Japan Earthquake: Nuclear Plants at Fukushima Daiichi

AI Thread Summary
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.
  • #3,401
tsutsuji said:
...
I am also wondering whether the following scenario in NUREG-1150 is not more or less similar with what happened at Fukushima :



This sounds close enough to the "D/G Inoperable due to Tsunami flood" analysis on page 12 of http://www.nisa.meti.go.jp/english/files/en20110406-1-1.pdf and professor Yoshiaki Oka's analysis :



Some mysterious Mitsubishi emplyee, Haruki, is also being quoted as saying :



Erick Krock, who is probably not a nuclear specialist concludes :



But you would still need to cool these higher elevated Diesel Generators with a distinct and secure cooling system.

The relevance of NUREG-1150 (albeit with a link to part 2 : http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1150/v1/sr1150v1part-2.pdf ) was suggested in http://www.bloomberg.co.jp/apps/news?pid=90920000&sid=aQkgwhzUb4pI (18 March 2011)

The following part of NUREG-1150 is also being quoted by Joseph E. Shepherd :

And to think that they had a lake up beyond those hills that could have been used for cooling water for Diesels in an emergency.
 
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  • #3,402
Joe Neubarth said:
And to think that they had a lake up beyond those hills that could have been used for cooling water for Diesels in an emergency.

How big are the backup diesels they use in these plants? We install generators up to 3MW with fan-driven air-cooled radiators.
 
  • #3,403
Actually there's a lake just outside the perimiter fence of the site, about 1km from the reactor buildings themselves!.
 
  • #3,404
artax said:
Actually there's a lake just outside the perimiter fence of the site, about 1km from the reactor buildings themselves!.

Why would we assume 1km of cooling pipe would survive an earthquake?
 
  • #3,405
No, they could have used that water for emergency cooling of the reactors AFTER the damage instead of sea water. Sorru... hadn't followed the previous threads very comprehensively!
Some images just released... mostly terrible resolution!
http://cryptome.org/eyeball/daiichi-npp6/daiichi-photos6.htm
 
  • #3,406
WhoWee said:
Why would we assume 1km of cooling pipe would survive an earthquake?
As long as a fault line does not cross the channel to the lake, there should have been no problem. The actual earthquake site was a long distance away.
 
  • #3,407
I don't think it has been posted yet, especially considering they are useless..
http://www.meti.go.jp/press/2011/04/20110411007/20110411007-6.pdf
that's some of the famous T Hawk picture .. but the dumb down version they release is ...

edit .. artax posted faster... so they got posted b4...
 
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  • #3,408
http://www.meti.go.jp/press/2011/04/20110411007/20110411007-5.pdf

ok this has not (bellow the legend of the squared items)
-Transit vehicles (unmanned)
-Camera car (unattended six in total)
-Cables
-Debris collection area
-Remote control range of movement of heavy equipment
-Movement range Kuroradanpu
 
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  • #3,409
It just shows they're hiding stuff, they must have collected really good images of inside the buildings by now. I mean to make decisions on what to do next you would get much better resolution, and why doesn't the drone get any closer?... is the radiation THAT high they're worried about electronics damage?
 
  • #3,410
any word on restoring power to control centers? or are they given up on this?
 
  • #3,411
Joe Neubarth said:
As long as a fault line does not cross the channel to the lake, there should have been no problem. The actual earthquake site was a long distance away.

Given the level of second-guessing as to the design of these facilities - "should have been" doesn't seem to meet the level of future expectations?
 
  • #3,412
WhoWee said:
Given the level of second-guessing as to the design of these facilities - "should have been" doesn't seem to meet the level of future expectations?
Should have been, because the poster (ME) is not a geologist. I don't know if there is even a little fault line between the lake and the bluffs where the diesels should have been built in the original design. It seems totally impossible to me that any design engineer would have put the diesel generators down at sea level if he knew that they were to be used in case of a loss of electricity accident (which almost certainly would have been caused by an earthquake and tsunami.) Engineers when millions of lives are at stake are supposed to plan for a worst case scenario. I know there are accounts of Tsunamis that were as large as the one that hit Fukushima. Something was very wrong with the planning, and in forty years nobody took corrective measures. The degree of culpability for this horrific mess is going to be massive considering the time span.
 
