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Japan Earthquake: nuclear plants

by gmax137
Tags: earthquake, japan, nuclear
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AntonL
#7867
May20-11, 07:37 AM
P: 521
Quote Quote by jlduh View Post
Yes this statement is very clear apparently: melting of pellets in 1,2,3 AND 4...

They must state that kind of things with some evidence on hand.
Guys, don't always analyse word for word and draw conclusion from English press releases. Get a proper English translation from the Japanese text. Furthermore, the subject of the press release is that 1 to 4 will get decommissioned 7&8 shelved and NOT on damage or fault analysis.
westfield
#7868
May20-11, 08:06 AM
P: 145
Quote Quote by jlduh View Post
Just for your information, and as i found this point very important, i just sent a mail to the author of this interview to try to clarify this sentence:

"TEPCO's civil engineering group estimates the maximum tsunami risk and maximum earthquake risk for each power plant site. I was informed the maximum tsunami at the Fukushima Dai-1 site might be 10 meters".

as it was declared in this interview.

By the way, what he is saying in this interview is somewhat different than what he declared a few weeks ago here, saying: "When I was in charge, the thought of a
tsunami never crossed my mind."

http://thescotsman.scotsman.com/worl...ami.6741474.jp

Of interest in this second article, this extract with obviously one mistake:



18.7 ft is 5.7m for the max projected tsunami so it's consistent with Tepco study.

But "13 ft high land on which it stands" is non sense as the platform is 10m high...
I'm only guessing of course but perhaps they are referring to the lowest point on the site where the intake infrastructure, some diesel tanks and some other buildings are located which is indicated as O.P. 4000 (Just over 13')

- edit - wow, that seems quite low. If it didn't have the sea-wall there even a big ocean swell would threaten that elevation.

westfield
#7869
May20-11, 08:46 AM
P: 145
Quote Quote by elektrownik View Post
Interesting that they do not rule out restarting Units 5 & 6 in that statement.
AntonL
#7870
May20-11, 09:54 AM
P: 521
Quote Quote by http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110520e10.pdf
-From 2:15 pm, May 20th, we changed the amount of water injected to the
reactor pressure vessel of Unit 3 by the feed water system from 9m3/h to 12m3/h.
and remembering that 9m3/h is also supplied through the reactor fire extiguishing system making a total 21m3/h

Unit 3 seems to be worrying Tepco more than they wish to admit right now

jpquantin
#7871
May20-11, 10:14 AM
P: 33
Quote Quote by zapperzero View Post
We may have the evidence ourselves. The fuel in SFP #4 (from the first movie) looked damaged to me, some bails seemed to be missing.
Can you point on SFP4 images where you see damages? Would be interesting to share.
mscharisma
#7872
May20-11, 10:17 AM
P: 82
Quote Quote by NUCENG View Post
...
The first is the elevation (above sea level).
The second is AVZ (Above vessel zero) which measures from the bottom inside of the RPV
The third is TAF which sets 0 at the Top of Actve Fuel.
The fourth is AIZ (Abave Instrumrnt Zero) which basically references level (positive and negative) from the midpoint between the top 2 instrument taps.

The human factors lessoned learned after TMI2i ncluded control room modifications to use one reference. However some plants picked a different one.
...
Forgive me if this is nonsense, but NISA has always reported water levels from TAF (starting March 14). Would that be an indication that TAF is the zero point?

http://www.nisa.meti.go.jp/english/f...20110315-1.pdf
ottomane
#7873
May20-11, 10:50 AM
P: 15
According to the graph above we finally have ice inside of R3.

The data seems to be really trustworthy.

Nevertheless, I don't understand why they increase the cooling effort while temps are falling. What do they know?
~kujala~
#7874
May20-11, 10:57 AM
P: 110
Quote Quote by jpquantin View Post
Can you point on SFP4 images where you see damages? Would be interesting to share.
Hello jpquantin,
As you have calculated the loss rates of SFP 4 is it possible that the SFP 4 at some point has overflowed?
When they spray water over the SFP is there any mechanism that prevents it from overflowing except "let's stop the pumps"?
Jorge Stolfi
#7875
May20-11, 11:28 AM
P: 279
I am traveling again; I hope to get back to my plots next week... All the best.
StrangeBeauty
#7876
May20-11, 11:29 AM
P: 61
Quote Quote by AntonL View Post
and remembering that 9m3/h is also supplied through the reactor fire extiguishing system making a total 21m3/h

Unit 3 seems to be worrying Tepco more than they wish to admit right now

Quote Quote by ottomane View Post
According to the graph above we finally have ice inside of R3.

