Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[etudiant]

I get different numbers for Chernobyl from http://www.oecd-nea.org/rp/chernobyl/c02.html
where did you get yours from?

Ce-137 ==> ~85 PBq or ~2.3 GigaCi
I-131 ===> ~1760 PBq or ~48 GigaCi
You can get the rest from the table in the link
PBq = 10^18 Bq
GigaCi = 10^12 Ci

Peta is 10^15, rather than 10^18, at least afaik.

 

[Bioengineer01]

You guys and gals, of course, knew this all along. Right?

"The dangers of fukushima are greater than we think."

http://us1.campaign-archive1.com/?u=...&id=68c85cc08a

Edit by Borek: large quote possibly violating owner copyright deleted.

Yes, it is like a revolver pointed to Mother Earth with only one bullet loaded, but we don't know whether it will fire or not. I hate those who did this to us. I don't like being forced to play Russian Roulette with my family and friends...

 

[Bioengineer01]

If there were dangerous materials released from the boiling and burning fuel and concrete, including explosive Hydrogen, said materials could be problematic.

Yes, but water makes it worse...

 

[elektrownik]

Between NISA releases 158 and 159 the core presures of reactor #1 have abruptly fallen from 679 kPa and 1674 kPa to 126 kPa and 101 kPa (?), respectively:
http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/cur/out/plot-pres-un1-t-T-full.png
Since the other variables remained stable, it may be a transcription error (today is sunday; only a lowly trainee in the office, perhaps?), or they recalibrated the instruments and found that the previous readings were garbage.

They installed new pressure measure system and discovered that old data were wrong...
http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110602_02-e.pdf
http://www.tepco.co.jp/en/news/110311/images/110604_10.jpg

Also your plots of water level for unit 1 are worng, new sensor show that water level is "DS - Down Scale" which mean at lat -5m, not -4m

 

[Bioengineer01]

If there were dangerous materials released from the boiling and burning fuel and concrete, including explosive Hydrogen, said materials could be problematic.

Now that's exactly the point.

I propose encasing it (them) in a ten meter thick* cocoon of dry sand.
You propose pouring water on it .
Right?

Shall we continue from there?*(ten meter radius around each corium at minimum)

Agree with more sand added as the sand melts and mixes with the Corium, that worked in Chernobyl, we should not experiment here, same stuff as was mixed in Chernobyl... And, absolutely NO water...

 

[Bioengineer01]

A bit too much hyperbole for me.

He has discredited himself so that I don't listen to him.

But the other side is just as bad.

I didn't like his last statements at all... Although, he has chosen a "no win" position to be in... Very difficult to be him right now...

 

[Quim]

Yes but they are still hight radioactive, you don't want radioactive fuel rods to be exposed to air... water is not only coolant but also radiation shield

What or whom does SFP 1 need to be shielded from?

Judging from the radiation readings that have been released recently, it appears that no human will be working anywhere near that SFP for the next 150 years or so.

The rods in unit one are putting out about 2% of the heat and radiation that the #4 pond was said to be producing early on.
I can't say what would be the result of those particular rods meeting air but if it were a problem it would be easy enough to fill the pool with sand.

In post #5395 Jorge Stolfi estimated the total volume of a SFP as about 1600m³
"In that case, from the ~1690 m³ you should subtract ~95 m³ to get the free volume of the SFP."

But the fuel rods are only occupying the lower half of that space so 800 m³ of sand would be a permanent fix for that - if its a problem.
Tepco doesn't seem worried about it.


This is no longer a functioning reactor building.
It is now a gravesite.

 

[Jorge Stolfi]

They installed new pressure measure system and discovered that old data were wrong...
http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110602_02-e.pdf
http://www.tepco.co.jp/en/news/110311/images/110604_10.jpg

Yep. Isn't it a great feeling when you find that you have been plotting and analyzing garbage data for three months?

