Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[tsutsuji]

Of interest, here is a picture of what they define as being the diesel generator building 6B for reactor N°6: http://www.tepco.co.jp/en/news/11031.../110517_22.jpg
(...)

The http://www.tepco.co.jp/en/news/11031.../110517_22.jpg link is broken because of "..." in the URL. I recommend using [PLAIN]https://www.physicsforums.com/Prime/buttons/quote.gif in order to provide the quoted person's name and manage url/links safely.

I think it is only the exhaust system and the cooling, IIRC they are in the basement in each turbine building. Keep in mind that the power of diesel generators in place range from rougly 3 up to 5 MW (3000~5000 kW each), the engine should be a V18. On the tepco website (japanese side only) it is possible to find some images and you can see their dimensions.

I would be glad if you could provide the links to these images.

 

[PietKuip]

Beware, you compare readings from Unit 2 S/C and drywell temp RPV for Unit 3...

Thank you. Unfortunately it is now too late to add a note to https://www.physicsforums.com/showpost.php?p=3305757&postcount=7528

 

[~kujala~]

Notes concerning soil amplification:

1. Ground shaking is amplified in soft sediments and dampened in hard rock:

Flash animation:

"[URL amplification
[/URL]
(Source: U.S. Geological Survey)

2. In the U.S. they have already made soil amplification maps for some areas in the U.S. to predict the level of shaking depending on soil quality. Here we have the map for LA area:

http://earthquake.usgs.gov/learn/glossary/images/amplification.jpg"

Flash animation and LA region amplification map can be found in this page:
http://earthquake.usgs.gov/learn/glossary/?term=amplification"

And here they have made a research concerning earthquake ground motions in the central U.S.:
http://gsa.confex.com/gsa/2002NC/finalprogram/abstract_31500.htm"

Do they have these kind of maps in Japan?
Surely they must have?

3. The differences between mudstone and bedrock:

The velocity of transmits shear waves (S-waves) is one contributor to the amplification rate. It's dependend on the area we are talking about. In the San Fransisco Bay area they have 5 level chart for soil types and shaking amplification. In that area mudstone and bedrock have different qualities:

Soil type B: 1500 m/sec > Vs > 750 m/sec
Includes volcanics, most Mesozoic bedrock, and some Franciscan bedrock. (Mesozoic rocks are between 245 and 64 million years old. The Franciscan Complex is a Mesozoic unit that is common in the Bay Area.)

Soil type C: 750 m/sec > Vs > 350 m/sec
Includes some Quaternary (less than 1.8 million years old) sands, sandstones and mudstones, some Upper Tertiary (1.8 to 24 million years old) sandstones, mudstones and limestone, some Lower Tertiary (24 to 64 million years old) mudstones and sandstones, and Franciscan melange and serpentinite.

http://earthquake.usgs.gov/regional/nca/soiltype/

Shaking is stronger where the shear wave velocity is lower. So it's stronger for mudstone than for bedrock.

4. Conclusion: To have nuclear plants built on bedrock and mudstone are two different things. Building on bedrock is safer.

If Fukushima plant's foundation is built on mudstone - not bedrock - and the local geological qualities for mudstone and bedrock differ in that area then it may have had some impact on the scale of the catastrophe.

But surely the Japanese must have made some calculations concerning the safety of building nuclear plants on mudstone if that happens to be the case?

 

[jlduh]

The http://www.tepco.co.jp/en/news/11031.../110517_22.jpg link is broken because of "..." in the URL. I recommend using [PLAIN]https://www.physicsforums.com/Prime/buttons/quote.gif in order to provide the quoted person's name and manage url/links safely.
I would be glad if you could provide the links to these images.

