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Japan Earthquake: nuclear plants

by gmax137
Tags: earthquake, japan, nuclear
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artax
#2035
Mar30-11, 08:31 AM
P: 159
Quote Quote by morningperson View Post
It means the Tc-99m was produced within six hours prior to detection.
sorry but it doesn't, it could have been produced up to many times the half life ago. it depends on your detectio limit and amount produced.
basically if 1kg was produced after 6hrs there'd be 1/2kg, then after six more 1/4 after 6more 1/8.
so after x half lives there's 1/(2^x) where ^ means to the power.
rasherz
#2036
Mar30-11, 08:31 AM
P: 8
Quote Quote by |Fred View Post
Hi rasherz , Help from someone fluent in Japanese listening to the Tepco press point would be lovely , welcome to the thread .
I'm not sure that I can answer you question , but I would like to mention that tepco is mostly monitoring radiation in regards to the plants.

Heath related issue ie isotopes found in the air of cities in watter etc.. Is done by gov agency and non gov agency.. So the tepco press conference would not be in my opinion the best place to get info you are looking for.
I'm just living here, my Japanese is ok, but the technical vocabulary is a bit difficult to follow. Also to be honest, I'm getting better information from here. My wife is Japanese and I'm giving her updates based on what's on this forum, well ahead of the news. There's still a lot of smoke and mirrors going on. No mention on TV about the smoke coming from the second plant 12 kms south, as far as I know. It's hard to decide what's just sensationalism in the western media and what is being spoon fed to us by TOEPC a few days late. So far so good with this forum.
Thanks guys.
jensjakob
#2037
Mar30-11, 08:33 AM
P: 123
Quote Quote by TCups View Post
Jens:

Three levels of panels where? At the top floor? I think there are two above, but could be wrong. Doesn't change the reference line with respect to comparison of damages above vs below, though, right? More damage in the lower sections of Bldg 4 with much less overall damage to the roof top of Bldg 4 the way I see it. Corrections?

http://i306.photobucket.com/albums/n...Top2Levels.png
I would say 3 levels above groundfloor. 1 level standing on the west-side, 2 levels fallen to the ground.

Am searching all I can for pictures from inside - that can give the clues.

This picture shows 3 levels of panels, but it looks like it is a different construction (lighter) then #3 :-(
http://img.ibtimes.com/www/data/imag...hi-reactor.jpg

Allthough this image:
http://www.pmw.de/pm_online/data/PCP...ma-504x378.jpg
could support the theory that there are only 2 levels above the refueling deck
artax
#2038
Mar30-11, 08:38 AM
P: 159
yes unit one, the first to explode was smaller output and different wall design by the looks of things, where have they removed panels of unit 2 to avoid a future explosion like the others? is it the one in the side, quite low down? emanating steam? and is it above the fuel pool?
TCups
#2039
Mar30-11, 08:41 AM
TCups's Avatar
P: 494
Quote Quote by jensjakob View Post
I would say 3 levels above groundfloor. 1 level standing on the west-side, 2 levels fallen to the ground.

Am searching all I can for pictures from inside - that can give the clues.

This picture shows 3 levels of panels, but it looks like it is a different construction (lighter) then #3 :-(
http://img.ibtimes.com/www/data/imag...hi-reactor.jpg
Jens:

I believe Units 3, 4 have two levels of concrete columns, reinforced, to bear the weight of the overhead crane. At 3, the north end wall has collapsed, and the crane fell below. I believe the original square hole on the north face of Bldg 4 was below the level of the reactor access floor.
Astronuc
#2040
Mar30-11, 08:45 AM
Admin
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P: 21,869
Two panels sit above the reactor service floor according to http://www.physicsforums.com/showpos...&postcount=305 (AtomicWombat, page 20, post #305). See also the ridge at the bottom of the two panels.