So, to simplify the picture, all three reactors are at atmospheric pressure. So they probably have a hole at the bottom, and their fuel is lying on the concrete at the bottom of the drywell, optimistically. And their "primary containments" seem to be leaking like sieves.

(But how could a manometer measure 1.6 MPa if everything is at atmospheric pressure? Perhaps a steam leak from Fukushima Daini, traveling through a crack in the Earth's mantle?)

Also your plots of water level for unit 1 are worng, new sensor show that water level is "DS - Down Scale" which mean at lat -5m, not -4m

Thanks. I wasn't sure what exactly was the bottom of the instrument's scale and conservatively guessed -4 m.

(They could make our life a bit easier by writing "< 5000mm", "> 400 C" etc. instead of just "downscale" or "offscale"...)

 

[Astronuc]

What or whom does SFP 1 need to be shielded from?

Judging from the radiation readings that have been released recently, it appears that no human will be working anywhere near that SFP for the next 150 years or so.

The rods in unit one are putting out about 2% of the heat and radiation that the #4 pond was said to be producing early on.
I can't say what would be the result of those particular rods meeting air but if it were a problem it would be easy enough to fill the pool with sand.

In post #5395 Jorge Stolfi estimated the total volume of a SFP as about 1600m³
"In that case, from the ~1690 m³ you should subtract ~95 m³ to get the free volume of the SFP."

But the fuel rods are only occupying the lower half of that space so 800 m³ of sand would be a permanent fix for that - if its a problem.
Tepco doesn't seem worried about it.


This is no longer a functioning reactor building.
It is now a gravesite.

The SFPs must be secured in order to eventually access the reactors and cores of Units 1, 2 and 3, which must eventually happen in order to mitigate further release of fission products. As long as the reactor service floors are contaminated and cluttered with debris, it is impossible to begin removing the spent fuel. As it stands, the SFPs have direct communication with the atmosphere, and thus a direct path between released fission products and the environment.

The spent fuel must be removed from the SFPs of Units 1-4 in and placed in casks. That can only happen after the debris is removed, and most likely will have to be done remotely, and possibly robotically.

 

[elektrownik]

The bad thing is that TEPCO know that unit 1 is at atmospheric pressure science some time, why ? Because of scale of instruments which they instaled in last days. They can show 3 times atmospheric pressure only. Old data were showing 15 times atmospheric pressure, so if they would not know that unit 1 is at atmospheric pressure they should install indicator with much more bigger scale...


Finally:
-From 10:16 am to 10:48 am on June 5, we started the water
injection to the spent fuel pool of Unit 1 by a temporary motor
driven pump.
-At 1:08 pm on June 5, we started the water injection to the spent
fuel pool of Unit 3 by a temporary motor driven pump (from 1:14 pm
to 2:16 pm, we added hydrazine (antioxidant)).

 

[turi]

What or whom does SFP 1 need to be shielded from?

Judging from the radiation readings that have been released recently, it appears that no human will be working anywhere near that SFP for the next 150 years or so.

The rods in unit one are putting out about 2% of the heat and radiation that the #4 pond was said to be producing early on.
I can't say what would be the result of those particular rods meeting air but if it were a problem it would be easy enough to fill the pool with sand.
[...]

The rods would melt and release various volatile radioactive isotopes into the air. Why would you want that? Just so you don't have to care about the SFP 1 anymore?

 

[SteveElbows]

Finally:
-From 10:16 am to 10:48 am on June 5, we started the water
injection to the spent fuel pool of Unit 1 by a temporary motor
driven pump.

Japanese version of status updates said that they injected just 15t. This is very small amount compared to what goes into reactor 4 pool, and is further indication that unit 1 pool is not a major concern at this time.

 

[inkling01]

Yes, it is like a revolver pointed to Mother Earth with only one bullet loaded, but we don't know whether it will fire or not. I hate those who did this to us. I don't like being forced to play Russian Roulette with my family and friends...

I hope you don't mind, but I sent you a PM

 

[Bioengineer01]

Well, I share all your views, you avoided me to write it!

