Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[|Fred]

When reactor #3 exploded it caused most of this damage to unit 4 from the reports I have read

Please stand corrected, as this statement is not true. see attachment.

This is the southern wall of this reactor building. There is an almost identical hole in the northern wall

Thank you, notice that this hole is located on the floor below the operating floor and notice the way and that the wall still standing on the North on the operating floor.

What doe not make sens to me is that the pool are open to the air and located south.
assuming the watter level droped the hydrogen would have populated the operating floor going up from the pool rather than seeking ways across concrete , if anything it could have some how populated the top of the reactor core vessel.

But the floor bellow the operating floor makes little if no sens ? is there a structure that runs bellow the OP floor North to South on the whole level and is connected to the pool?

 

[shogun338]

This is the image after explosion #3 before #4. I don't think we have an explosion video for #4. #4 had fresh fuel in SFP.
https://www.physicsforums.com/showpost.php?p=3197547&postcount=539

http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichiov_march14_2011_dg.jpg

Thanks for the pics. I see what your saying now . So just the spent fuel pools leaking most of the water out causes hydrogen to build up in the buildings causing them to explode .

 

[Borek]

What i think is even if there is a catastrophic radiactivity, it will be held confidential for various reasons.

You can buy a radiometer for something like $300 and check the radiation level by yourself, no way contamination can be held confidential.

 

[TCups]

Please stand corrected, as this statement is not true. see attachment.

But the floor bellow the operating floor makes little if no sens ? is there a structure that runs bellow the OP floor North to South on the whole level and is connected to the pool?

Fred:
The link between the open holes on the north and south walls of Unit 4, one level below the top floor, would seem to be the open tops of the SFP on the south and the equipment pool on the north. A blast in the top floor would, transmit a hydraulic shock wave into the pools if they were full of water. If not full of water, then they would be directly connected by air space and still subject to direct damage from the blast.

Consider, though, that if there were still some water in the equipment pool on the north end of Bldg 4, and if the damage were from hydraulic transmission of the shock wave, then that "tongue" of material we initially saw hanging out, whatever it was, may have been carried out by the water that gushed out.

 

[TCups]

Hi Fred,
This is the southern wall of this reactor building. There is an almost identical hole in the northern wall (see my attachment) that has what looked to me like a discharge of corium lava. It may be just melted insulation. I am still unsure. Based on the position of the fuel crane (northern wall), it seems that this melted mass is unlikely to be corium.

I can explain the holes in the opposing sides assuming they are adjacent to the equipment pool (on one side) and the SFP on the other. Hydrogen would accumulate over the SFP. Once it reached the explosion limit the explosion would be strongest there, presumably strong enough to blow out both the SFP containment and the exterior wall.

Reactor diagrams also show that adjacent to the equipment pool the exterior wall is the only barrier to the outside environment. So this would be a weak point.

I find it difficult to explain why so many panels below the operating floor on the east and west side also blew out, especially since hydrogen is a light gas and would not tend to settle deep in the building..

AW:

The picture you attached:
https://www.physicsforums.com/attachment.php?attachmentid=33678&d=1301381377

ls the north wall, and the outward "flow" appearance may be the result of water that gushed through the hole after the blast.

Two things about this picture have always seemed incongruent, though.

1) if the damage to bldg 4 were from an internal blast strong enough to blow that side panel out, then why the heck does the top wall seem to fall inward, not outward?!

2) look at the full length of the vertical column on the NE corner. It is damaged and appears to me to have buckled inward from the concussion of the blast at Bldg 3, doesn't it?

Another question: why don't we have video of the blast at Bldg 4? Did it occur after dark?

Something strange happened at Bldg 4, and we don't have all he information.

 

[AntonL]

1) if the damage to bldg 4 were from an internal blast strong enough to blow that side panel out, then why the heck does the top wall seem to fall inward, not outward?!

Another question: why don't we have video od the blast at Bldg 4? Did it occur after dark?

To 1) I can only think that a hydrogen blast is followed by an implosion as all the air that has been displaced gushes back into the vacuum created. Maybe someone will want to correct me on this. Thus depending on the blast dynamics the north wall could have been sucked back into the building.

Also a lot of the blast energy went down the building, as unit was under maintenance and blast/fire doors hatches etc would be open, have a look at the panels of the fuel service tunnel to the west of the building, all the panels where dislodged there at ground level

Bldg 4 explode around 6 in the morning - no helicopters in the sky circling and filming

 

[TCups]

To 1) I can only think that a hydrogen blast is followed by an implosion as all the air that has been displaced gushes back into the vacuum created. Maybe someone will want to correct me on this. Thus depending on the blast dynamics the north wall could have been sucked back into the building.

Bldg 4 explode around 6 in the morning - no helicopters in the sky circling and filming

The video of the blasts at 2, 3 were from the ground. More likely, things were starting to get "hot" and the camera crews were evacuated.

How the hell does the blast blow out all the east side panels at ground level, and yet, leave the north side panels at the same corner intact? It makes no sense.

I would love to get my hands on a full set of structural drawings of those buildings.

