Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[fusefiz]

This may well be a naive reaction, but it seems to me that the obvious thing to do with the radioactively contaminated water in the turbine buildings is to pump it back into the reactors. Is there something wrong with that action? If/when they are able to re-establish core cooling, perhaps they could then work on dealing with the water contamination (salt, radioactive elements, etc) and leaks. But until then, why not reuse this water for the evaporative cooling?

 

[jensjakob]

Trench dimensions:
3x4x76 meters.
Source: http://www3.nhk.or.jp/daily/english/28_h37.html

3x4x76 = 912 m3.

Lets say 70% is full of water = 638 m3 of water. That is a lot of water...

I would like to learn:
1. Did it fill up from the Tsunami wave? Plausible.
2. When did last time inspect it - i.e. has it been dry after the Tsunami hit?
3. The article above talks about "a poodle of water" - which is VERY different from other stories of "filled to the brim".

Bottomline:
1. We don't know how much water is in the trenches
2. It would be good to learn how water rthere is
3. And if the trenches has been reported dry since the tsunami

and
4: Has these trenches been regularly checked for water seeping out of the containment?

 

[Joe Neubarth]

This may well be a naive reaction, but it seems to me that the obvious thing to do with the radioactively contaminated water in the turbine buildings is to pump it back into the reactors. Is there something wrong with that action? If/when they are able to re-establish core cooling, perhaps they could then work on dealing with the water contamination (salt, radioactive elements, etc) and leaks. But until then, why not reuse this water for the evaporative cooling?

Pump highly radioactive water to an area where it can be heated and release more radioactive delayed neutron precursors or accelerate gamma or Beta emitting dispersal?

Not a good idea.

 

[Bodge]

This failure in reporting is the incompetence of journalists and "experts", at NHK and other places. Some of them get it right, though. For example this guy: http://yokosonews.com/live/ He reported accurately that the true dose rate might be several times higher. And he seems to be mainly a culture and entertainment reporter. It seems that he had his info straight from watching a Tepco press conference...

Katz from Yokoso News is a legend! He has been broadcasting, whilst monitoring and translating several Japanese sources simultaneously. 10 hours a day since the crisis started, all with great professionalism and humour.

 

[rogerl]

Guys. If radioactive water keeps leaking and outside to the Pacific Ocean. How many miles off shore will the danger remain? I only eat fish and concerned about this.

 

[|Fred]

This data is not from the 'weather channel', are you intentionally trying to discredit the report?

ZAMG is the state meteorological and geophysical services in Austria (link provided in my original post), in mundane terms it's the Austrian weather channel.
I quoted the actual report rather than a press mixed version (press did not even bothered linking there source).
In the initial paper produced by the Zamg Dr. Gerhard Wotawa explains that they only feed 2 measuring points to there mathematical model extrapolating from data from the first few days.
This model gave result that are up to 40 points different from an other model based on similar data.

It does raise the question of reliability on what is presented as hard fact, in my opinion.

 

[M. Bachmeier]

I'm sorry, but does this discussion need to be a post apocalyptic (re: Joe Neubarth type of speculative fiction) or a valuable resource toward possible solutions?

Sorry Joe, you see the negative 10E* potential outcome in your fiction, but that is the nature of fiction. And with respect you help make my point clear.

I suggest something different.

There are thousands of people who could contribute toward amortization of this issue. The first step is (in a situation like this) a forensic analysis of what went wrong. This is missing (with respect to time). A very top down kind of analysis has been occurring. Who's asking what happened in the first hour.. minutes, 2hrs. + 24hrs.

The young minds who regularly contribute to this forum could be a sounding board + all others toward a bottom up analysis (which in this case needs to happen faster than normal) in order to participate in potential solutions with regard to substantive input.

What happened in the first hr. after main power loss? (not just a summary)?

What happened in the first 12 Hr. Re: after main power loss and backup failure?

What decisions were made based on 'then' expectations and loss of data?

I think this is a case where forensic analysis would be better served as a balance between speculation and hypothesis WRT initial conditions leading outward where possible. Followed by the active post-forensic approach that is seemingly dominant.

