Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[Sirius (b)]

Find the blueprint original by GE for this Mk., on the Section B-B, West facing you see that the SFP is in the S-SE corner of the containment buildings. The Southerly hole corresponds to the exact location of SNF assemblies, and it's confirmed via both: footage and thermal imagery.

I don't like waking up to reactors blowing up, but Good Night, all :tongue2:

P.S. Bah, here's the bp:

http://img291.imageshack.us/img291/1236/fukunitbwr1920.th.jpg
http://img23.imageshack.us/img23/9085/fukunitbwr3024f.jpg - (5,024 x 3,547) 2 MB
10 MB (9,889 x 6,984 pixels) - http://www.megaupload.com/?d=H0MPDIEP

 

[razzz]

I agree it is speculative and an error by orders magnitude is possible.

I was trying to get some numbers to the quite common statement that it is better to pollute the sea rather than the atmosphere/land.

Assume the worst then add your numbers with Tokyo Electric numbers then divide by 2, that should be close enough to the truth. [Edit: I see no reason not to figure a continuous steady flow of contamination into the, atmosphere, lithosphere and hydrosphere except when accelerated by the occasional explosion, unless someone can prove different]

Units 1&3 and pond 4 spewed a lot of their nuke material airborne so you can figure those are less than unit 2. Pond 2 might be an unknown.

The scientists are looking for hard numbers to base-on unless you work for Tokyo Electric, then all 'this' never happened. It must have been their worst nightmare finally to succumb to conditions for outside help, whereby having to release all their known figures to scientific circles. (I doubt the US was surprised by the numbers even though they try to downplay it at times)

Some say polluting the Pacific is less hassle due to its vastness or it's already a cesspool, I'm never quite sure which one they are relying on. Polluting the atmosphere works only at loftier levels and even then background benchmarks are raised.

Like changing exposure time to contamination, instead of a yearly dose limit, once in a lifetime higher exposure limit will be used. Difference is, you can't ever be exposed again after attaining the lifetime limit, technically but mainly to get the 'cleanup' workers in and out safely. Lots of them until the robots show up.

 

[shogun338]

Total activity levels of 70,000 - 80,000 Bq/kg were found in spinach leaves from one garden, while levels of roughly 9,000 Bq/kg were found in cabbage from another. Based on the Japanese Ministry of Science (MEXT) reports, 20-30% of this radioactivity is caused by cesium-137, which is far above the Japanese government limit of 500 Bq/kg for vegetables. The limit for iodine-131 it is 2,000 Bq/kg. http://www.panorientnews.com/en/news.php?k=910

 

[ceebs]

http://www.yomiuri.co.jp/dy/national/T110407005117.htm"

Tokyo Electric Power Co. is considering alternative methods, including the construction of improvised systems, to cool reactors at the crippled Fukushima No. 1 nuclear power plant.

Ongoing operations--which involve pouring water directly into the reactor cores to lower temperatures inside the pressure vessels of the Nos. 1 to 3 reactors to below 100 C--have not worked as expected, and restoration of the reactors' existing cooling systems is not likely to happen soon.

The discouraging outlook has prompted TEPCO to begin exploring new options.

 

[|Fred]

Find the blueprint original by GE for this Mk., on the Section B-B, West facing you see that the SFP is in the S-SE corner of the containment buildings. The Southerly hole corresponds to the exact location of SNF assemblies, and it's confirmed via both: footage and thermal imagery.

I'm familiar with those print (I actually posted them on this board), and although I'm not confident that are fully accurate for the 4th unit, for argument sake I will and I had gladly work with.. Still I'm not able to grasp your observation/affirmation. Could you please point out on those print your hole and how it is the location of Spent Nuclear Fuel.

To my best knowledge thermal imagine totally infirm your assessment , do does the blue print.. I could be mistaken after three weeks of intense home made forensic, on could lost his eye.

 

[Emreth]

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.

You are a new poster here and i understand you haven't gone over the thousands of posts. All the things you mention were discussed here a while ago and debunked basically.
Reactor 3: The big blast is not directly related to the destruction of the top parts of the reactor, there were images posted here that show it's still there, with a crane collapsed over it, and steam escaping from the connection chute between that and the SFP. Also notice that the truss structure over the containment is intact unlike over the SFP. The thermal imagery, somehow surprisingly paints a rather rosy picture, with nothing substantially warm. A lot of seemingly hot spots arise from changes in the range of the IR measurements, with debris lying around at essentially ambient temperature. There are hot spots (70degC) over the SFP and the leaking parts from the PCV but that's about it, the rest are more or less cooler than a human being (less than 36degC), if a person was there it would be glowing red.

