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Japan Earthquake: nuclear plants

by gmax137
Tags: earthquake, japan, nuclear
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thehammer2
#9037
Jun6-11, 12:19 PM
P: 16
Quote Quote by radio_guy View Post
All this talk of AREVA and their treatment plant..

whatever happened to this guy?
http://blogs.wsj.com/japanrealtime/2...-water-faster/

They are working a close (5 day) deadline to overflowing.... maybe they should give it a shot? i'm sure areva won't lend their new on site plant for testing, but they really don't have a lot to lose if it doesn't work as planned...

this is one of those situations where they should give this guy and the company what they want and use the solution, no politics, less industry nepotism, pick THE best solution and run with it.
Well, one source of reticence to use new things that people come up with only after the disaster has hit is because if it is tried and doesn't work, then they'd still have the radioactive water to deal with. However, in addition, they'd have the new cleanup material itself to deal with. Because of the contact with the radioactive water, it would become radioactive waste that would have to be decontaminated.

In any disaster, people always come out of the woodwork with these seeming revolutionary fixes. While some of them may actually work, testing them in the face of a crisis is not wise, as introducing fresh unknowns is the exact opposite of what to do during a crisis and can make things worse.

New methods of mediation are to be tested under controlled conditions, not the chaos of a disaster, and especially not when there is a method that works but is on a timescale that seems to be "too slow" or faces logistical hurdles that can be overcome with time.
clancy688
#9038
Jun6-11, 12:32 PM
P: 546
Quote Quote by dh87 View Post
The document says 130,000 TBq of I-131 and 6,000 TBq of Cs-137. Then, there's a mysterious "Iodine value conversion" before apparently adding the numbers to get 370,000 TBq.
INES Manual, page 5 paragraph 1.4.1, page 15f paragraph 2.2

The mystery behind iodine value conversion is explained there.

http://www-pub.iaea.org/MTCD/publica...S-2009_web.pdf
mscharisma
#9039
Jun6-11, 12:44 PM
P: 82
Quote Quote by thehammer2 View Post
Well, one source of reticence to use new things that people come up with only after the disaster has hit is because if it is tried and doesn't work, then they'd still have the radioactive water to deal with. However, in addition, they'd have the new cleanup material itself to deal with. Because of the contact with the radioactive water, it would become radioactive waste that would have to be decontaminated.

In any disaster, people always come out of the woodwork with these seeming revolutionary fixes. While some of them may actually work, testing them in the face of a crisis is not wise, as introducing fresh unknowns is the exact opposite of what to do during a crisis and can make things worse.

New methods of mediation are to be tested under controlled conditions, not the chaos of a disaster, and especially not when there is a method that works but is on a timescale that seems to be "too slow" or faces logistical hurdles that can be overcome with time.
Would agree that one should proceed with extreme caution to avoid making a bad situation even worse. However, what would keep TEPCO (or anyone) from conducting such a controlled experiment? Time is clearly running out as far as the contaminated water and storage solutions are concerned. While I as a non-technical person lack the understanding of most technical aspects discussed here and elsewhere, I very much miss the Plan B (or C etc.) planning that one would look for from a common sense perspective, especially in a disaster this profound. So why not test alternatives?
thehammer2
#9040
Jun6-11, 12:58 PM
P: 16
Quote Quote by mscharisma View Post
So why not test alternatives?
Oh, I'm definitely not suggesting that they don't test what this guy's developed. Test the hell out of it and do it quickly if possible, just don't do it at any nuclear plant currently going through a severe accident. We're talking long cleanup timeframes, so test it offsite and once we know the new procedure is more effective than what we've got, only then implement it.
Jorge Stolfi
#9041
Jun6-11, 01:01 PM
P: 279
Quote Quote by dh87 View Post
I am not sure that your statement that the volatile elements would be trapped if the uranium oxide remained solid is correct. My argument doesn't invalidate your guesstimate of 10%, but my guesstimate would be higher.
Indeed, according to the Cristoph Mueller slides posted earlier, once the fuel is completely molten, the radioactive elements that remain in the liquid melt (corium) will produce 30% of the decay heat power that would be produced by the intact fuel; the other 70% of the decay heat power is due to more volatile elements that will end up elsewhere.

Some of that 70% will escape to the atmosphere, some will be washed out by the cooling water, and perhaps some will be deposited inside the reactor or containment in places and forms that cannot be easily washed out. In any case those 70% are a big contamination problem but should not pose much of a heat management problem. Is this correct?

