Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[SteveElbows]

Page IV-96 in the "Japanese Government report to the IAEA" shows an image that labels the large pipes that converge at the vent stack between Units 3 and 4, the "SGTS exhaust pipe junction".

http://www.kantei.go.jp/foreign/kan/topics/201106/iaea_houkokusho_e.html

Perhaps they are thinking that maybe the hydrogen flowed through the connecting pipe (about 200m of pipe all told) while the hydrogen was being produced and accumulating in Unit 3, and before Unit 3 exploded. Agree that it would be impossible for any hydrogen to travel through broken pipe after the explosion.

Actually I think the photo is not referencing the large pipes at all.There are yellow arrows on the photo that seem to clearly be pointing to some much smaller pipework. Its possible not to spot this because the junction of these smaller pipes is the same shape as for the larger pipes, and the large pipes dominate the picture, but it really does look like smaller pipes are what they are talking about, and we don't have good visual evidence for if/when these pipes were damaged.

 

[zapperzero]

http://ex-skf.blogspot.com/2011/06/just-in-power-outage-in-reactors-1-and.html

 

[tsutsuji]

What we need is not just a geologist (like me) but a geologist that reads Japanese and can find the data.

A quick scan through the Report of Japanese Government to the IAEA Ministerial Conference on Nuclear Safety June 2011 http://min.us/mvoVGLP appears silent on the matter of site geology. Maybe I missed it but a search on 'geology' got only one inconsequential result and there were no results on 'mudstone'.

For what it's worth, there is a 1:50,000 geological map of the Namie-Tomioka area available at http://tochi.mlit.go.jp/tockok/tochimizu/F3/data/G/0720G.jpg (verso : http://tochi.mlit.go.jp/tockok/inspect/landclassification/land/l_relay_map.html?url=..%2F..%2F..%2Ftochimizu%2FF3%2Fdata%2FG%2F0720GR.tif )

A geomorphological map : http://tochi.mlit.go.jp/tockok/tochimizu/F3/data/L/0720L.jpg

A soil map : http://tochi.mlit.go.jp/tockok/tochimizu/F3/data/S/0720S.jpg (verso : http://tochi.mlit.go.jp/tockok/inspect/landclassification/land/l_relay_map.html?url=..%2F..%2F..%2Ftochimizu%2FF3%2Fdata%2FS%2F0720SR.tif )

Land use map : http://tochi.mlit.go.jp/tockok/tochimizu/F3/data/U/0720U.jpg

Book : http://tochi.mlit.go.jp/tockok/tochimizu/F3/data/pdf/0720t.pdf

(Main menu : http://tochi.mlit.go.jp/tockok/inspect/landclassification/land/l_national_map_5-1.html )

 

[rowmag]

What we need is not just a geologist (like me) but a geologist that reads Japanese and can find the data.

A quick scan through the Report of Japanese Government to the IAEA Ministerial Conference on Nuclear Safety June 2011 http://min.us/mvoVGLP appears silent on the matter of site geology. Maybe I missed it but a search on 'geology' got only one inconsequential result and there were no results on 'mudstone'.

Not sure if this is what you are looking for, but you can download a paper on TEPCO's civil engineering for the site, which was submitted to a civil engineering journal in 1967, from here:
http://www.doboku-g.com/DownloadPDF.aspx?TocID=6608

You will have to provide a mail address twice (and not an obviously free mail address), and check a box agreeing to let the journal send you notices now and then, click on the button in the lower right, and then you will be mailed a URL from which to download the PDF file.

Figure 2 shows a cross-section through the site, showing how they shaved off everything above an elevation of +10 m. The labels on the right are, from top to bottom:

Sandy loam
Sand
Weathered mudstone
Mudstone
Sandstone

The solid black line on Figure 11 shows the level of groundwater measured before starting. It starts inland at an elevation of +26.5 m, and comes out at the (former) cliff at an elevation of +14.5 m, or above where the eventual ground level will be (+10 m) after they have shaved down the cliff, so they had to put in some drainage system to deal with it.