To tell you the truth, if i posted this image at first with the comments I did, it was because I also share as a possibility the fact that this picture has been "arranged" for communication purposes, especially when you discover that in parallel, as you said, in the last map before this one (28 may), these VERY VERY VERY VERY high dose rubble (if I want to compare with this "high dose rubble of 12 mSv/h! ) of 950 and 550 mSv/h were not reported!

So basically they find 550 and 950 mSv/h rubble, and they communicate with a "nice" picture of a "high dose rubble" of 12 mSv/h? Guys, if they put a cone on every little bit of concrete like this one (the red one) with 12mSv/h or more, i can tell you that the all plant is going to be flooded with cones in addition to water...

Hahahahaha...Very good one

 

[Quim]

eventually access the reactors and cores of Units 1, 2 and 3

Possibly you industry guys need to pause and take a deep breath. Nobody is going to "access the reactors and cores of Units 1, 2 and 3" in the lifetime of you or your grandchildren.

There are no more "reactors" or "cores" in units 1,2 or 3.
There are blobs of corium which hopefully, but not necessarily, live mostly in what is left of the primary containment vessels. These blobs should not be dug up in any way.

 

[Bioengineer01]

They don't post pictures - it is wrong.

They post pictures - it is wrong.

I think you are trying to make way too much from random facts. And it is not something that fits this thread.

Sorry Mentor, you probably know a lot more physics than me, but I did work in a F50 Corporation, they have FULL departments of people that all they do all day long is to discuss details of how to arrange pictures like this to achieve the communications goal that they have. Nothing they report is random, unless you can get your hands on raw data that sometimes leaks out form a whistle blower that doesn't want to be identified. A 6 billion top line corp. in the USA may have 100+ people working on communications...

 

[Bioengineer01]

Do you honestly think that Arny Gundersen is painting an inaccurate tapestry? If so, please paint me an accurate one, and give me links to get accurate information.

Andy, you can get a much better picture of the consequences of radiation from Dr. Helen Caldicott, here is her web site: http://www.helencaldicott.com/ she was a high income high prestige MD, that delved into the effects of radiation on health and decided to make it her life goal to fight those who were spreading lies and creating cover ups. I call her the Mother Theresa of radiation protection. Of course the Nuclear industry calls her nuts. But never ever dears to engage her on a serious scientific discussion on the matter.

 

[elektrownik]

http://www3.nhk.or.jp/daily/english/05_21.html"

 

[Quim]

The rods would melt and release various volatile radioactive isotopes into the air. Why would you want that? Just so you don't have to care about the SFP 1 anymore?

I don't agree with your scenario.

 

[radio_guy]

Possibly you industry guys need to pause and take a deep breath. Nobody is going to "access the reactors and cores of Units 1, 2 and 3" in the lifetime of you or your grandchildren.

There are no more "reactors" or "cores" in units 1,2 or 3.
There are blobs of corium which hopefully, but not necessarily, live mostly in what is left of the primary containment vessels. These blobs should not be dug up in any way.

Cleanup for the 50%? melted core at TMI took 5 years..
http://www.threemileisland.org/downloads//226.pdf

I have a feeling it won't take generations and generations to cleanup the majority of this mess. but the site will never be 100% again.

 

[Quim]

Cleanup for the 50%? melted core at TMI took 5 years..

I have a feeling it won't take generations and generations to cleanup the majority of this mess. but the site will never be 100% again.

Each of the situations at #s 1,2 and 3 are far worse than TMI.

The way I see it, although the site around the containment structures can and should be cleaned up, the corium blobs themselves should not be disturbed.

There is nothing to be gained from mucking about with the corium.

 

[radio_guy]

Each of the situations at #s 1,2 and 3 are far worse than TMI.

The way I see it, although the site around the containment structures can and should be cleaned up, the corium blobs themselves should not be disturbed.

There is nothing to be gained from mucking about with the corium.

