Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[ottomane]

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~]

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]

I am traveling again; I hope to get back to my plots next week... All the best.

 

[StrangeBeauty]

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

[PLAIN]http://k.min.us/iwCuA.JPG[/QUOTE]

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?

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-com/release/11051503-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]

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/world/asia/14plume.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/articles/2011/mar/mar13_C7F_reposition.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-reagan-fought-contamination-amid-effort-aid-20110325-052432-393.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]

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]

http://www.tepco.co.jp/en/press/corp-com/release/11051503-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]

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]

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]

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]

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]

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/files/en20110315-1.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.

 

[Bandit127]

http://www.tepco.co.jp/en/press/corp-com/release/11051503-e.html

Where is all that water going by the way?

At least some of it is turning to steam. Unit 3 has been above 100°C, but at atomospheric pressure for weeks. Water is either going straight through or turning to steam (probably both), but it simply cannot be in the RPV if the temperature and pressure data are to be believed.

I suggest that Tepco are trying to turn a gas cooled reactor vessel back into a water cooled one. With some limited success, looking at the tempertaure trends from 15th/16th May.

 

[ihatelies]

In my opinion the explosion of #3 from the spent fuel pool is much worse for Japan and the rest of the world than if the explosion occurred in the reactor itself.

So, many here have jumped on me about my theory that the explosion of #3 came from the reactor containment. Some argued that is not possible, and that it must have come from the spent fuel pool of #3. Arnie Gunderson thinks the explosion is from the spent fuel pool of #3.

I believe if the explosion came from the spent fuel pool of particularly #3 , but possibly others, it's way worse, and I hope that is not the case.


First, we acknowledge that in both the reactor and the spent fuel has plutonium in it. The plutonium comes from two sources: First it comes as a by product of the fission reaction in the reactor. I don't think that plutonium is a great risk, because the molecules are interspersed in the rod fuel. In a complete catastrophic explosion, it would not travel far from the reactor.

The second source of plutonium is the mixing of finely ground (nanometer) plutonium powder with the uranium in the new fuel rods that were placed into the #3 reactor in August. Alternatively known as MOX fuel, they mix between 6% and 15% plutonium powder in. I believe the Fukushima rods were somewhere in the lower half of this range.

During manufacture, the powder is "sintered" into pellets. What is unclear in everything I have read is whether the sintering melts the powder into solid metal pellets, or whether it simply binds the material into a pellet, but the powder still remains on the inside. Given my knowledge of powder metallurgy it takes a lot of heat and pressure to render powder into solid metal, and I suspect they would not subject the plutonium to enough to completely bind it, for fear of a reaction during manufacturing.

Once the rods are brought to operating temperature in the reactor core, my guess is they reach a high enough temperature to bind the powder completely. I haven't found anything specific on this topic, so if it's been discussed here, or someone can point me to it, then I apologize in advance. If my guess is correct, then even if the reactor core exploded, it would not pose a very widespread damage to the environment - from plutonium at least - because the bound plutonium would be released in relatively large chunks.

However there exists the possibility that new plutonium enriched rods were waiting in the spent fuel pools to be loaded. If my analysis above is correct, these rods would not have their plutonium bound yet, and in the case of an explosion, the nanometer powder could be released.

I guess this is more of a set of questions for discussion rather than a statement. My question would be this: 1. Does anyone know if the plutonium powder is bound into solid metal during the sintering process? 2. Did any of the spent fuel pool contain plutonium enriched rods ready to be loaded? and 3. If so, is this a danger if the #3 spent fuel blew up rather than the reactor?

Again, pardon my ignorance if this has already been discussed thoroughly.

 

[ihatelies]

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.

Yes, it's like truck bedliner material, except thicker. There are also clip rings for chains, and all kinds of other things all over the deck. washdown is normal.

I don't think they scrub it with brushes and soap very often - I can't remember, but it's more than an acre of deckspace.

 

[zapperzero]

1. Does anyone know if the plutonium powder is bound into solid metal during the sintering process? 2. Did any of the spent fuel pool contain plutonium enriched rods ready to be loaded? and 3. If so, is this a danger if the #3 spent fuel blew up rather than the reactor?

Again, pardon my ignorance if this has already been discussed thoroughly.

It has indeed. Read, man, read!
1. http://tinyurl.com/3eh3rku
2. No. Also, see http://tinyurl.com/4xwp93t
3. Blew up, as in went prompt critical?

 

[rowmag]

I think you are referring to page 1 of this:

https://www.physicsforums.com/newreply.php?do=newreply&p=3310549

That caught my eye at first too, but then I looked at the following:

http://www.tepco.co.jp/nu/fukushima-np/plant-data/f1_2_Chart3.pdf

If you look at pages 3 and 4, you can see what looks like the same
behavior being recorded by a different sensor (?) on a paper strip
chart that has been scanned in. There are two scales at the bottom,
which differ in both offset and scale factor:

原子炉水位 (広帯域) [mm] = Reactor water level (wideband) [mm]
and
原子炉水位 (燃料域) [mm] = Reactor water level (fuel region) [mm]
[...]