 

[SteveElbows]

Just looking through the report to IAEA for other details that may be an improvement on what we knew before. Is any detail in the following, dealing with reactor 4, more detailed than we knew before, eg more precise location of fires?

http://www.kantei.go.jp/foreign/kan/topics/201106/pdf/chapter_iv-3.pdf from page IV-90

At around 6:00 on March 15, an explosion assumed to be a hydrogen explosion occurred in the reactor building, and the whole part upward from the one floor below the operation floor as well as the western wall and the wall along the stairs were collapsed. Furthermore, at 9:38, a fire was identified in the northwest part of the fourth floor of the reactor building, but TEPCO confirmed at about 11:00 that it had gone out on its own. A fire was also reported to have broken out in the northwest part of the third floor of the building around 5:45 on March 16, but TEPCO was not able confirm this fire on-site at around 6:15.

Fukushima Daini also has some mild interest from me after reading the same document. Towards the end of the document linked to above it goes through the situation at this plant, and a table of events appears to show control rod drift alarms going off in several of the reactors on dates such as 12th & 13th.

 

[MiceAndMen]

Actually I think the photo is not referencing the large pipes at all.There are yellow arrows on the photo that seem to clearly be pointing to some much smaller pipework. Its possible not to spot this because the junction of these smaller pipes is the same shape as for the larger pipes, and the large pipes dominate the picture, but it really does look like smaller pipes are what they are talking about, and we don't have good visual evidence for if/when these pipes were damaged.

Eh, possible I guess. I had considered the yellow arrows to be just generally indicative of the direction of flow, but maybe not. The Oyster Creek blueprints show 2 "trains" for the SGTS, each culminating in a 2600 cfm flow to the stack. That's about 1.2 m³/s each. You definitely don't need a 2m diameter pipe to handle that.

Here's a part of that image with the English overlay removed. Perhaps someone would be kind enough to translate what it says in Japanese?

 

[zapperzero]

Interesting why they are installing this not in center of SFP, sfp is weakest there ?, the point where they are installing it is strongest I think (because of drywell thick): http://www.tepco.co.jp/en/news/110311/images/110607_1f_2.pdf

They are installing what amounts to a supporting wall at a place where it will not shed its load on the floor below, but at the "neck" of the "lightbulb". Makes sense. I still wonder what made them think the SFP floor might crack and why they are only worried about this particular SFP. Perhaps it's because the others have less water in them, giving an adequate margin of (structural) safety?

 

[SteveElbows]

Other stuff from report that seemed like it might be news to me:

"Spraying onto the PVC" at reactor 3 at 07:39 on the 13th march.

Do we know what this means exactly? I know some people though that later actions by fire crews around 20th-21st march may have been targeting more than just the fuel pools, but we have little info about this possibility. Do we know what form 'Spraying onto the PVC' might have taken on the 13th?

Other interesting matter is estimates for percentage of stuff released from each reactor.



Reactor 1:

TEPCO analysis:

The radioactive materials contained in the fuel just before the accident were released into the RPV as the fuel was damaged and melted, and the analysis was carried out for the leakage assumed from PCV with the increase of PCV pressure, and almost all the noble gases were vented out into the environment. The ratio of released radioactive

iodine to the total iodine contained (hereinafter referred to as release ratio) was approximately 1% from the analysis result, and the release of other nuclides was less than 1%.

Page IV-42

NISA analysis:

As for release ratio of radioactive nuclides, the analytical results show about 1% of tellurium, about 0.7% of iodine and about 0.3% of cesium. However the release ratios are changed according to the injection flow rates of seawater, the results may be changed by operation condition because the operation condition was not cleared.

Page IV-43

Reactor 2:

TEPCO analysis:

The leakage of radioactivity was analyzed assuming that the radioactivity contained in the fuel was released to RPV after fuel collapse and melting and that it leaked to the PCV. It is estimated that nearly all the noble gas was released to environment, and the release rates of iodine and other nuclides are less than about 1%.

Page IV-59

NISA analysis:

Results showed the release rate of radioactive materials to be about 0.4% to 7% for iodine nuclides, about 0.4% to 3% for tellurium nuclides, and about 0.3% to 6% for cesium nuclides. Release rates may change with operating conditions, as release rates vary with the sea water flow rate and the set operating conditions are unclear.

