Register to reply

Japan Earthquake: nuclear plants

by gmax137
Tags: earthquake, japan, nuclear
Share this thread:
Maxion
#8029
May23-11, 08:38 AM
P: 36
Quote Quote by jlduh View Post
I agree. I was talking about the withe dots for example in this picture already posted, which are a totally different subject than the fringing in the satellite image, as i mentionned it...

Yeah, I kind-of ignored that subject because those white dots are definitely an image artifact that I have never seen before. The color white comes when the bayer-filter registers all three color channels as fully saturated. The only artifact that comes close is hot pixels when shooting with high ISOs and long exposure, but they aren't white, or very rarely are.
jlduh
#8030
May23-11, 08:40 AM
P: 468
Quote Quote by SteveElbows View Post
More detailed analysis of accumulated turbine building water from march sampling finally published:

http://www.tepco.co.jp/en/nu/fukushi...10522_04-e.pdf

Any comments?
For experts: how can you interpret that water from N1 is significantly less contaminated (orders of magnitude lower for most isotopes) than N2 and N3, and that Ba-140, La-140 (short half life) and Sr 89 and 90 are much lower in this N1 water (see page 3 of pdf)?

Is La-140 a daughter isotope in the decay process of other elements?
ModelX
#8031
May23-11, 08:52 AM
P: 1
Quote Quote by Maxion View Post
Yeah, I kind-of ignored that subject because those white dots are definitely an image artifact that I have never seen before. The color white comes when the bayer-filter registers all three color channels as fully saturated. The only artifact that comes close is hot pixels when shooting with high ISOs and long exposure, but they aren't white, or very rarely are.
The "funny" pixels are not always white. It looks like impulse noise affecting one or more color components to me. I've seen artifacts like these when the CCD power source had noise or when there was some RF interference. There can be several places where the noise could be introduced: in CCD, in ADC converter or when transfering digital data from imager to the processing system. Sometimes the data transfers are done using YUV data channels, so a single bit off could change the overall luminance or color. It's not at all certain that radiation is causing this.
jarvik
#8032
May23-11, 08:53 AM
P: 22
Quote Quote by zapperzero View Post
Yep. Ruthenium, Strontium, Uranium and Plutonium present. That's used fuel, basically. It needs to have melted down for this stuff to be mobilized, I think.
The U, Pu and Ru are below detection limits as the are all reported as < X.

While there certainly is Radioactive Sr present in large amounts (3rd table), most of the Sr in table 2 (by mass) will be stable Sr from sea water.

Sea water will also contain trace amounts of U, though that leads me to my 3rd point, the detection limits in table 2 are two high to be useful from the point of view of detecting fuel failure etc.

Crap load of 134/137Cs and 90Sr to deal with for long-term clean up though. Pity the table didn't give volume estimates of the various "pools" so we could easily convert this to total inventories of the isotopic activities.
Maxion
#8033
May23-11, 08:55 AM
P: 36
Quote Quote by ModelX View Post
The "funny" pixels are not always white. It looks like impulse noise affecting one or more color components to me. I've seen artifacts like these when the CCD power source had noise or when there was some RF interference. There can be several places where the noise could be introduced: in CCD, in ADC converter or when transfering digital data from imager to the processing system. Sometimes the data transfers are done using YUV data channels, so a single bit off could change the overall luminance or color. It's not at all certain that radiation is causing this.
I never said it was ;) I tried to ignore the subject because my knowledge of how an image is formed on a sensor and it's path to becoming a RAW or JPG is quite limited. I do know that it is not caused by the cameras normal operation under normal operating conditions.
jarvik
#8034
May23-11, 09:02 AM
P: 22
Quote Quote by jlduh View Post
For experts: how can you interpret that water from N1 is significantly less contaminated (orders of magnitude lower for most isotopes) than N2 and N3, and that Ba-140, La-140 (short half life) and Sr 89 and 90 are much lower in this N1 water (see page 3 of pdf)?

Is La-140 a daughter isotope in the decay process of other elements?
I'd like to hear an expert on this too,

My non-expert thinking is the I and Cs isotopes are more volatile and more readily escape the fuel than Sr so the increased Sr in # 2 and 3 likely means much greater damage to fuel and containment for those units.
jpquantin
#8035
May23-11, 09:20 AM
P: 33
Quote Quote by jarvik View Post
The U, Pu and Ru are below detection limits as the are all reported as < X.
One can question this "<". For U in page 2 they explicitly stated "ND" (not detected?). Moreover for Zr in page 2, the detection limits would not be the same for each sample analyzed ... (I understand Italic numbers as being recalculated from analysis of diluted solutions).