The only explanation I can put forth is a scary one --

1) the overhead crane protected the top north wall from the brunt of the blast force.
2) the explosion was more than hydrogen gas. It occurred in the spent fuel pool, and breeched not only the outside wall of the SFP, but also its inside wall and floor, with a large portion of the blast venting to the lower levels of Bldg 4.

The scary implication of this hypothesis is that the fuel in the SFP of Unit 3 melted "down" into the building or was blown down into the lower building when the hydrogen blast occurred. Nasty.

 

[AntonL]

Also a lot of the blast energy went down the building, as unit was under maintenance and blast/fire doors hatches etc would be open, have a look at the panels of the fuel service tunnel to the west of the building, all the panels where dislodged there at ground level

And what caused the welds on these pipes to break and unfurl? (https://www.physicsforums.com/showthread.php?p=3198789&highlight=pipes#post3198789") as arrowed and you can see fuel service tunnel panels been blown out to the right of the arrow

received no answers to #589 yet

 

[TCups]

And what caused the welds on these pipes to break and unfurl? (https://www.physicsforums.com/showthread.php?p=3198789&highlight=pipes#post3198789") as arrowed and you can see fuel service tunnel panels been blown out to the right of the arrow

received no answers to #589 yet

Uhhhhh. . . How about something very hot blasting out of that big hole? At the very least, the concrete and steel lining the wall of the SFP blew outward.

Also, the tunnel is connected to the top floor via an open vertical shaft for the lift of the fuel, right?

Bottom line, if the fuel in the SFP was the source that fueled the blast, then something very very bad happened to the fuel.

 

[Lefteris]

You can buy a radiometer for something like $300 and check the radiation level by yourself, no way contamination can be held confidential.

I might be a bit overreacting but I am thinking of doing that since I live in Tokyo and I am getting bombarded with different opinions concerning safety/leaving/staying.

The problem is that when I checked the internet for ordering through there, everything everywhere seems to be sold out or at extremely low stock(close to being sold out) and there was a huge variety of measuring tools, whose differences I did not understand. Things like radiation meter,dosimeter, geiger meter. So I don't know what's what.

What should someone buy to measure radiation in the environment? And if possible can anyone recommend any sites which would ship internationally?(to Japan specifically)

 

[jlduh]

ON PLUTONIUM, CLARIFICATIONS WANTED from experts here:

1) we know that in normal functionning a reactor is producing a signifiant amount of plutonium (is saw some data just earlier on this thread, with basically a standard reactor producing enough plutonium every two months to build a bomb as historically most of the civil nuclear program started to get enough plutonium to make bombs: megawatts were in direct relation with megatons, to say it in a short sentence, and they were at first produced to get megatons. Now, and since the end of the cold war and military denuclearisation of the world -to some extent-, megawatts have vastly replaced megatons, which by the way increased the problem of what to do with excess plutonium produced that was no more going into bombs, and MOX fuel (retreatment) is one of the options developped to deal with this problem.

So there is obviously plutonium in various amounts in all places of the plant (reactors and SFP) where there is fuel used or in use, with of course more Pu in used fuel.

Now the question for specialists: can we easily identify and separate (by measurements/analysis) Pu from MOX used i the reactor 3 from "normal" Pu generated in any other reactor and coming from them or from SFP? Are they different somewhere? (i would guess so but fact is better than guess!)

2) i re-ask this question because i got i think no answer on this one:

(https://www.physicsforums.com/showpost.php?p=3215058&postcount=1734)

I need some clarification (promised, this is not political ) related to the hypothesis that it seems there is now some plutonium in the environment of the plant: when we talk about "millisieverts" for example, this is a measure of the dose equivalent radiation, which tries to quantitatively evaluate the biological effects of ionizing radiation.

The equivalent dose to a person is equalled to the absorbed dose, in gray, multiplied by a weighting factor. The weighting factor is determined by a combination of the radiation type, the tissue absorbing the radiation, and some other factors.

So my question is the following one: does the dose equivalent take into account the presence of very toxic elements like plutonium even in small quantities, and if yes, how is it measured by the equipments and integrated in the measurement in millisieverts for example?

In other words, can measurements in millisieverts still be compared to "safe limits" of doses per 24h, or per year for example (in fact i know that it's more a probabilist approach: one dose creates an excess risk of cancers of X/million people) EVEN IF THERE IS SOME ELEMENTS LIKE PLUTONIUM AROUND?

 

[PietKuip]

You can buy a radiometer for something like $300 and check the radiation level by yourself, no way contamination can be held confidential.

People should not waste their money on such sophisticated instruments. A pocket dosimeter (for less than a tenth of that price) will be sufficient for taking away anxiety.

 

[liamdavis]

I might be a bit overreacting but I am thinking of doing that since I live in Tokyo and I am getting bombarded with different opinions concerning safety/leaving/staying.

The problem is that when I checked the internet for ordering through there, everything everywhere seems to be sold out or at extremely low stock(close to being sold out) and there was a huge variety of measuring tools, whose differences I did not understand. Things like radiation meter,dosimeter, geiger meter. So I don't know what's what.