I find it hard to just assume the fuel is in a solid blob melting away, it could be all broken up in bits, shattered when the cold seawater hit it, it could be in multiple blobs.. i can envision a few of these scenarios.

They will make plans about what they can and cannot do once they are able to see what they are dealing with, right now it's just all assumptions and I feel it's a bad call to base what their future actions will be on that.

otherwise, can you point me in the direction of some solid proof that the core is in one solid blob in the bottom of the building? I would like to see it, bet it looks cool.

 

[Bioengineer01]

Peta is 10^15, rather than 10^18, at least afaik.

You are correct, THANKS! I'll edit the post.

 

[Bioengineer01]

Yep. Isn't it a great feeling when you find that you have been plotting and analyzing garbage data for three months?

So, to simplify the picture, all three reactors are at atmospheric pressure. So they probably have a hole at the bottom, and their fuel is lying on the concrete at the bottom of the drywell, optimistically. And their "primary containments" seem to be leaking like sieves.

(But how could a manometer measure 1.6 MPa if everything is at atmospheric pressure? Perhaps a steam leak from Fukushima Daini, traveling through a crack in the Earth's mantle?)
Thanks. I wasn't sure what exactly was the bottom of the instrument's scale and conservatively guessed -4 m.

(They could make our life a bit easier by writing "< 5000mm", "> 400 C" etc. instead of just "downscale" or "offscale"...)

I can't make the sudden increases in temperature in Unit 3 RPV compatible in my mind with a complete meltdown and a hole in the bottom of the RPV ... Comments?

 

[Bioengineer01]

http://www3.nhk.or.jp/daily/english/05_21.html"

Your link didn't work, here is the corrected one that hopefully will work:

http://www3.nhk.or.jp/daily/english/05_21.html

 

[dh87]

Hi to all.
I run a rapid back of the envelope calculation on the CS137 quantity TEPCO estimated.

If I got it right from Wolfram Alpha the activity of CS137 is 3.214 TeraBq/gram.

Having TEPCO estimated overall CS137 at 720,000 TeraBq, that would lead to 720,000/3.214=224,020 grams of CS137.

I then tried to understand in what relation that value is in respect to the total CS137 inventory that can be expeced from 1,2,3 cores.

I know this has been much more accurately estimated somewhere before in this 3d but I unfortunately do not have the possibility of searching the whole discussion right now.

However from wiki I got a fission yield of 6.0899% for CS137. That yield together with the mass ratio of U235 vs CS137 leads me to estimate in about 6.26 tonns the amount of U235 that has to undergo fission to pruduce this amount of CS137 (224,020/0.060899*235/137 grams).

Now if I remeber correctly at 32% of thermal efficiency 1 tonn of U235 has to undergo fission to produce 1 Gigawatt for one year.

Being almost exactly 2 gigawatts the overall power output of the concerned units, it would seem that the estimated CS137 already in the water is in the order of magnitude of 3 yrs worth of fission process.

In other words that would lead me to think that this estimates means that much of the molten fuel is already soluted in water.
On the other hand this conclusion, in a way reassuring, seems unreaalistic to me.

what I am I doing wrong ?
what do you think ?
thanks in advance

I think that the 720,000 TBq is just in the water. There's also a significant airborne release of Cs. I can't find the numbers at the moment. I think that a lot of the radioactive Cs and Sr may not be in the cores any more, as I tried to say in post #8701 (https://www.physicsforums.com/showpost.php?p=3336116&postcount=8701).

Edit: An estimate for airborne Cs-137 release is only 10,000 TBq, on p. 20 of this document: http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/f12np-gaiyou_e.pdf. So, the Cs-137 in the water appears to be the major release.

 

[jim hardy]

jorge stolfi

i want to personally extend thanks to you for your work in making hose graphs.

curious, whatever happened to 3 on 21st accompanied high water injection through "fire line"?
i don't know what fire line is - does it go into vessel(core spray perhaps) or does it spray down the drywell?

Do you think drywell got hot enough to burn cable insulation and jet pump oil reservoirs?