See also images:

Tcups, page 21, #330
various on page 23
jinxdone, page 24, #381
Tcups, page 29, #463

The third set of panels sit below the ridge and below the reactor service floor. A blast out at the third level could mean damage to the SFP.
Gilles
#2041
Mar30-11, 08:48 AM
P: 30
Quote Quote by artax View Post
sorry but it doesn't, it could have been produced up to many times the half life ago. it depends on your detectio limit and amount produced.
basically if 1kg was produced after 6hrs there'd be 1/2kg, then after six more 1/4 after 6more 1/8.
so after x half lives there's 1/(2^x) where ^ means to the power.
and as I said it is a daughter nuclide of Mo-99, which has a longer half-life (66 h) so actually it rather tracks the presence of its parent. But still 66 h is a rather short period compared to 20 days.
artax
#2042
Mar30-11, 08:48 AM
P: 159
there's some reasonable reactor workings animation here, doesn't really explain where the H2 explosions were though!
still pretty useful stuff.

http://edition.cnn.com/interactive/2...pan/index.html

oh, and I think you can ignore the cyclical behaviour of radiation in the dose/time graph!
DrDu
#2043
Mar30-11, 08:57 AM
Sci Advisor
P: 3,593
Quote Quote by morningperson View Post
It means the Tc-99m was produced within six hours prior to detection.
No, it doesn't because Tc 99m is formed in the decay of Mo 99, which has about 3 days half-life time (I ignore whether Mo 99 has some other long lived precursor). Gilles pointed that out, too, in a mail which overlapped mine. After 20 days there will still be about 0.6 % of Mo99 be left, which is enough to produce large quantities of Tc.

Edit: Seems Gilles was again faster than I :-)
AntonL
#2044
Mar30-11, 09:03 AM
P: 521
Quote Quote by DrDu View Post
No, it doesn't because Tc 99m is formed in the decay of Mo 99, which has about 3 days half-life time (I ignore whether Mo 99 has some other long lived precursor). Gilles pointed that out, too, in a mail which overlapped mine. After 20 days there will still be about 0.6 % of Mo99 be left, which is enough to produce large quantities of Tc.

Edit: Seems Gilles was again faster than I :-)
After 20 days there will still be about 0.6 % of Mo99 be left, which is enough to produce large quantities of Tc. hey thanks for this explanation, this now clears many things in my mind
artax
#2045
Mar30-11, 09:08 AM
P: 159
Yes,me too thanks DRdu !, I haven't done much with understanding grow and decay of daughter products!
Astronuc
#2046
Mar30-11, 09:08 AM
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Quote Quote by rasherz View Post
Hi, long time listener, first time caller. I'm currently living in Japan, pretty far from danger but concerned about the water and food becoming contaminated. I don't want to sound political but, in today's press conference the TOEPC spokesman only mentioned iodine levels (good news because of the short half life), no mention of cesium. Does anyone have an explanation for this?
Iodine is a concern because of the uptake to the thyroid gland which is pretty sensitive.

http://en.wikipedia.org/wiki/Thyroid

I'm not sure about the pancreas.

Cs would also be important to know.

The further away from Fukushima, the lower the risk of contamination. The winds (jet stream) tend to blow west to east, but there are times when they can north or south, and a little bit westward, i.e., NNW or SSW.

I would expect that the other plants, e.g., Tohoku Electric's Onagawa and Higashidori plants are monitoring activity to the north, and JAPCO's Tokai plants to the south. What do they report?
liamdavis
#2047
Mar30-11, 09:14 AM
P: 30
Correct me if I am wrong but my understanding is that pure water does not become radioactive. Rather, it emits radioactivity from material that is suspended or in solution in it. Hence the steam in the turbine, having recently been in the reactor, presents no radiological safety problem. That this is accomplished by the action of a “water polisher” employing HEPA and carbon filters in the primary (RV) coolant loop.

Where I am leading is that the polishing units in the plants may be inoperable and, if operable, may be in an environment where they cannot safely be serviced. However, the function of a water polisher could be employed outside of the plant to separate radioactive material from the water in the trench and from water they are proposing to store in tanks at a remote location on site. These tanks are described as being piped to each of the buildings for temporary water storage.

My thought is to employ one or several water polishing units to separate the non-radioactive water and dispose of it in the sea. This would lessen the difficulty caused by finite storage capacity and allow more discretionary use of water for cooling. It could later be employed in the remediation of ground water at the test wells used for sampling.