Tsutsuji my original post was this one, but i edited it in between so read the EDIT first!

https://www.physicsforums.com/showpost.php?p=3306526&postcount=7568

By the way The BLACK SMOKE at N°3 was first reported the 21 st of march at 3:55pm (japan time i guess) , so you were right, bt it seems that some was still reported the 23 st (not clear):

http://english.kyodonews.jp/news/2011/03/79925.html

For those interested in history of what happened then, the part of this PF thread for this date starts here (page 44):

https://www.physicsforums.com/showthread.php?t=480200&page=44

 

[jlduh]

Notes concerning soil amplification:

1. Ground shaking is amplified in soft sediments and dampened in hard rock:

Flash animation:

"[URL amplification
[/URL]
(Source: U.S. Geological Survey)

2. In the U.S. they have already made soil amplification maps for some areas in the U.S. to predict the level of shaking depending on soil quality. Here we have the map for LA area:

http://earthquake.usgs.gov/learn/glossary/images/amplification.jpg"

Flash animation and LA region amplification map can be found in this page:
http://earthquake.usgs.gov/learn/glossary/?term=amplification"

And here they have made a research concerning earthquake ground motions in the central U.S.:
http://gsa.confex.com/gsa/2002NC/finalprogram/abstract_31500.htm"

Do they have these kind of maps in Japan?
Surely they must have?

3. The differences between mudstone and bedrock:

The velocity of transmits shear waves (S-waves) is one contributor to the amplification rate. It's dependend on the area we are talking about. In the San Fransisco Bay area they have 5 level chart for soil types and shaking amplification. In that area mudstone and bedrock have different qualities:


http://earthquake.usgs.gov/regional/nca/soiltype/

Shaking is stronger where the shear wave velocity is lower. So it's stronger for mudstone than for bedrock.

4. Conclusion: To have nuclear plants built on bedrock and mudstone are two different things. Building on bedrock is safer.

If Fukushima plant's foundation is built on mudstone - not bedrock - and the local geological qualities for mudstone and bedrock differ in that area then it may have had some impact on the scale of the catastrophe.

But surely the Japanese must have made some calculations concerning the safety of building nuclear plants on mudstone if that happens to be the case?

very interesting data which confirms that mudstone can hardly been described as bedrock from seismic standpoint...

So the Tepco site stating Bedrock is not lying by approximation, it's lying by using one word to describe something else.

THANKS!

Also of interest this recent article which summarizes the long history of battles and lawsuits of japanese residents against nuclear industries on the matter of earthquake resistance, very complete article:

http://www.staradvertiser.com/news/20110517_Japan_officials_ignored_or_hid_nuclear_risks.html

Today things are changing a bit:

In 2007, a district court ruled against the plaintiffs, finding no problems with the safety assessments and measures at Hamaoka. The court appeared to rely greatly on the testimony of Haruki Madarame, a University of Tokyo professor and promoter of nuclear energy, who since April 2010 has been the chairman of the Nuclear Safety Commission of Japan, one of the nation’s two main nuclear regulators.

Testifying for Chubu Electric, Madarame brushed away the possibility that two backup generators would fail simultaneously. He said that worrying about such possibilities would “make it impossible to ever build anything.” After the Fukushima Daiichi disaster, Madarame apologized for this earlier comment under questioning in Parliament. “As someone who promoted nuclear power, I am willing to apologize personally,” he said.

In the early days of nuclear power generation in Japan, the government and nuclear plant operators assured the public of the safety of plants by promising that they would not be located on top of active fault lines, Ishibashi, the seismologist, said in an interview.

But he said that advances in seismology have led to the gradual discovery of active fault lines under or near plants, creating an inherent problem for the operators and the government and leading to an inevitable conclusion for critics of nuclear power

Note also this part, where "solid bedrock" seems to have had some variations in the mouth of some people:

Her group filed the lawsuit in 1999, a year after the operator suddenly announced that it had detected a five-mile-long fault near the plant, reversing decades of claims that the plant’s vicinity was free of active faults.

Chugoku Electric said the fault was too small to produce an earthquake strong enough to threaten the plant, but Ashihara’s suit cited new research showing the fault line could in fact be much longer, and produce a much stronger earthquake. It got a boost in 2006, when a seismologist announced that a test trench that he had dug showed the fault line to be at least 12 miles long, capable of causing an earthquake of magnitude 7.1.