 

[|Fred]

From a "dirty boom" at unit 3?

so we are talking about the rods in the pool

M. Bachmeier,
Tepco did not provide data for the first 12h or so.. Mitsuhiko Tanaka pointed just like you did that the first 12h are crucial to understand what could have happen.. from the initial data he does figure a few thing
Reactor 1 Core vessel at t+12 is at 0.80Mpa donw from 7MPa , First reading of Containment Vessel is at 0.8Mpa (twice the design spec) up from 0.1MPA normal operating pressure.

 

[dave2004]

Guys. If radioactive water keeps leaking and outside to the Pacific Ocean. How many miles off shore will the danger remain? I only eat fish and concerned about this.

A very quick and dirty back of the envelope:
length of beach, let's say 500m on both sides of the factory, makes 1000m
area up to 500m from shore
average depth between beach and 500m distance: 100m
makes a volume of 5x10^7 m3

If you consider dumping for example 5000m3 of highly contaminated waste, you would dilute it by a factor 10'000.
(if uniformly distributed, not considering fish living close to the pipes leading into the sea, those I would avoid)
In my opinion, sea pollution is less of a problem than land pollution because of its 3 dimensions (on land Cs will stick to a certain limited depth where the plants have roots).

 

[georgiworld]

My Nephew, who was living in Tokyo and is now coming home:

http://www.chugai-pharm.co.jp/hc/Satellite?c=CrpCorner_C&cid=1259593215924&pagename=Chugai%2FCrpClassification

Just thought I'd try to remind people that this is also a human issue. It affects all of us. Our judgment, our empirical approach, our perceived knowledge and our humanity. I guess there are some things we can't be empirical about.

How do you explain this?

Goldman Sachs Employees Told Not to Leave Japan
http://www.cnbc.com/id/42304574

 

[trinon]

According to the same article those 20 to 50% might as well be 10% when the French do the math. (assuming it's math they are doing)

What french calculation are you quoting?

Anyway, is there another dispersion model calibrated with CTBTO data available? The ZAMG model (the national authority to analyse CTBTO data in Austria) does a good job on the prediction of radioactive emission according to their recent http://zamg.ac.at/display.php?imgPa...urce=©+ZAMG&imgWidth=1199&imgHeight=740"

They also made a nice animation of the model available to the public:http://zamg.ac.at/pict/aktuell/20110325_Reanalyse-I131-Period1.gif"

 

[M. Bachmeier]

How do you explain this?

Goldman Sachs Employees Told Not to Leave Japan
http://www.cnbc.com/id/42304574

My nephew is the taller guy asking questions in English.

 

[Astronuc]

The best source I could find for seawater interactions of fission products was related to the dissolution of Plutonium Dioxide in radioisotope power generators used in space exploration:
http://www.osti.gov/bridge/servlets/purl/4839392-lrKndC/4839392.pdf

Basically, the microspheres they tested did not dissolve very well into sea water (about 0.012 - 0.016 μg/mg/day - p19) and (this isn't relevant yet, but if PuO₂ were released into the open ocean it's a good thing) if they are encrusted with marine growth their dissolution rates go down by about half (about 0.0048 - 0.0076 μg/mg/day - p19.)

This obviously doesn't take into account the presence of other compounds in close proximity that might chemically interact with the Pu.

From the OSTI report - the ambient temperature was 15°C. I expect the temperatures in core are much high - ~ 200°C or higher, especially if proper cooling is not obtained.

The PuO₂ microspheres were also stoichiometric oxide, as opposed to irradiated fuel with a spectrum of fission products, so of which, e.g., I, Cs, Br, Rb are readily soluble in water.

 

[ExecNight]

I have been following this thread out of curiousity. And after such a long time, people still talking about possibilities just tells me something is wrong.

What i think is even if there is a catastrophic radiactivity, it will be held confidential for various reasons. And people will start talking about Fukushima again when cancer rates around the region increases ten times..

 

[TCups]

so we are talking about the rods in the pool

Well, speaking about what happened early on, Unit 1 blew up immediately after venting. That might make operators reluctant to go ahead and immediately vent Units 2 and 3. So pressure builds until Unit 2 and 3 explode. Unit 2 blows through the torus suppression pool without a lot of external damage to the building. Plutonium doesn't get on the ground that way. But Unit 3 was, as Ed Sullivan might have said, a "big, big, really big" explosion. My best analysis of the photos says it blew up and out of the south end of the top floor of Bldg. 3. If the source were from inside the primary containment and it didn't blow out of the torus pool, then it blew the drywell cap, came out the side of the primary containment, through the chute, and into the SFP.

