Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[TCups]

If that's the case, does that mean the void in front of the gate (ie closer to the camera) in that image is the SFP, which appears empty in the frames prior to your screengrab?

"Ding, ding, ding"

Yes! -- at least the top of the SFP appears empty. What is down there 10 meters deep, I can't say. But it appears that the steam is coming from a jet on this video and earlier videos, and that jet seems to be from the side of the SFP near the region of where the gate would be. And whatever the structure is in the screen shot, it "appears" to be a slot-like channel in the upper end of the north side of the SFP of 3 with, perhaps a slab-like gate.

Maybe there are other interpretations.

 

[curious11]

"Ding, ding, ding"

Yes! -- at least the top of the SFP appears empty.

For clarity : the view here is the same orientation as the heli-cam, so the suggestion is that the pool at the bottom of the image is now empty, and partially open to the east side of the building?

[PLAIN]http://i.min.us/jjU8wO.jpg

 

[timeasterday]

"Ding, ding, ding"

Yes! -- at least the top of the SFP appears empty.

So is that some sort of structural beam running across the screen image just above gate? Something that came down from the ceiling?

 

[TCups]

a better picture of the operating floor (I added a few comments)
[PLAIN]http://i.min.us/jjU8wO.jpg[/QUOTE]

Fred:

The SFP at units 3 and 4 is on the southeast corner with the exposed (outside) wall of the SFP to the south and the reactor side of the SFP to the north.

 

[Gilles]

If the core did achieve criticality, I would expect pressure spikes as the water boiled to steam. I don't think we've seen any evidence of that.

a possible scenario (sorry I'm not an expert in nuclear reactors, I just try to imagine reasonable conditions ) : control bars have been damaged at least at the top of fuel assemblies, due to very high temperatures and/or chemical reaction with steam, and have been partially destroyed. The top of fuel rods can become critical when they're bathed with liquid water, the boron concentration being too low to absorb neutrons. Some kind of self-regulation occurs, when liquid water is above the top of damaged bars, nuclear fission can start periodically - it then produces much more heat that vaporizes the water and the water level decreases, until the system becomes sub-critical, and steam recondensates. The period and amplitudes of oscillations are such that the whole thermal and pressure inertia is enough to smooth the variations, acting like a low-pass filter. Is it conceivable ?

 

[artax]

interesting pictures.
http://allthingsnuclear.org/

poor guys!

and more on the workers in the plant here:-

http://www.telegraph.co.uk/news/wor...nami-Fukushima-Fifty-the-first-interview.html

 

[jlduh]

BEWARE concerning the picture you posted FRED on the internal top floor layout: This is a picture i previously posted here i think three days ago (i did only a print screen capture of the video of Mr Tanaka's conference) and i mentionned that IT WAS PRESENTED BY TANAKA AS THE INTERIOR OF TOP FLOOR OF REACTOR N°6 WHICH IS A DIFFERENT GENERATION OF BWR REACTOR (i mentionned that the building is square from the top, the other ones 1 to 5 are rectangular). He presented this because he wanted to show the various parts of a reactor fully opened with the reactor's cover, the containement vessel's cover and the pool. But the actual layout and position from a geographical standpoint are probably different in reactors 1 to 5.

So this picture can be misleading if used to describe damaged reactors.

I didn't find until now actual pictures of the damaged reactors previously taken before the accident.

 

[ivars]

http://www.reuters.com/article/2011/03/28/uk-nuclear-japan-massachusetts-idUSLNE72R01I20110328"

 

[TCups]

BEWARE concerning the picture you posted FRED on the internal top floor layout: This is a picture i previously posted here i think three days ago (i did only a print screen capture of the video of Mr Tanaka's conference) and i mentionned that IT WAS PRESENTED BY TANAKA AS THE INTERIOR OF TOP FLOOR OF REACTOR N°6 WHICH IS A DIFFERENT GENERATION OF BWR REACTOR (i mentionned that the building is square from the top, the other ones 1 to 5 are rectangular). He presented this because he wanted to show the various parts of a reactor fully opened with the reactor's cover, the containement vessel's cover and the pool. But the actual layout and position from a geographical standpoint are probably different in reactors 1 to 5.

So this picture can be misleading if used to describe damaged reactors.

