Japan Earthquake: Nuclear Plants at Fukushima Daiichi

In summary: RCIC consists of a series of pumps, valves, and manifolds that allow coolant to be circulated around the reactor pressure vessel in the event of a loss of the main feedwater supply.In summary, the earthquake and tsunami may have caused a loss of coolant at the Fukushima Daiichi NPP, which could lead to a meltdown. The system for cooling the reactor core is designed to kick in in the event of a loss of feedwater, and fortunately this appears not to have happened yet.
  • #3,291
|Fred said:
Thank you, I'll pay extra attention to my directions. Now, in red the hole that you pointed at in your earlier post .
Concerning it's location it is S/N on the west part of the unit 4, and according to the photo it is on the level just bellow the operating floor and not bellow as you state, it would match the isolation condenser level that I mentioned earlier if we assume blueprint are accurate for this point on unit 4.
There is no crossing of fuel storage located (in blue) as it is located on the east part of the building
[PLAIN]http://i.min.us/ikC5W8.jpg[/QUOTE]

The pool runs the whole length and does cover the damaged area, and it just shows how much you know, or pretend to know. Thank you all for your side of the perspective, I will now return to the real world.

Artax,

There's been a documented INES Level 3 at Fukushima Dai-ni on March 11th.
 
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  • #3,292
Sirius (b) said:
I haven't read physicsforums during this three-week period, instead I was in a company of Russian nuclear engineers & Chernobyl liquidators, and you better take my word for it, when I say that they are still scarred by the accident of April, 1986 and wouldn't want the events that I've mentioned to have taken place.

There was steam, as well as black & grey smoke coming out directly from the RPV during the first week, much later the SFP South of it began to give off steam. The "(70degC)" figure you're quoting is from the Ministry of Defense of Japan operation with CH-47 hovering 3000 feet above the plant, facing West and taking those thermal images - their press releases contain those figures with hilarious arrows pointing who-knows-where, they might as well be pointing to a bucket full of liquid nitrogen.

First week photo Unit 3:
c5b510cc2750.jpg


Second week
4396570b0f05.jpg


No water in the containment or RPV on the 2.5-3rd week inside reactor 3, SPF steaming, tho:
eeadca36cf90.jpg


Fred, N-S line runs along the coast, please sort out your directions, before replying.

Unit 4 blown hole: http://img84.imageshack.us/img84/810/unit4sfp.jpg

There was a lot of insider information not available to the general public, but you can't hide contaminated soil out to 50 km for long.



Those are from Unit 3.

I reviewed the thermal images and the hilarious arrows you refer to -- I believe that the arrows were indicating the hot spot temperature measurements, keyed to the window width and window levels (which varied from image to image). Most were monitoring the temperatures at the surface of the spent fuel pools, as I recall.

All of the additional photos you list are at the level of the access floor to the reactor and spent fuel pools, including one that seems, very convincingly, to show not only the rails of the overhead crane, but also the large winch atop the rails, directly over the location of the top of the reactor containment vessel. That same arrangement, sort of an "H" with the two long rails running east-west and the winch machinery spanning the two rails, can be seen as a cold defect, also directly over the reactor containment vessel with some heat signatures at the periphery of what would be the reactor containment plug. The latter is consistent with steam leakage. All of that is concordant with all of the photos that have been analyzed in depth, right down to the details of the crane, the crane position, the location of the venting, steam, etc.

Further, the explosion out of spent fuel pool of unit 3 had ample energy to send rods and fragments of rods aloft. Actually, that point is not debatable, because we have the video of the explosion. The only debate is whether or not the explosion came from the SFP or vertically, out of the reactor containment. An explosion within the reactor containment is not excluded by an intact plug, but it would certainly exclude vertical ejection of damaged fuel rods from the reactor pressure vessel.

For the sake of argument, even if the rods came from the reactor pressure vessel, and even if the containment plug were blown, the the ejected rods would still have to get past the plug, the drywell cap, and the pressure vessel cap to be ejected vertically and thrown a long distance away from Bldg 3.

I have no idea whether your "inside" information is valid or not; but if it is, then we should rename Unit 3 " The Houdini Unit" because it was one helluva impressive escape that is impossible to see from any of the photos or IR images available on line, so far, and would be akin to one of Harry's great tricks, IMO.

http://www.houdinitribute.com/img/cell1.jpg

(sorry, linked the wrong photo first time)
 
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  • #3,293
Sirius (b) said:
The pool runs the whole length, you stupid ignorant.

