Japan Earthquake: Nuclear Plants at Fukushima Daiichi

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The Fukushima Daiichi nuclear plant is facing significant challenges following the earthquake, with reports indicating that reactor pressure has reached dangerous levels, potentially 2.1 times capacity. TEPCO has lost control of pressure at a second unit, raising concerns about safety and management accountability. The reactor is currently off but continues to produce decay heat, necessitating cooling to prevent a meltdown. There are conflicting reports about an explosion, with indications that it may have originated from a buildup of hydrogen around the containment vessel. The situation remains serious, and TEPCO plans to flood the containment vessel with seawater as a cooling measure.
  • #5,551
jpquantin said:
Well agree with you (found skimmer illustrated in http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110418e5.pdf" from Tepco). Do you mean skimmer level does not give SFP level ?

Samy24 said:
Where is the water in the skimmer surge tank going? Why are they releasing this water? Does not matter, but just curious.
Dunno. Maybe they pumped water out of skimmer surge tank for some reason, so that if they pour too much water it overflows into skimmer surge tank. Or maybe it got damaged by quake+explosion+aftershocks.
 
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Engineering news on Phys.org
  • #5,552
Dmytry said:
The fission energy per Bq of I-131 is then 1.1E-3 J
http://www.wolframalpha.com/input/?i=(((8.0252+days)/ln(2))/second)*(6.9E9+eV)

100KW of fission, for 1 day, makes 7.8E12 Bq of I-131.
http://www.wolframalpha.com/input/?i=(100kw*1+day)/((((8.0252+days)/ln(2))/second)*(6.9E9+eV))

edit: note, noscript strips parens out of the url. The final formula is:
(100kw*1 day)/((((8.0252 days)/ln(2))/second)*(6.9E9 eV))

you guys do the concentrations and volumes, it's late night here. I didn't check my sources, so beware.

Thanks - it'll be useful:smile:
 
  • #5,553
Leaks of radioactive materials from fuel rods have been suspected at a nuclear power plant in Tsuruga, the Fukui prefectural government said Monday, citing a rise in density of the toxic substances in coolant water. [...]

According to Japan Atomic, 4.2 becquerels of iodine-133 and 3,900 becquerels of xenon gas were detected per cubic centimeter Monday, up from 2.1 and 5.2 becquerels, respectively, during previous measurements conducted last Tuesday.
Radiation leaks from fuel rods suspected” at Japan’s Tsuruga nuclear plant — Radioactive Xenon up 75,000%
Any ide what this could mean ?
 
  • #5,554
I just made an insight, I don't know if there is any truthness in it, probably not.

TEPCO says SFP 4 is contaminated because they have sprayed contaminated seawater there.

We also know that SFP 2 is propably high-level contaminated.

So perhaps what TEPCO is saying about SFP 4 is true. Wouldn't this same apply to SFP 2?

The theory is that seawater sprayed to SFP 4 has been taken in front of unit 4 whereas seawater used to cool SFP 2 has been taken in front of unit 2.

And because the highest level of radiation in seawater is in front of unit 2 we would also see the highest level of radiation in SFP 2.

This would be called recycling... The high-level leakages from the reactor number 2 to the sea would be seen all around the Fukushima plant. :biggrin:
 
  • #5,555
On the high resolution pictures that were taken a while back we can see the truck and fire hose taking watter from what will be known after as contaminated trench. So what they are suggesting is not so far fetched and could actually by a true full explanation.
 
  • #5,556
elektrownik said:
Any ide what this could mean ?
I don't know the details, but whenever there is a failure of a fuel rod(s) in a reactor, there is a spike in the Xe and Kr in the coolant (usually classified as a Xe spike). Normally the longer lived Xe-133 increases then settles down. One can measure the Xe-138/Xe-133 and/or Xe-135/Xe-133 to determine if the leak is tight (low ratio) or open (high ratio).

If it is one or a few failures, this is not unusual, although it is undesirable.

The cause of cladding breach could be debris (e.g., small pieces of wire) fretting, grid-to-rod fretting, or perhaps a faulty weld. More details would be necessary to understand the significance.
 