I didn't find until now actual pictures of the damaged reactors previously taken before the accident.

Understand that they are different reactors, yes. But the general layout of the SFP relative to the RV's primary containment and the lift shaft appear to be quite similar. If so, as postulated before, the steam seems to vent from the general region of the transfer chute gate.

 

[dave2004]

Data plots

I just stumbled upon someone who plotted various variables over time for reactors 1,2, and 3 (pressures, water levels,...), this might be helpful to understand how things evolve in the reactors:

http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/v6/Main.html

 

[Bodge]

Someone has plotted all the reactor data 12-27th March onto 3 graphs:

http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/v6/Main.html

edit: lol - see above post. I would love to see data from the past 48hrs too.

 

[TCups]

Someone has plotted all the reactor data 12-27th March onto 3 graphs:

http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/v6/Main.html

edit: lol - see above post. I would love to see data from the past 48hrs too.

Duh! Does it not seem reasonable that there would be a protocol for data acquisition and data reporting after any nuclear power plant accident that would be standardized?

 

[|Fred]

I did specify that it was not a picture from unit 1-4 it is a picture of the 6th pictured here
http://www.stufftotweet.com/tweetthis/wp-content/plugins/wp-o-matic/cache/c357f_Units_5_and_6_March_16_2011_annotated_copy_thumb.jpg

The building has a different orientation reason why South North on the wall are not in the right place in respect of unit 1-5.
Tanaka did said that the layout of the operating floor was the same (he toke part in the design of unit 4)
(for the time being and until provided with better information I'm taking his word for it , The documents from oyster creek do not give us better information as we now know that despite what has been done in infography in the media, the Fukushima reactors do not use a Mark-1 but an "improved" Mark-1 with a different Containment vessel for ex)

 

[jlduh]

I wanted to mention some important details in the last french IRSN report from this morning (source: http://www.irsn.fr/FR/Actualites_presse/Actualites/Pages/201103_situation_au_japon.aspx#1 ).

They are giving infos on the levels of water found in the basement of reactor n°2 and N°3, and the levels are much higher than what i have seen reported so far. They are talking about 1 m of water in the basement of turbine building at N°2 and 1,5m in the basement of turbine building at N°3! Until now i was staying with numbers like 15 or 30 cms of water in N°3 (when the 3 workers were injured walking in this water)...

Does it mean that this level has dramatically increased in between?

Something else, IRSN is reporting that they found also contaminated water in several "wells" outside of buildings of reactors N°2 and 3.

I see that has been reported (in other recent sources) contaminated water in a trench outside of these reactors, maybe is it the same info or a related info.

 

[Joe Neubarth]

a possible scenario (sorry I'm not an expert in nuclear reactors, I just try to imagine reasonable conditions ) : control bars have been damaged at least at the top of fuel assemblies, due to very high temperatures and/or chemical reaction with steam, and have been partially destroyed. The top of fuel rods can become critical when they're bathed with liquid water, the boron concentration being too low to absorb neutrons. Some kind of self-regulation occurs, when liquid water is above the top of damaged bars, nuclear fission can start periodically - it then produces much more heat that vaporizes the water and the water level decreases, until the system becomes sub-critical, and steam recondensates. The period and amplitudes of oscillations are such that the whole thermal and pressure inertia is enough to smooth the variations, acting like a low-pass filter. Is it conceivable ?

The answer to that (as you described it) is no.

 

[havemercy]

US 7th flotte is sending fresh water to FUkushima (2'000 m3) :

the question is, how long do you thing, this fresh water will last given the need of water to cool down the reactors and the pools ?

YOKOSUKA, Japan - Commander, Fleet Activities Yokosuka (CFAY) began transferring fresh water to two fuel barges, which will be used to support cooling efforts at the Fukushima Daiichi nuclear power plant March 25.