What should someone buy to measure radiation in the environment? And if possible can anyone recommend any sites which would ship internationally?(to Japan specifically)

This first link is for a company that calibrates and sells radiation measuring tools. I do not know their inventory status but they were swamped with orders recently and had difficulty getting freight shipments to Japan.

http://www.ki4u.com/products1.php


Next are some social networks providing on-line mapping of their meter readings. The third one is the one that started or organized it, as I understand.

http://japan.failedrobot.com/

http://www.rdtn.org/

http://community.pachube.com/node/611


Last is an article describing the modification of a cold war analog geiger counter to produce a digital output and link it to the internet.

http://freaklabs.org/index.php/Blog/Misc/Hacking-a-Geiger-Counter.html

 

[Astronuc]

There is a difference between the Pu/TU isotopic vector of Pu produced in UOX (UO₂) vs MOX. The MOX fuel basically recycles from irradiated UOX. In that case, MOX fuel generates more of the higher order Pu-242, and isotopes of Am and Cm.

I'll post a picture later of the production chain of Pu and TU (transuranics) elements.

I was looking for a graph or table of Pu isotopes as a function of burnup.

Note that Units 1, 2 and 3 were only a few months into their current cycles, and that affects burnups. Also, they are all probably roughly quarter core batch sizes, so there would four groups of assemblies with different ranges of burnup, and consequently different proportions of Pu, and different Pu isotopic vectors.

Pu-238 is produced by successive neutron capture in U-236 + 2 beta decays or from neutron capture in Np-237 + 1 beta decay.

The spent fuel would have several batches of with the highest levels of burnup for that fuel.

Update:

Isotopic vector for typical Reactor Grade (RG) Pu and WG Pu

Isotope   RG Pu  WG Pu
           w/o     w/o
 Pu-238    2.5    0.05
 Pu-239   54.7   93.6
 Pu-240   26.1    6.0
 Pu-241    9.5    0.3
 Pu-242    7.2    0.05

PuO₂ is usually mixed with depleted UO₂

 Depleted U
Isotope     w/o
 U-234    0.00119
 U-235    0.25000
 U-238   99.74881

 

[AntonL]

a pressure increase is expected with the volume of water injected into a closed system

but more worrying the temperature is approaching the 300 degree design limit
below history since last high temperature alarm first temperature reports from 22/3

22/3 11:20 383 degree C .227Mpa_g 33 l/min 11:20
23/3 04:00 >400 degree C .270Mpa_g 300 l/min 03:33
23/3 16:00 305 degree C .358Mpa_g 188 l/min 11:00
24/3 17:00 217 degree C .367Mpa_g 113 l/min 21:45
25/3 10:00 197 degree C .349MPa_g 120 l/min 15:30
26/3 13:00 212 degree C .380MPa_g no new reading
27/3 05:30 212 degree C .407MPa_g no new reading
27/3 09:00 224 degree C .416MPa_g no new reading
28/3 03:00 273 degree C .443MPa_g 113 l/min 14:00

Yesterday I very much expected the below, but 113l/min should be more than enough to keep the reactor cool since 24th, something happened on the 27th that temperatures should rise again!

Tokyo Electric Power Company has begun pouring more fresh water into the No.1 reactor at the Fukushima Daiichi nuclear power plant to cool it down.

TEPCO says the surface temperature of the No.1 reactor rose from 212.8 degrees Celsius as of 6 AM on Monday to 329.3 degrees 20 hours later.

It blames heat generated by the reactor's nuclear fuel. The reactor is designed to operate up to 302 degrees under normal conditions.

The power company raised the volume of water into the reactor from 113 liters a minute to 141 liters at 8 PM on Monday. As a result, it says, the reactor's temperature fell to 323.3 degrees as of 6 AM on Tuesday.

TEPCO says it will continue closely monitoring the reactor while fine-tuning water volume.
Tuesday, March 29, 2011 16:19 +0900 (JST)

It blames heat generated by the reactor's nuclear fuel. I hope they meant rest heat !

while fine-tuning water volume it seems they have no analysis team working to obtain parameters for the crippled station, control by prediction with periodic checking is better than control by alarm - a sign that Tepco seems to be very much understaffed to deal with this overwhelming situation

 

[jlduh]

@ Lefteris: I think you can already have a good view of the air contamination through all the measurements (from independant people) that have mutiplyied on the net in the last two weeks.

If you go back a few pages behind there is a post with several links and applications (i remember one: http://community.pachube.com/ )

I follow also since the very beginning this measurement done by a guy somewhere in Tokyo:

http://www.denphone.com/denphone-tokyo-office-geiger-counter

Be aware that measurements are always subject to inaccuracies and sometimes mistakes (calibration and so on) and this can even be more true if individual with no background do it. BUT if you use several sources of infos (even the official ones) and try to get a global figure of the data you have access to, you can get a good feeling of what is going on.

Having you own geiger counter in Tokyo will be just an other one in the multitude that are already in use there (a lot of people rushed on them!), if you were living in the counstryside in the North/Northwest side of Fukushima my answer would be probably different (unfortunately we don't see many people from there on the forum, and they should be the most concerned based on the first two weeks of the crisis and the data I've seen, and I'm not sure the picture is as clear there than in Tokyo from the measurements standpoint).

Also, to my knowledge, if you imagine that you can also seriously assess the level of contamination of what you eat or drink (which is an other legitimate concern in addition to the one concerning the air), my knowledge (maybe wrong, other can confirm or infirm) is that these generic counters are not adapted to measure the risk of what you ingest through the food and drink, this requires a heavier procedure which is not possibly done by individuals.