  • #5,557
Nullpunkt said:
Nice side by side video on youtube of #1 and #3 explosion

http://www.youtube.com/watch?v=1Q3ljfLvHww"

Very impressive to see the difference in shape and power.

If you look at the frame by frame version of #3 explosion,
you can clearly see the fireball, followed by the implosion and catapult shot.

http://www.youtube.com/watch?v=9PHQ3IJHJbw"

It seems to me, that the implosion/explosion also has impact on structure of building #4.
Could be the reason for the curved damage seen on the left side of the building #4, after it blow up.

I, for one, have never been able to "clearly see" the implosion of Bldg 3. If an explanation of the mechanism for an implosion following the initial fireball was given, I guess I missed it. By "implosion", is it meant that some type of negative pressure developed with sufficient force to suck the building inward? What exactly is implied by "implosion" and what inference as to the nature of the explosion can be drawn if in fact implosion occurred?
 
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  • #5,558
TCups said:
What would be most helpful is a sticky that has, without additional interpretation, and indexed as appropriate (including location, date and time), links and graphics (with original source and copyright data) of ...
One could do that: a thread where each of the regulars has their own few postings that they try to hold up to date.

Another possibility is a wiki. There is http://fukushimafaq.wikispaces.com/ and http://fukushima.wikispaces.com/
 
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  • #5,559
triumph61 said:
At the Original Foto, the Truck in Unit4 is not to see, the Door is closed.

Two frame from the previously linked 'Tour' video (04.22.) are attached: one is about the door of U3, one is about the door of U4.

It's interesting, that while U3 is more damaged than U4, the tunnel of U3 looks more intact.

U4: Is it possible that the door was opened and the truck was pushed out by the explosion?

PS.: U4.: actually, I could not find the door on the pictures, even on the aerial photos...
 

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  • #5,560
Rive said:
Two frame from the previously linked 'Tour' video <..>
Those a very fine looking frames. I've been looking for a good version of this particular 'Tour' video unsuccessfully for a while, and would be grateful for a repost of the link.
 
  • #5,561
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  • #5,562
Interesting comment in the TEPCO status reports on Daiini - that 'Residual heat removal system (A) was disabled due to the earthquake." Only RHR (B) systems are operating. This comment was made for all 4 reactors.

I would have assumed that both A and B trains of the RHR system would have been qualified to the Design Basis Earthquake, so it appears that it may not have been adequately designed for a DBE?? That would not bode well for the other TEPCO plants - that are running today.

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110502e9.pdf
 
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  • #5,563
RealWing said:
Interesting comment in the TEPCO status reports on Daiini - that 'Residual heat removal system (A) was disabled due to the earthquake." Only RHR (B) systems are operating. This comment was made for all 4 reactors.

I would have assumed that both A and B trains of the RHR system would have been qualified to the Design Basis Earthquake, so it appears that it may not have been adequately designed for a DBE?? That would not bode well for the other TEPCO plants - that are running today.

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110502e9.pdf
Ya. Everyone's been making up as a fact everywhere that the reactor withstood the quake, whereas the fact was that they made it up out of thin air.
 
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  • #5,564
Would be too coincidental for the hourly webcam to register an explosion of some kind. And the no-wind (see ocean) situation is probably a better explanation for this odd shaped plume. Still, what is happening on the most recent webcampicture ?

http://www.tepco.co.jp/nu/f1-np/camera/index-j.html
 
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  • #5,565
DSamsom said:
Would be too coincidental for the hourly webcam to register an explosion of some kind. And the no-wind (see ocean) situation is probably a better explanation for this odd shaped plume. Still, what is happening on the most recent webcampicture ?

http://www.tepco.co.jp/nu/f1-np/camera/index-j.html

You see all those nice green reassuring pine trees in the foreground? I'll bet you a dime to a dollar that they'll be crispy brown in twelve months. Pine trees is like that
 
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  • #5,566
TCups said:
Sorry to be running so far behind -- PF seems to be having server problems that coincide with my reading time.