On the other hand the corium will contain many long-lived isotopes which could be a huge health hazard if they were ejected to the atmosphere. While the contribution of an element to the heat production rate is inversely proportional to its half-life (among other things), its potential for health damage is largely independent of it, at least for lifetimes up to a decade or two. So, while the corium keeps 30% of the decay heat production, it may include a larger fraction of the total health damage potentia of the original fuel.
etudiant
#9042
Jun6-11, 01:17 PM
PF Gold
P: 866
Quote Quote by thehammer2 View Post
Well, one source of reticence to use new things that people come up with only after the disaster has hit is because if it is tried and doesn't work, then they'd still have the radioactive water to deal with. However, in addition, they'd have the new cleanup material itself to deal with. Because of the contact with the radioactive water, it would become radioactive waste that would have to be decontaminated.

In any disaster, people always come out of the woodwork with these seeming revolutionary fixes. While some of them may actually work, testing them in the face of a crisis is not wise, as introducing fresh unknowns is the exact opposite of what to do during a crisis and can make things worse.

New methods of mediation are to be tested under controlled conditions, not the chaos of a disaster, and especially not when there is a method that works but is on a timescale that seems to be "too slow" or faces logistical hurdles that can be overcome with time.
Well, there are a couple of easily answered questions. notably as how well, if at all, the process works in a salt water environment and how easily it scales.
The test demo used 15 milligrams of material for 100 ml of contaminated water, or 150 grams/ton.
At Fukushima, we have about 100,000 tons of water to deal with, so we need 15,000 kilograms of material.
The claim is the material components are 'easy to obtain and rich in supply' .
To be useful, or at least comparable to the AREVA effort, the new approach must clean up 1000 tons/day of contaminated water. That takes about 1500 kg of material. Can/will Dr Ohta and his partners deliver at that pace?
Bioengineer01
#9043
Jun6-11, 01:27 PM
P: 123
This is good news for the location of the Corium in Unit 3 and very bad news for the location of the Corium in Units 1 and 2, a lot more of decay heat production present in the melted fuel than originally thought...
Bioengineer01
#9044
Jun6-11, 01:43 PM
P: 123
Quote Quote by mscharisma View Post
Would agree that one should proceed with extreme caution to avoid making a bad situation even worse. However, what would keep TEPCO (or anyone) from conducting such a controlled experiment? Time is clearly running out as far as the contaminated water and storage solutions are concerned. While I as a non-technical person lack the understanding of most technical aspects discussed here and elsewhere, I very much miss the Plan B (or C etc.) planning that one would look for from a common sense perspective, especially in a disaster this profound. So why not test alternatives?
Answer: Human beings: Patents; Licenses; Agreements -- Summary: "Greed"
mscharisma
#9045
Jun6-11, 01:59 PM
P: 82
Quote Quote by thehammer2 View Post
Well, one source of reticence to use new things that people come up with only after the disaster has hit is because if it is tried and doesn't work, then they'd still have the radioactive water to deal with. However, in addition, they'd have the new cleanup material itself to deal with. Because of the contact with the radioactive water, it would become radioactive waste that would have to be decontaminated.

In any disaster, people always come out of the woodwork with these seeming revolutionary fixes. While some of them may actually work, testing them in the face of a crisis is not wise, as introducing fresh unknowns is the exact opposite of what to do during a crisis and can make things worse.

New methods of mediation are to be tested under controlled conditions, not the chaos of a disaster, and especially not when there is a method that works but is on a timescale that seems to be "too slow" or faces logistical hurdles that can be overcome with time.
Quote Quote by thehammer2 View Post
Oh, I'm definitely not suggesting that they don't test what this guy's developed. Test the hell out of it and do it quickly if possible, just don't do it at any nuclear plant currently going through a severe accident. We're talking long cleanup timeframes, so test it offsite and once we know the new procedure is more effective than what we've got, only then implement it.
Glad to hear/read I'm not the only one seeing it that way: look for Plan B (and C etc.) while working on Plan A. Of course, my and probably most everyone's concern is the release into the ocean, certainly the easiest and cheapest for TEPCO.

I understand from discussions and links here that additional storage via containers and/or underground storage have been or are being considered, but how realistic is it that AREVA's cleaning and/or reuse of water for cooling (what I call Plan A) will suffice, especially in the typhoon season? (Sorry if this has been calculated and discussed here already and it slipped me by since ... well, me and numbers is a whole different disaster.)