So my answer is:

1) for air: redundant in tokyo, analyse what's already available and see trends.

2) for food and drink: there is no easy solution for an individual.

Others who have knowledge on that, please precise my answer because i think it's important for people from Japan reading this forum.

 

[Lefteris]

This first link is for a company that calibrates and sells radiation measuring tools. I do not know their inventory status but they were swamped with orders recently and had difficulty getting freight shipments to Japan.

http://www.ki4u.com/products1.phpNext are some social networks providing on-line mapping of their meter readings. The third one is the one that started or organized it, as I understand.

http://japan.failedrobot.com/

http://www.rdtn.org/

http://community.pachube.com/node/611Last is an article describing the modification of a cold war analog geiger counter to produce a digital output and link it to the internet.

http://freaklabs.org/index.php/Blog/Misc/Hacking-a-Geiger-Counter.html

Amazing links liam. Thanks a bunch! It will certainly come in handy!

Edit: Jiduh, I know you are right and I think that the links liam posted will suffice.
As for food and drink I really have no idea what to do eithr than staying off fish for now and generally sticking to imported foodstuff. The big question is until when.

 

[Demidrol]

Who has the cartograms downloads from burnout on cluster for the blocks № 1-4 at the time of the accident ?

 

[jlduh]

Lefteris: avoid milk, especially fresh vegetables with big leafs, fresh fish from around tokyo and pacific around the area suspected - right now the ocean and local coasts is a big unknown.

The links provided give a big amount of numbers which is useful to some extent, but remember that a followed trend (a graph) is telling you sometimes more than a bunch of individual data, that's the interest of the link i provided: http://www.denphone.com/denphone-tok...geiger-counter

Something else: the real local situation in the sum of general trends AND local particularities. This is even more true when another factor is put in the game: rain. Because rain can wash some contamination coming from a higher altitude. So in this case contamination at ground level can become more like a "spotted leopard" with local "spots" of higher concentration.

 

[AntonL]

Lefteris: avoid milk, especially fresh vegetables with big leafs, fresh fish from around tokyo and pacific around the area suspected - right now the ocean and local coasts is a big unknown.

MUSHROOMS are a big NO-NO for a very long time

http://racerocks.ca/biology/fungi/fungrad.htm

 

[jlduh]

YESSSS, i forgot MUSHROOMS you are right!

Astronuc, thanks for your (as usual!) detailed answer on Plutonium. So it means that TEPCO should be able to know from where this plutonium came from: N°3 MOX or the others.

An other question, I've heard this sentence: "because Plutonium is so dense and heavy, IT CANNOT go very far and be transported to a great distance from its source point, so it should stay around the vicinity of the plant".

I know it's a very dense element, but is this sentence 100% true?

Still waiting for answer for the relation between millisieverts and toxicity of Plutonium (see my post above)

 

[|Fred]

So my question is the following one: does the dose equivalent take into account the presence of very toxic elements like plutonium even in small quantities, and if yes, how is it measured by the equipments and integrated in the measurement in millisieverts for example?

I don't know about how you define toxicity of the element, radiation wise the measurement given in sievert does take into account the fact that we believe alpha particles do more damage to Human cells that beta, by a factor 20.

In other word if you have a 20mSv/h reading it could come from n beta decay or n/20 alpha decay (or any mix in between )

Regarding any isotopes the way they can be transported is If I'm not mistaken closely related to what they are: gaz, metal ..

 

[Borek]

And what caused the welds on these pipes to break and unfurl?

(...)

Have they survived quake intact?

 

[Borek]

The problem is that when I checked the internet for ordering through there, everything everywhere seems to be sold out

I am afraid situation won't change in the following weeks.

At the same time, if your knowledge about these devices is low, I doubt buying one makes sense at the moment. There were already links posted (in this thread) to sites where people monitor radiation levels in Japan on their own.

 

[liamdavis]

Amazing links liam. Thanks a bunch! It will certainly come in handy!

Edit: Jiduh, I know you are right and I think that the links liam posted will suffice.
As for food and drink I really have no idea what to do eithr than staying off fish for now and generally sticking to imported foodstuff. The big question is until when.

Here is a basic article about food from the Health Physics Society. They also have some information about the fukushima situation.

AntonL, I had no idea about the mushrooms, thank you.
liam

http://hps.org/publicinformation/ate/faqs/radiationnuclearpower.html

http://hps.org/fukushima/

http://hps.org/

 

[Borek]

People should not waste their money on such sophisticated instruments. A pocket dosimeter (for less than a tenth of that price) will be sufficient for taking away anxiety.

I was not suggesting anyone to buy one, sorry if it sounded this way. What I was aiming at was the fact that it is impossible to hide high levels of radiation; it is about as easy as trying to keep fact that it is raining confidential.

 

[jlduh]

Just seen at NHK that they have 20 new High resolution pictures of the plant, taken by a small drone plane used to take pictures of volcanoes for example. They presented two with an expert.

Does somebody know if these pictures are available somewhere?

Also, i saw this:

http://www.suasnews.com/2011/03/470...se-footage-of-power-plant-taken-by-u-s-drone/

The video was from US plane, it seems japan didn't release it until know?

