is: do hypotheses (4) and (5) make any sense?

Previously it was hard to imagine how an explosion could compress damaged fuel rods into a configuration resulting in criticality. Is the above any more plausible? In any case, something complex must have happened inside Unit 3 to account for what is seen in the videos.

 

[PietKuip]

Tepco just annouced that they will be putting Hydrazine into the spent fuel pool (I think in #1) to counter corrosion, but I read on wikipedia that Hydrazine is also used as rocket fuel! Is Hydrozine usually used in NPP?

Yes, this sounds odd. But hydrazine is used to prevent corrosion of steel parts in steam circuits - it removes oxygen molecules. Concentrations are very low, less than 1 ppm.

Even stranger: vitamin C is recommended as a substitute!
http://pubs.rsc.org/en/Content/Database/HAZ1307001305

 

[MiceAndMen]

Yes, this sounds odd. But hydrazine is used to prevent corrosion of steel parts in steam circuits - it removes oxygen molecules. Concentrations are very low, less than 1 ppm.

About the only good thing you can say about hydrazine is that it's not radioactive. Some formulations are incredibly toxic. One good whiff and your liver is history.

 

[pdObq]

Gundersen made an update to his previous hypothesis about SFP #3.

(1) The orange flash in the video was the Stored Fuel Pool in Unit 3 exploding, because is so localized to the area of the SFP, and because its shape is channeled vertically upward
(2) The fact that the explosion expands outward somewhat to the right, but not to the left, also supports that hypothesis based on the structure of the plant
(3) If the contents of the fuel pool were lifted upward, this cannot have been only an external hydrogen explosion, something exploded in the pool itself
(4) Some other people (not Gundersen himself) suggested that since plutonium melts at a higher temperature than uranium, plutonium could have accumulated in a mass at the bottom of the pool
(5) This could cause a prompt, but "moderated" criticality

Contentions 1, 2, and 3 seem correct on the basis of the evidence. New question is: do hypotheses (4) and (5) make any sense?

Previously it was hard to imagine how an explosion could compress damaged fuel rods into a configuration resulting in criticality. Is the above any more plausible? In any case, something complex must have happened inside Unit 3 to account for what is seen in the videos.

I just had this idea:

a) hydrogen-oxygen mixture ingited in north of building causing deflagration, possibly detonation and shock wave resulting in explosion just as in unit 1

b) for some reason there is an plume of mostly hydrogen sitting above the SFP (i.e. not enough oxygen in the mixture), for example accumumulated under the fuel handling machine.

c) flame front of first explosion a) reaches plume b) which then ignites but burns off rather slow (just deflagration), causing the visible "orange flash" and subsequent smokey mushroom.

That's of course just some speculation by a not-at-all-expert. (But it also includes a possible explanation why fhm3 probably is in orbit .) Would this be plausible?

 

[MiceAndMen]

You may be putting word into the article "TEPCO suspects the blueprint is one of its internal documents, if proven to be genuine,the document is subject to the restrictions imposed under its regulations on nuclear materials protection."

Perhaps they don't have a literal list of enemies, but it's obvious they're not happy about it. If one drawing escaped their control there might be others. One would hope that they are more concerned about the source of the leak than websites that publish it. That they are concerned about the release of a 45 year old drawing at all is mystifying. There is no competitive advantage to be gained by keeping the drawings secret at this point.

 

[Rive]

Gundersen
...
(3) If the contents of the fuel pool were lifted upward, this cannot have been only an external hydrogen explosion, something exploded in the pool itself...

The main problem with this idea is that now any worker can take a walk around the site without much hurry.

Any explosion IN the SFP would shatter fuel pieces around the unit. But only possible traces of particles were found, not pieces.

 

[AntonL]

Tepco knew a lot more than is openly or willingly given to public. I have come across below documents, these published ten minute logs of water level and pressure parameters at the most critical time after the tsunami and before explosions, and temperature after 20/3 and depicting were actual temperature sensors are placed.

There are some interesting data like unit 3 the fuel was uncovered 3/4 (-3metres) for more than two hours on the 19th March (does anyone remeber this event?)