My comment was based on the first page of:
http://www.tepco.co.jp/nu/fukushima-np/plant-data/f1_6_Katogensho3.pdf

Oops, cut-and-paste error on my part. That was the link I meant to refer at the beginning of my post.

Thanks for information. And thanks MiceAndMen for the Rosetta Stone, from which we can conclude that "(N/R)" means "Narrow Range" and "(W/R)" means "Wide Range" on page 1 of these plots:

http://www.tepco.co.jp/nu/fukushima-np/plant-data/f1_6_Katogensho3.pdf

And that Wide Range and Fuel Zone Range are what are indicated on pages 3 and 4 of these plots:

http://www.tepco.co.jp/nu/fukushima-np/plant-data/f1_2_Chart3.pdf

 

[mscharisma]

... 2. Did any of the spent fuel pool contain plutonium enriched rods ready to be loaded? ...

The attached document claims on page 4 there were new fuel rods in the spent fuel pool of #3 as well but, unless I overlooked something, does not address plutonium enrichment.

Edit: sorry, can't get upload to work. Please see attachment to post # 7552.

 

[tsutsuji]

http://www.tokyo-np.co.jp/article/national/news/CK2011052002000194.html?ref=rank includes a diagram showing the inlet canal repairs being planned. That part needing repair was damaged by the tsunami.

Together with the planned works to contain water leaks around buildings, this will provide a two-fold containment of the water leaks.

They say that the upcoming rainy season (the so-called "tsuyu" rain falling in June and July : see http://www.japan-guide.com/e/e2277.html) is also a worry, but my feeling is that these works will take time, so that the rainy season might be over when the works are finished.

 

[Ms Music]

So, many here have jumped on me about my theory that the explosion of #3 came from the reactor containment. Some argued that is not possible,

You must be confusing this forum with another. Most here, including one of the nuclear experts (Astronuc), agrees that it appears the explosion may have originated in the containment area.

Where we don't agree with you is when you insist the pressure vessel squirted out like a hotdog, somehow managed its way around the overhead crane support (whatever it is called), up through your hole in the roof, and then vanished.

 

[zapperzero]

http://www.tokyo-np.co.jp/article/national/news/CK2011052002000194.html?ref=rank
Together with the planned works to contain water leaks around buildings, this will provide a two-fold containment of the water leaks.

I wonder what happens if they manage to plug the leaks and the water reaches ground level inside the reactor buildings because they aren't pumping it out fast enough. I don't see them establishing loop cooling. Not while they have no idea which RPVs are leaking and how.

 

[SteveElbows]

The live video feed seems to be showing the Megafloat making its journey to the nuclear plant at the moment.

 

[zapperzero]

The live video feed seems to be showing the Megafloat making its journey to the nuclear plant at the moment.

Pics or it didn't happen.
EDIT: It's there allright. Pea soup also. :P

 

[imandylite]

[PLAIN]http://img17.imageshack.us/img17/8203/megafloat.jpg

Megafloat in process

from the livefeed

http://www.youtube.com/user/tbsnewsi?feature=feedlss#p/l/-ZPYlazljME"

 

[etudiant]

The live video feed seems to be showing the Megafloat making its journey to the nuclear plant at the moment.

With 10,000 ton capacity, versus about 100,000 tons of highly radioactive water currently in the plant, increasing by 500 plus tons/day, we can only hope TEPCO has more Megafloats on order.
Afaik, the water treatment plant from Areva will sharply reduce the radioactivity of the treated water, but it will still be 1000-10,000 times the prior limit for ocean discharge. So the site will need a huge amount of storage until TEPCO figures out how to clean the water further, or the government will have to waive the rules.
Given the level of outflow to date, that would probably add little incremental contamination.

 

[Gary7]

You are incorrect.

I fully understand and have never disputed the article's byline. I do not know the exact time it was published. Let us assume you are correct, and that it was published at 11:15pm on the 13th (EST). This means the article was published at Japan time of 1:14pm on the 14th. This was just two hours after Unit #3 exploded.

The assertion that a helicopter flew from Daiichi to the USS Ronald Reagan, and that the ship took evasive action for two hours (as quoted by the crew member), and that this information was released in time for the New York Times to publish the article two hours after the explosion, is, frankly, quite hard to believe. Then, when the AP reported all of this happening on Sunday the 13th "two days after the earthquake", we have to believe they really mean it all happened on Monday the 14th (three days after the earthquake), but that they are converting a portion of the time for the benefit of readers in the US (and to the confusion of readers everywhere else in the world).