  • #3,413
|Fred said:
any word on restoring power to control centers? or are they given up on this?

Right now, the control centers are not a desirable place to spend long periods of time.
 
  • #3,414
Joe Neubarth said:
Should have been, because the poster (ME) is not a geologist. I don't know if there is even a little fault line between the lake and the bluffs where the diesels should have been built in the original design. It seems totally impossible to me that any design engineer would have put the diesel generators down at sea level if he knew that they were to be used in case of a loss of electricity accident (which almost certainly would have been caused by an earthquake and tsunami.) Engineers when millions of lives are at stake are supposed to plan for a worst case scenario. I know there are accounts of Tsunamis that were as large as the one that hit Fukushima. Something was very wrong with the planning, and in forty years nobody took corrective measures. The degree of culpability for this horrific mess is going to be massive considering the time span.

I'm not a geologist either, but when considering the island itself moved about 8' - a 1km run of pipe just doesn't seem like the answer?
 
  • #3,415
Will silt fences really make a difference in reducing the Iodine and Cesium contamination of the ocean, or is this just good PR?

My chemistry is limited to what I read in wikipedia, and to my limited understanding the Iodine and Cesium will be in some form of a salt and a such dissolved in the water and thus pass straight through the silt fences. Could a more knowledgeable contributer please correct me.


[PLAIN]http://k.min.us/ikouag.JPG
[PLAIN]http://k.min.us/iksAqg.JPG
 
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  • #3,416
Michio Kaku (26 March 2011) on plant design :

They should have had a tsunami wall much greater than 15 ft ; They should not have put the generators in the basement.
6:25 - 6:37 at
 
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  • #3,417
INES 7 on the way ?
"NEWS ADVISORY: Japan eyes raising level of nuke crisis to most severe"
 
  • #3,418
So soon we reach to level 8
 
  • #3,419
Joe Neubarth said:
Yet, we have San Onofre in San Diego County which is sitting east of San Clemente island. There is an earthquake fault running just up the eastern coast line of San Clemente with a very large and sharp depression off shore and an unstable island above. Somehow I sincerely doubt that they considered this when they built San Onofre. I am not and have not been impressed with site engineers. Fukushima is just a reconfirmation of that lack of confidence.

I just drove by San Onofre yesterday. It has a 30foot sea wall and you can see what looks like new tertiary off-sight backup power above and slightly inland from the plant itself.

As for fault lines, you can't build in California without being next to a fault line. I'm not sure what island you think is unstable or why.
 
  • #3,420
Demidrol said:
So soon we reach to level 8

There is no level 8 in INES, they will need to create it ;) this could be good idea, before fukushima there wasnt case in INES for >1 reactor disaster in one time...
 
  • #3,421
Demidrol said:
So soon we reach to level 8

Please explain?
 
  • #3,422
WhoWee said:
Please explain?

All major events have occurred at the station in its first week. And the Japanese are their actions (no action) for a month only do worse. And not all reports on time ... IMHO
 
  • #3,423
Don't know if that was posted here before:

http://www.mod.go.jp/j/approach/defense/saigai/tohokuoki/temp.html

Daily thermal images from the reactors.
INES 7 on the way ?
"NEWS ADVISORY: Japan eyes raising level of nuke crisis to most severe"

Hm, link please?
 
  • #3,424
elektrownik said:
INES 7 on the way ?
"NEWS ADVISORY: Japan eyes raising level of nuke crisis to most severe"

maybe it's the system SPEEDI ?
 