Page IV-59

Reactor 3:

TEPCO analysis :

The analysis results show that, along with the damage to the core and the core melt of reactor fuel, the embedded radioactive materials were released into the RPV and moved to the S/C, with the noble gases almost all being released into the environment through PCV vent operation, and approximately 0.5% of the radioactive iodine was released.

Page IV-75

NISA analysis:

From the results of the severe accident analysis, however, it can be estimated that radioactive materials were released into the environment by the wet vent operation starting at noon on March 13, and almost all the noble gases in the core were released, and the iodine and cesium in the core were released at ratios of approx. 0.5% to 0.8% for each.

Page IV-80

So the NISA analysis for reactor 2 suggests a much wider range of possible radioactive release for this reactor compared to the others.

 

[zapperzero]

Not sure if this is what you are looking for, but you can download a paper on TEPCO's civil engineering plans for the site, which was submitted to a civil engineering journal in 1967, from here:
http://www.doboku-g.com/DownloadPDF.aspx?TocID=6608

You will have to provide a mail address twice (and not an obviously free mail address)

mailinator.com (throwaway address) worked just fine. Thanks.

I just realized the download link may be on a long-ish timer or even permanent. Here:
http://mailinator.com/displayemail.jsp?email=toho&msgid=139050825

EDIT: link is now dead. suppose you'll have to make your own mailinator addresses.

 

[SteveElbows]

Eh, possible I guess. I had considered the yellow arrows to be just generally indicative of the direction of flow, but maybe not.

Im pretty convinced they are referring to the smaller pipes. Just look at exactly where they are highlighting the joining of the pipes from reactor 3 & 4, its well underneath the large pipe. Easy to miss because the join is the same shape as the larger pipe, and these other pipes are so small that its hard to see, but the yellow arrows are following the route of the smaller pipes round the outside of reactor 4 so I stick to this view.

 

[swl]

I suppose an expert could do a better job than I, otoh since in the context it is more a question of producing a rough order of magnitude estimation.. :-)

If the spent fuel after ten years in the pool is at >100 Sv/h, I'd expect it to be at >1000 Sv/h after one year in the pool, and plausibly at >10000 Sv/h at the time of removal from the core, i.e when the fuel has been fully spent. So, doing simple interpolation I'd find it plausible that half spent fuel could have an activity of >5000 Sv/h, give or take one order of magnitude.

Then does it seems unlikely that any fuel has left containment or sfp in pellet or rod form?

 

[MadderDoc]

Just looking through the report to IAEA for other details that may be an improvement on what we knew before. Is any detail in the following, dealing with reactor 4, more detailed than we knew before, eg more precise location of fires?

http://www.kantei.go.jp/foreign/kan/topics/201106/pdf/chapter_iv-3.pdf from page IV-90

"At around 6:00 on March 15, an explosion assumed to be a hydrogen explosion occurred in the reactor building, and the whole part upward from the one floor below the operation floor as well as the western wall and the wall along the stairs were collapsed.

The extension of the damage caused by the explosion has afaik not been described by Tepco in such detail before, however since it has for a long time been reasonably assumable that the damage caused by the explosion had largely the extension seen in post explosion photos it is not an improvement to what we 'knew' before.

Furthermore, at 9:38, a fire was identified in the northwest part of the fourth floor of the reactor building, but TEPCO confirmed at about 11:00 that it had gone out on its own.

Based on what Tepco has said before, I thought the fire at 09:38 occurred in the _third_ floor, so this is news to me.

A fire was also reported to have broken out in the northwest part of the third floor of the building around 5:45 on March 16, but TEPCO was not able confirm this fire on-site at around 6:15."

I think this also adds to what we knew before. Afaik, previous reports have not included the location
of this fire.

 

[elektrownik]

Other stuff from report that seemed like it might be news to me:

"Spraying onto the PVC" at reactor 3 at 07:39 on the 13th march.

Do we know what this means exactly? I know some people though that later actions by fire crews around 20th-21st march may have been targeting more than just the fuel pools, but we have little info about this possibility. Do we know what form 'Spraying onto the PVC' might have taken on the 13th?