The data seems to be really trustworthy.

Nevertheless, I don't understand why they increase the cooling effort while temps are falling. What do they know?
Quote Quote by tepco
At 2:33 pm on May 15, we started injecting boric acid through the fire extinction system.
http://www.tepco.co.jp/en/press/corp...1051503-e.html

Temps start to go down, without increasing flow rate, after adding boric acid starting on the 15th. Is there another scenario besides renewed criticality which makes sense here? (ok, yes, the sensors themselves are all suspect ;)

It is interesting that they continue to increase water injection at this point. Sensor #2 is the only one that went up recently. #6 is not going down much at this point.

Where is all that water going by the way?
ihatelies
#7877
May20-11, 11:47 AM
P: 45
Quote Quote by Gary7 View Post
The article I linked to earlier clearly states the decontamination occurred on Sunday, two days after the earthquake. Also, the New York Times reported on Sunday March 13th that USS Ronald Reagan encountered radiation. If the events on the USS Ronald Reagan transpired a few hours after the explosion of #3, the New York Times could not have reported on this on the 13th.

http://www.nytimes.com/2011/03/14/wo...lume.html?_r=1

To put this in even finer detail: The explosion at #3 occurred at about 11:01 am on Monday the 14th (Japan time). This would be 9:00pm on the night of the 13th, EST. Given the time it takes for the helicopter to travel to the aircraft carrier, get decontaminated, and then for the aircraft carrier to reposition itself, and then for that information to get to the reporter, and to have him write the copy and send it to the editors for publishing, it would seem that the only way the New York Times could have reported on this on the 13th would be if they were in possession of a time machine.

Since I think this is of some relevance to the explosion at #3, I have invested a bit of time in the details. However, since it has very little value in helping understand the physics of the event, I will be more than happy if the moderators see fit to delete any and all discussion of the so-called "ballistic radiation levels" and "contaminated food and water" of the USS Ronald Reagan.
You are incorrect.

Read the article from the NYT it says clearly it was written and published online the 13th and published in the paper the 14th of March.

Look here at the Navy announcement referenced in the NYT article:

http://www.cpf.navy.mil/media/news/a...position.shtml

It is dated the 14th of March - because that was the local date. The way the NYT was able to reference an article that was published a day later is that they wrote it the night before.

The NYT issued that article on the 13th of March at 11:15 pm which is their normal news deadline for the following day publication.

In these days of tweets, it doesn't take long for the news of something to get out. At that particular time, all eyes in the world were on the effects of the earthquake/Tsunami and the beginning of the reactor crisis. I was watching this happen, real time. The Navy can issue a press report directly from the ship - no "time machine" needed.

The logs would tell that the Reagan experienced the problem shortly after the explosion of #3 and turned and went the other direction. First post of it on this thread is number 93 at 1:45 pm Eastern on the 14th.

And, it has very much value in understanding the physics of the event. There was a cloud of radioactive material that caused an aircraft carrier to abandon its mission and take on another. We need to know what was in that cloud, because that will tell you what happened a few hours earlier, and it will tell you what hit the west coast of North America 4 days later.

Furthermore, despite your wanting to delete all evidence of my posts. The quote about contaminated air and water supplies on the ship comes directly from the articles posted above.
http://ca.news.yahoo.com/uss-ronald-...52432-393.html

Quotes from the article reveal that air and water contamination was detected. What they do not say is what kind of particles caused the problem - but they do say "low level radiation" several times, although their actions do not coincide with that assessment:

"The level of contamination in the air made it difficult to conduct accurate checks on people, so Powell took over the ship's barber shop — a poorly ventilated space that protected the air inside and kept the contamination level low enough to conduct accurate "frisks," or tests.

Meanwhile, the ship itself was taking evasive action, trying to move out of the area of the radioactive plume. After about two hours, it succeeded, Powell said.
"And then after that, we just started checking out the helicopters, checking out all the people, put them all in this little tiny room," he said. "It was kind of scary."
...
"At one point, the carrier's commanding officer announced that there was some radiation in the ship's drinking water supply, and "I know everybody went down to the vending machines to grab (a) bottle of water," Duke said."
...
"Cmdr. Ron Rutan, the Reagan's chief engineer who supervised the swabbing of the deck and other surface areas, said such a cleanup was unprecedented.
"I don't know of any aircraft carrier that's ever been contaminated like this," he said."
Here's a picture of them washing down the deck of the carrier - looks to me like more than just a simple rinse off of a couple helicopters.