That, to me, seems the most likely route to get Pu out, up, and back down on the ground.

Correct me if I am wrong, but there was no Plutonium in the SFP at Unit 4, right?

 

[M. Bachmeier]

Well, speaking about what happened early on, Unit 1 blew up immediately after venting. That might make operators reluctant to go ahead and vent Units 2 and 3. So pressure builds until Unit 2 and 3 explode. Unit 2 blows through the torus suppression pool without a lot of external damage to the building. Plutonium doesn't get on the ground that way. But Unit 3 was, as Ed Sullivan might have said, a "big, big, really big" explosion. My best analysis of the photos says it blew up and out of the south end of the top floor of Bldg. 3. If the source were from inside the primary containment and it didn't blow out of the torus pool, then it blew the drywell cap, came out the side of the primary containment, through the chute, and into the SFP.

That, to me, seems the most likely route to get Pu out, up, and back down on the ground.

Yes forensic inquiry, what precipitated these events, those are questions that are traditionaly asked afterward, but this seems to be a case where forensic investigation needs to be on par with events.

 

[jlduh]

Trench dimensions:
3x4x76 meters.
Source: http://www3.nhk.or.jp/daily/english/28_h37.html

3x4x76 = 912 m3.

Lets say 70% is full of water = 638 m3 of water. That is a lot of water...

I would like to learn:
1. Did it fill up from the Tsunami wave? Plausible.
2. When did last time inspect it - i.e. has it been dry after the Tsunami hit?
3. The article above talks about "a poodle of water" - which is VERY different from other stories of "filled to the brim".

Bottomline:
1. We don't know how much water is in the trenches
2. It would be good to learn how water rthere is
3. And if the trenches has been reported dry since the tsunami

and
4: Has these trenches been regularly checked for water seeping out of the containment?

The questions you ask are very legitimate. I have a hard time imagining that those trenches don't have been to some extent filled with seawater during the tsunami above them...

On the volumes of water in the trenches, if i look at this picture of the Tepco press conference, I see m3 written in the last column at the right side of the board, and if i sum up the volumes indicated for reactor 1 to 3, i end up with 13 300 m3 (3100 + 6000 + 4200)...
(click)
http://www.netimago.com/image_183582.html

This would be much more than your calculations.

As said before, a shame these conferences are not translated or transcrypted to english?

For Goldman Sachs asking employees to stay there, I think it's because anyway Goldman Sachs is more dangerous for human life than 3 wrecked reactors, so no real danger for those who are inside it's core...

 

[AtomicWombat]

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?

The idea is to fill the reactor & keep it full, even if the water is boiling. The problem appears to be at least 2 reactors are leaking.

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

From the UCS site:

So that's 7ton*540Mcal/ton = 3780 Mcal
1 Calorie is 4.2 Joules, so 4.2*(J/Cal)3780 Mcal = 15876 MJ ~ 16 GJ

3. Where does all this steam go?

Either to the condenser (for the reactors - assuming it's working) or straight into the atmosphere (esp. for the spent fuel ponds).

 

[jlduh]

About the concerns for the pollution in the ocean, some basic infos:

1) it seems there is a North to South current that passes along the coast at Fukushima, so if pollution is massive it will probably move towards the south.

http://www.netimago.com/image_183571.html

2) then the current at a bigger scale is dominated by the Kuroshio
http://en.wikipedia.org/wiki/Kuroshio_Current

which then crosses the Atlantic.
http://www.netimago.com/image_183574.html
http://en.wikipedia.org/wiki/Ocean_current

If the pollution is really massive, can we anticipate that surfers on the west US coast will be much less sexy with lead swimming pants?

Or maybe we'll have a "great radioactivity patch" to compare with the "great garbage patch" already existing in the middle of Pacific Ocean:
As said previously, i think dilution in the ocean is a difficult task to predict (i don't even know if models exists similar to what exists for atmospheric regime, see the ZAMG simulation for example) .