 

[shogun338]

Water leaked out of spent fuel pools at the Onagawa nuclear plant in northeast Japan after a strong aftershock rocked the region late on Thursday, but there was no change in the radiation levels outside the plant, operator Tohoku Electric Power said on Friday. http://www.reuters.com/article/2011/04/08/japan-leak-idUSL3E7F80BF20110408

 

[shogun338]

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. http://www.nytimes.com/2011/04/09/world/asia/09japan.html?_r=1

 

[shogun338]

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 .

 

[Cire]

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.

I don't believe this occurred. At the time of the explosion TEPCO was pumping in water using a fire engine. You don't overpressure a massive pressure vessel and not have a nylon fire hose still attached to the feed line not burst. If the RPV over-pressurized then every pipe, fitting, connection to the reactor with a lower pressure rating would have gone first, followed by the RPV assuming it didn't depressurize fast enough.

The RPV is approximately 6 inches thick. The pressures required to yield a 6 inch thick piece of steel even at elevated temperatures is huge. I understand the reactor has an operating pressure, but the failure pressure is much higher.

The failure mode of an over pressurized reactor with a corium slag at the bottom would be to fail the bottom of the RPV. This is the same failure mode you see when a water heater fails. It looks like this..



If that occurred with the reactor we'd be looking at the reactor vessel sitting somewhere outside of the building.

This is why you design the system to fail anywhere but the RPV.

 

[ohohohoh]

Is there any information, whether they installed the "direct torus vent system" in Fukushima (unit 1,2 3) or not?

For "direct torus vent system" look at: http://www.nirs.org/factsheets/bwrfact.htm

 

[NUCENG]

Is there any information, whether they installed the "direct torus vent system" in Fukushima (unit 1,2 3) or not?

For "direct torus vent system" look at: http://www.nirs.org/factsheets/bwrfact.htm

Just found this today.

 

[razzz]

Just found this today.

Put a leash on it so it can't go to far. Need to know where it is at all times.

 

[|Fred]

Is there any information, whether they installed the "direct torus vent system" in Fukushima (unit 1,2 3) or not?

If you are referring to the 1980's US mandatory Upgrade to Mark 1 design, I was stated on numerous occasion that Hitachi did implement those update on the Fukushima plant.

 

[|Fred]

Just found this today.

Yes that's the info that has been spread in the news from the past 2 days it was initiated (I believe) by a reuters Paper by Roberta Rampton and Ayesha Rascoe dated from the 6th http://uk.reuters.com/article/2011/04/06/uk-japan-markey-idUKTRE73540Y20110406

"(Reuters) - The core at Japan's Fukushima nuclear reactor has melted through the reactor pressure vessel, Democratic Congressman Edward Markey told a hearing on the nuclear disaster on Wednesday.

"I have been informed by the Nuclear Regulatory Commission that the core of Unit Two has gotten so hot that part of it has probably melted through the reactor pressure vessel," said Markey, a prominent nuclear critic in the House of Representatives.

The leaked email originate directly from congressman Edward Markey's Office via a few forwarded mail by Neubauer (personal investigation)

http://markey.house.gov/docs/4-6-11markey_e-mail_2_-nrc_question_regarding_fukushima_unit_2.pdf

http://markey.house.gov/docs/4-6-11.markey_e-mail_1_-_nrc_question_regarding_fukushima_unit_2.pdf

So we can hardly consider them as concurring evidence but rather direct sourcing of the reported information. The information being


Based on radiation readings in the drywell and the torus, the NRC staff speculates that part of the Unit 2 core may be out of the reactor pressure vessel and may be in the lower space of thedrywell. Lower radiation readings in the torus suggest that there is not core material in the torus.


Open to argumentation

 

[ian_scotland]

Originally Posted by Astronuc
FK-I Units 1-5 are MK I containment, but FK-I Unit 6 is Mk II.
Unit 1 is a BWR/3, Units 2-5 are BWR/4 and Unit 6 is a BWR/5.

Unit 4 containment is the advanced type (this is not necessarily the case of the other BWR/4 unit in the plant, and likely not the case)

Concerning the discussion as to possible explosion paths or visible damage to unit 4... Astronuc and Fred appear to have differences of opinion as to the containment types. Until we can be certain of the plan/layout of this building is it not difficult to understand what evidence we are seeing in the photo's?

EDIT Ok, it appears that its Astronuc who is correct about unit 4 containment, from the images in this linked METI document:
http://www.meti.go.jp/press/2011/04/20110408004/20110408004-3.pdf
Thank you to both for replying

 

[artax]

Inside Fukushima Evacuation Zone

http://energheia.bambooz.info/index.php?option=com_content&view=article&id=156%3Ainside-fukushima-evacuation-zone&catid=60%3Avideo&Itemid=85&lang=it

Tetsuo Jimbo, founder of Video News Network, a TV broadcasting website, and a colleague ventured into the area on Sunday. Before setting out, Mr. Jimbo consulted a radiation expert, who advised he spend a maximum of two hours in the zone. The 49-year-old journalist stayed for two and a half. A face mask -- the kind worn to fend off hay fever -- was his only protective gear. He admits he and his colleague got "kind of scared" when a host of large dump trucks drove by and the drivers were covered in what looked like "full radiation-proof suits" and gas masks.