Assessment (that the pool did not run the whole length) was based on available literature,diagrams and photo.
If you have otherwise knowledge and new informations they are more than welcome. Having said that It would be appreciated thought if those informations could come from something a bit more conclusive and elaborate than "I know because I know an you don't".
 
  • #3,294
To all: please don't post images wider than about 700-800 pixels. If you have wider images either resize them before posting, or post only links. Wide images break forum formatting and make it difficult to read the thread.
 
  • #3,295
REGARDING IMAGE POSTINGS, IMAGE SIZE

Hmm. As a Mac user, I feel left out of this. I must be missing something. None of the postings I see in this thread come up with images automatically displayed -- only the link to the image. And clicking on the link opens the image sized to the window, with the capability to click and zoom.

Are any of the images or image links I am posting causing this problem? Apologies if so, but if so, it is a problem that isn't at all apparent when I am viewing the thread, so it is an easy thing to overlook. Please send me a PM if my posting are a problem. Thanks.
 
  • #3,296
Tcups when you post image you use the board hosting function , it make thumbnail and ajax pop up display.. it's fine..

The issue Borek is Referring to is inlay image using the [ img] [/ img] code
 
  • #3,297
shogun338 said:
Broken pieces of fuel rods have been found outside of Reactor No. 2, and are now being covered with bulldozers, he said. The pieces may be from rods in the spent-fuel pools that were flung out by hydrogen explosions. Looks like we where right about fuel rods blown out of spent fuel pools .

Is there any new information available regarding the distribution pattern?
 
  • #3,298
shogun338 said:
Broken pieces of fuel rods have been found outside of Reactor No. 2, and are now being covered with bulldozers, he said. The pieces may be from rods in the spent-fuel pools that were flung out by hydrogen explosions. Looks like we where right about fuel rods blown out of spent fuel pools .
According to whom? Please cite sources when making claims.
 
  • #3,299
Sirius (b) said:
Racer,

The height of the gas vent towers is 130 metres. There 3 are distinct pieces of debris seen emerging from the vertical dust cloud, they could be either: FHM, PCV dome, concrete DW plug, reactor lid itself. The SFP is not the cause of the explosion, there may have been hydrogen in the secondary containment (reactor room), but the trigger was the thermal explosion inside the RPV - cold water coming into contact with 3/4 melted core, which, possibly fell down to the bottom of the RPV, triggering the steam release via the most likely route - bolted top. While the torus may have been destroyed in the event, I would worry about fuel from the core and SFP of Unit 3.

Concrete was pulverised in the detonation, that is steel debris flying sky-high to 500 metres+, with the cloud reaching up-to 1 km, or more.

P.S. What pressure was reported for Unit 3 D/W, RPV prior to the explosion? The core had already melted to some percentage before then, otherwise you can't have the observed events.
Yes. Whatever was the cause of the damages seen to Unit 4 building, it blew a hole 8 metres in diameter South to North through it, around the level the fuel assemblies would be stored at.

If anyone is interested in latest thermal imagery of the plant, PM me and I'll get them sourced and uploaded.

I'm interested in the latest thermal imaging of the site, can you get hold of it?
 
  • #3,302
artax said:
I'm interested in the latest thermal imaging of the site, can you get hold of it?

http://www.mod.go.jp/j/approach/defense/saigai/tohokuoki/kanren/230408.pdf
 
  • #3,303
"Still, concerns about the plant remain high. The Nuclear Regulatory Commission speculated Wednesday that some of the core of the No. 2 reactor had flowed from its steel pressure vessel into the bottom of the containment structure. The theory implies more damage at the unit than previously believed.

While a spokeswoman for Tokyo Electric dismissed the analysis, a spokesman for the Nuclear and Industrial Safety Agency of Japan agreed that it was possible that the core had leaked into the larger containment vessel.

The possibility raised new questions. The Nuclear Regulator Commission said that its speculation about the flow of core material out of the reactor vessel would explain high radiation readings in an area underneath, called the drywell.

But some of the radiation readings at Reactors Nos. 1 and 3 over the last week were nearly as high as or higher than the 3,300 rems per hour that the commission said it was trying to explain, so it would appear that the speculation would apply to them as well. At No. 2, extremely radioactive material continues to ooze out of the reactor pressure vessel, and the leak is likely to widen with time, a western nuclear executive asserted.