  • #3,425
clancy688 said:
Don't know if that was posted here before:
Hm, link please?
It was on kyodo, at this moment there in nothing more about...
 
  • #3,426
elektrownik said:
It was on kyodo, at this moment there in nothing more about...

You can still see it on the main page, but it's not a link - and there's an exclamation mark behind it. Maybe it was a mistake...? Can you remember what it said inside the news?

Edit: There it is

http://english.kyodonews.jp/news/2011/04/84721.html

"may raise"

Edit 2: Holy **** o.o

The Nuclear Safety Commission of Japan released a preliminary calculation Monday saying that the crippled Fukushima Daiichi nuclear plant had been releasing up to 10,000 terabecquerels of radioactive materials per hour at some point after a massive quake and tsunami hit northeastern Japan on March 11.
 
  • #3,427
WhoWee said:
I'm not a geologist either, but when considering the island itself moved about 8' - a 1km run of pipe just doesn't seem like the answer?
A pipe was not in my thoughts.
But if the whole island moved about eight feet or more, a pipe would be fine.
 
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  • #3,428
clancy688 said:
Hm, link please?

http://mainichi.jp/select/today/news/20110412k0000m040162000c.html
 
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  • #3,429
timeasterday said:
How big are the backup diesels they use in these plants? We install generators up to 3MW with fan-driven air-cooled radiators.

I would like to know it too.

The generators Exelon is using in the United States are :

Locomotive-sized emergency backup diesel generators at plants that start automatically if offsite power is lost.

http://www.exeloncorp.com/assets/newsroom/downloads/docs/Fact_ExelonPlantsAreWellProtected.pdf

And locomotives are air-cooled, aren't they ?
 
  • #3,430
shogun338 said:
Steam, Nitrogen Leak

Radioactive steam and nitrogen is escaping from the containment vessel at the No. 1 reactor and the company is checking radiation levels around the reactor, spokeswoman Megumi Iwagarbagea said by phone today.

Tepco started injecting nitrogen into the vessel to reduce the risk of a hydrogen explosion. The pressure inside the vessel is rising more slowly than expected, indicating a leak, Iwagarbagea said. Work continues at the reactor and other parts of the Fukushima Dai-Ichi power station, she said. http://www.bloomberg.com/news/2011-04-11/tepco-chief-rebuffed-in-fukushima-as-crisis-enters-second-month.html
Depending upon the location of the leak, this could be the Level 7 instigator. Very serious report that could end up being a minor issue or a major one.
 
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  • #3,431
clancy688 said:
Don't know if that was posted here before:

http://www.mod.go.jp/j/approach/defense/saigai/tohokuoki/temp.html

Daily thermal images from the reactors.

why the hot spots in the turbine bldgs?
 
  • #3,432
tsutsuji said:
I would like to know it too.

The generators Exelon is using in the United States are :



And locomotives are air-cooled, aren't they ?

Yes, they are radiator cooled. They mention "locomotive-sized" which I take it to mean very big. The larger generators we make (>3MW) typically use remote-mounted radiators unless they are CHP applications.
 
  • #3,433
Joe Neubarth said:
A pipe was not in my thoughts.
But if the whole island moved about eight feet or more, a pipe would be fine.
Perhaps, with so many variables it is hard to predict. IMO - the only certain system would be something powered by the reactor heat in the event of electrical failure.
 
  • #3,434
Krikkosnack said:
Tsunami Warnings/Advisories

http://www.jma.go.jp/en/tsunami/


A strong earthquake with a preliminary magnitude of 7.1 shook buildings in Tokyo and a wide swathe of eastern Japan on Monday, with an advisory for a one-meter tsunami issued after the quake. reuters

AntonL said:
It is now downgraded to 6.6 but most interesting it triggered a swarm of nine aftershocks within two hours, a 5.2 only ten minutes later followed four minutes later by a 4.7

Whereas, the 7.1 quake on 7 April had two 4.6 aftershocks about an hour later and the third 7.5 hours later

http://earthquake.usgs.gov/earthquakes/recenteqsww/Maps/10/140_35_eqs.php

Follow Up: the swarm of aftershocks continues 22 aftershocks in 8 hours !
compare this to 67-22 = 45 for the week preceding todays 6.6 event
something is rumbling beneath the Earth - any seismologist here?