What would be most helpful is a sticky that has, without additional interpretation, and indexed as appropriate (including location, date and time), links and graphics (with original source and copyright data) of:

1) technical drawings and diagrams of the physical plan at Fukushima

2) photos and videos of Fukushima

3) relevant tables, graphs & charts (ie, of radiation measurements, RPV and SFP parameters, etc.)

4) links to related articles

Going forward, perhaps posters could include such appropriate links and attachments, not only in their posts, but also appended to the appropriate sticky.

This thread is an amazing source. It deserves to be indexed and footnoted and perhaps, technically edited to better organize and categorize the content. I predict it will be a long-lasting source for technical and historical research.

In the aftermath of the Columbia Space Shuttle accident in 2003, some people worked on a "Columbia Loss FAQ" for quite a while. Unfortunately it's offline now, but copies are still available through archive.org.

HTML version: http://replay.web.archive.org/20050212050722/http://www.io.com/~o_m/columbia_loss_faq_x.html

Text version: http://replay.web.archive.org/20050307183230/http://www.io.com/~o_m/columbia_loss_faq.html

Maybe those can be used to get an idea of one possible way to consolidate information in one place. A lot of what we get by way of media stories on the web is sure to disappear off the internet over time.
 
  • #5,567
MiceAndMen said:
In the aftermath of the Columbia Space Shuttle accident in 2003, some people worked on a "Columbia Loss FAQ" for quite a while. Unfortunately it's offline now, but copies are still available through archive.org.

HTML version: http://replay.web.archive.org/20050212050722/http://www.io.com/~o_m/columbia_loss_faq_x.html

Text version: http://replay.web.archive.org/20050307183230/http://www.io.com/~o_m/columbia_loss_faq.html

Maybe those can be used to get an idea of one possible way to consolidate information in one place. A lot of what we get by way of media stories on the web is sure to disappear off the internet over time.
Things are already disappearing, and access as well; Kyodo news for instance has trimmed accessibility. There is software to add wikis to sites, perhaps this forum's host has such a capability?
 
  • #5,568
From NHK: "The Japanese government is about to begin releasing data projecting the spread of radiation from the Fukushima Daiichi nuclear plant that it initially withheld for fear of causing panic.

The data in question is in a computer system called SPEEDI that predicts the spread of radioactive substances based on actual radiation measurements at various locations and weather conditions.

A joint task force of the government and Tokyo Electric Power Company says about 5,000 undisclosed bits of data will be released from Tuesday.

The information will be carried on the websites of the science ministry, the Nuclear and Industrial Safety Agency, and the Nuclear Safety Commission.
The secretary-general of the joint task force and prime the minister's advisor, Goshi Hosono, apologized for the delay in releasing the data."

http://www3.nhk.or.jp/daily/english/02_32.html?play
 
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  • #5,569
Someone told me the other day that pieces of fuel had been found a few miles (or kilometers) from Dai ichi. Is this confirmed? Or bogus?
 
  • #5,570
mikefj40 said:
From NHK: "The Japanese government is about to begin releasing data projecting the spread of radiation from the Fukushima Daiichi nuclear plant that it initially withheld for fear of causing panic.The data in question is in a computer system called SPEEDI that predicts the spread of radioactive substances based on actual radiation measurements at various locations and weather conditions.

A joint task force of the government and Tokyo Electric Power Company says about 5,000 undisclosed bits of data will be released from Tuesday.

The information will be carried on the websites of the science ministry, the Nuclear and Industrial Safety Agency, and the Nuclear Safety Commission.
The secretary-general of the joint task force and prime the minister's advisor, Goshi Hosono, apologized for the delay in releasing the data."

http://www3.nhk.or.jp/daily/english/02_32.html?play

I have refrained from condeming both the government and Tepco but this has changed everything.
These numbers must be horrifying to people who understand their significance.
This ongoing catastrophe is being managed by the eternal wisdom of Japanese bureaucrats.

The Bridge over the River Kwai. Be happy in your work!

They are willfully withholding vital information from the world!
Who do they think they are?

They do this, just as Japanese physicians hide the truth from their terminal patients because they believe the patients is better off not knowing the truth. Aside from the fact that they are demonstratively wrong regarding health, they are are giving themselves god-powers.