“It’s a little like pulling a thread out of your tie,” said the executive, who spoke on the condition of anonymity to protect business connections in Japan. “Any breach gets bigger.”

Flashes of extremely intense radioactivity have become a serious problem, he said. Tokyo Electric’s difficulties in providing accurate information on radiation are not a result of software problems, as some Japanese officials have suggested, but stem from damage to measurement instruments caused by radiation, the executive said.

Broken pieces of fuel rods have been found outside of Reactor No. 2, and are now being covered with bulldozers, he said. The pieces may be from rods in the spent-fuel pools that were flung out by hydrogen explosions. "

http://www.nytimes.com/2011/04/09/world/asia/09japan.html?ref=world"
 
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  • #3,304
shogun338 said:
Broken pieces of fuel rods have been found outside of Reactor No. 2, and are now being covered with bulldozers, he said. The pieces may be from rods in the spent-fuel pools that were flung out by hydrogen explosions. Looks like we where right about fuel rods blown out of spent fuel pools .

Astronuc said:
According to whom? Please cite sources when making claims.

[PLAIN]http://k.min.us/ik74PC.JPG
http://www.nytimes.com/2011/04/09/world/asia/09japan.html?_r=2and

[PLAIN]http://k.min.us/imOrOa.JPG
"[URL Report, Official Use Only, Fukushima Assessment, March 26th, 2011
last paragraph page 13[/URL]
 
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  • #3,306
elektrownik said:
http://www.mod.go.jp/j/approach/defense/saigai/tohokuoki/kanren/230408.pdf

The latest thermal imagery, including the window/level scale on the left hand side show the highest temperatures of Bldgs. 1-4.

I believe these are 23C and 33C at Bldg 1, not sure which structures, but presumably the SFP and over the region of the reactor, the 30C hole in the east face of Bldg 2, the 35C SFP 3 and the 46C SFP4, partially obscured by the FHM, complete with tabular data of the temps and daily trends measured at the indicated hot spot (arrow) on the right. Presumably, the measured temperatures could be accurately calibrated against areas of background ambient temperature (and that almost certainly wouldn't be a bucket of liquid nitrogen).

Thanks for posting, electrownik.

PS: for any of those currently experiencing an alternate "dog star" reality, I see nothing hilarious here and see no reason to question |Fred's IQ.

see:
https://www.physicsforums.com/showpost.php?p=3235922&postcount=3309
 
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  • #3,308
NISA has reported some of the 7 April aftershock consequences : http://www.chunichi.co.jp/s/article/2011040990003059.html

According to that article :

Cooling at Onagawa plant's fuel pools was stopped for 1 hour 23 minutes at unit 2, 59 minutes at unit 3, 53 minutes at unit 1.

Cooling at the Higashidori plant's pool was stopped for 26 minutes.

Radiation within Fukushima Daiichi plant's unit 1 containement rose to 100 Sv/h up from the earlier 30 Sv/h, but the validity of the measurement is questioned. Temperature at that unit went up from 223°C to 260°C then later decreased to 246°C.
 
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  • #3,309
I think the vgb doc Its a good collection of most available (unit 1 and 3 have been reported flooded, that's the only detail I could point out after a brief read), thanks ohohoh

AntonL, I have the intuition that the article comes down to the previously mentioned leaked email , with some cheese around.. Could be mistaken of course.
|Fred said:
<click

edit: the more I look into this leaked mail story the more I have the feeling there is a agenda at play, that one could resume as congressman ask NRC information change a could be to a there is in order to make his point.

quoted from http://www.marketwatch.com April 6, 2011, 8:41 p.m

Rep. Ed Markey (D., Mass.), a critic of nuclear power, said in a statement that the NRC believes the core of Unit 2 at the Fukushima plant has "gotten so hot that part of it has probably melted through the reactor pressure vessel." Mr. Markey also said that at least one other reactor core has been severely damaged.

Speaking to reporters Wednesday, Mr. Virgilio said the NRC didn't have evidence that the core at Fukushima's Unit Two had melted through the reactor vessel.

"That's not in the situation report that we have from the team in Japan, and that's as of this morning," he said.

The NRC, he said, believes there was significant fuel damage in three reactors and four spent-fuel pools, "but we don't believe at this point in time that that core has left the vessel.""