For the last week I binned the number of aftershocks into 6 hour periods or quarter days
Zero being today's 6.6 event, below is the graph,
in the little map red=last hour, blue=last 24 hours, yellow=last week

Status Mon Apr 11 18:11 UTC 2011
[PLAIN]http://k.min.us/iknF6a.JPG
 
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  • #3,435
AntonL said:
Follow Up: the swarm of aftershocks continues 22 aftershocks in 8 hours !
compare this to 67-22 = 45 for the week preceding todays 6.6 event
something is rumbling beneath the Earth - any seismologist here?

There is a bigger aftershock still due. This 6.6. was pretrigerred, got of too early, hence it was small, hence so much energy still unsettled ( many aftershocks) . Since it got triggered before its time, the bigger energy it was supposed to release is still in the fault.

I expect one more aftershock >7, perhaps >7.5 very soon - 1-2 week time. May be some >M6 foreshock swarming ( 3-5) before that.

Almost every huge (>9.0) quake had one late (up till 3 months ) huge aftershock. At least Sumatra had.

I am not a seismologist, God forbid. For seismologist, EQ are unpredictable. I predicted both 7.1 and 6.6 aftershock both time and magnitude wise, and expect one more , the biggest, to come. Without any probability, just happen.
 
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  • #3,436
Here is a pdf to the report showing the radiation in the environment years later from the 1986
Edwin I. Hatch Nuclear Plant Accident in Georgia USA where water from the spent fuel pool was released outside into a swamp on the plant property . If you look at the plant on Google Earth you can see the small creek that flows from this swamp into the Altamaha river which is right next to the plant . I fish this area often in the summer months and never knew this was the location the swamp drained into until I found it recently on the internet . The Japanese people will be dealing with much worse in the decades to come .
Assessment of Results of Augmented Radiological

Environmental Monitoring Program for the Years 2000 through 2007 http://www.nrc.gov/info-finder/reactor/hat2.html
 

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  • #3,437
Radiation Up To 4 Times Higher Than Chernobyl Evac Zone Found In Soil 30 km Away From Fukushima; Rice Harvest In Question

Now a new study from Hiroshima and Kyoto Universities has found that the radioactive content of soil samples beyond the 30 km semi-evacuation zone is as much as 400 times the normal. From Asahi: "The predicted changes in the level of radiation at the ground surface were calculated after analyzing the amounts of eight kinds of radioactive materials found in the soil and taking into consideration the half-lives of each material. The study results are considered more accurate than the study conducted by the science ministry, which only released information concerning two types of radioactive material. [Scholars] collected soil samples from five locations in the village at depths of five centimeters. All the locations were outside the 30-km radius and were by roadways in various hamlets. The study found cesium-137 at levels between about 590,000 and 2.19 million becquerels per cubic meter." Comparing this to Chernobyl: "After the Chernobyl nuclear accident in the former Soviet Union in 1986, residents who lived in areas where cesium-137 levels exceeded 555,000 becquerels were forced to move elsewhere. The amounts of cesium-137 found in Iitate were at most four times the figure from Chernobyl."

http://www.asahi.com/english/TKY201104080169.html
 
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  • #3,438
timeasterday said:
Yes, they are radiator cooled. They mention "locomotive-sized" which I take it to mean very big. The larger generators we make (>3MW) typically use remote-mounted radiators unless they are CHP applications.

I have seen radiator cooled emergency diesels at some plants and water cooled EDGs at other plants. The EDGs are typically 10 or 12 cylinder locomotive engines; their capacity is in the 1.5 to 2.5 MW range.
 