[PLAIN]http://k.min.us/ilnQ3E.JPG

Here are all the files:

http://k.min.us/ilnOrs.pdf" Water levels and pressure
http://k.min.us/ilskVG.pdf" temperature

http://k.min.us/ilrLwi.pdf" Water levels and pressure
http://k.min.us/ilrN4q.pdf" temperature

http://k.min.us/ilnMjk.pdf" Water levels and pressure
032_1F3_04181300.pdf sorry cannot find this document can you find it?
unfortunately original documents cannot be found - they have been pulled from the Tepco site, these were google cached - the net does not forget (but it forgot one)

For May you can download these values
www.tepco.co.jp/nu/fukushima-np/f1/images/0[/URL]xy_1Fx_mmdd0600.pdf

were x is 1,2,or 3
y is 1 for water levels, pressure and CAMS, 2 temperatures
mm is month ie 05
dd is day ie 09

example http://www.tepco.co.jp/nu/fukushima-np/f1/images/032_1F3_05090600.pdf

Nice images of temperature graphs and temperature sensor locations
[PLAIN][PLAIN]http://k.min.us/in4JQ0.JPG
[PLAIN]http://k.min.us/in9ewE.JPG

 

[Rive]

Here is another stab of it (a higher resolution image is attached):
http://gyldengrisgaard.dk/fuku_docs/20110324_down_3thumb.jpg
...
3) Signature of heat on the winch, and possibly a burn through of the southern boom in this location
4) Missing rails on the top of this section of the southern boom.
5) Areas in which the booms have sunk into the concrete deck of the service floor, extending the NW broken region of the floor.

Excellent work.
3) IMO the crane is not 'burn through', here the crane directed the steam to the release path.
4) there everything covered with that gray dust.
5) On one of the T-Hawk videos it can be seen that the service floor is broken only under the north crane boom.

Yes. We appear to have seen enough fuel racks to hold the recorded number of assemblies in the pool. Here is a rough lineout of the stacking in the pool, as much as can be gleaned from the two released videos.
http://gyldengrisgaard.dk/fuku_docs/P5080106thumb.JPG

That was fast :-)

IMO the 'cooling equipment' is partly the new fuel storage racks (with some black cover on the top, whick makes them look like damaged) and the fuel inspection machine - so there is one more rack. And that's all, we have seen everything.

 

[elektrownik]

OMFG did you saw CAMS data 3/14 for unit 3 ? It is error or 100% of unit 1 core is damaged

 

[Rive]

Your sketch shows 30*(7+7+12+12+10)+40 = 1480 slots for fuel assemblies; perhaps there are another 60 in the blind corner at right. On the other hand, some slots seem to be empty.

Yet a previous post claims that there were (548 in-use + 1331 spent + 202 new) = 2081 assemblies in the pool. If that number is correct, then we are missing 500 to 600 assemblies. Seems a bit too much for roundoff error...

At 2010 Dec. there were 783 spent assemblies. Plus the core (548) gives the 1331 for 2011 March. Plus the 202 new -> 1533. According to the various sources the maximal capacity of that pool was 1590.

 

[pdObq]

You see that the SFP is tied into the outside of the containment concrete. It hangs sort of like a window box off of the containment structure. There is a very thin piece of concrete that ties the bottom of the SFP to the outer frame of the building. There is nothing supporting the SFP from below.

From looking back at that GE cut-out drawing of a mark I containment, there seem to be at least a bunch of pillars unders the SFP. Well, but for my personal taste there could be a bit more structural support down there.

I have a couple of new images on my website. One of the crane being moved and inserted into the side of the building at the work floor level. Not sure why. Move due to structural worries? Moved so work to shore up the SFP could begin? Needed to inject water directly in the pool?

Also some new images of the leaning reactor 4 along with vertical landmarks to try to figure out the leaning. I mentioned in another post that I received confirmation from the TBS tech crew that it is not an optical illusion of the camera and also from workers at the plant that 4 is leaning over.

That's fair enough, but like for the previous posters, that's not sufficient evidence for me that it really is leaning. But there is also no evidence that it definitely is not leaning. So, let's see how the situation develops.

They have poured in tons of water, the soil around the building could be becoming unstable adding to the sinking. There were previous concerns about the groundwater levels making the NPP buoyant. [...] So you have a reactor building that is floating to an extent, lots of water added to the situation, constant earthquakes and two confirmations that this isn't a camera trick.

Asahi Shimbun article about the floating buildings http://www.asahi.com/english/TKY201104010166.html

Manichi article about bedrock being 46 meters down http://mdn.mainichi.jp/mdnnews/news/20110427p2g00m0dm091000c.html

Study confirming the NPP is on floating mudstone base not bedrock http://www.iitk.ac.in/nicee/wcee/article/9_vol3_733.pdf

info and photos of r4 sinking and the moved crane http://www.houseoffoust.com/fukushima/r4sinking.html

images of yesterday's steam and smoke show http://www.houseoffoust.com/fukushima/May8smoking.html

• First article: Only relevant part is this sentence: "The pumps are located around the reactor building and designed to prevent the building from moving due to the buoyancy of the groundwater."
  