Anyhow that's US politic and am clueless on that matter
 
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  • #3,310
TCups said:
PS: for any of those currently experiencing an alternate "dog star" reality, I see nothing hilarious here and see no reason to question |Fred's IQ.

Love hurts (?)
 
  • #3,311
Has the Onagawa plant been given an accident number or rating?
 
  • #3,312
hbjon said:
Has the Onagawa plant been given an accident number or rating?
Unless they have fuel failures, or core or containment failures, there is no accident, and therefore no need for a rating at this time. If they lose power or cooling, but regain it within a specified time limit, it's not reportable as an accident.

http://www.world-nuclear-news.org/RS_New_earthquake_disrupts_grid_power_0704111.html

Diesel generators have replaced grid power at Higashidori nuclear power plant . . . .

Power from the grid through two of three connections was lost at the Onagawa nuclear power plant, where three reactors have been in cold shutdown since 11 March. Cooling systems are still in operation. . . .
As far as I know, Onagawa still has connection to the grid. There EDGs are apparently operational.
 
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  • #3,313
Now, in the light of recent experience at Fukushima, Tepco is proposing to design and install a system of tide barriers with watertight doors at Kashiwazaki Kariwa units 1 to 4. In addition, the company says it has installed facilities on the upland part of the site to provide backup power and water injection to both reactors and spent fuel pools, and taken measures to ensure cooling functions in the event of tsunamis flooding the reactor buildings. http://www.world-nuclear-news.org/RS-Tsunami_countermeasures_for_Kashiwazaki_Kariwa-0804118.html
 
  • #3,314
shogun338 said:
Now, in the light of recent experience at Fukushima, Tepco is proposing to design and install a system of tide barriers with watertight doors at Kashiwazaki Kariwa units 1 to 4. In addition, the company says it has installed facilities on the upland part of the site to provide backup power and water injection to both reactors and spent fuel pools, and taken measures to ensure cooling functions in the event of tsunamis flooding the reactor buildings. http://www.world-nuclear-news.org/RS-Tsunami_countermeasures_for_Kashiwazaki_Kariwa-0804118.html

Will that be sufficient to reassure the Group of Concerned Scientists and Engineers Calling for the Closure of the Kashiwazaki-Kariwa Nuclear Power Plant ( Japanese blog at http://kkheisa.blog117.fc2.com ; Initial 2007 English statement at http://cnic.jp/english/topics/safety/earthquake/kkscientist21aug07.html ) ?
 
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  • #3,315
Astronuc said:
Unless they have fuel failures, or core or containment failures, there is no accident, and therefore no need for a rating at this time. If they lose power or cooling, but regain it within a specified time limit, it's not reportable as an accident.

They might have to signal it as a level-1 incident, no ? Or even as a level-0 anomaly ?
 
  • #3,316
vanesch said:
They might have to signal it as a level-1 incident, no ? Or even as a level-0 anomaly ?

Fukushima Daini reactors 1,2,4 are INES 3...
 
  • #3,317
Proposals made by 16 Japanese experts on nuclear power engineering, nuclear physics and radiology on April 1 : http://search.japantimes.co.jp/cgi-bin/ed20110407a1.html
 
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  • #3,318
tsutsuji said:
NISA has reported some of the 7 April aftershock consequences : http://www.chunichi.co.jp/s/article/2011040990003059.html

According to that article :

...

Radiation within Fukushima Daiichi plant's unit 1 containement rose to 100 Sv/h up from the earlier 30 Sv/h, but the validity of the measurement is questioned. Temperature at that unit went up from 223°C to 260°C then later decreased to 246°C.

I'm part of the newbies brought to this quality conversation by the focus on a rational analysis of this event. I'm just impressed !

Well, if we make the assumption that CAMS reading are trustable for drywell 1, in reactor 1 radiation spikes; this seems to be correlated to temperature. What is the likely cause of radiation spikes with quick decrease, with temperature being correlated, and SPC radiation not increasing ?

Do CAMS only measures gamma radiation ?
 
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  • #3,319
jpquantin said:
I'm part of the newbies brought to this quality conversation by the focus on a rational analysis of this event. I'm just impressed !

Well, if we make the assumption that CAMS reading are trustable for drywell 1, in reactor 1 radiation spikes; this seems to be correlated to temperature. What is the likely cause of radiation spikes with quick decrease, with temperature being correlated, and SPC radiation not increasing ?