After initially resisting, the company reversed its position three years ago to accept the finding. But a spokesman for the Chugoku Electric said the plant was strong enough to withstand an earthquake of this size without retrofitting.

“This plant sits on solid bedrock,” said Hiroyuki Fukada, assistant director of the visitor center for the Shimane plant, adding that it had a 20-foot, ferro-concrete foundation. “It is safe enough for at least a 7.1 earthquake.”

However, researchers now say the fault line may extend undersea at least 18 miles, long enough to produce a magnitude 7.4 earthquake. This prompted Ashihara’s group to appeal last year’s ruling.

So I'm happy to extract again this last sentence here in a PF forum where science means something:

"However, researchers now say the fault line may extend undersea at least 18 miles, long enough to produce a magnitude 7.4 earthquake. This prompted Ashihara’s group to appeal last year’s ruling"

then the question is: what do we do with this new knowledge?

How many nuclear plants in the world are still on places where it was considered safe at the time of their design and construction (for whatever reason) and where it can no more be considered that way with new scientific findings?

As life of old plants everywhere seem to be extended, and as retrofitting seems impossible in some cases like theses, what do we do? Do we wait for the next big one?

 

[Astronuc]

Tepco is providing daily updates in English
http://www.tepco.co.jp/en/news/110311/

The image cited by mamoru and jlduh is described as:
Building for diesel generator 6B of Unit 6
http://www.tepco.co.jp/en/news/110311/images/110517_22.jpg

Before posting make sure links are not parsed (...)

Heavy oil tank swept up by Tsunami (I believe this is one of the tanks of diesel fuel that was moved from the shoreline to is present location.)
http://www.tepco.co.jp/en/news/110311/images/110517_17.jpg

 

[tsutsuji]

EDIT: this platform is cooling equipment for the EDG building, it's much clearer in the video, i extracted this picture which shows it (the blue wall at the top was from the reactor behind). So EDG are not on a platform as i imagined above...

http://www.netimago.com/image_200947.html

Can anyone locate the camera location on Google maps?

By the same token, I mentioned yesterday a report that a transmission tower tower had been collapsed by the quake : https://www.physicsforums.com/showthread.php?p=3305099#post3305099 : I would be glad for any picture showing the collapsed transmission tower, or for the location of that transmission tower on google maps.

 

[mamoru]

I would be glad if you could provide the links to these images.

http://www.tepco.co.jp/fukushima1-np/bi3916-j.html" (sort of vintage )

http://www.tepco.co.jp/fukushima1-np/b42403-j.html"

http://www.tepco.co.jp/fukushima1-np/b42615-j.html"

I think I gathered few others, but I'm not at home now.

I made some posts about F-1 with some image I took from Tepco material and some original work by myself (all in italian language).
The first post gives you the exact position of D/G in R3: click on the image to open the bigger one and look on the North side of the basement plan.

http://giappopazzie.blogspot.com/2011/05/post-tecnico-4-approfondimento-sulla.html"

http://giappopazzie.blogspot.com/2011/04/post-tecnico-no2-quanta-acqua-ci-sta.html"

http://giappopazzie.blogspot.com/2011/05/post-tecnico-4-approfondimento-sulla.html"

 

[Astronuc]

Can anyone locate the camera location on Google maps?

By the same token, I mentioned yesterday a report that a transmission tower tower had been collapsed by the quake : https://www.physicsforums.com/showthread.php?p=3305099#post3305099 : I would be glad for any picture showing the collapsed transmission tower, or for the location of that transmission tower on google maps.

The camera appears to be north of Unit 6.