Furthermore, we would have to believe the NYT actually referenced a press release posted earlier by the Pacific Fleet, despite no such reference being made. Bear in mind if the NYT actually did reference the Pacific Fleet's press announcement, it means the Pacific Fleet had even less than two hours to produce this announcement.

I have no personal interest in deleting anyone's posts; they all stand or sink on their own merits. I do not believe the movings of the USS Ronald Reagan are particularly germaine to the meltdown(s). I suppose I would also say that I am somewhat disappointed that the very high standards of discussion on this forum have been slightly compromised by the continued musings of a certain conspiracy theorist, but this is a personal opinion.

 

[Atomfritz]

With 10,000 ton capacity, versus about 100,000 tons of highly radioactive water currently in the plant, increasing by 500 plus tons/day, we can only hope TEPCO has more Megafloats on order.
Afaik, the water treatment plant from Areva will sharply reduce the radioactivity of the treated water, but it will still be 1000-10,000 times the prior limit for ocean discharge. So the site will need a huge amount of storage until TEPCO figures out how to clean the water further, or the government will have to waive the rules.
Given the level of outflow to date, that would probably add little incremental contamination.

Maybe the megafloat's purpose is just to take up 10k tons of water, being pulled out to the ocean, then emptied, towed back and so on?

In case of storage tank capacity problems Tepco would probably be happy to be "forced" to get rid of the lesser radiocative waters in the ocean, somewhat distant to the coast, to make room for new highly contaminated effluents.

I hope I am wrong...

 

[Luca Bevil]

Maybe the megafloat's purpose is just to take up 10k tons of water, being pulled out to the ocean, then emptied, towed back and so on?

In case of storage tank capacity problems Tepco would probably be happy to be "forced" to get rid of the lesser radiocative waters in the ocean, somewhat distant to the coast, to make room for new highly contaminated effluents.

I hope I am wrong...

That would not b epoliticaly acceptable.

I remember watching Arnie Gundersen say that a decontamination on such a scale (as per amount of water processed, I think) has never been attempted before.

Does anyone have any idea about what tha capabilities of the AREVA plant could be ?

Both in terms of hourly flow treated and performance in contamination removal ?

 

[Atomfritz]

5 Tons of Seawater Has Entered Hamaoka N-Plant Reactor Core

Nagoya, May 19 (Jiji Press)--Chubu Electric Power Co. <9502> officials said Thursday about 5 tons of seawater is estimated to have entered a reactor core at the company's Hamaoka nuclear power plant in central Japan.
During work to shut down the No. 5 reactor in accordance with a government request, Chubu Electric found an estimated 400 tons of seawater has flooded into the main steam condenser.
In addition, the firm's assessment of the purity of water inside the reactor's pressure vessel, which contains nuclear fuel, showed some 5 tons of seawater came from the condenser, the officials said.
Water that circulates through the vessel should not be salty but fresh, because salt causes corrosion.
The steam condenser, designed to convert waste steam from a power-generation turbine into water, has some 64,000 tubes, each 3 centimeters in diameter, in which seawater is injected to cool the steam. Normally, the steam-converted pure water never has direct contact with the seawater running through the tubes, the officials said.

(2011/05/19-18:46)

http://jen.jiji.com/jc/eng?g=eco&k=2011051900816

This is strange.
Wasn't the plant shut down on government request?

I am no expert, but i think this should have been detected by the water purity systems?!?
In the Soviet Union it was regular to have reactors shut down to weld damaged condenser pipes when leaks were developing.

Maybe they are running their plants even if seawater is leaking in, to avoid even more electric shortages?

(I think small leaks, leading to only trace impurities that can be remedied by water purity systems could be unproblematic, and be repaired at the next scheduled refuelling outage. But I may be wrong)

Hope some nuclear expert can comment on the things happened in Hamaoka.

Does anyone have any idea about what tha capabilities of the AREVA plant could be ?

Both in terms of hourly flow treated and performance in contamination removal ?

I remember a number about 3.5 cubic meters a day, but I am not sure if it was data from this decontamination plant or another one. I think I read it in a powerpoint presentation.

 

[etudiant]

The Areva plant was listed as having a 1200 ton/day capacity, reducing the radioactivity of the processed water by up to 99.99%, Presumably this means that if the incoming water is contaminated to 1 million times the allowable level, it will deliver output at about 100 to 1000 times the allowed amount.

Afaik, the plant works by precipitating out the contaminants, rather than by absorption or filtering, so there will be a quantity of radioactive residue to be managed.
Japan is also getting a shipboard waste water treatment they built for the Russians back from them,
but this has only 7000 tons/yr capacity and is designed to handle low level contaminated liquid.