This was beautifully illustrated in the Kurosawa film, Ikiru where a middle aged bureaucrat has terminal cancer and is lied to by his physician.
http://www.imdb.com/title/tt0044741/usercomments?filter=best

They don't have the right to do this to a patient and they don't have the right to do this to our planet.

Can't we just call this a world's problem and not a Japanese one.

Can someone figure out what to do? Can't we creat some world agency with unlimited resources?
 
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  • #5,571
  • #5,572
georgiworld said:
These numbers must be horrifying to people who understand their significance.

They haven't released anything yet and when they do the numbers will be significant to those closest to the site. Being old enough to live through weapons testing in the '50's and '60's I'm not all that concerned, even though I live in California. This is not that big of a deal for those of us 5000 miles away.

Interesting graph of worldwide radiation dosage from '45 - '10 http://www.nytimes.com/imagepages/2011/05/03/science/03radiation_graphic.html?ref=science from today's NYT article "Drumbeat of Nuclear Fallout Fear Doesn’t Resound With Experts" http://www.nytimes.com/2011/05/03/science/03radiation.html?ref=radiation

Before I get too far afield for this thread let me just say that the best thing about everyone's contribution to this thread is the absence of fear-mongering and an overwhelming desire to understand what's happening in an information-poor environment. I'm reserving judgment until the numbers are published and those that know much more than me make sense of it.
 
  • #5,573
Ms Music said:
Someone told me the other day that pieces of fuel had been found a few miles (or kilometers) from Dai ichi. Is this confirmed? Or bogus?

You'll find the answer a few pages back... it was suggested as a possibility as of some reading could have indicated that.. This speculation made in an US report ... Some people reading the report translated that as a fact. Point is we don't know for sure.

I have refrained from condeming both the government and Tepco but this has changed everything.These numbers must be horrifying to people who understand their significance. This ongoing catastrophe is being managed by the eternal wisdom of Japanese bureaucrats.

The people who followed from day one knew that http://www.bousai.ne.jp/eng/ was really not updated for the important areas: Fukushima prefecture etc.. it was (still is) "under survey".. Today they are saying that this will finally have it up to date..

I would say that people concerned did not wait for that :they is several others webs sites to get the info from...and there has been since almost day 1..
 
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  • #5,574
|Fred said:
Today they are saying that this will finally have it up to date..

Fred, thanks for the link. Looks like they posted new monitoring data today (5/2) for Fukushima http://www.mext.go.jp/english/incident/1303962.htm and Miyagi http://www.pref.miyagi.jp/kokusai/en/accidents_fukushima_nuclear.htm (I'm going to miss those oysters...).

It looks like they aren't filling in the historical blanks and just starting with current readings. I'd like to see data for isotopes other than "radioactive iodine" and "radioactive cesium" too.
 
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  • #5,575
Cainnech said:
To whom it may be of interest, two articles by Michio Ishikawa written on March 15, 2011 and April 11, 2011.

http://www.gengikyo.jp/english/shokai/Tohoku_Jishin/article_20110318.html
http://www.gengikyo.jp/english/shokai/Tohoku_Jishin/article_20110413.htm

1.he forgot to mention the criticality.
Through them, the corium is open again.
water penetrates into the corium.
the opening is large enough, it can cause a steam explosion.
2. why the corium is inside the water? why it is not at the bottom of the vessel?
have you seen his pictures too.
not vote because several factors.
 
  • #5,576
Ms Music said:
Someone told me the other day that pieces of fuel had been found a few miles (or kilometers) from Dai ichi. Is this confirmed? Or bogus?
I don't believe that is correct. The SFP of unit 4 looks more or less intact, and there is not large opening in the cores of Units 1 or 3, and the roof of unit 2 remains intact.

The roof of unit 1 looks like it collapsed onto the reactor service building floor.
http://www.tepco.co.jp/en/news/110311/images/110415_1f_3_1.jpg

Roof of unit 3 is covered by debris.
http://www.tepco.co.jp/en/news/110311/images/110415_1f_3_4.jpg

For fuel to escape from the core, the large cement plug would have to be removed, as would the drywell cap, the reactor vessel head, the steam dryer and the steam separator. There is no clear path for the fuel to be ejected from the cores.