 

[tsutsuji]

By the way The BLACK SMOKE at N°3 was first reported the 21 st of march at 3:55pm (japan time i guess) , so you were right, bt it seems that some was still reported the 23 st (not clear):

http://english.kyodonews.jp/news/2011/03/79925.html

To sum up, we have

a) "grayish smoke" at 3:55 PM on March 21st and

b) "black smoke" on March 23rd afternoon :

JAIF also said work at units 1, 2, 3 and 4 was suspended after black smoke rose from unit 3 yesterday afternoon. Work resumed at around 05:30 Japan time (21:30 on 23 March central European time)
http://www.worldnuclear.org/_news_database/rss_detail_features.cfm?objID=4A9D7859-1491-40DE-8802DB48852FA882

 

[KJones]

Yeah, that advice looks pretty good (and makes them look a lot more responsible than their Japanese counterparts), but this statement now (basically that 'we're packing up and heading home because everything's fine now') looks shockingly stupid and irresponsible, don't you think?

(And *unbelievably* badly timed.)

Off-topic responses to slightly off-topic comments: (1) This NHK article says the NRC is not continuing 24-hr monitoring of the situation, but is not removing its team from Japan. (2) The NRC is a separate federal agency from the Dept of Energy -- they are different organizations. Dr. Lyons is a DOE official rather than NRC, although I think he was previously an NRC commissioner. When the old AEC was split in the US, the NRC was set up to regulate and inspect (the safety watchdog, FWIW) while the DOE was given responsibility for R&D and promotion of nuclear power.

 

[bytepirate]

Can anyone locate the camera location on Google maps?

By the same token, I mentioned yesterday a report that a transmission tower tower had been collapsed by the quake : https://www.physicsforums.com/showthread.php?p=3305099#post3305099 : I would be glad for any picture showing the collapsed transmission tower, or for the location of that transmission tower on google maps.

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110516e20.pdf

 

[pdObq]

Notes concerning soil amplification:

Thanks for looking up all that information and clearing that up!

My naive first thought was that the softer soil might even act to damp the accelerations via dissipation like a piece of rubber, but apparently that's not how this works.

But surely the Japanese must have made some calculations concerning the safety of building nuclear plants on mudstone if that happens to be the case?

They certainly had done calculations, see that paper originally referred to by NancyNancy (see links in EDIT below), in which they compared simulation results with measured acceleration from unit 6 sensors during a smaller earthquake. Maybe someone also recognized the risks, but since the plant had already been built, they would probably try to hide that away from the public and from themselves.

So the Tepco site stating Bedrock is not lying by approximation, it's lying by using one word to describe something else.

Well, as ernal_student said before, maybe one should consult the original Japanese version before saying they were outright lying. Could be a translation issue. [sarcasm] And in some sense it's not totally untrue, "built on solid bedrock" could be interpreted as "there's bedrock somewhere below if you go deep enough".[/sarcasm]

EDIT: In this post I summarized the relevant content of the links NancyNancy provided (follow back the quotes): https://www.physicsforums.com/showthread.php?p=3291249#post3291249 . Here the direct link to the study again for convenience: http://www.iitk.ac.in/nicee/wcee/article/9_vol3_733.pdf .

PS: Regarding that discussion about "partially embedded". Looking back at that study again, from the context you can tell what they mean, and that is that from the ground level to the bottom of the building/concrete structure it's 17m. That's also how I had read it originally.

 

[jlduh]

Can anyone locate the camera location on Google maps?

By the same token, I mentioned yesterday a report that a transmission tower tower had been collapsed by the quake : https://www.physicsforums.com/showthread.php?p=3305099#post3305099 : I would be glad for any picture showing the collapsed transmission tower, or for the location of that transmission tower on google maps.

I've put the EDG building right in the middle of the screen, follow this link:


http://maps.google.com/maps?ftr=mis...37.430616,141.032771&spn=0.0023,0.006539&z=18

The camera was above this on the map (North), looking towards south/west direction, on the ground close to very end of the limit of the plant.

That's where they seem to have installed the big number of tanks that we see in the video. I imagine that these tanks are for storing the tons of "weakly contaminated water" that they are pumping out of the basements from N°5 and 6?

 

[rowmag]

very interesting data which confirms that mudstone can hardly been described as bedrock from seismic standpoint...