I have a hard time to understand why this secrecy. This culture of secrecy, partial infos and misleading conclusions or presentations is generating a culture of doubt and fear, and we can understand it.

 

[jlduh]

Borek

What I was aiming at was the fact that it is impossible to hide high levels of radiation

Even in food which is much more difficult to independently assess?

Now for HIGH and VERY HIGH levels of radioactivity, it seems they have an other method: "it is OVER 1 sievert"!

 

[TCups]

Have they survived quake intact?

Borek:

Ref: http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichiov_march14_2011_dg.jpg

Hard to tell at this resolution, but they (the pipes south of unit 4) appear to be intact after explosion at #3 and before explosion at #4. By comparison, I believe some breaks can be seen in similar size pipes between Bldg 3 and 4, although the light is different and "ballooning" of the bright portions of the pipe on the south side of Bldg 4 could obscure breaks.

 

[Borek]

Still waiting for answer for the relation between millisieverts and toxicity of Plutonium (see my post above)

Found this: http://yarchive.net/physics/plutonium_toxicity.html

 

[jlduh]

Fred

I don't know about how you define toxicity of the element, radiation wise the measurement given in sievert does take into account the fact that we believe alpha particles do more damage to Human cells that beta, by a factor 20.

In other word if you have a 20mSv/h reading it could come from n beta decay or n/20 alpha decay (or any mix in between )

Regarding any isotopes the way they can be transported is If I'm not mistaken closely related to what they are: gaz, metal ..

Ok thanks. My point is that until now, medias and autorities have based their conclusions given in their communicates on dose or doses/h, in millisievert or millisievert/h. Under a certain dose (dose rate X time of exposure) it is safe. Period.

My question around toxicity of Pu is: does this simple and UNIQUE equation

dose (mSv) < safe limit

is enough to caracterize the safety concerns even with for example Pu around?
Does it tell the all story?
Would be surprised about that but maybe I'm wrong...

 

[Astronuc]

YESSSS, i forgot MUSHROOMS you are right!

Astronuc, thanks for your (as usual!) detailed answer on Plutonium. So it means that TEPCO should be able to know from where this plutonium came from: N°3 MOX or the others.

An other question, I've heard this sentence: "because Plutonium is so dense and heavy, IT CANNOT go very far and be transported to a great distance from its source point, so it should stay around the vicinity of the plant".

I know it's a very dense element, but is this sentence 100% true?

Still waiting for answer for the relation between millisieverts and toxicity of Plutonium (see my post above)

Both U and Pu are hazardous IF ingested - which is the key. As long as U and Pu stay outside the body, it's not a big deal. The problem arises when U and Pu get into the food or water cycle, or are inhaled, i.e., ingested. Both U and Pu are heavy metals, and they will do damage to certain organs, just as mercury (Hg), arsenic (As) and lead (Pb) would do damage IF ingested.

As far as I know, U is a problem for kidneys, and Pu may be taken up in the bones.

Both present a radiological hazard in addition to the chemical hazard. Pu isotopes have shorter half-lives, so the same number of atoms or mass presents a greater hazard IF ingested.


As for the source of the Pu (and U), there is a clear distinction on the isotopics that I amended (updated) to my previous post. However, it may not be so clear depending on how impure the Pu used in the Chinese detonations.

However, if there is Pu-238, then it more likely came from the spent fuel than another source.

For now, it appears that the Pu and U particles/fines are confined to the plant. However, like any dust, they could be transported - in minute quantities.

See this for various reports on Radiation Effects
http://www.hps.org/publicinformation/ate/cat25.html

 

[|Fred]

My question around toxicity of Pu is: does this simple and UNIQUE equation dose (mSv) < safe limit

if you are holding a bag "give you" 20mSv/h it does not matter if it is plutonium or iodine.
BUT: il will require less plutonium than idoine to give those 20mSv/h

 

[Dancewithbear]

I don't know about how you define toxicity of the element, radiation wise the measurement given in sievert does take into account the fact that we believe alpha particles do more damage to Human cells that beta, by a factor 20.

In other word if you have a 20mSv/h reading it could come from n beta decay or n/20 alpha decay (or any mix in between )

Regarding any isotopes the way they can be transported is If I'm not mistaken closely related to what they are: gaz, metal ..

Alpha radiation though is not penetrating i.e. it’s easily stopped by skin, clothing, paper pretty much anything. The danger is in ingesting/inhaling it or otherwise introducing internally. http://orise.orau.gov/reacts/guide/alpha.htm

I think (please correct me if I’m wrong as I am just learning this like many) the danger comes from the decay process once its inside the body. i.e. if inhaled and it lodges in the lung some amount will be expelled through normal processes but what remains may be resting on cells and the energy of decay can adversely affect cells (cell dies) or worse affects cell division were random things can happen potentially cancer.
http://www.epa.gov/rpdweb00/understand/alpha.html

That said the feared health effects are not always realized. Nagasaki survivors showed low effects from the Plutonium bomb. It’s pretty much a crap shoot with short term exposure. Long term exposure as in mines and home radon definitely show effects.
http://www.rerf.or.jp/general/qa_e/qa12.html
http://www.msnbc.msn.com/id/42312474/

 

[|Fred]

For now, it appears that the Pu and U particles/fines are confined to the plant. However, like any dust, they could be transported - in minute quantities.