YOKOSUKA, Japan (March 25, 2011) – Barge YOGN-115, carrying 1.04 million litres (275,000 gallons) of fresh water, departs Commander, Fleet Activities Yokosuka (CFAY) to support cooling efforts at the Fukushima Daiichi nuclear power plant. CFAY port operations cleaned and filled two barges, totaling nearly 1.89 million litres (500,000 gallons) of fresh water. (U.S. Navy photo by Mass Communication Specialist 3rd Class Mikey Mulcare)



A total of 1.89 million litres (500,000 gallons) are being distributed between the barges that have been cleaned of fuel to support fresh water. The first Barge YOGN-115 departed CFAY at approximately 11:00 a.m. and will be escorted by a Japan Maritime Self Defense Force multipurpose support ship JS Hiuchi (AMS 4302). The second barge is scheduled to leave within the next 24 to 48 hours. The water will eventually be used to replace the seawater currently being used in cooling efforts at the plant.

“We have two barges here,” said CFAY Operations Officer Lt. Cdr. Michael Weatherford. “They can both hold up to approximately 300,000 gallons of fresh water each. But the max capacity is reduced to make the barges seaworthy for ocean travel,” Weatherford explained. “The request was for one million gallons so when I told them we could get 500,000 gallons we started working on getting these barges released from our custody over to the [Japan Maritime

http://www.c7f.navy.mil/news/2011/03-march/069.htm

 

[AntonL]

Are the daily updates still coming out from TEPCO re. reactor temperatures, CAMS and containment pressures?

I haven't seen any new data for a while.

yes here is the latest http://www.meti.go.jp/press/20110328008/20110328008-3.pdf

 

[Astronuc]

a possible scenario (sorry I'm not an expert in nuclear reactors, I just try to imagine reasonable conditions ) : control bars have been damaged at least at the top of fuel assemblies, due to very high temperatures and/or chemical reaction with steam, and have been partially destroyed. The top of fuel rods can become critical when they're bathed with liquid water, the boron concentration being too low to absorb neutrons. Some kind of self-regulation occurs, when liquid water is above the top of damaged bars, nuclear fission can start periodically - it then produces much more heat that vaporizes the water and the water level decreases, until the system becomes sub-critical, and steam recondensates. The period and amplitudes of oscillations are such that the whole thermal and pressure inertia is enough to smooth the variations, acting like a low-pass filter. Is it conceivable ?

If the control rods are fully inserted and they are intact, then the water level in the core does not matter, and the core is subcritical. This is by design.

If the control rods were to melt and some of the boron lost, the core may still be subcritical, but by a lesser amount.

If the fuel material was washed out, then the core is less likely to become critical, because the fuel material would end up in the water, which is at the bottom of the core or in the plenum underneath the core, where there is a lot of hardware.

If somehow the control rods were fail and lose all their boron, and the fuel was intact, then criticality would be a concern.

One we know the situation/status of the control rods and fuel, then we can perform simulations on the margins to criticality.

An indication of control rod breach would be tritium and lithium in the water. I don't know if they are being measured.

 

[AntonL]

US 7th flotte is sending fresh water to FUkushima (2'000 m3) :

the question is, how long do you thing, this fresh water will last given the need of water to cool down the reactors and the pools ?

Considering residual heat loads for reactors and published heat loads for SFP then there is enough energy to boil about 400m3 of water per day

With all the leaks they need a lot more

 

[jensjakob]

http://www3.nhk.or.jp/daily/english/28_h28.html

"pumping in 16 tons of water every hour in #2, might cut down to the 7 tons that are evaporated every hour".

1. What happens to the 9 tons that doesn't evaporate?
2. How much thermal energy does it take to evaporate 7 tons of cold water?
3. Where does all this steam go?

 

[dave2004]

Considering residual heat loads for reactors and published heat loads for SFP then there is enough energy to boil about 400m3 of water per day

With all the leaks they need a lot more

Does the US army not have transportable desalination units? A quick google search turns up there are units for flatbeds that have capacities of 140'000 GPD which I assume to be gallons per day and should be able to cope with generating enough water.

 

[Reno Deano]

I wanted to mention some important details in the last french IRSN report from this morning (source: http://www.irsn.fr/FR/Actualites_presse/Actualites/Pages/201103_situation_au_japon.aspx#1 ).

They are giving infos on the levels of water found in the basement of reactor n°2 and N°3, and the levels are much higher than what i have seen reported so far. They are talking about 1 m of water in the basement of turbine building at N°2 and 1,5m in the basement of turbine building at N°3! Until now i was staying with numbers like 15 or 30 cms of water in N°3 (when the 3 workers were injured walking in this water)...