But sediments along the Japanese coasts with local concentrations of contamination due to local currents are probably the worst to anticipate. But again not sure there are a lot of studies available concerning mecanisms of nuclear pollution in the ocean (maybe some related to the submarines?).

 

[Astronuc]

This may well be a naive reaction, but it seems to me that the obvious thing to do with the radioactively contaminated water in the turbine buildings is to pump it back into the reactors. Is there something wrong with that action? If/when they are able to re-establish core cooling, perhaps they could then work on dealing with the water contamination (salt, radioactive elements, etc) and leaks. But until then, why not reuse this water for the evaporative cooling?

Pump highly radioactive water to an area where it can be heated and release more radioactive delayed neutron precursors or accelerate gamma or Beta emitting dispersal?

Not a good idea.

Pumping contaminated water back to the site of the contamination is not good certainly. Eventually, whatever is leaking out becomes more contaminated, and that means increased dose rate and cumulative dose for those involved.

Assuming the fission has ceased, the delayed neutron precursors, the longest-lived being Br⁸⁷ (t_1/2 = ~55 s), are long decayed away.

I'm not sure where they plan to put the contaminated water. Perhaps back in the torus, if it has spare volume. If the contaminated water contains solid fission products, then this would suggest fuel washout, which then suggests some leak path from the primary system, e.g., feedwater system, the reactor water cleanup system, or possibly from somewhere in containment, from the lower levels of the containment, or containment sump and torus.

Ideally the contaminated water would be 'contained' in containment, but that does not appear to be the case, otherwise the contaminated water should be flowing in a closed system. However, with contaminated water in the turbine building, this would seem to be hampering efforts to re-establish a closed system.

Solutions of uranyl ions (e.g., uranyl nitrate hexahydrate) would normally be precipitated in a caustic solution, typically with ammonium hydroxide. The precipitate would be collected, dried and then calcined to an oxide powder. This may be an option, but it requires a special portable chemical process plant. Otherwise the solution has to be dewatered, perhaps by vacuum dehydration in a process similar to the production of freshwater from seawater, which leaves behind a more concentrated solution. The problem then is one of collecting the water - with submersible pumps or vacuum hoses. Given the radioactive contamination in the water, perhaps this operation requires remotely operated vehicles (ROVs).

If there is a leak in containment or the piping of the feedwater and attendant systems, then that has to found and stopped in order to reduce/mitigate further contamination.

I wonder if the boric acid solution is buffered. In PWRs, it is common to buffer with LiOH in western PWRs, and KOH in Russion VVERs. The pH in the coolant is kept near neutral ~7.0, to slightly basic up to about pH = 7.4. Acidic water increases the corrosion of stainless steel and nickel alloys.


FYI - [PDF] Mark I Containment Report
http://www.nei.org/filefolder/Report_-_BWR_Mark_I_Containment_03192011_2.pdf

 

[M. Bachmeier]

The window of opportunity to contribute toward effective analysis of the pre-conditions and short term resulting conditions is potentially small.

I wonder if this wonderfully large group of intellect would participate in revision of perceived indictments perceived and known toward solutions... These being in short supply.

 

[turbo]

I'd like to request that people PLEASE re-scale images to maybe 800 pixels or 1000 at the most (horizontally) before posting them. This is a fast-moving thread, and it is very hard to follow the discussion, follow links, etc, when you have to scroll back and forth to see the text. Large images force the forum window to expand to fit, and any text on the same page of posts bleed out of the window, necessitating the scrolling.

Please, just some common courtesy. Thanks.

 

[jlduh]

I'd like to request that people PLEASE re-scale images to maybe 800 pixels or 1000 at the most (horizontally)

You are right, sorry for the big image, i edited and replaced it by a vignette

 

[turbo]

You are right, sorry for the big image, i edited and replaced it by a vignette

Thank you very much! This page of posts is now easily manageable, and allows others to perhaps have two instance of a browser open in order to follow external links that may be overloaded and slow to load. Much appreciated!