I also don't believe that any fuel rods are found outside of the containment area. I suspect steel reinforcement rods were mistakenly identified as fuel rods.
 
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  • #5,577
Astronuc said:
I don't believe that is correct. The SFP of unit 4 looks more or less intact, and there is not large opening in the cores of Units 1 or 3, and the roof of unit 2 remains intact.

The roof of unit 1 looks like it collapsed onto the reactor service building floor.
http://www.tepco.co.jp/en/news/110311/images/110415_1f_3_1.jpg

Roof of unit 3 is covered by debris.
http://www.tepco.co.jp/en/news/110311/images/110415_1f_3_4.jpg

For fuel to escape from the core, the large cement plug would have to be removed, as would the drywell cap, the reactor vessel head, the steam dryer and the steam separator. There is no clear path for the fuel to be ejected from the cores.

I also don't believe that any fuel rods are found outside of the containment area. I suspect steel reinforcement rods were mistakenly identified as fuel rods.

@Astronuc:

What type(s) of scattered debris following a hydrogen explosion might have a 900 mSv/hr activity? It would seem to me something from the SFP of Unit 3 would be at the top of the suspect list, but perhaps not so. Your opinion? Thanks.
 
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  • #5,578
The Gunderson video from fairewinds.com, April 25 I think. Gunderson is a nuclear engineer. From his analysis of the data, he suspects the fuel storage pond at #3 reactor blew up in the explosion, accounting for the high levels reported in some surrounding debris, such as 1 Sv emanating from a chunk of concrete. I don't have the exact date of the video to hand, but could find it if anyone interested.

According to the IAEA charts, containment vessel breaches are suspected at 2 out of 3 reactors; TEPCO has admitted partial meltdowns at all three; increasing amounts of I-131 indicate some criticality somewhere, either intermittent or ongoing. Anyone have a solution?

And how would 334,000 Bq/kg get into the evaporated sewage sludge? (Today's Fukushima news.)

Astronuc said:
I don't believe that is correct. The SFP of unit 4 looks more or less intact, and there is not large opening in the cores of Units 1 or 3, and the roof of unit 2 remains intact.

The roof of unit 1 looks like it collapsed onto the reactor service building floor.
http://www.tepco.co.jp/en/news/110311/images/110415_1f_3_1.jpg

Roof of unit 3 is covered by debris.
http://www.tepco.co.jp/en/news/110311/images/110415_1f_3_4.jpg

For fuel to escape from the core, the large cement plug would have to be removed, as would the drywell cap, the reactor vessel head, the steam dryer and the steam separator. There is no clear path for the fuel to be ejected from the cores.

I also don't believe that any fuel rods are found outside of the containment area. I suspect steel reinforcement rods were mistakenly identified as fuel rods.
 
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  • #5,579
flooding reactor 1 leaves tepco puzzled and cooling rate back to 6m3/h

http://mdn.mainichi.jp/mdnnews/news/20110502p2a00m0na012000c.html
 
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  • #5,580
mikefj40 said:
From NHK: "The Japanese government is about to begin releasing data projecting the spread of radiation from the Fukushima Daiichi nuclear plant that it initially withheld for fear of causing panic.

The data in question is in a computer system called SPEEDI that predicts the spread of radioactive substances based on actual radiation measurements at various locations and weather conditions.

Looks like SPEEDI stuff is going here:
http://www.nsc.go.jp/mext_speedi/index.html

Estimated integrated effective doses from 3/12 to 4/24:
-->Infant (1-year olds) internal (thyroid) exposure to iodine: http://www.nsc.go.jp/mext_speedi/0312-0424_in.pdf

-->Adult external exposure from I-131, I-132, Cs-137 and Cs-134: http://www.nsc.go.jp/mext_speedi/0312-0424_ex.pdf
(10 mSv is the shelter-indoors level, per notation arrow)

Hourly wind-borne spread plots here:
http://www.nsc.go.jp/mext_speedi/past.html
(Could be helpful for answering questions such as why a spike showed up at such and such a place at a certain time.)
 
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