I have a question,... The reporter in the video gets to within a few km of the power plant, (can't tell but I think he's south of it) and the dosimeter reads 106uS/Hr. He's holding the dosimeter at chest height. Now will that be mainly gammas from wherever or airbourne particulates giving alpha and Beta? or could be a combination of both.
AND would a ground reading (putting meter on the ground) be significantly higher.

If he was told a max of two hours then two and a half then an extra half hour isn't going to make that much difference, unless that half hour was at the area of highest activity. Must say I really feel for the dogs.

 

[elektrownik]

What this mean: radiation in drywell go from 30Sv (from previous nisa report) to 100Sv in newest report ?
source: http://www.meti.go.jp/press/2011/04/20110408004/20110408004-3.pdf

 

[denislaurent]

What this mean: radiation in drywell go from 30Sv (from previous nisa report) to 100Sv in newest report ?
source: http://www.meti.go.jp/press/2011/04/20110408004/20110408004-3.pdf

Unit#1 : Temperatures and Pressures quickly increasing too.

 

[elektrownik]

It look that N2 wasnt good idea... 100Sv wow

 

[ohohohoh]

If you are referring to the 1980's US mandatory Upgrade to Mark 1 design, I was stated on numerous occasion that Hitachi did implement those update on the Fukushima plant.

What exactly has been implemented? Do you have links?

Look at page 21 at the Areva Document http://fairewinds.com/sites/default/files/AREVA%20Fukushima.pdf
There you can see venting into the containment. And you can read "Release of unfiltered venting?"

Does Dr. Matthias Braun from the French-German nuclear power firm Areva not know for sure what is in Fukushima plant or was is not there?

 

[denislaurent]

It look that N2 wasnt good idea... 100Sv wow, in Chernobyl, after explosion in reactor core was 50Sv...

Nitrogen or earthquake ?

Temperature & Activity trend inversion looks simultaneous to N2 injection, which started 24 hours before the quake. (April 07 01h31 JST from Tepco)

100 Sv is what they had in Units #2 & #3 drywells on 15/18 March, now 3 weeks ago.

 

[NUCENG]

If you are referring to the 1980's US mandatory Upgrade to Mark 1 design, I was stated on numerous occasion that Hitachi did implement those update on the Fukushima plant.

One of the things I am watching is how we are getting information and how reliable sources are. Can you tell me what posts and sources contained that info? I did a search and saw some speculation both ways (including mine), but did not find a reference to official released information. Thanks.

 

[ceebs]

Nitrogen or earthquake ?

Temperature & Activity trend inversion looks simultaneous to N2 injection, which started 24 hours before the quake. (April 07 01h31 JST from Tepco)

100 Sv is what they had in Units #2 & #3 drywells on 15/18 March, now 3 weeks ago.

if you look at the last weeks readings for dry and wet wells, reactor one has been acting oddly for at least a week.

 

[htf]

Thank you for the updated estimates. ZAMG:s upper boundary is still less than the total Chernobyl emissions of the same isotopes (from the great source of Wikipedia).

Yes, I know, I haven't seen any total estimations of emission of any nuclide directly to the sea. That is one of the reasons I myself dared the task.

They also estimate the uncertainty of their simulation between 10 to 1000, depending on the location of the measured data. And their estimation is based on the emission only to the atmosphere.

You made a simple estimation of the amount of radioactivity released to the ocean by one(!) leakage. It is probably an overestimation but nevertheless it shows that we have to expect a huge amount of radioactivity released to the ground and the ocean. I don't think anybody can quantify this amount at the moment.

There was a report in the news of a simulation done by French scientists (not the Areva thing, that analysis was performed by the German division of Areva). The analysis was performed and published a few days after the accident and they reported that ~10% of Chernobyl accident has been released in the first days of the Fukushima accident.

But it could be much more in my opinion: what damage was done by the Earth quake? You wouldn't expect the leakage in the cable channel from a "normal" accident. And what about the fuel pools? There are now speculations that a part of the core has melted through the RPV. ...

I think it cannot be excluded the we already exceeded Chernobyl. The impact on the people is less severe because only a minor part was deposited to populated areas.

So there is plenty of room for speculations!

 

[MadderDoc]

Sorry, I may not be able to update my plots of Fukushima Daiichi vars until next tuesday.
(However the scripts and files are availabe at the site, if anyone cares...)
http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/cur/

While you are away, people may use these monitor fies (pressure, waterlevel, temperature and major events):
http://www.gyldengrisgaard.dk/fukmon/

I attempt to keep these data sets updated with the most recent data from the Japanese METI site:
http://www.meti.go.jp/press/

 

[artax]

Another interesting video inside the zone, if a bit over the top at the end.