Does it mean that this level has dramatically increased in between?

Something else, IRSN is reporting that they found also contaminated water in several "wells" outside of buildings of reactors N°2 and 3.

I see that has been reported (in other recent sources) contaminated water in a trench outside of these reactors, maybe is it the same info or a related info.

--------------------
I assume all of you posters are aware that they (TEPCO) tried to and succeeded in adding copious quantities of seawater to the 4 reactors and spent fuel pools, after significant explosions damaged upper portions (and possibly seals on the primary containment-not RPV). They did this during a station blackout and probably had to rely on analog guages, if that, to determine flows and pressures. Also, the unit(s) radwaste systems collect water from floor drains throughout the plants, including the Turbine buildings. The radwaste systems have a finite limit on their capacity. To protect the radwaste tanks, there are overflows to other areas where the water can be collected or disposed of, but not in a controlled manner. Now with all the water being washed over the spent fuel pools and out of the RPV, there is a chance much radioactivity was also washed over and out of the reactor building. Also, there were deliberate discharges from the RPVs to keep them from going solid with water and bursting from hydraulic effects. When ever they stopped pumping water into the RPV or Primary Containment there was the inevitable back flow of fluids due to increased RPV pressure or via the vent path. During normal operations connecting piping systems and hoses can involve less than leak tight fittings, even under the most favorable of working conditions. The reactor radwaste systems are inter-connected with the Turbine Building since there is also contaminated water to be collected from the Turbine Building. Under the best of conditions such a large piping system is fraught with leaks and failed valves, including check valves. Now the magnitude of the assault on the Japanese plants, I would expect many piping systems designed for normal operation to not perform as designed. Water, water everywhere and not a drop fit to drink or step in!

Let me tell you, things happening at the plants are totally new to the workers and managers and the high radiation levels significantly hamper making insitu observations and corrective actions in timely manner. Insitu photos/videos and observations, radiochemistry and radiation measurements, stablizing reactor pressures and temperatures, and getting reactor plant system guages back on line; are the only way to accurately determine the damage and future recovery actions. Speculations based on views of the exterior of the Reactor Buildings is welcomed fodder for the uniformed masses.

 

[Borek]

2. How much thermal energy does it take to evaporate 7 tons of cold water?

About 18-19 GJ, depending on the initial temperature.

Unless I am wrong.

 

[divmstr95]

Are the daily updates still coming out from TEPCO re. reactor temperatures, CAMS and containment pressures?

I haven't seen any new data for a while.

Use this website:

http://www.nisa.meti.go.jp/english/

 

[jlduh]

Again, every day that passes amazes me to see how weak and improvised is the response on the ground to control the consequences of this catastroph. I understand that Japan is fighting the consequences of a terrible earthquake and tsunami in addition to this nuclear crisis, but it seems that the autorities are continuing to put the responsability on Tepco shoulders to control the situation, and try to keep up with what's going (and regularly when a mistake is done, they say: "i urge you to improve your safe safety management for workers",or "I urge you to be careful when you transmit wrong measurements". It's like a scenario where a private company deals with regulation autorities and these ones tell them: "this is your responsability to manage this mess, and please do it in accordance with regulation standards and requirements")

We will have maybe the first Iso 14000 certified nuclear catastroph in Fukushima (in words, not in facts of course!)?

ok I'm a little bit sarcastic, but...

This is no more a tepco problem, this is 1) a Japan problem and even more 2) an international problem! Is the Japan state so weak to take the lead around this mess? Of course Tepco knows more about the plant than Japan autorities but again this is a different subject. Where are military resources from Japan? Two weeks after the beginning of the crisis we talk about a barge with 2000 m3 of fresh water coming to rescue, and this is from US troops? That's almost a joke to me...

This is a situation of great exception, and a lot of people in the world are waiting for an international response to this crisis, I'm not even sure we can talk of a Japan response until now based on what we saw in the last 2 weeks. I don't know what is going on with international experts and resources on the ground, but if this is a (long and difficult) battle against this damn nuclear plan that is going on (like the BATTLE of tchernobyl has been called), then when will this battle get large adequate exception means to be won?