 

[rhody]

Astronuc,

"Correct me if I am wrong, but there was no Plutonium in the SFP at Unit 4, right? "

Considering there is plutonium in the Reactor core of #3, and if you address TCups question (above), possibly in the SFP for Unit #4 as well, one would think because of the danger of contamination of that extremely long lived radioactive element (plutonium), that more urgency would be given to addressing the isolation/safe removal if possible from both sources. You said in an earlier post that the plutonium rods are diversely spread in the core, right ? If I had to do a cost/risk benefit analysis of the danger and had to choose spreading more short lived radioactive elements while being able to safely remove the longer lived ones, that course of action would seem logical, no ?

Rhody...

 

[Joe Neubarth]

Pumping contaminated water back to the site of the contamination is not good certainly. Eventually, whatever is leaking out becomes more contaminated, and that means increased dose rate and cumulative dose for those involved.

Assuming the fission has ceased, the delayed neutron precursors, the longest-lived being Br⁸⁷ (t_1/2 = ~55 s), are long decayed away.


FYI - [PDF] Mark I Containment Report
http://www.nei.org/filefolder/Report_-_BWR_Mark_I_Containment_03192011_2.pdf

I debated the delayed neutron precursor statement and then thought, "We do not know where all of the Plutonium and Uranium is." We know some is scattered outside the reactor, but there is a strong possibility that it is in the Turbine area, and if so may be splitting as we speak. How much, if any, of that that is from the core we do not know. But I suspect that the core has lost some of its fuel.

Hopefully some of the Uranium fuel is still in the core and if so, exposure to more neutrons is not a good thing as it just makes things dirtier and dirtier. That will just yield more delayed neutron precursors and even more radiation. Nobody caught on to the fact that if the Boron in the control rods was probably totally dissolved in reactor water if we had a full meltdown and that water was being replaced (Not always with borated water), the net total volume of boron in the reactor had probably greatly decreased, and may have resulted in a power transient type reaction which could have taken the uranium lava out from the bottom of all containment. I suspect that has happened in part or in whole.

 

[AtomicWombat]

I would like to learn:
1. Did it fill up from the Tsunami wave? Plausible.
2. When did last time inspect it - i.e. has it been dry after the Tsunami hit?
3. The article above talks about "a poodle of water" - which is VERY different from other stories of "filled to the brim".
4: Has these trenches been regularly checked for water seeping out of the containment?

This NHK report (with an expert interview) was very clear that it was just centimeters from the brim and still rising.
http://www.youtube.com/watch?v=G3QJ8mxZOxA"

At least some of the water must come from the turbine building - for >1000 mSv/hr I'm tempted to say most of it. Tsunami water is generally not radioactive. If they did a radioisotope analysis (as done for the water in the turbine buildings) it would be very clear how much of the water is from the turbine building.

 

[AtomicWombat]

Guys. If radioactive water keeps leaking and outside to the Pacific Ocean. How many miles off shore will the danger remain? I only eat fish and concerned about this.

This can only really be answered by sophisticated modelling followed by monitoring.

 

[AtomicWombat]

Astronuc,

"Correct me if I am wrong, but there was no Plutonium in the SFP at Unit 4, right? "
Rhody...

Yes I'm not Astronuc, but the short answer there is plutonium in all spent nuclear fuel at the site, including that partially "burned" in reactors 1 & 2.

http://www.fas.org/nuke/intro/nuke/plutonium.htm"

"A useful rule of thumb for gauging the proliferation potential of any given reactor is that 1 megawatt-day (thermal energy release, not electricity output) of operation produces 1 gram of plutonium in any reactor using 20-percent or lower enriched uranium; consequently, a 100 MW(t) reactor produces 100 grams of plutonium per day and could produce roughly enough plutonium for one weapon every 2 months. Light-water power reactors make fewer plutonium nuclei per uranium fission than graphite-moderated production reactors. "

 

[turbo]

Astronuc,

"Correct me if I am wrong, but there was no Plutonium in the SFP at Unit 4, right? "

Considering there is plutonium in the Reactor core of #3, and if you address TCups question (above), possibly in the SFP for Unit #4 as well, one would think because of the danger of contamination of that extremely long lived radioactive element (plutonium), that more urgency would be given to addressing the isolation/safe removal if possible from both sources. You said in an earlier post that the plutonium rods are diversely spread in the core, right ? If I had to do a cost/risk benefit analysis of the danger and had to choose spreading more short lived radioactive elements while being able to safely remove the longer lived ones, that course of action would seem logical, no ?