Yes this explain one of video where we can see that they are spraying water from fire truck to center location in unit 3, many peoples were pointing that it is strange.

 

[elektrownik]

http://www.yomiuri.co.jp/dy/national/T110525006455.htm"

 

[SteveElbows]

http://www.yomiuri.co.jp/dy/national/T110525006455.htm"

Old news, discussed here when it first emerged, this was the stuff about 3cm, 7cm and 10cm holes.And as usual I think the government analysis differs somewhat from the TEPCO analysis that this story covers. Stuff I posted about last night in the report to IAEA gives a much more detailed account of when and how radioactive substances got into the environment at various moments, and where venting was not the cause this obviously also involves containment damage.

 

[rowmag]

mailinator.com (throwaway address) worked just fine. Thanks.

I just realized the download link may be on a long-ish timer or even permanent. Here:
http://mailinator.com/displayemail.jsp?email=toho&msgid=139050825

That worked.

By the way here's part two of that article, if you want to do your magic again, with some illustrations of seawall construction:
http://www.doboku-g.com/DownloadPDF.aspx?TocID=6637

 

[MiceAndMen]

Entire 385-page Report of Japanese Govt to IAEA

I combined all 13 chapters into a single PDF. About 11 MB. Contains bookmarks for all chapters and for the individual reactor summaries.

http://min.us/mvoVGLP

 

[tsutsuji]

Here's a part of that image with the English overlay removed. Perhaps someone would be kind enough to translate what it says in Japanese?

SGTS排気管合流部　SGTS exhaust pipes confluence part
４号機　unit 4
３号機 unit 3
排気筒　exhaust stack

 

[zapperzero]

That worked.

By the way here's part two of that article, if you want to do your magic again, with some illustrations of seawall construction:
http://www.doboku-g.com/DownloadPDF.aspx?TocID=6637

With pleasure, it's the least I can do. Here:

http://61.192.182.113/DobokuDownloa...LGPO2MUt9Q2WTiBIj0GfYG/AHbo+dwLZudeiM5z4KXA==

 

[MiceAndMen]

SGTS排気管合流部　SGTS exhaust pipes confluence part
４号機　unit 4
３号機 unit 3
排気筒　exhaust stack

Thanks, tsutsuji.

Thank you, too, rowmag and zapperzero for those article links.

 

[MadderDoc]

Other stuff from report that seemed like it might be news to me:

"Spraying onto the PVC" at reactor 3 at 07:39 on the 13th march.

Do we know what this means exactly? I know some people though that later actions by fire crews around 20th-21st march may have been targeting more than just the fuel pools, but we have little info about this possibility. Do we know what form 'Spraying onto the PVC' might have taken on the 13th?<..>

I don't think so, it makes no sense, I suspect there could be language trouble. All three Tepco
press releases from March 13th from as early as 9am say that "spraying in order to lower pressure level
within the reactor containment vessel has been cancelled', here's the context:

"High Pressure Core Injection System has been automatically shut down and water injection
to the reactor is currently interrupted. We are examining alternative way to inject water.
Also, following the instruction by the government and with fully securing safety, steps to
lowering the pressure of reactor containment vessel has been taken. Spraying in order
to lower pressure level within the reactor containment vessel has been cancelled."

 

[zapperzero]

Another link from the excellent ex-skf blog.

Circumstantial evidence that Fukushima Dai-ichi containment broke after the earthquake but before the tsunami:

http://www.yomiuri.co.jp/science/news/20110608-OYT1T00583.htm?from=top

http://translate.google.com/translate?js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&sl=ja&tl=en&u=http%3A%2F%2Fwww.yomiuri.co.jp%2Fscience%2Fnews%2F20110608-OYT1T00583.htm%3Ffrom%3Dtop

Apparently there's Cesium in the water found in the basements at Fukushima Dai-ni. TEPCO says that water came in when the tsunami happened.

 

[biffvernon]

So now we know that the power station is built on solid geology not alluvium. 'Mudstone' should be read as stone rather than mud. The buildings are not going to slide into the sea, as someone suggested a great many posts ago.

The significant detail about how permeable the rock immediately below the reactors buildings is to the movement of groundwater and potentially radioactive cooling water still eludes us.