Is it plausible that JAEA may not be able to detect concentration lower than 1.2 mg per liter for Pu?
tsutsuji
#8036
May23-11, 09:21 AM
PF Gold
P: 1,220
Quote Quote by jlduh View Post

Note 2: At DAINI plant, which is newer, they added some buildings close to the sea but to me, these pumps are still outside, close to these buildings (the 3 aligned white/grey circles each time)

Some details about Daini are provided in this article :
Unit 3 was undamaged and continued to cold shutdown status, but the other units suffered flooding to pump rooms where equipment transfers heat from the reactor circuit to the sea - the ultimate heat sink.
http://www.world-nuclear-news.org/RS...s_1803112.html
I wonder how enough seawater pumps at Daini unit 3 could remain safe after being flooded by the OP+6m ~ OP+14m wave reported and depicted on dramatic pictures at http://www.tepco.co.jp/en/press/corp.../110409e10.pdf, if they are located outdoors. How can we explain the Daini unit 3 miracle ?

The following attachments are from http://www.youtube.com/watch?v=M23LpgDL8Ho , a video explaining how the Tokai NPP (located further South in Ibaraki prefecture) survived the March 11th tsunami. The video says that the seawater pumps are enclosed in "more than 6 m" high walls, while the tsunami wave was only "more than 5 m" high. Two pumps survived. The third pump didn't survive because its wall was still under construction and not finished.

Tokai NPP's pump protecting wall is also depicted on a diagram at http://www.asahi.com/photonews/galle...0_toukai2.html and on photographs at http://mytown.asahi.com/areanews/iba...104190562.html (according to that article, the seawater pumps are also providing cooling for the emergency diesel engines ; One diesel engine stopped because the seawater pump for that engine was flooded through a hole in the wall. The reason for the existence of the hole is that the wall was under construction ; If the wall had been 70 cm lower, the Tokai NPP might have had the same destiny as Fukushima Daiichi)
Attached Thumbnails
video1min44.jpg   video2min09.jpg  
jarvik
#8037
May23-11, 09:48 AM
P: 22
Quote Quote by jpquantin View Post
One can question this "<". For U in page 2 they explicitly stated "ND" (not detected?). Moreover for Zr in page 2, the detection limits would not be the same for each sample analyzed ... (I understand Italic numbers as being recalculated from analysis of diluted solutions).

Is it plausible that JAEA may not be able to detect concentration lower than 1.2 mg per liter for Pu?
Oh I thought it was odd that U was given as ND while most others are reported as <X. The analsyis here is evidently a relatively rough chemical analysis as only the major ions of sea water are given values (Na, Ca, Cl etc) as even expected minor ions like Si are only given <X. From my own experience an analyitical lab will give you an actual value OR give you <X where x is the detection limit in question.

I'm not sure I follow you on the Zr, the < X value is the same for all straight samples and reduced by the dilution factor as appropariate for dilution runs.

The inability to detect Pu I think is another reflection of this being a wet chemical method and not a radiometric method which would be far superior at detecting Pu.

In all honesty the detection limits seem piss poor for the question that will obviously be asked from the data (fuel failure?) but more appropriate for asking what % is sea water and water % is fresh water sourced in each sampling pool.

For a comparison I recently have gotten some chemical elemental (30 elements) analysis data back for some work I'm doing and looking at it the reported detection limits vary by element but for example they have a detection limit of 0.05 mg U /kg soil and 0.5 mg Mo/kg soil for the lab we went with. Seems far better than Tepcos lab sadly.
zapperzero
#8038
May23-11, 09:54 AM
P: 1,045
Quote Quote by jlduh View Post
Is La-140 a daughter isotope in the decay process of other elements?
Yes. It is daughter of Ba-140, which in turn can be found in the decay chains of both U-238 and U-235, iirc. But I can't find a chart so... let's wait for the experts.
jarvik
#8039
May23-11, 09:57 AM
P: 22
Quote Quote by zapperzero View Post
Yes. It is daughter of Ba-140, which in turn can be found in the decay chains of both U-238 and U-235, iirc. But I can't find a chart so... let's wait for the experts.
Er.. you mean fission product of U I expect.
zapperzero
#8040
May23-11, 10:21 AM
P: 1,045
Quote Quote by jarvik View Post
Er.. you mean fission product of U I expect.
Err. Yes. Found a chart as well :D