So in lay(wo)man's terms, any educated guess from you knowledgeable people what the chances for success of the current Plan A are? Does anyone here know what TEPCO's plan is in case the contaminated water volume will exceed storage and/or cleaning capacity?
Jorge Stolfi
#9046
Jun6-11, 02:02 PM
P: 279
Quote Quote by rowmag View Post
I still wonder at what point it makes sense to seal up the harbor entrance and declare it a giant storage/evaporation pond.
I believe that they plan to do that in fact. I saw a PDF somewhere, showing the temporary barriers thay have already set up and the plans for more permanent ones.
radio_guy
#9047
Jun6-11, 02:08 PM
P: 24
Quote Quote by Bioengineer01 View Post
Answer: Human beings: Patents; Licenses; Agreements -- Summary: "Greed"
seems to be the way things go, and because of it we miss out on a lot of great advances.

I'm not saying it scales, I don't even think they know as they don't have any way to test it full scale, but if he's been developing similar things to clean up industrial pollution I would say he has a bit of credibility. I'm sure getting a plant to put to waste and large amounts of radioactive water isn't exactly an easy thing to obtain to prove a point..

from what I understand it's basically the same process Areva uses but it precipitates a lot, lot faster and that's why I suggested it could be tested out in their plant on site.

I am 100% convinced it comes down to patents, trade secrets, money, and exclusivity.


and to the other point, I don't see a whole lot of people jumping up and down screaming they have the gimmick to fix it all. I see someone who worked on similar things and modified a process to fit the extraordinary situation, and worked with a company to pitch the solution to the government, then disappeared from view apparently.
jim hardy
#9048
Jun6-11, 02:26 PM
Sci Advisor
PF Gold
jim hardy's Avatar
P: 3,748
for a glimpse of what they could do with those fuzzy videos, check this video of a coal plant named Fukushima:

http://www.vision-systems.com/articl...wer-plant.html

i still think there is considerable throttling of information.
Bandit127
#9049
Jun6-11, 02:31 PM
P: 190
For the sake of clarity, a question and a curse.

Is the use of the term 'meltdown' used here to be considered a partial meltdown?

I understand this to mean the melting of fuel rods and the relocation of that melt within the reactor vessel. I understand that it does not necessarily mean that corium has formed (the fuel rods could have 'granulated') but that it could be the case.

I also think that it does not mean full meltdown, which I understand is the departure of corium from the reactor vessel to somewhere else - in this case the drywell.

My curse is that the term 'meltdown' is in common use and has been for years, but it has not been defined by the scientific community.

(Perhaps one of the legacies of Fukushima will include a reliable definition of the term and that people will learn it in journalism college).
razzz
#9050
Jun6-11, 02:42 PM
P: 205
The ex-skf site for a non-technical blogger does the best job of gathering together and translating some of the available information concerning the Fukushima disaster. His own mini-conclusions or comments are usually well founded.

As far 'Arnie' goes, the only defense I'll give him is that even he has a hard time comprehending the overwhelming events at Fukushima.

Germany is the only country regularly reporting fallout numbers (maybe a few others) and has drawn the conclusion to cease their nuclear energy production.

The workup on hydrogen explosion outputs report leads me to believe a (compression) shock-wave of that magnitude (Unit 3) is not a good thing to have traveling around or in your nuclear fuel possibly creating some sort of chain reaction.
Jorge Stolfi
#9051
Jun6-11, 02:52 PM
P: 279
NUCENG provided the following very informative post about the thermocouple temperature sensors used in nuclear reactors:

http://www.physicsforums.com/attachm...5&d=1307050278

As Jim Hardy observed, thermocouples become useless if the two wires get connected by water, since the electrochemical (battery) effect will swamp the tiny thermoelectric signal. I woudl guess that the thermocouples used in reactors are encased in waterproof and insulating sleeves of some sort; is that so? But these may not have been designed for a "drywell" filled with very hot high-pressure steam...

Presumably that is the explanation for very low "temperatures" (down to -130 C or lower) recorded in the TEPCo datasheets.
SteveElbows
#9052
Jun6-11, 02:54 PM
P: 630
Quote Quote by Bandit127 View Post
Is the use of the term 'meltdown' used here to be considered a partial meltdown?

I understand this to mean the melting of fuel rods and the relocation of that melt within the reactor vessel. I understand that it does not necessarily mean that corium has formed (the fuel rods could have 'granulated') but that it could be the case.