 

[SteveElbows]

Another link from the excellent ex-skf blog.

Circumstantial evidence that Fukushima Dai-ichi containment broke after the earthquake but before the tsunami:

Im really not at all convinced that the article is claiming that the Dai-ichi contamination reached Dai-ni via the sea, let alone that this happened before the tsunami.

Does it not seem far, far more likely that it reached the other plant via the air, and accumulated in water there due to the rain?

 

[tsutsuji]

This article in the Los Angeles Times says the report to the IAEA is 750 pages long. So either the LA Times story is wrong or there's a lot more to it than what's posted on the Japanese government's website.

http://www.latimes.com/news/nationworld/world/la-fg-japan-nuclear-report-20110608,0,7481490.story

Here are the number of pages of the Japanese language pdfs available at http://www.kantei.go.jp/jp/topics/2011/iaea_houkokusho.html :

001 pages 00-0-hyoushi.pdf
002 pages 00-1-mokuji.pdf
040 pages 00-2-gaiyo.pdf
002 pages 01-hajimeni.pdf
010 pages 02-shikumi.pdf
060 pages 03-jishin-tsunami.pdf
120 pages 04-accident.pdf
036 pages 05-kinkyu.pdf
006 pages 06-kankyo.pdf
012 pages 07-dose.pdf
004 pages 08-kokusai.pdf
012 pages 09-communication.pdf
010 pages 10-torikumi.pdf
004 pages 11-sonota.pdf
012 pages 12-kyokun.pdf
002 pages 13-musubi.pdf
005 pages app-chap02.pdf
064 pages app-chap04-1.pdf
053 pages app-chap04-2.pdf
022 pages app-chap04-3.pdf
113 pages app-chap05.pdf
025 pages app-chap06.pdf
005 pages app-chap07.pdf
001 pages app-chap08.pdf
018 pages app-chap09.pdf
066 pages app-chap10.pdf
009 pages app-chap11.pdf

So I find a total of 714 pages (and 66.8 MB file size)

 

[SteveElbows]

Im really not at all convinced that the article is claiming that the Dai-ichi contamination reached Dai-ni via the sea, let alone that this happened before the tsunami.

Does it not seem far, far more likely that it reached the other plant via the air, and accumulated in water there due to the rain?

Furthermore I expect that Ex-SKF are interested in this story because of the possibility that the radiation comes from damage at Dai-ni itself, certainly I would not be at all surprised to learn that there had been a bit more damage at that plant than we are generally lead to believe. The report to IAEA mentions this other plant and some of the detail troubles me.

 

[zapperzero]

Here are the number of pages of the Japanese language pdfs available at http://www.kantei.go.jp/jp/topics/2011/iaea_houkokusho.html :
So I find a total of 705 pages (and 66.8 MB file size)

As usual, the appendices seem especially interesting. Those to chapters 4 and 5 contain charts of pressures & temps (some of it is stuff we saw in raw form in TEPCO's report, on the photographed strips of paper), plant schematics, detailed fallout maps with exact positions of the monitoring posts. Some have English labels.

These appendices are absent from the English version (for now, at least).

Starts to look more like what I'd expect from a professionally-run organization (albeit one using circa 1970 vintage technology).

No energy spectra though, not that I can find. Just the usual cesium and iodine measurements.

 

[Danuta]

Fukushima nuclear disaster surprisingly getting some recent MSM coverage. Arnie G. speaks on CNN. June 7th.

Only half the vid...

http://edition.cnn.com/video/#/video/politics/2011/06/07/jk.radiation.gundersen.cnn"

 

[tsutsuji]

The geologist would bring the information, and point to sources of information, both raw and compiled.

Information on the geology and underground water exists for that location.

I am convinced of that.

On page 11 of the roadmap at http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110517e5.pdf they said that they were planning to perform a seepage analysis as part of their examination of groundwater shielding methods.

 

[tonio]

Which once again points out how unfortunate it is that we are lacking a poster knowledgeable of the subject of geology.

It simply can't be true that the underground rock formations, water tables and streams at the Fukushima site are an unknown.

Somebody did the engineering for that dam.