Rhody...

As I understand it, not all the uranium in the fuel rods is 235, though the fuel is enriched to enhance that. Lots will be U 238, which by absorption of neutrons will convert to plutonium 239. So any fuel rods that have seen a lot of use should have a decent fraction of plutonium. So dispersed fuel from the spent fuel pools could elevate the levels of plutonium detected outside - not just the MOX fuel used in #3.

Astro and others, if I am way off base, please say so.

 

[rhody]

Yes I'm not Astronuc, but the short answer there is plutonium in all spent nuclear fuel at the site, including that partially "burned" in reactors 1 & 2.

http://www.fas.org/nuke/intro/nuke/plutonium.htm"

"A useful rule of thumb for gauging the proliferation potential of any given reactor is that 1 megawatt-day (thermal energy release, not electricity output) of operation produces 1 gram of plutonium in any reactor using 20-percent or lower enriched uranium; consequently, a 100 MW(t) reactor produces 100 grams of plutonium per day and could produce roughly enough plutonium for one weapon every 2 months. Light-water power reactors make fewer plutonium nuclei per uranium fission than graphite-moderated production reactors. "

Thanks AW,

I understand, a lot of toxic fuel to isolate and somehow safely remove... I wish them well in the herculean effort that will be required. Thanks Turbo, you and AW pretty much nailed it.

Rhody...

 

[AtomicWombat]

In part, from above reference:

"Dr. Sekimura of Tokyo university pointed out the possibility of damage to the fuel in the spent fuel pool of unit-3 since it would appear that the heavy crane have dropped into the fuel pool in this movie. (05:40, March 28)"

I wonder if this makes sense:

1) vertical shaft
2) SFP3
3) Fuel rod handling equipment in SFP3
4) Region of the transfer chute and gate

TCups,
Do you realize that is a view from the north - the opposite side from which you were previously suggesting the SFP was on.

 

[TCups]

TCups,
Do you realize that is a view from the north - the opposite side from which you were previously suggesting the SFP was on.

CORRECTION

[STRIKE]It is a view from the north, looking into the south end of Unit 3, I believe. [/STRIKE] The SFP's are in the southeast corners of Units 3, 4. The original screenshot I annotated WAS NOT the SFP. It was a shot of the equipment pool on the north end of Bldg 3. The original post has been corrected. Sorry for the error.

 

[razzz]

From
http://en.wikipedia.org/wiki/Boiling_water_reactor

Size

"...A modern BWR fuel assembly comprises 74 to 100 fuel rods, and there are up to approximately 800 assemblies in a reactor core, holding up to approximately 140 tons[vague] of uranium. The number of fuel assemblies in a specific reactor is based on considerations of desired reactor power output, reactor core size and reactor power density..."

It's a starting point since some of the reactors are first generation, may not be loaded with such large amounts.. No wonder no one wants to talk about it. Germany has the right idea, decommission any current operating BWRs.

Seems to me, in a Murphy's Law event, with the amounts of fuels involved between 3 crippled reactors and 4 spent pools, every combination and variation of a meltdown/partial meltdown is happening.

What's the worst case scenario fix, vaporized the whole complex with a nuke? Or just post a no swimming sign in the Pacific Ocean and tell the Japanese that they can check out but they can never leave. If not, time will be spent for the next couple of decades robotically cleaning up and that is after the situation stabilizes because of the known and unknown (like a +8.0 Earth movement with accompanied sloshing).

I'm sure the think-tanks discussed all possibilities and will concluded by using percentages. If the DOD hasn't been tracking plumes and taking hi-res pics with sensor readings, they should be de-funded.

 

[AtomicWombat]

It is a view from the north, looking into the south end of Unit 3, I believe. The SFP's are in the southeast corners of Units 3, 4.

I personally can't say with any confidence where the SFPs are in any reactor building, but I'm fairly confident the layered structure beneath the fallen gantry crane beam is the northern external wall of the primary containment. Indeed the smoke appears to rise through the broken roof frame work very close to the northern edge of what's left.

I don't know how to do thumbs so I won't attempt to repost your image.