So the Tepco site stating Bedrock is not lying by approximation, it's lying by using one word to describe something else.

What site is that? Do you have link to the original Japanese?

 

[biffvernon]

very interesting data which confirms that mudstone can hardly been described as bedrock from seismic standpoint...

All this talk of mudstone and bedrock is quite meaningless until the material is better defined. I've no idea what the Japanese words were that got translated into English but mudstone is any rock that was once a fine grained sediment. It can be very hard and very strong. Bedrock is just what's below, under any recent superficial deposits. It can be very soft and very weak.

Using terms that aren't defined does not tell us much.

Different rocks alter both the frequency and the amplitude of earthquake waves. It's not simple.

 

[pdObq]

What site is that? Do you have link to the original Japanese?

rowmag, see this post for an earlier discussion of that and follow back the quotes (by clicking on the blue box with the white arrow, I am sure you know) to get to a link to the English website that states that.

https://www.physicsforums.com/showthread.php?p=3305982#post3305982

 

[jlduh]

What site is that? Do you have link to the original Japanese?

This is the english version:

http://www.tepco.co.jp/en/challenge/energy/nuclear/plants-e.html

I don't read japanese so it's difficult to find the japanese page for me, but the tree index for the english page is from main page "Challenges of Tepco" -> Nuclear -> Tepco power plants

Maybe this will help to find the page in japanese if the japanese site structure is the same (not sure!)

BUT: THERE IS A SECOND PLACE WHERE THEY MENTION THIS...

In the SAFETY SECTION of the site (you could try to find the japanese version):

http://www.tepco.co.jp/en/challenge/energy/nuclear/safety-e.html

Designed for the Largest Conceivable Earthquake
Before constructing a nuclear power plant, the site is carefully studied for previous earthquake records and geological features. This study establishes that there is no active fault under the site. Then, the building, the equipment, the piping, and other equipment are all designed to withstand the strongest possible earthquake in the area.

Hard-to-Shake Structure
Reactor buildings are built directly on solid bedrock after all soil has been removed. Furthermore, the reinforced concrete walls are far thicker than those used in other buildings. The building itself is a strong dice-like structure. Therefore, in the event of an earthquake, reactor buildings shake far less than an ordinary building.

They even add some illustrations, and to me these illustrations are self explanatory of what they mean, or would like to mean (and then translation is out of subject):

http://www.netimago.com/image_200971.html

 

[tsutsuji]

The camera appears to be north of Unit 6.

Thanks. I am happy to be able to locate this separate EDG building now on Google maps here on the north of reactor No 6.

Influenced by http://www.asahi.com/english/TKY201104060126.html I had on mind only two possibilities : EDG in turbine building basement in Daiichi or EDG in reactor building as in Daini, and the following sentence :

TEPCO documents show that the emergency diesel generators located in the turbine buildings at the Fukushima No. 1 plant were flooded by the tsunami and rendered inoperable, except for the one at the No. 6 reactor.
http://www.asahi.com/english/TKY201104060126.html

had wrongly made me imagine that the Emergency Diesel Generators were also in the basement of unit 6's turbine building.

the following paragraph :

“Most are located in generator rooms in basement 1 of the turbine buildings,” Arai said, pointing to a diagram in a Tepco brochure of the Dai-Ichi plant. The turbine buildings holding eight of the generators are about 140 meters from the seafront, another two generators were on the ground floor behind reactor 4, which was offline for maintenance. Three others were in and around reactor 6, which was also offline.
http://www.bloomberg.com/news/2011-04-25/japan-s-terrifying-day-saw-unprecedented-exposed-fuel-rods.html

was containing better information, but I read it very quickly only a few days ago after someone posted the link here, and I had failed to memorise the details.

I am happy to be able to locate the "around reactor 6" one(s). Comparing the shapes, I think it is also quite easy to recognise the "behind reactor 4" one on the Google maps aerial view.

...

Thanks.

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110516e20.pdf

That's great. Thanks.