If I'm not mistaken they are in hot rods boiling to melt.

I don't think it is dust friendly (but I may be mistaken)

Can the Pu or the other Metal (fission product) of fuel interact with the water (disolve oxydise) and end up in the sea or in the steam ? (I don't think it is likely but I may be mistaken expecialy since we use salty water)

Can the Pu or the other Metal burn at be carried by the smoke, I think they can and that's the reason they so desperately try to cool the Fuel in the pool

 

[Astronuc]

Alpha radiation though is not penetrating i.e. it’s easily stopped by skin, clothing, paper pretty much anything. The danger is in ingesting/inhaling it or otherwise introducing internally. http://orise.orau.gov/reacts/guide/alpha.htm

I think (please correct me if I’m wrong as I am just learning this like many) the danger comes from the decay process once its inside the body. i.e. if inhaled and it lodges in the lung some amount will be expelled through normal processes but what remains may be resting on cells and the energy of decay can adversely affect cells (cell dies) or worse affects cell division were random things can happen potentially cancer.
http://www.epa.gov/rpdweb00/understand/alpha.html

That said the feared health effects are not always realized. Nagasaki survivors showed low effects from the Plutonium bomb. It’s pretty much a crap shoot with short term exposure. Long term exposure as in mines and home radon definitely show effects.
http://www.rerf.or.jp/general/qa_e/qa12.html
http://www.msnbc.msn.com/id/42312474/

The harm from alpha emitters come from when they are inhaled - damage to the lining of the lungs - as well as ingested. U and Pu are heavy metals, but Pu has greater radiotoxicity due to shorter half-lives. In addition to the alpha emission, there is usually a gamma ray, and some isotopes decay be beta emssion.

See - https://www.physicsforums.com/showpost.php?p=3217152&postcount=15 - for related material.

 

[TCups]

RE: BLAST MECHANISM AT BLDG 4 (HYPOTHESIS) UNCONFIRMED

Could this have happened at Bldg 4?

A) fuel overheats and may have caused either fire(s) in the subjacent floor, or a hydrogen explosion in the superstructure, or both, but more importantly,

B) The heat and weight of the contents of the SFP4, or the force of the secondary hydrogen explosion from above, or both cause the overheated mass of fuel rods to breech the floor of the SFP, gaining access to the lower floors, and suqsequently, the external damage visible on the previous photos. UNCONFIRMED

Note that the outside walls immediately adjacent to the primary containment are on the east side of the building as the reactor is located off center and to the east of the east-west centerline of the building.

If hot fuel made it all the way to the water in the torus suppression pool, then there might be another big steam blast as well. UNCONFIRMED

Note also that this type of high pressure explosion within the confines of Bldg 4 would partially vent through those broken pipes on the south side, correct?

Updated. Current data does not support the conclusion of this type of explosion.

 

[AntonL]

And what caused the welds on these pipes to break and unfurl? t

Have they survived quake intact?

Cannot be confirmed, however I cannot imagine the quake to this kind of damage to the welds

 

[TCups]

Cannot be confirmed, however I cannot imagine the quake to this kind of damage to the welds

Then how about a huge blast from inside Bldg 4, maybe from hot fuel rods from SFP4 melting and dropping through, eventually into the torus suppression pool?! See post above.

 

[havemercy]

http://www.asn.fr/

Presse conference of this morning from the French ASN.

They say, for the first if i am not wrong, that the hearts of number 1, 2 and 3 reactor have partial meltdonw - they always previously said that the reactor was dammaged.

They also say that the pools - without referring to specifif number - are now cooled with water trough internal piping.

 

[AntonL]

Then how about a huge blast from inside Bldg 4, maybe from hot fuel rods from SFP4 melting and dropping through, eventually into the torus suppression pool?! See post above.

TCups I admire your imagination and investigating every angle but here I have to disagree stretched a bit too far in my humble opinion

 

[TCups]

TCups I admire your imagination and investigating every angle but here I have to disagree stretched a bit too far in my humble opinion

I certainly hope so. . .

BTW, how do you explain the extent of damage seen to the exterior of Bldg 4? Far fetched as it seems, this is all I can come up with.

 

[Joe Neubarth]

The video of the blasts at 2, 3 were from the ground. More likely, things were starting to get "hot" and the camera crews were evacuated.

How the hell does the blast blow out all the east side panels at ground level, and yet, leave the north side panels at the same corner intact? It makes no sense.

I would love to get my hands on a full set of structural drawings of those buildings.

The only explanation I can put forth is a scary one --

1) the overhead crane protected the top north wall from the brunt of the blast force.
2) the explosion was more than hydrogen gas. It occurred in the spent fuel pool, and breeched not only the outside wall of the SFP, but also its inside wall and floor, with a large portion of the blast venting to the lower levels of Bldg 4.

The scary implication of this hypothesis is that the fuel in the SFP of Unit 3 melted "down" into the building or was blown down into the lower building when the hydrogen blast occurred. Nasty.

I have seen you guys ask questions that you are answering by yourselves over and over again. The direction of the blasts are shaped by the physical weakness of the structures around them, just like water flows where the least resistance is.