  • #3,439
artax said:
No, they could have used that water for emergency cooling of the reactors AFTER the damage instead of sea water. Sorru... hadn't followed the previous threads very comprehensively!
Some images just released... mostly terrible resolution!
http://cryptome.org/eyeball/daiichi-npp6/daiichi-photos6.htm

Honeywell should be embarrassed by those photos! Is that what our military has been spending money on?
 
  • #3,440
Joe Neubarth said:
...when millions of lives are at stake ...

Where did you get that idea?
 
  • #3,441
I realize this is speculation on my part, but all of these latest statements including the one about 10,000 TBq per hour for a number of hours really seems to point to them knowing quite a bit more than they are letting on.
 
  • #3,442
Considering that at d + almost 30 , they aren't any closer to restore cooling , if anything situation is worse , containment is not really containing , what option do they have ? They can't let it bleed out for ever ...
 
  • #3,443
tsutsuji said:
This sounds close enough to the "D/G Inoperable due to Tsunami flood" analysis on page 12 of http://www.nisa.meti.go.jp/english/f...110406-1-1.pdf and professor Yoshiaki Oka's analysis :

Emergency DGs started at the earthquake. But Tsunami damaged ultimate heat sinks (sea water pumping and cooling system) of units 1F1-4. caused common cause failure

If the intake structure was damaged enough to compromise the service water system (whatever its name is in a BWR), then none of the cooling systems would be available, right? Regardless of whether the diesels were running or not? I don't have a clear idea of the BWR systems, and how the steam-driven (RCIC?) is supposed to work in the long term. Can you maintain cooling that way (steam driven pumps) in the long-term, or do you necessarily need to cool the water in the torus, removing the heat via the service water system? Does anyone have a link to a good description of these systems?
 
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  • #3,444
ivars said:

The report is probably the following one : http://www.rri.kyoto-u.ac.jp/NSRG/seminar/No110/iitatereport11-4-4.pdf

http://www.rri.kyoto-u.ac.jp/NSRG (Nuclear Safety Research Group at Research Reactor Institute, Kyoto University) provides a link to http://hamanora.blog.ocn.ne.jp/kaiin02/ where there is more to read.
 
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  • #3,445
|Fred said:
Considering that at d + almost 30 , they aren't any closer to restore cooling , if anything situation is worse , containment is not really containing , what option do they have ? They can't let it bleed out for ever ...

An interesting question, indeed. Posited another way: If the emergency efforts to cool the reactor cores are (and it would seem, can only be) a temporary solution as long as the coolant (water) is not contained in a closed system,

Then only three alternatives exist:

1) Continue to spill contaminated water and slowly (relatively) contaminate the ground water and ocean while temporizing. (possibly, to allow time to deal with the spent fuel in the SFPs?), or

2) Somehow devise a stable, permanent system to contain, decontaminate and if possible, recirculate the water being used for cooling the cores (unlikely), or

3) Prepare to let the cores melt and deal with the consequences.

Is there another option I am missing? If not, then option (3), it seems, is most likely the "not if, but when" final event in the Fukushima disaster sequence.

Which begs the question: What might be done while temporizing with the current efforts to cool the cores to mitigate the ultimate consequences of one or more melted reactor cores with loss of the primary containment? If the answer to that question is "nothing effective", then, is option (1) with ongoing contamination by un-contained, highly contaminated water for as long as humanly possible worse than option (3)?

I don't know.
 
  • #3,446
Astronuc said:
Here is another good overview of the Fukushima event.
www.vgb.org/vgbmultimedia/News/Fukushimav15VGB.pdf

a good overview, but:
"Recriticality in Unit 2 ?
(according to soil samples,
might explain radioactivity spike on march 16)"

is there *any* evidence for a recriticality in #2?
the spike on march 16th could be much better explained by (undetected??) melting/burning fuel in #4 SFP (imho):
there was an explosion before:
http://www.tepco.co.jp/en/press/corp-com/release/11031504-e.html
and a fire afterwards:
http://www.tepco.co.jp/en/press/corp-com/release/11031606-e.html
and in the meantime, the (then uncooled) fuel took a nap?
 