I've always been impressed with the vocabulary used in civil nuclear industry (for example, the protection enveloppes are called "lines of defense", Reno DEANO just above is talking about the "assault on the japanese plant" ;o)) and this is related with the fact that civil nuclear has been historically a direct "byproduct" or sister of military nuclear (to make bombs plutonium was required). For the russians in Tchernobyl, from day one it was clear: this is a state and military problem with state and military -huge- ressources and management to cope with the accident (of course no war is clean in reality even if some use a vocabulary like "chirurgical weapons" to create the impression it can be: the tchernobyl battle was also a "dirty" battle from environment and human standpoint of course).

I don't know if i express well the point that i saw several times expressed in one way or another on this forum but clearly, i see a huge difference in scale between the problem and the "solutions". Like if everybody was willing to underscale the response in order to underscale the problem... I really don't think that now that the "toothpaste went outside of the tube", a private company can handle the crisis (even if from the juridic standpoint they are probably responsible), the scale has to be upgraded to one or two levels concerning the strategical leadership.

I'm talking about Leadership. Time is critical and involves some leadership decisions to be made. The inertia from this standpoint is blatant.

EDIT: an other example of the weak and confusing leadership from the state standpoint (i already mentioned earlier on this thread this problem citing an interview of the Minamisoma's mayor who was upset with unclear decisions from government): More evacuees return to homes near nuclear plant!

http://www3.nhk.or.jp/daily/english/28_14.html

How hell can peole there understand something to the misleading communication of authorities and unclear leadership scale of the current problem? "No evacuation order between 20 and 30kms (just "advice" to leave on a volunteer basis) for the two first weeks must mean that it is not so serious, this is a plant problem and the autorities are not even steeping into take the leadership on the site, this is a sign that the situation is not so serious": isn't this that a lot of japan folks not knowledgeable of the details can think and spread around?

 

[Joe Neubarth]

Considering residual heat loads for reactors and published heat loads for SFP then there is enough energy to boil about 400m3 of water per day

With all the leaks they need a lot more

Unless they are trucking it off site, they will eventually run out of space to store the contaminated water. All of the concrete basement structures will eventually adsorb tremendous amounts of radiation that can only be eliminated by carting the cement away. (Not Practical, and it would add to air particulate radiation), so they need to cap those highly radioactive spots once they figure out what to do with the Reactor cores/Lava flow (depending upon what you believe is happening.)

They have got an environmental mess there that they will be tending to for a great, great many years.

 

[Joe Neubarth]

Again, every day that passes amazes me to see how weak and improvised is the response on the ground to control the consequences of this catastroph. I understand that Japan is fighting the consequences of a terrible earthquake and tsunami in addition to this nuclear crisis, but it seems that the autorities are continuing to put the responsability on Tepco shoulders to control the situation, and try to keep up with what's going (and regularly when a mistake is done, they say: "i urge you to improve your safe safety management for workers",or "I urge you to be careful when you transmit wrong measurements". It's like a scenario where a private company deals with regulation autorities and these ones tell them: "this is your responsability to manage this mess, and please do it in accordance with regulation standards and requirements")

We will have maybe the first Iso 14000 certified nuclear catastroph in Fukushima...

This is no more a tepco problem, this is 1) a Japan problem and even more 2) an international problem! Is the Japan state so weak to take the lead around this mess? Of course Tepco knows more about the plant than Japan autorities but again this is a different subject. Where are military resources from Japan? Two weeks after the beginning of the crisis we talk about a barge with 2000 m3 of fresh water coming to rescue, and this is from US troops? That's almost a joke to me...

This is a situation of great exception, and a lot of people in the world are waiting for an international response to this crisis, I'm not even sure we can talk of a Japan response until now based on what we saw in the last 2 weeks. I don't know what is going on with international experts and resources on the ground, but if this is a (long and difficult) battle against this damn nuclear plan that is going on (like the BATTLE of tchernobyl has been called), then when will this battle get large adequate exception means to be won?

I've always been impressed with the vocabulary used in civil nuclear industry (for example, the protection enveloppes are called "lines of defense", Reno DEANO just above is talking about the "assault on the japanese plant" ;o)) and this is related with the fact that civil nuclear has been historically a direct "byproduct" or sister of military nuclear (to make bombs plutonium was required). For the russians in Tchernobyl, from day one it was clear: this is a state and military problem with state and military -huge- ressources and management to cope with the accident (of course no war is clean in reality even if some use a vocabulary like "chirurgical weapons" to create the impression it can be: the tchernobyl battle was also a "dirty" battle from environment and human standpoint of course).