Do CAMS only measures gamma radiation ?
According to the article - The Continuous Air Monitoring (CAM) PIPS Detector--Properties and Applications - this particular type of detector detects/counts alpha and beta particles.
http://www.canberra.com/literature/946.asp
http://www.canberra.com/products/509.asp

This one counts beta/gamma -
http://www.canberra.com/products/543.asp

I suspect they use a beta-gamma detector, and it has to be rated for the temperature limit in the containment. That precludes several scintillation detectors. Perhaps they use compensated GM detectors.
 
  • #3,320
shogun338 said:
Now, in the light of recent experience at Fukushima, Tepco is proposing to design and install a system of tide barriers with watertight doors at Kashiwazaki Kariwa units 1 to 4. In addition, the company says it has installed facilities on the upland part of the site to provide backup power and water injection to both reactors and spent fuel pools, and taken measures to ensure cooling functions in the event of tsunamis flooding the reactor buildings. http://www.world-nuclear-news.org/RS-Tsunami_countermeasures_for_Kashiwazaki_Kariwa-0804118.html

One of the problems at the Fukushima nuclear accident is we did not know reactor conditions well after the earthquake and tsunami attack. We think about reactor measuring system again. We have to make the measuring instruments of the very important parts of nuclear plant as dual system. One is for controlling and the other is for emergency situation. The emergency instruments must have it's own battery, and have a wireless communication system to transfer data to outside. If after tsunami attack we knew the plant condition more well, present big nuclear disaster would not happen. We could do proper treatment against the dangerous situation.
 
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  • #3,321
daumphys said:
One of the problems at the Fukushima nuclear accident is we did not know reactor conditions well after the earthquake and tsunami attack. We think about reactor measuring system again. We have to make the measuring instruments of the very important parts of nuclear plant as dual system. One is for controlling and the other is for emergency situation. The emergency instruments must have it's own battery, and have a wireless communication system to transfer data to outside. If after tsunami attack we knew the plant condition more well, present big nuclear disaster would not happen. We could do proper treatment against the dangerous situation.

wireless communication is very difficult in a building like a reactor. It's probably impossible near the RPV.
 
  • #3,322
OFFTOPIC: http://noe.orf.at/stories/509185/" reports that wild hog meat bought in supermarkets has Cesium radiation levels of 1060 Bq/kg (allowed 600Bq/kg). This is a result of the hog's preference in the winter season to forage for a type of truffle (mushroom) which is deep in the ground and as such more likely to be contaminated by Cesium fallout from Tschernobyl of 25 years ago.
 
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  • #3,323
I linked to this way back when...

Contaminated Wild Pig

Wild boar are particularly susceptible to radioactive contamination due to their predilection for chomping on mushrooms and truffles, which are particularly efficient at absorbing radioactivity. Indeed, whereas radioactivity in some vegetation is expected to continue declining, the contamination of some types of mushrooms and truffles will likely remain the same, and may even rise slightly -- even a quarter century after the Chernobyl accident.

From..."[URL Quarter Century after Chernobyl
Radioactive Boar on the Rise in Germany[/URL]
 
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  • #3,324
Latest simulation out of http://db.eurad.uni-koeln.de/prognose/data/alert/ddcs_hem_1h_movtotal_1.gif" presents the high-end possibility of as much as 10Bq (Cs-137) in air within the next few days within my country. Converting this value to absorbed dose, this activity will presumably yield about 2 microsieverts/hr at a distance/depth of 1 cm. If anybody could anyone confirm/clarify this calculation, i would greatly appreciate it as i am a bit perturbed right now. Thank you for this forum. It is such a tremendous resource.
 
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  • #3,325
intric8 said:
Latest simulation out of http://db.eurad.uni-koeln.de/prognose/data/alert/ddcs_hem_1h_movtotal_1.gif" presents the high-end possibility of as much as 10Bq (Cs-137) in air within the next few days within my country. Converting this value to absorbed dose, this activity will presumably yield about 2 microsieverts/hr at a distance/depth of 1 cm. If anybody could anyone confirm/clarify this calculation, i would greatly appreciate it as i am a bit perturbed right now. Thank you for this forum. It is such a tremendous resource.

I can't answer your question, but what country are you in?
 
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