More when I have had some sleep.
liam
artax
#2048
Mar30-11, 09:15 AM
P: 159
wonder how many picrutes that bloody drone's taken, and how many have been released to the 'general public' who just don't understand these things and will panic!!!
I want to see more, where's that Assange bloke when you need him!
artax
#2049
Mar30-11, 09:22 AM
P: 159
Quote Quote by liamdavis View Post
Correct me if I am wrong but my understanding is that pure water does not become radioactive. Rather, it emits radioactivity from material that is suspended or in solution in it. Hence the steam in the turbine, having recently been in the reactor, presents no radiological safety problem. That this is accomplished by the action of a “water polisher” employing HEPA and carbon filters in the primary (RV) coolant loop.

Where I am leading is that the polishing units in the plants may be inoperable and, if operable, may be in an environment where they cannot safely be serviced. However, the function of a water polisher could be employed outside of the plant to separate radioactive material from the water in the trench and from water they are proposing to store in tanks at a remote location on site. These tanks are described as being piped to each of the buildings for temporary water storage.

My thought is to employ one or several water polishing units to separate the non-radioactive water and dispose of it in the sea. This would lessen the difficulty caused by finite storage capacity and allow more discretionary use of water for cooling. It could later be employed in the remediation of ground water at the test wells used for sampling.

More when I have had some sleep. liam
I'm pretty sure it's not just suspended solids that become radioactive, it's any soluble ions too which is why de ionised water is used.
However I'm pretty sure the 'polishers' will be ion exchange filters or resins and will be able to 'remove' the majority of radiation from the water.

The problem is the collection of the water after it's been pumped into the building,... beacuse like the missing fuel at chernobyl..... they've no idea where it's going as there's no seals/containment anymore!
jensjakob
#2050
Mar30-11, 09:25 AM
P: 123
On the drone pictures, I cant find the "fuel rods" that was pointed out on the ground by TCups in the early image analysis.

Meaning either I cant see them, or they have been moved - meaning that someone knows what they were.
TCups
#2051
Mar30-11, 09:50 AM
TCups's Avatar
P: 494
BEFORE & AFTER
(just for grins)
The before from : DigitalGlobe.com
The after from post #2009, as referenced by Fred

http://i306.photobucket.com/albums/n...eforeAfter.jpg

Comments:

@Jens:
I can't place much significance to the white rods (what ever they are) detailed in the first helicopter fly by vs not seeing them well in the satellite and drone images. The speculation that they could be loose fuel rods ejected from SFP3 has not been substantiated.

@Astronuc:
Thanks for confirmation - two tiers of concrete columns frame the reactor access floor at the top of Bldg 3, 4. Damage to the SFP4 below the level of the reactor access floor (ie, out the side or bottom of SFP4) and into the lower levels of Bldg 4 might be one explanation to the apparent intensity of the explosion in the lower floors. As has been suggested by another poster (JoeN?), in a cold shutdown with fuel removed, a lot of heavy doors otherwise closed during operation may have been left open.
rasherz
#2052
Mar30-11, 09:53 AM
P: 8
Quote Quote by Astronuc View Post
Iodine is a concern because of the uptake to the thyroid gland which is pretty sensitive.

http://en.wikipedia.org/wiki/Thyroid

I'm not sure about the pancreas.

Cs would also be important to know.

The further away from Fukushima, the lower the risk of contamination. The winds (jet stream) tend to blow west to east, but there are times when they can north or south, and a little bit westward, i.e., NNW or SSW.

I would expect that the other plants, e.g., Tohoku Electric's Onagawa and Higashidori plants are monitoring activity to the north, and JAPCO's Tokai plants to the south. What do they report?
I'm living NNW from the plant, but still in a safe area, way up North. It's not really a short-term concern for me. My worries are that most food processing occurs in the industrial heartland of Japan, near Tokyo. The nearby prefectures supply most of the domestically grown food for these products. Without accurate levels of Cs being made available I feel like we're being (lied to) held back from information that might be important when grocery shopping. Perhaps I'm overreacting, but Topec has a history of doing this.


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