Edit: I also found http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110516e19.pdf showing pictures of earthquake damages to various Tepco power lines. It includes elements of that same "Yonomori line".

 

[I_P]

I am a little wary of the rises that are shown far away from the plant on that date, simply because they may have been caused by changing weather conditions which sent stuff in direction of Tokyo.

So I tend to go by radiation dose measurements from the site itself, which also rise over the same period. Shame there are some gaps in such data during this time, although I suspect that was inevitable given site evacuations that these smoke events & higher readings caused.

The changes caused by weather are an order of magnitude smaller Steve. The rise on the 20th is an abrupt spike and then falls with a rate reminicient of isotope decay. Its a real shame that the perimeter monitoring network was not immediately re-established. The 'drive around with a counter out the window' technique doesn't provide a reliable picture of the releases.

 

[SteveElbows]

The changes caused by weather are an order of magnitude smaller Steve. The rise on the 20th is an abrupt spike and then falls with a rate reminicient of isotope decay. Its a real shame that the perimeter monitoring network was not immediately re-established. The 'drive around with a counter out the window' technique doesn't provide a reliable picture of the releases.

If you are talking about Tokyo readings, then no, I am not completely convinced that what we see at that time is caused by something other than wind taking stuff in the direction of Tokyo for perhaps the first time since the disaster, and it may also have been raining for the first time. I will have to go back and see if I have any weather data left from that period.

But in any case, the readings from the site itself spike on that date too, and I am not trying to attribute these higher site readings to the weather. So it does not matter too much whether I am right or wrong about the cause of readings from further away, we still know that something was going on in the period around 20th/21st->23rd March that caused higher radiation.

 

[PietKuip]

Then there is the tsunami where the sea reportedly receded leaving 300 feet of the sea floor exposed before the tsunami arrived. No intake for the water cooling system during that period.

Siting plants at higher levels would not help for that aspect of a tsunami. Are power plants designed to handle the lows?

The cooling inlets may fall dry for 15 minutes, due to distant earthquakes that would not scram the reactor. Can a reactor at full power survive that?

 

[rowmag]

This is the english version:

http://www.tepco.co.jp/en/challenge/energy/nuclear/plants-e.html

I don't read japanese so it's difficult to find the japanese page for me, but the tree index for the english page is from main page "Challenges of Tepco" -> Nuclear -> Tepco power plants

Maybe this will help to find the page in japanese if the japanese site structure is the same (not sure!)

Thanks jlduh, and pdObq. Unfortunately, as I think ernal_student noted once before, the Japanese TEPCO pages are all disaster-related now, and I didn't find the equivalent of the English page. Perhaps such PR material was taken down as being likely to incite anger under the circumstances.

 

[jlduh]

Thanks jlduh, and pdObq. Unfortunately, as I think ernal_student noted once before, the Japanese TEPCO pages are all disaster-related now, and I didn't find the equivalent of the English page. Perhaps such PR material was taken down as being likely to incite anger under the circumstances.

ROWMAG, read my updated post as I provide a second english link in the "safety" section:

https://www.physicsforums.com/showpost.php?p=3306751&postcount=7594

 

[jlduh]

As we talk about bedrock, i post this:

http://criticality.org/2011/04/japan-sinking-pacific/

see the very impressive animation showing all the aftershocks earthquakes lately:

http://www.youtube.com/watch?v=SjfWBnSeDik&feature=player_embedded#at=76

I post also this very interesting (and complex) study about seismic assessment of nuclear plants (unfortunately no Daichi data):

http://www.iter-consult.it/Meetings...P and experience feedback in Japan (JNES).pdf

See page 28: the graph shows that in automatic shutdown, the control rods have to be inserted while the building is shaked by the Earth quake of course (see the timing), and of course one risk could be that while shaking, the cross rods could not slide properly in between the fuel elements...

Of course they state it is not possible, but...