I have not followed your discussion much as I know from experience in reading numerous summary reports that we will only know the truth after the Japanese have decided what it is. That is going to be one hell of a report running thousands of pages, and it may not be written as it should if the decision is made to cap the whole reactor building, if, indeed, the reactor containment vessel exploded on three. Right now, all of the guess are just guesses. Since I am days behind most of your observations and have trouble telling one wall from another I am in awe of your summaries so far.

Let me go back and ask a simple question, "What was the large structure that was lifted hundreds of feet into the air that we can clearly see in the dark cloud explosion of Reactor Three? You can see it coming back down out of the top of the cloud and impacting the ground. Exactly where, I do not know, but I am certain you guys have already figured that out."

 

[jlduh]

If i try to summarize (and i try to keep it simple and understandable for non specialists):

1) dose and dose rate in mSv and mSv/h define the radioactivity at the point of measurement coming from various elements around emitting in alpha and beta rays. A dosimeter detects the various emissions and corrects (by calculation) them with factor taking into account the fact that alpha is more energetic than beta and so can cause more damages to cells. The corresponding results is expressed in mSv/h for example. RIGHT?

2) a specific element can be dangerous and toxic by:
2-A its chemical effects
2-B its radioactive effects
RIGHT?

3) If ingested of inhaled, then these to possible effects can add together.
RIGHT?

4) if ingested or inhaled, these effects are increased by the fact that they go closer to or even in direct contact with target organs that they can damage.
RIGHT?

Note that chemical effects have to take into effect the fact that byproducts of several chemical transformation in the body can appear and be also harmful. Don't know if it's the same with radioactive isotopes inside the body?

The particularity of radioactivity is that it can harm even at distance through rays, which is not the case of chemical effects (the chemical product can be inhaled or ingested or go through skin, but in this case, the distance is no more there of course). Again one element can have chemical AND radioactive effects, the difference has to be understood.

 

[TCups]

I have seen you guys ask questions that you are answering by yourselves over and over again. The direction of the blasts are shaped by the physical weakness of the structures around them, just like water flows where the least resistance is.

I have not followed your discussion much as I know from experience in reading numerous summary reports that we will only know the truth after the Japanese have decided what it is. That is going to be one hell of a report running thousands of pages, and it may not be written as it should if the decision is made to cap the whole reactor building, if, indeed, the reactor containment vessel exploded on three. Right now, all of the guess are just guesses. Since I am days behind most of your observations and have trouble telling one wall from another I am in awe of your summaries so far.

Let me go back and ask a simple question, "What was the large structure that was lifted hundreds of feet into the air that we can clearly see in the dark cloud explosion of Reactor Three? You can see it coming back down out of the top of the cloud and impacting the ground. Exactly where, I do not know, but I am certain you guys have already figured that out."

Uh, large pieces of the roof? "Clearly" may be a relative term here, though. I clearly see large holes blasted in the south, east and north sides of Bldg 4, for example. I don't know that I clearly see a single large piece of debris falling in the remnants of the explosion of Bldg 3, but it is certainly possible.

Here's a question, though: just how hot do dry fuel rod assemblies get? Hot enough to melt the steel lining of the SFP4 and damage concrete?

PS: Joe - I am neither a novelist nor an engineer. I am a radiologist. I spend all day, every work day looking at complicated pictures, asking myself questions about what is normal and what isn't, and then, hopefully, answering them for the patients and referring physicians who ordered the test and are counting on my best opinion of what I see and what I think it means. Sorry if I can't break out of that habit. Sometimes, though, such observations and speculation may lead others to lines of thought and conclusions they may not have otherwise considered. At least that is how it works in medicine.

 

[Astronuc]

If i try to summarize:

1) dose and dose rate in mSv and mSv/h define the radioactivity at the point of measurement coming from various elements around emitting in alpha and beta rays. A dosimeter detects the various emissions and corrects (by calculation) them with factor taking into account the fact that alpha is more energetic than beta and so can cause more damages to cells. RIGHT?

2) a specific element can be dangerous and toxic by:
2-A its chemical effects
2-B its radioactive effects
RIGHT?

3) If ingested of inhaled, then these to possible effects can add together.
RIGHT?

4) if ingested or inhaled, these effects are increased by the fact that they go closer to or even in direct contact with target organs that they can damage.
RIGHT?

Note that chemical effects have to take into effect the fact that byproducts of several chemical transformation in the body can appear and be also harmful. Don't know if it's the same with radioactive isotopes inside the body?

The particularity of radioactivity is that it can harm even at distance through rays, which is not the case of chemical effects (the chemical product can be inhaled or ingested or go through skin, but in this case, the distance is no more there of course). Again one element can have chemical AND radioactive effects, the difference has to be understood.

That's more or less correct.

Each radionuclide has a chemical effect and a radiological effect. Non-radioactive isotopes just have the chemical effect.

Heavy metal radionuclides (heavier than lead) have the chemical effect of being a heavy metal as well as the radiological effect of their radioemission - alpha, beta and gamma. Outside of the body, distance and shielding can limit the exposure. Alphas are stop by few cm of air or layer of skin, betas are bit more penetrating (which is energy dependent), and gammas are most penetrating (also depending on energy). Beta particles represent a continuous spectrum of energy from a given radionuclide (assuming its a beta emitter) while gammas generally have discrete energies due to characteristics of the particular nucleus and its characteristic energy levels.