 

[|Fred]

Concerning the discussion as to possible explosion paths or visible damage to unit 4... Astronuc and Fred appear to have differences of opinion as to the containment types.

Hi, Ian

I do not believe we have different opinion , as Astroduc pointed out according to the Japanese released information Units 2-5 are based on GE MK1 BWR/4.
I have no reason do dispute this information.

having said that Unit 4 GE MK1 BWR/4 used the advanced primary containment, this information was hinted by a Japanese engineer (who's name I've currently forgot but did mentioned in a previous post) Engineer who toke part in the built of the Unit 4 (and only 4).

Furthermore when looking at the blue print that I found I can not help but notice that those blue print seems to fit better unit 1 and 3 but less so 4( no proper analysis is possible on 2). As mentioned earlier I'll gladly assume similarity until better material is provided

 

[Sirius (b)]

You are a new poster here and i understand you haven't gone over the thousands of posts. All the things you mention were discussed here a while ago and debunked basically.
Reactor 3: The big blast is not directly related to the destruction of the top parts of the reactor, there were images posted here that show it's still there, with a crane collapsed over it, and steam escaping from the connection chute between that and the SFP. Also notice that the truss structure over the containment is intact unlike over the SFP. The thermal imagery, somehow surprisingly paints a rather rosy picture, with nothing substantially warm. A lot of seemingly hot spots arise from changes in the range of the IR measurements, with debris lying around at essentially ambient temperature. There are hot spots (70degC) over the SFP and the leaking parts from the PCV but that's about it, the rest are more or less cooler than a human being (less than 36degC), if a person was there it would be glowing red.

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:

Second week

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

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.

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 .

Those are from Unit 3.

 

[|Fred]

What exactly has been implemented? Do you have links?

One of the things I am watching is how we are getting information and how reliable sources are. Can you tell me what posts and sources contained that info?

I don't write down my sources I got those information from a page somewhere one Hitachi web site, and a concurring hint on GE web page . could not find the Hitachi page .. managed to google the GE

All of the modifications were made in accordance with regulatory requirements. In the United States, for example, the NRC issued a generic industry requirement in 1980 for the Mark I containment that the industry used to make modifications.

We understand that all of the BWR Mark I containment units at Fukushima Daiichi also addressed these issues and implemented modifications in accordance with Japanese regulatory requirements.

The modifications made to Mark I containments include:
“Quenchers” were installed to distribute the steam bubbles in order to produce rapid condensation and to reduce loads on the unit. In a reactor, exhaust steam is piped into a suppression chamber, which is known as the torus and is a large, rounded suppression pool that sits next to the reactor core. It is used to remove heat when large quantities of steam are released from the reactor. In the torus, the steam bubbles go under water. With the modification to the Mark I, the quenchers, which are also underwater, make steam bubbles smaller by breaking up the larger bubbles. This in turn reduces pressure.

Another modification is the installation of deflectors inside the torus. When that steam goes in, the water level rises. The deflectors that were added break up the pressure wave that is produced and help relieve pressure on the torus.

A further modification was made to the “saddles” on which the torus sits — basically the series of leg-like structures that support it. The con

 

[artax]

fascinating Tokaimura accident (INES level 4) which I don't remeber so can't have been highly publicised?

http://en.wikipedia.org/wiki/Tokaimura_nuclear_accident

 

[|Fred]

...

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

 

[tsutsuji]

The Japanese government and Tepco are investigating the possibility of circulating water in the containment, which they call the "water-sarcophagus" technique : http://www.tokyo-np.co.jp/article/national/news/CK2011040802000039.html

 

[|Fred]

Ps:

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

I personally don't make out of rare pictures a compelling evidence for an evolution on the water in the RPV.. Considering picture were few, and not necessarily representing evolving status across the days... and I can actually prove it with the below time coded picture 27/03 where we do get vapor coming out of PCV.

 

[htf]

fascinating Tokaimura accident (INES level 4) which I don't remeber so can't have been highly publicised?

http://en.wikipedia.org/wiki/Tokaimura_nuclear_accident

I do remember it. There were several reports in German news.

Here is a chronology of Japan's accidents in nuclear industry (in German only):

http://www.zdf.de/ZDFmediathek/beitrag/video/1292992/Tickende-Zeitbomben-Japans-Atomanlagen#/beitrag/video/1292992/Tickende-Zeitbomben-Japans-Atomanlagen

The Tokaimura accident is at 2:00 min. You can see how careless the workers acted - they used buckets to fill a Uranium solution into a tank - to save time they filled it with 10 times the allowed quantity.

Is using buckets to handle enriched Uranium common in nuclear industry?