http://www-nds.iaea.org/sgnucdat/c3.htm
Jorge Stolfi
#8041
May23-11, 10:34 AM
P: 279
Quote Quote by zapperzero View Post
This. From the live feed. No zooming and no cropping on my part.
Sigh. Try to locate the *pillars*. Do NOT use the outline of the building (walls, corners and roof) since it is obscured by hanging debris, sagging beams, paint spots and such. Then check the pipes in the tower.
Jorge Stolfi
#8042
May23-11, 10:39 AM
P: 279
Quote Quote by jlduh View Post
2 for N1, 3 for N2 to 4 but at N4, because they were doing maintenance on the core, it seems they were also doing maintenance on the pumps because they seem to be removed on this picture.
I think that the missing pumps were swept away by the tsunami. One of them (an isolated pump due west from unit #2) is still lying on its side, not far away from its presumed base. I would guess that the other missing ones were rolled into the sea by the receding wave.
tsutsuji
#8043
May23-11, 11:24 AM
PF Gold
P: 1,220

Diagram from http://www.yomiuri.co.jp/science/new...OYT1T01008.htm

It shows that in order that the contaminated water moved from unit 2 does not leak into the ground water, it will not be allowed to fill more than the second basement floor of the process main building.
zapperzero
#8044
May23-11, 11:51 AM
P: 1,045
Quote Quote by Jorge Stolfi View Post
Sigh. Try to locate the *pillars*. Do NOT use the outline of the building (walls, corners and roof) since it is obscured by hanging debris, sagging beams, paint spots and such. Then check the pipes in the tower.
I see I have a reputation which is following me , and it's not a good reputation

Anyway. I was interested in the pictures because you can just make out a gantry crane and the huge beam it travels on. Second pic shows a tower that is rarely present in the feed.
tsutsuji
#8045
May23-11, 12:41 PM
PF Gold
P: 1,220
Quote Quote by jlduh View Post

Note 2: At DAINI plant, which is newer, they added some buildings close to the sea but to me, these pumps are still outside, close to these buildings (the 3 aligned white/grey circles each time)


This diagram is taken from http://www.asahi.com/national/update...104050625.html

The upper part is Fukushima Daiichi.
The lower part is Fukushima Daini.

The horizontal red rectangles are the emergency diesel generators.
The small vertical red pins are named "seawater pump"
The quadrilateral shape around Daini's seawater pump is named "seawater pump building"
扉 is "door".

According to this diagram, at least the pumps sending seawater to provide cooling for the diesel generators are indoors at Daini. Perhaps only these pumps are indoors while the other pumps are outdoors ?
~kujala~
#8046
May23-11, 12:45 PM
P: 110
Quote Quote by jlduh View Post
For experts: how can you interpret that water from N1 is significantly less contaminated (orders of magnitude lower for most isotopes) than N2 and N3, and that Ba-140, La-140 (short half life) and Sr 89 and 90 are much lower in this N1 water (see page 3 of pdf)?
I am a non-expert but still trying to answer this one as I have a theory.
They did not spray sea water to unit #1 SFP.
AFAIK the first spray they did (and all sprays after that) were done using fresh water.
March 31st 13:03~16:04 Water spray by Concrete Pump Truck (Fresh water) ...

The really contaminated water in the unit #1 could be in the basement of the reactor building whereas the water in the basement of the turbine building could have come mainly from tsunami/SFP sprayings. Also perhaps some groundwater has leaked in but not enough to affect the levels of contamination heavily.

Once they measure SFP contamination levels in #1 it could further confirm this kind of theory.
The expected result would be to see low-level contamination in #1 SFP.


Register to reply

Related Discussions
8.9 earthquake in Japan: tsunami warnings Current Events 671
New Nuclear Plants Nuclear Engineering 9
Gen IV Nuclear Plants Nuclear Engineering 10
New Nuclear Plants Nuclear Engineering 14
Astronomer Predicts Major Earthquake for Japan General Discussion 65