When inhaled, radionuclides are on the surface of the lungs, and radiation can damage the cells lining the lung - which affects the transport of oxygen and CO₂ - as well as increasing the risk of lung cancer or pulmonary disease. Depending on the isotope, the radionuclide could pass into the blood stream where it would be transported anywhere in the body.

Similarly, if ingested, the radionuclides irradiate the cells lining the alimentary canal - mouth to anus. There is also the increased risk of the radionuclide entering the blood stream where it will be transported to and taken up by a particular organ, if not excreted.

Iodine favors the thyroid gland.

Cs, Rb, would like affect the systems using Na, K.

Sr, Ba, would be more likely to affect those systems using Ca.

Heavy metals damage nerves (brain), kidneys and other organs.


This is why fission products and transuranics (radionuclides) are supposed to kept out of the environment - and exposures are to be As Low As Reasonably Achieveable/Practicable (ALARA/ALARP)!

 

[rhody]

This thought has been percolating in my mind for a couple of weeks,
finally, the media choose to address it, something for all to consider... from the Washington Times

http://www.washingtontimes.com/news/2011/mar/24/fears-rise-that-japan-could-sell-off-us-debt/"

Some lawmakers and market analysts are expressing rising concerns that a demand for capital by earthquake-ravaged Japan could lead it to sell off some of its huge holdings of U.S.-issued debt, leaving the federal government in an even tighter financial pinch.

Others say a major debt sell-off by Tokyo is unlikely, but noted that the mere fact that questions are being raised speaks volumes about the risks involved in relying so heavily on foreign investors to fund U.S. debt.

“This natural disaster in Japan concerns me that it could speed up what’s coming, because they are the second leading buyer of our debt,” Sen. Rand Paul, Kentucky Republican, told The Washington Times. “Small degrees of differences in how much they buy of our debt, I think, can make a big difference in interest rates that we have to pay people to buy our debt.”

With the federal government having piled up $14.2 trillion in debt, budget experts are warning that the country is on an unsustainable fiscal path. Congress, they say, must find cuts in all areas of the budget, while reforming the entitlement programs — Social Security, Medicare and Medicaid — that are the biggest drivers of national spending.

Rhody...

P.S. Keep up the excellent postings, this is an amazing time capsule of events that warrant future academic study, captured here for all time (except for links that may be deleted before a study is done).

 

[AntonL]

Here's a question, though: just how hot do dry fuel rod assemblies get? Hot enough to melt the steel lining of the SFP4 and damage concrete?
.

The SFP in Unit 4 is generating about 2MW of heat by reports that I have seen, enough to support your idea

However, should the pool have been dry long enough for it to melt the steel lining and damage the concrete you would have had huge amounts of contamination etc. this did not happen in unit 4,

Forget that idea

 

[Dancewithbear]

If i try to summarize (and i try to keep it simple and understandable for non specialists):

I have looked at this over the past few days and it seems that examining a specific detail leaves out other factors to the extent that one misses the big picture.

A lot of links have been provided. This one has navigational links on the left to explore including detection and treatment.
http://orise.orau.gov/reacts/guide/define.htm

On the one hand mSV/h is mSV/h but to know what to do you need to know what the source is and what other risks are within scope.

i.e. Plutonium is most dangerous if you inhale or ingest it. Cesium will likely be more predominate (than PU) and with a 30yr half-live is likely the thing your most affected by in a practical sense while iodine may be the biggest short term/immediate concern. You need to know what is there and take appropriate measures based on what it is. In that sense mSV/h is a risk rating.

An analogy to this is like the effect of a football play. It may be negligible as an incomplete pass or it may be a game changing touchdown or may result in a career ending injury. Generally by itself its inconsequential when examined in terms of 32 teams with 16 games each for the season over 10 years. There are many random factors not immediately apparent. It’s the result of these random events that determine the final outcome.

In the end look at the probability of exposure to the contaminants present and take appropriate measures to mitigate risks.

 

[DrDu]

Fred
Ok thanks. My point is that until now, medias and autorities have based their conclusions given in their communicates on dose or doses/h, in millisievert or millisievert/h. Under a certain dose (dose rate X time of exposure) it is safe. Period.

My question around toxicity of Pu is: does this simple and UNIQUE equation

dose (mSv) < safe limit

is enough to caracterize the safety concerns even with for example Pu around?
Does it tell the all story?
Would be surprised about that but maybe I'm wrong...

Especially in case of Plutonium, all its detrimental health effects are due to it's radioactivity although there exists the persistent ( and wrong!) myth that Pu is so dangerous due to its chemical toxicity.

The problem with the simple statement of save dose in mSv is that in fact there are no instuments that would allow to measure directly the dose in mSv (although some counters for external gamma dose mainly are gauged in this way).
E.g. to receive a dose of 1 mSv in 50 years it requires about ingestion of about 80000 Bequerel of Caesium 137 but only about inhalation of 15 Bq of Plutonium. The activity in Bq in the environment is relatively simple to determine.