Page 18: about the fault N°2 (NCO) "At establishment permission, fault ②was estimated to be 7~8km (M<6.5) and non active fault". But it's now estimated 27～36km (36km for conservative evaluation)

 

[etudiant]

Siting plants at higher levels would not help for that aspect of a tsunami. Are power plants designed to handle the lows?

The cooling inlets may fall dry for 15 minutes, due to distant earthquakes that would not scram the reactor. Can a reactor at full power survive that?

Very interesting question.
The heat of vaporization is about 2000 joules/gram. So a 1 gigawatt plant at full cry would need to vaporize 3 gigajoules worth of water every second, or about 1.5 million grams of water, about 1.5 tons worth. The 15 minute dry spell would vaporize 1350 tons of water. That seems a manageable amount, about equal to the water quantity in SFP 4. No idea if the reactors are designed to have that much reserve capacity though.

 

[NUCENG]

Siting plants at higher levels would not help for that aspect of a tsunami. Are power plants designed to handle the lows?

The cooling inlets may fall dry for 15 minutes, due to distant earthquakes that would not scram the reactor. Can a reactor at full power survive that?

Yes. Assuming loss of offsite power. Diesels will be tripped if they try to satrt without cooling water which will protect them during the drawdown period. The high pressure DC systems can inject cooling water for long enough for the drawdown period. At Fukushima that is the isolation condenser at unit 1 and the RCIC and HPCI systems at the other plants. If the water returns and the diesels are undamaged from the tsunami they can be started and then the low pressure AC systems will also be available. The Fukushima event made this scenario impossible due to failure to protect safety systems from the tsunami or from flooding.

 

[pdObq]

http://www.tepco.co.jp/fukushima1-np/bi3916-j.html" (sort of vintage )

http://www.tepco.co.jp/fukushima1-np/b42403-j.html"

http://www.tepco.co.jp/fukushima1-np/b42615-j.html"

I think I gathered few others, but I'm not at home now.

I made some posts about F-1 with some image I took from Tepco material and some original work by myself (all in italian language).
The first post gives you the exact position of D/G in R3: click on the image to open the bigger one and look on the North side of the basement plan.

Wow, you have some very nice stuff on your site. Are you planning on an English version?

Regarding the EDGs, those things must weigh A LOT. It makes a lot of sense to put them as close to the ground as possible both from the engineering and the building cost point of view.

In general, I think they should try to distribute them as much as possible around the site (also elevation-wise if the terrain is appropriate - what if they had had at least one backup EDG located on the higher grounds behind?), and it should be possible to easily route power from any EDG to any unit in case of emergency.

Another option would be to put a small gas power plant into the vicinity (not only as backup but also regularly operating), but not too close.

But as those recent reports suggest, it wasn't necessarily the tsunami's fault...
Which makes me wonder if there is serious damage in other plants not affected by the tsunami that were reported in cold shut down early on?

 

[tsutsuji]

http://www.tepco.co.jp/fukushima1-np/bi3916-j.html" (sort of vintage )

http://www.tepco.co.jp/fukushima1-np/b42403-j.html"

http://www.tepco.co.jp/fukushima1-np/b42615-j.html"

thanks.

I made some posts about F-1 with some image I took from Tepco material and some original work by myself (all in italian language).
The first post gives you the exact position of D/G in R3: click on the image to open the bigger one and look on the North side of the basement plan.

http://giappopazzie.blogspot.com/2011/05/post-tecnico-4-approfondimento-sulla.html"

Sorry, I am lost. "click on the image" : which one ? Can you provide a direct link to this image ?

 

[jlduh]

Wow, you have some very nice stuff on your site. Are you planning on an English version?

Regarding the EDGs, those things must weigh A LOT. It makes a lot of sense to put them as close to the ground as possible both from the engineering and the building cost point of view.

In general, I think they should try to distribute them as much as possible around the site (also elevation-wise if the terrain is appropriate - what if they had had at least one backup EDG located on the higher grounds behind?), and it should be possible to easily route power from any EDG to any unit in case of emergency.

Another option would be to put a small gas power plant into the vicinity (not only as backup but also regularly operating), but not too close.