I also think that it does not mean full meltdown, which I understand is the departure of corium from the reactor vessel to somewhere else - in this case the drywell.
My experience during this crisis is that in the Japanese media, meltdown is indeed being used as a label for fuel melting, and in this context it does not tell us where the core has ended up at all.

As far as official estimates by government agencies and TEPCO, everything I've seen in english suggests that they dont like to talk about anything beyond the point of fuel melting and slumping in the bottom of the reactor vessel. They have not ruled out the possibility that some of the core has escaped the reactor vessel, because sometime a phrase along the lines of 'most of the fuel remains in the reactor vessel' has been used, and I have not seen anybody push them for estimates of what percentage of core might not be in reactor vessel anymore. Its quite possible that the analysis documents contain projections for how much of a variety of radioactive substances are believed tobe in the reactor vessel, the drywell, the suppression chamber, some of the graphs and tables look like they may be showing this, but as I cant read Japanese Im waiting a while before going on about this stuff in detail.

Personally although I have expressed skepticism with people who are convinced that core has left reactor in one or more cases, because I dont see concrete evidence of this, I dont rule it out either. And frankly most of the official analysis to date does not add enough to make me more certain one way or the other.

Likewise I certainly dont assume that the core melting & containment damage time estimates that TEPCO and now government agency have published match the reality. Their analysis may end up being close to the reality but it may not, as best I can tell its based on simulations and the bits of real data they have, and certain assumptions are bound to have been made either in terms of the data fed in or the model the software uses. Leaving aside the track record of TEPCO which may make us cynical, I cannot actually judge which of the 2 simulations, with their quite different time estimates for when various things happened, is closest to the truth. At some point I will compare the real data we have with the government analysis to see if it seems to fit better than the TEPCO one does, but I dont necessarily expect to gain too much from this exercise, in great part due to missing temperature data over a crucial time period in the early days.
SteveElbows
#9053
Jun6-11, 03:16 PM
P: 630
Quote Quote by jim hardy View Post
for a glimpse of what they could do with those fuzzy videos, check this video of a coal plant named Fukushima:

http://www.vision-systems.com/articl...wer-plant.html

i still think there is considerable throttling of information.
Well as the article mentions, this tech is apparently already used by the long range TV camera feed.

Really I think its trying to solve some very different issues to those that the TEPCO on-site feed has. Its trying to overcome issues caused by vast distance. Most of the TEPCO cam quality issues are due to their compression & streaming setup, either because its just not great equipment, not setup very well or because they are dealing with bandwidth issues, eg trying to keep the server load down to a certain rate.

I've little doubt that it could be improved a fair bit, either by tweaking settings, or investing in a different server setup that has more grunt. There are also things that could be done with exactly what the camera is looking at that may help. For example the large portion of detailed green plants that we see shifting in the breeze are taking up a fair percentage of the available bandwidth, and its a waste.

There are also some issues with how things look at night, which is a typical issue with video and photography and may or may not be trivial to improve.

I dont think the feed quality is a significant part of a deliberate ploy to keep us ill-informed. Im sure their natural corporate instincts would not involve giving us a brilliant window into everything that happens there in realtime, and I doubt they are too dedicated to bringing us the best possible images from site. But compared to other coverups, and things that would make a bigger difference such as exactly where the camera(s) are sited and what can really be seen, the image quality doesnt seem like a difference maker.

Put it this way, there have been very few events that were happening at any point in a visible way on the live camera, that have made me cry out for better resolution & detail. Sure Id like that detail, but I cant actually think of a worthy event that I would actually have learnt anything more about if the camera had been better quality. Mostly nothing is happening, sometimes we may see the arm of some equipment moving around, sometimes we will see clouds emerging from one or more reactor or fuel pools. I dont really feel like Im missing much by not seeing these things in better quality.

What would make a difference to me is camera shots from other vantage points, where I may actually get to see some of the day to day work being carried out, or more photo footage of the reactor buildings in higher detail. They probably dont want to do that for a number of reasons. In the grand scheme of things this does not bother me all that much, making sure we get to learn of things in a timely and detailed manner is far more important.
Bioengineer01
#9054
Jun6-11, 03:30 PM
P: 123
New Video from Arnie Gundersen about the evacuation zone size and how it was calculated for US nuclear power plants

http://www.youtube.com/watch?v=bB2mr...embedded#at=18


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