• Only relevant part in second article: "There is bedrock 46 meters underground."
  
• Third one: The study itself is not about confirming that it floats on mudstone. The study is about testing if FEM simulations correctly predict the measured responses of unit 6 to some earlier earthquakes. They conclude it does. That unit 6 is founded on mudstone is stated only in a few sentences describing the input parameters to their model: "The reactor building is partially embedded and is founded on mudstone at an elevation 17m below ground surface."
  
• Fourth: See above, not enough evidence to decide whether it is leaning or not for me.
  
• Fifth: Might be interesting but it's a different topic.

Overall still some interesting bits and pieces in my view. I don't know enough about geology to draw any qualified conclusions, but probably mudstone should be considered more stone than mud. Does anyone know how much that weakens if it soaks up enough water? And how much would be enough water?

 

[~kujala~]

I think one reason TEPCO is not so worried about the unit 3 is the CAMS readings.
On March 14th 7:00 they had quite high reading (167,0 Sv/h) but after that it has been going steadily down. On March 18th it was still 105,0 Sv/h but after a month it was only 15,8 Sv/h.

CAMS D/W(A)
March 14th 7:00 167,0 Sv/h
March 18th 11:50 105,0 Sv/h
April 18th 15,8 Sv/h

http://i.min.us/ilnMjk.pdf

On May the levels have also been going down. On May 1st it was 13,7 Sv/h and on May 9th it was 12,1 Sv/h.

CAMS D/W(A)
May 1st 5:00 13,7 Sv/h
May 9th 5:00 12,1 Sv/h

http://www.tepco.co.jp/nu/fukushima-np/f1/images/031_1F3_05090600.pdf

I think what they are more interested in each reactor is the radiation readings and only if they see both temperatures rising and radiation rising will there be a "strong" reaction but if there is only temperature rising the reaction is subtler.

 

[pdObq]

OMFG did you saw CAMS data 3/14 for unit 3 ? It is error or 100% of unit 1 core is damaged

You mean unit 1? Did you see D/W value for 4/8 ?

added: Does anyone have an idea at what level those sensors saturate or get damaged?

 

[rowmag]

You may be putting word into the article "TEPCO suspects the blueprint is one of its internal documents, if proven to be genuine,the document is subject to the restrictions imposed under its regulations on nuclear materials protection."

I agree with Fred, and fear this is, again, a matter of overparsing a translated statement.

Perhaps they don't have a literal list of enemies, but it's obvious they're not happy about it. If one drawing escaped their control there might be others. One would hope that they are more concerned about the source of the leak than websites that publish it.

If you read the original Japanese version of the article, that is exactly the impression given:

http://www.asahi.com/national/update/0425/TKY201104250626.html

"東電側は２４日夜の記者会見で、「基本的には内部資料として持たせていただいているもののはずなんですが、それがどういった経緯で、というのは確認していない」と説明した。"

I can't translate the tone exactly, but my reading is that this is a somewhat whiny (or offended) way of saying, "Those are our internal documents, and we don't know how they leaked out."

"また、問題の図面が東電のものだとすれば「核物質防護上の規制がかかっている」対象と認めた。"

TEPCO "admitted" (認めた) that if these diagrams are theirs, they would be subject to regulations on the protection of nuclear materials.

"これまでも設計図について、東電は「メーカーのノウハウがある」などの理由で公表を拒否している。 "

They have also previously refused to release blueprints, because they include "the maker's [GE's] knowhow."My reading is that TEPCO is concerned about getting into trouble for leaking documents that they had a responsibility to safeguard -- both for public safety legal reasons (protection from terrorists, for example), and for reasons of contractual obligation to GE. I don't see an implied threat to foreign bloggers, and indeed, don't see jurisdictionally how they could even make a credible one if they wanted to.

As far as the rules themselves, don't know exactly what TEPCO is referring to, but searching turns up stuff like this:
http://law.e-gov.go.jp/htmldata/S32/S32HO166.html
which, at admittedly just a glance, seems to apply to nuclear materials materials handlers -- like TEPCO.

I stress the above is all my reading only, and I am not an expert at Japanese law, or Japanese language, for that matter. Opinions and corrections would be welcome from ernal_student, Susudake, and whoever else may be able weigh in.