I clearly said that the "ballistic" comment was from a blog that I can no longer locate - you can take that one with a grain of salt if you want.
etudiant
#7878
May20-11, 12:05 PM
PF Gold
P: 858
The Reagan clearly got indications of more than just an inconsequential amount of contamination, at least imho.
The people who really got exposure, whose experience caused the carrier to alter course, were the crew of the helicopter that went close to the plant. They got the intense scrubbing, as did their machine.
It was interesting that the press release said none of the ship crew was exposed to significant radiation.
That leaves the air crew exposure open, at least afaik.
zapperzero
#7879
May20-11, 12:16 PM
P: 1,042
Quote Quote by StrangeBeauty View Post
http://www.tepco.co.jp/en/press/corp...1051503-e.html
It is interesting that they continue to increase water injection at this point. Sensor #2 is the only one that went up recently. #6 is not going down much at this point.

Where is all that water going by the way?
Sensor #2 is RPV bottom head. You do not want it to go up. That's where the fuel is, in the best-case scenario. Water is going out of the RPV and into the basement. How does it get there?
zapperzero
#7880
May20-11, 12:21 PM
P: 1,042
I think summer forest camouflage for an aircraft carrier crew is comedy gold.

But I also wonder, if the deck was heavily contaminated, why aren't those guys at least wearing plastic bags on their feet ala TEPCO electrician crews? Respirators? They each have one, it's part of their firefighting equipment.

Maybe it wasn't that bad after all?
tsutsuji
#7881
May20-11, 12:21 PM
PF Gold
P: 1,220
http://www.47news.jp/CN/201105/CN2011051801000828.html (referring to 2011/05/18 Kyodo news) tells the story of the failed venting attempts at unit 2, based on a report sent to Tepco-related persons :

On March 13th 11 AM two valves were opened, but the pressure did not come down and no rise of radiation was monitored in the environment.

On March 15th 00:02 AM two different valves on another system were opened, but the pressure did not come down.

The rupture disks are supposed to break at 5.3 atmospheres. The containment pressure was 3.8 atmospheres on the first attempt, and 7.4 on the second attempt.

Batteries are required to keep the valves open, and it is feared that the battery power ran out.

The explosion took place at 6:10 AM on March 15th.

The article concludes saying that Tepco is investigating the causes of the venting failures and the connection with the suppression pool damage.
ihatelies
#7882
May20-11, 12:38 PM
P: 45
Quote Quote by zapperzero View Post
I think summer forest camouflage for an aircraft carrier crew is comedy gold.

But I also wonder, if the deck was heavily contaminated, why aren't those guys at least wearing plastic bags on their feet ala TEPCO electrician crews? Respirators? They each have one, it's part of their firefighting equipment.

Maybe it wasn't that bad after all?
I wondered that too.

The picture is obviously carefully staged for the photographer, but I'm surprised if they took off gear for a picture.

The only thing we have to go on as far as how bad it was is what they said and what they did.

Like all the other mysteries in this series of events, if they would simply release the data they have of what was in the cloud, then the smart folks here could likely interpret what happened - but for some reason they have chosen not to do that, or at least I haven't seen it.
etudiant
#7883
May20-11, 12:46 PM
PF Gold
P: 858
Aircraft carrier decks are covered with an anti skid compound.
It is almost ideal for trapping crud, whether radioactive or not. So the crew gets lots of experience cleaning the deck. This is probably the first time in Navy history that a deck cleanup made the news.
NUCENG
#7884
May20-11, 12:52 PM
Sci Advisor
P: 916
Quote Quote by mscharisma View Post
Forgive me if this is nonsense, but NISA has always reported water levels from TAF (starting March 14). Would that be an indication that TAF is the zero point?

http://www.nisa.meti.go.jp/english/f...20110315-1.pdf
It isn't nonsense. Not to make excuses, but that is probably why I jumped to the conclusion that the graphs were referenced to TAF. But looking at the vessel size and typical layout as pointed out here the graphs only make sense if they are based on AIZ instrument zero. The fact that NISA is using a different reference also makes sense since their priority is core uncovery. But it points out why this was a lesson to be learned from TMI2. Unless you are clear about the units you are using you can create confusion and confusion creates mistakes.


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