Well, I happen to be a geologist, specialized in soil and groundwater contamination. I am sure that the geology and geohydrology of the site are known, in order to be able to design the foundations of the plant and in order to design the groundwater withdrawal system, necessary to keep the basements of the plant dry (I understood that such a system exists).

I have added a simple sketch of what seems to me the most likely situation of the Fukushima plant. I assume the following, based on what I see at Google Earth:
- the plant has been built on a platform, partly excavated into the slope and partly situated on a layer of rubble, bulldozed into the sea.
- the general direction of ground water flow is perpendicular towards the sea;
- at the foot of the slope there is probably some kind of drainage ditch which collects both surface runoff and ground water coming from higher grounds;
- the whole platform is probably paved with concrete of asphalt and provided with a rainwater drainage system;
- the rain water and ground water collected in the drainage ditch and the drainage system is led into the sea.

Based on the above:
- contaminated surface runoff will probably be directly discharged into the sea unless this water is intercepted and collected somewhere (which is not the case afaik);
- contaminated surface runoff may leak into the ground in case of damaged pavements and/or drainage pipes;
- contaminated water in the reactor buildings may leak into the ground in case of damaged walls/floors/underground pipes, etc.

The time it takes for the contaminated ground water to reach the sea depends on the permeability of the ground (which may consist of bedrock, rubble and possible also weathered bedrock (soil)), on the slope of the groundwater table towards the sea and on the chemical behavior of the radioactive substances.

Hope this helps.

 

[zapperzero]

Im really not at all convinced that the article is claiming that the Dai-ichi contamination reached Dai-ni via the sea, let alone that this happened before the tsunami.

Does it not seem far, far more likely that it reached the other plant via the air, and accumulated in water there due to the rain?

I did not claim it reached Dai-ni via water, nor does the article. That would be impossible, in the time given (an hour elapsed between quake and tsunami).

EDIT: I just saw your later post. Indeed, there are two possibilities:
1. unreported containment breach at Dai-ni
2. airborne transport from an as yet unreported pre-tsunami breach at Dai-ichi

 

[joewein]

Interesting why they are installing this not in center of SFP, sfp is weakest there ?, the point where they are installing it is strongest I think (because of drywell thick): http://www.tepco.co.jp/en/news/110311/images/110607_1f_2.pdf

The spot marked in green on the bottom left diagram is where the steel support pillars will be - under the middle of the pool.

Looks like they'll also build a concrete wall at the red spot next to the dry well wall.

 

[Bioengineer01]

Well now we can read about it in the english documents linked to today, at least if I have found the right bit and am putting 2 & 2 together properly, as part of their analysis they mention that steam may have been escaping from the HPCI.

Sorry if I can't be more precise, but I have a fuzzy memory about of a perimeter radiation sensor that went off early on in the event

 

[Bioengineer01]

It's funny, I was just looking at old news reports from the March 14-17th period, noting the vast amounts of deception and blatant lies fed to the world. I've often thought that you would have to be disconnected from reality to look at the video of the explosions, and then believe the nonsense the media was feeding 24/7

The actions of the US at the time, where they moved their entire rescue operation to the other side of Japan, avoiding the ocean down wind from the fires and explosions, told the real tale of the radiation escaping out to sea.

Of course nobody did any measurements at all of what was blowing down wind over the ocean, so it's about impossible to tell what the real amounts are.

I have also been struggling to understand at a macro level the order of magnitude of the release into the Pacific Ocean and can't find enough data to even guesstimate it. Very frustrating. My opinion and that of my colleagues is that the largest release has been and still is happening to the Ocean. Also, we all suspect that there is a continuous flow of isotopes to the ground water and from the ground water to the Ocean. The tell me that in most cases ground water in coastal sites flows to the Ocean. None of us has any information of deep water wells in the region and how they are interconnected, although we are certain that the information is out there.

 

[etudiant]

The amount of water in question is 3000 tons, in the DaiNi basement. Airborne contamination is pretty unlikely. Moreover, the tsunami flooding was with clean sea water.
So the contamination was locally sourced.
Is not cesium an indicator that some fuel elements have leaked?
Afaik, DaiNi was rated as INES 3 after the tsunami, saved by one outside power line, but no lasting damage was reported then.