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  • #3,447
TCups said:
3) Prepare to let the cores melt and deal with the consequences.
a core melt might be a cleaner solution than a continues feed and bleed, only if it can be guaranteed that the molten core does not go critical, and to prevent a steam explosion the dry well must dry which it is not.
 
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  • #3,448
TCups said:
An interesting question, indeed. Posited another way: If the emergency efforts to cool the reactor cores are (and it would seem, can only be) a temporary solution as long as the coolant (water) is not contained in a closed system,

Then only three alternatives exist:

1) Continue to spill contaminated water and slowly (relatively) contaminate the ground water and ocean while temporizing. (possibly, to allow time to deal with the spent fuel in the SFPs?), or

2) Somehow devise a stable, permanent system to contain, decontaminate and if possible, recirculate the water being used for cooling the cores (unlikely), or

3) Prepare to let the cores melt and deal with the consequences.

Is there another option I am missing? If not, then option (3), it seems, is most likely the "not if, but when" final event in the Fukushima disaster sequence.

Which begs the question: What might be done while temporizing with the current efforts to cool the cores to mitigate the ultimate consequences of one or more melted reactor cores with loss of the primary containment? If the answer to that question is "nothing effective", then, is option (1) with ongoing contamination by un-contained, highly contaminated water for as long as humanly possible worse than option (3)?

I don't know.

I don't know what the sea depths are near the plant, or what kind of logistic/financial nightmare it may be, but why couldn't they hire or buy a bunch of oil tankers to sit off the coast to facilitate easier siphoning of contaminated water from the plant to the oil tankers as an expendible temporary storage solution for the contaminated water?

It seems to be better than purposely dumping what is already collected/contained radioactive water into the ocean because 'they had no choice'. If it was an uncontrollable leak that's one thing, but if their problem is with storage (and it seems to be the case earlier with the purposeful dumping), then there are obvious solutions that can be had like hiring/buying oil tankers to store the water.
 
  • #3,449
Well it's now basically official, I guess they just felt like skipping 6!
The Japanese government's nuclear safety agency has decided to raise the crisis level of the Fukushima Daiichi power plant accident from 5 to 7, the worst on the international scale.

The Nuclear and Industrial Safety Agency made the decision on Monday. It says the damaged facilities have been releasing a massive amount of radioactive substances, which are posing a threat to human health and the environment over a wide area.
http://www3.nhk.or.jp/daily/english/12_05.html
 
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  • #3,450
Pheesh said:
Well it's now basically official, I guess they just felt like skipping 6!

http://www3.nhk.or.jp/daily/english/12_05.html

It baffles the mind how many so called 'experts' were on the news early in this disaster, who were adamant that the still developing situation could not possibly be worse than the TMI incident and that a disaster rating above 4 was impossible.

It seemed so obvious right from the very start the accident was worst than TMI because (1) there was reportedly a hydrogen explosion which for all intents and purposes can likely only occur if fuel rods were overheating leading to thermolysis of water catalysed with the zirc-water reaction to generate the hydrogen in the first place, and (2) the military subsequently detected I and Cs radioisotopes off the coast that obviously came from the reactor likely due to pressure releast from primary containment. Ultimately though, the facts have already demonstrated long ago that core overheating happened (likely with fuel cladding melting also since they didnt get cooling in there for a long time) and also that radioactive elements were already released into the atmosphere thus proven very early to be worse than TMI since TMI had fuel melting but no substantial amount of radioisotopes were released into the atmosphere and that there was no indications of breach in containment (not even the outer containment) for which was certainly not the case in the fukushima incident.
 
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