But as those recent reports suggest, it wasn't necessarily the tsunami's fault...
Which makes me wonder if there is serious damage in other plants not affected by the tsunami that were reported in cold shut down early on?

We know that Daini N°1 got problems just after events and that Tepco declared that they were "preparing for venting" (it finally did not happen). So here is one where we don't know clearly what happened.

And of course now there is the Hamaoka N°5 reactor with saltwater entering reactor during shutdown due to a leak. Is this leak related to earthquake, we don't know...

 

[mamoru]

thanks.



Sorry, I am lost. "click on the image" : which one ? Can you provide a direct link to this image ?

My bad, sorry... http://3.bp.blogspot.com/-JaxFid8Qo...Ako/t5TVRl5sb-4/s1600/R3++completa+small.jpg"

"Gruppo elettrogeno diesel" (Generating set) 3A and 3B in the upper part of the plan view on the left.

 

[tsutsuji]

Siting plants at higher levels would not help for that aspect of a tsunami. Are power plants designed to handle the lows?

The cooling inlets may fall dry for 15 minutes, due to distant earthquakes that would not scram the reactor. Can a reactor at full power survive that?

See IAEA/JNES/NIED Seminar on Nuclear Disaster & General Disaster Management against Tsunami and Earthquake, Tokyo, December 2007, “Safety Assessment and Disaster Management for Tsunami Hazards at Onagawa Nuclear Power Plant”, Y. Matsumoto, (Tohoku Epco, Japan) : http://www.jnes.go.jp/content/000015486.pdf page 10/14 showing a sort of underground tank / sump from which water is taken during a tsunami's low ebb.

See also:

attachment : section view of the turbine building and sea water circuits on page 10 of http://www.pref.fukushima.jp/nuclear/pdf_files/onhaisui-h19houkokusyo.pdf available from http://www.pref.fukushima.jp/nuclear/anzen/onhaisui.html

showing the same sort of design exists at Fukushima Daiichi.

...

thanks

 

[pdObq]

Interesting read about the great quake and land movement both horizontal and vertical at the http://ex-skf.blogspot.com/2011/05/fukushima-i-nuke-plant-ground-may-have.html"

I haven't read anything that said otherwise esp. parts of the island moving 8 feet to the east.

Interesting, thanks for sharing. That seems like very solid data, I mean it comes from the official "Japanse Geospatial Information Authority of Japan (GSI)" site after all (link from ex-skf's blog entry: http://www.gsi.go.jp/chibankansi/chikakukansi40005.html ).

And it comfirms what some people have mentioned on this forum based on the TEPCO webcam pictures.

Thinking of those pictures of that road and the pictures from the New Zealand quake, it's good that at least there was no crack and horizontal offset in the ground right through the site of the power plant.

 

[jlduh]

Concerning Tepco reassessment of seismic safety data which was required after the Kariwa plant event, read this Tepco communication for shareholders:

http://www.docstoc.com/docs/41609714/Creating-Disaster-resistant-Nuclear-Power-Stations

They say they did new geological surveys at Fukushima, they were due to June 2009 i think. But i can't find these studies.

They should be called something like "Fukushima Daiichi Units Geological Survey Seismic Safety Assessment"...

Maybe a japanese member could try to find this by googling some of these key words in japanese?

 

[mamoru]

Concerning Tepco reassessment of seismic safety data which was required after the Kariwa plant event, read this Tepco communication for shareholders:

http://www.docstoc.com/docs/41609714/Creating-Disaster-resistant-Nuclear-Power-Stations

They say they did new geological surveys at Fukushima, they were due to June 2009 i think. But i can't find these studies.

They should be called something like "Fukushima Daiichi Units Geological Survey Seismic Safety Assessment"

I think i downloaded some pdf document related to geological studies in F-1 weeks ago, they are in japanese and also shows the location where they bored some 300m below ground level around the npp, there are a lot of pages but i don't understand the subject and the my proficiency in the language is not that good.