I don't know if i express well the point that i saw several times expressed in one way or another on this forum but clearly, i see a huge difference in scale between the problem and the "solutions". Like if everybody was willing to underscale the response in order to underscale the problem... I really don't think that now that the "toothpaste went outside of the tube", a private company can handle the crisis (even if from the juridic standpoint they are probably responsible), the scale has to be upgraded to one or two levels concerning the strategical leadership.

I'm talking about Leadership. Time is critical and involves some leadership decisions to be made. The inertia from this standpoint is blatant.

We can always do what our dear sister Angela is doing in Germany and that is say, "No More Nukes!" I feel that this is impractical and will never be the solution globally. Nuclear Power is here to stay even if isolated to certain regions of the globe. We just have to design our plants better. From an engineering standpoint there are many questions about the design of Fukushima with respect to the region it was built, and many questions about their preparation for multiple emergencies. When you see statements like, "The plug did not fit." you know somebody did not do their homework on disaster preparedness. That is water over the dam now. What do we need to recover from this mess is the operative question now.

 

[Joe Neubarth]

http://www3.nhk.or.jp/daily/english/28_h28.html

"pumping in 16 tons of water every hour in #2, might cut down to the 7 tons that are evaporated every hour".

1. What happens to the 9 tons that doesn't evaporate?
2. How much thermal energy does it take to evaporate 7 tons of cold water?
3. Where does all this steam go?

1. Sits in pools and where possible leaks into the ground as all water does.
2. I think somebody answered this.
3. In this situation that which does not condense (Where designed, or on walls, steel girders and such) escapes to the winds.

 

[jlduh]

What do we need to recover from this mess is the operative question now.

Yes Joe, and my point was on this subject: leadership on the operative question.

I was not even talking about nuclear necessity of whatever related to this, i was saying: when the mess is spread around in a similar scenario that was not even foreseen in the worst case scenarios (which explains the unplanned actions: i remember everybody that US experts said quickly that using seawater to cool the cores like that was a desesperate decision -even if the only one!) , this becomes a state or international problem, and the leadership has to REFLECT this fact.

This is the limit of private companies in this matter i think, because they just can't handle it as fast and as strong as it should be. A nuclear plant which is in this situation of large and fast evoluting mess induces an exception state which a company cannot, "by design", handle...

Like it or not, but I'm afraid it's true, and will become more and more obvious as days will go...

 

[Reno Deano]

Again, every day that passes amazes me to see how weak and improvised is the response on the ground to control the consequences of this catastrophe. I understand that Japan is fighting the consequences of a terrible earthquake and tsunami in addition to this nuclear crisis, but it seems that the authorities are continuing to put the responsibility on TEPCO shoulders to control the situation, and try to keep up with what's going (and regularly when a mistake is done, they say: "i urge you to improve your safe safety management for workers",or "I urge you to be careful when you transmit wrong measurements". It's like a scenario where a private company deals with regulation authorities and these ones tell them: "this is your responsibility to manage this mess, and please do it in accordance with regulation standards and requirements")

You have no idea of the level of stress the Accident managers, workers, and Government is under during the unprecedented multiple reactor accidents. Confusion and indecisiveness is rampant in the Emergency Ops Center, Government (which is dealing with a more larger deadly crisis outside of the reactor plant grounds) and assist organizations. Combine this with the assistance from the World nuclear experts, which have never seen this type of situation to even one reactor, and are faced with three reactors and spent fuel pools with different levels of catastrophic damage. Due to the resultant Station Blackout, explosions, and emergency equipment failures, they were not allowed the grace of moving from one problem to another in an orderly fashion.

Yes, we all want timely and accurate data, but that is not the real world during a catastrophic nuclear emergency, or even a lesser one, believe me.

Do not condemn until you have walked in their shoes.

We will gain invaluable information and lessons learned from their mistakes and miscues, but during the next catastrophic reactor accident similar mistakes and miscue's will also be made.

Dean Chaney, CHP
37 Years in the Nuclear Reactor Industry