Is there a BWR guy in the house?

 

[Astronuc]

Possibly you industry guys need to pause and take a deep breath. Nobody is going to "access the reactors and cores of Units 1, 2 and 3" in the lifetime of you or your grandchildren.

There are no more "reactors" or "cores" in units 1,2 or 3.
There are blobs of corium which hopefully, but not necessarily, live mostly in what is left of the primary containment vessels. These blobs should not be dug up in any way.

Not necessarily so. One has no evidence of 'blobs of corium'. Any reference to corium is speculation.

Those outside of industry have little credibility regarding the state of the reactor/core/fuel.

There is an appropriate engineering solution, but it is unlikely to come from outside the industry.

 

[Bioengineer01]

Arnie Gundersen said:
"Well, I am in touch with some scientists now who have been monitoring the air on the West Coast and in Seattle for instance, in April, the average person in Seattle breathed in 10 hot particles a day"

http://www.chrismartenson.com/martensonr...on-worsens

Auch...

 

[Astronuc]

http://www3.nhk.or.jp/daily/english/05_21.html"

From the article -

The samples of plutonium-239 and 240 make up a total of 0.078 becquerels per kilogram.

This is close to the amount produced by past atomic bomb tests.

Even 1 Bq/kg is low. One would need to compare the concentration of Pu isotopes with comparable values from other regions and areas away from NPPs in order to discern the significance of the reported values.

 

[StrangeBeauty]

NHK has a recent video of various shots from around the site:
http://www3.nhk.or.jp/daily/english/05_06.html
The shot of the putzmeister looks like it has the dangling instruments at #4.

 

[SteveElbows]

I can't make the sudden increases in temperature in Unit 3 RPV compatible in my mind with a complete meltdown and a hole in the bottom of the RPV ... Comments?

Well I agree in so much as I have trouble making this temperature stuff compatible with the idea that the entire core has left the RPV. I am keeping an open mind in regards the spectrum of possibilities, but certainly the variety of temperature data from reactor 3 keeps many of the extreme reactor 3 possibilities somewhat beyond the realms of likely fact.

But even if the temp data is fairly accurate, I can still picture quite bad core damage, some holes and a certain amount of core material possibly escaping. This is not the same as the conclusion some people are keen to reach, that the core is sitting on the drywell floor, which for me remains a possibility, but one that is far from proven. It does not help that drywell temperature data is not collected in abundance.

 

[SteveElbows]

Each of the situations at #s 1,2 and 3 are far worse than TMI.

The way I see it, although the site around the containment structures can and should be cleaned up, the corium blobs themselves should not be disturbed.

There is nothing to be gained from mucking about with the corium.

Thats a judgement that needs not be made right now. For a good while the focus will be on site cleanup, dealing with radioactive water, and trying to get the wrecked-reactor equivalent of cold-shutdown.

The decision of whether to mess around with the cores at some future point is down to risk & reward analysis that can be done at the time. Sure the industry would like to be able to show the world that they can do a good job of handling this stuff, but they are unlikely to attempt it if the risk of causing further problems is too high, because those new problems would be bad PR and are not worth it. Rather, the sane parameters that could tip this decision one way or another are all about containment. If the risk of core material escaping into environment by leaving it alone is greater than the risk that comes with doing something to deal with it more substantially, and there is some practical method they can actually apply to deal with it, then they will be correct to muck about with the corium, not reckless.

 

[elektrownik]

Unfortunately, after they discover that two water sensors and two pressure sensors in unit 1 were wrong we can't trust any data

 

[Quim]

Thats a judgement that needs not be made right now. For a good while the focus will be on site cleanup, dealing with radioactive water...

I am suggesting that the best thing to do right now is to stop pouring water into the nuclide pile. Until the water flow out of the high radiation area is halted, we remain in the expansion of the problem mode, not the cleanup mode.

trying to get the wrecked-reactor equivalent of cold-shutdown.

Can you describe that?